Spent 4 hours yesterday milling up the wood for the doors. I got the rails made on the router table but ran into a problem trying to make the stiles. Long story, but the two jigs I built didn’t work and I was getting frustrated. So I cut my losses and put the tools down for the day. No sense working around sharp electrified things if you’re not in a good frame of mind.
Back at it today for another try. 104 hours total time.
The main sanding on the entertainment center body is FINISHED! I spent 3 hours in the shop today for a total time of an even 100 hours on the entertainment center. I put the whole thing together today and laid the top pieces on the carcasse, then put all three pieces next to each other. I then stood back and took a good look. Magnificent! When I look at a big project sometimes I’m surprised that Something can come from Nothing. It’s a really great feeling.
Next up: the doors! That’ll be a long and painstaking process. Then I have to figure out an easy and effective way to lay in 36 one quarter inch square ebony pins on the carcasse and another 32 or so 3/8th inch ebony pins on the doors. I figure it’ll take me several eye-busting weeks doing that. Then the finish- which I have no idea about yet.
Hey, one thing at a time. But I’m past the 100 hour mark! That makes it my biggest project to date (except for the studio build, which was a ton of little projects)
9 more hours done in the shop today. It was a great day to be outside. Around 80 degrees and slightly breezy. We won’t have many more like that for awhile.
I got the face frame for the cabinets all completed and installed and gave the bookcase faces their main sanding, and that’s about it. Yes, it really takes 9 hours to do that when you’re being really careful.
I also changed the design just slightly, but more on that later.
Got another 6 hours in today. More sanding (koff!), as well as some more face frame construction. I would have had another three hours but an unexpected call let to some unexpected audio work on a film next week that’ll go a long way toward paying for the ent. cent. Yay!
Tomorrow I tackle the face frame on the main center section, then figure out a good way to attach all three frames. After that it’s time to move on to the doors, then the ebony inlay.
Total time is 88 hours.
The list of reasons why everyone should start a business, and why the home is a great first frontier for many of those businesses, is long. Here are some examples:
1. Because of online and communications technology, you can start many businesses at little or no cost.
2. You can start a side business without foregoing your “secure” day job.
3. You can spend more of your time doing something you’re passionate about.
4. You can make a little extra money, and maybe eventually ramp up to replacing that day job.
5. The biggest companies now have many free or inexpensive solutions available for small business making it easier than ever to start and grow.
6. If you have a family, just imagine what a positive impact it could have on your children as they watch you toil, create, breakthrough, tough it out, and demonstrate how to take control of your life and live passionately rather than being a cog in the wheel.
7. Outsourcing enables you to streamline your activities (and the physical footprint) of your business so that you focus on doing the work you love and farm out the other stuff.
8. Home-based business is generally accepted - even preferred - as a mode of business in the marketplace these days (whereas before there were credibility issues).
9. Tax write-offs are often available.
10. You take control of your destiny rather than relying on someone else to make the right decisions for your future.
I spent 8 more hours in the shop today for a running total of 82 hours! Had to run back to the lumber yard for three more pieces of QSRO. Hopefully the final bits of solid wood I’ll have to buy. Came home and spent a quality 90 minutes in front of the planer driving my neighbors nuts with the noise. I got everything planed up and the rest of the day was spent gluing up one final panel (this one will be the main surface directly underneath the TV) as well as making the face frame for the left side bookcase. A funny thing happened whilst doing this. I had very carefully measured all the pieces and pocket screwed them together. Perfect 90 degree angles between them. The bookcase also has perfect 90 degree surfaces. When I applied one 90 degree surface to the front of the other one…..
everything was crooked.
It was like suddenly we didn’t live in Euclidean space-time any more. It was the weirdest thing. I could measure 90 degree angles all over the place, but the face frame was “slanted” by as much as 1/4 inch between the top of the case and the bottom. This utterly flummoxed me until I took the face frame apart, reconstructed it (with the same wood and the same screw.. in the SAME HOLES), and it worked. Amazing. I think I’ve discovered a unique quality of wood: it has the ability to bend spacetime.
So anyway, that’s how I spent my 8 hours today.
4 hours yesterday (total of 74 hours!) on the entertainment center. I planed up a bunch of thin pieces and glued them to the back where the TV will be mounted. This is so, when you look at the surface the TV is mounted on, you’ll see solid hardwood oak and not plywood (yuk!). I only applied solid wood where you’ll see the back around the edges of the TV, and not over the whole back “wall”, so right now I’ve got a roughly 16×9 TV “space” layed out. Looks kinda funny.
I also started in on the face frame but ran out of wood. Well, I have more QSRO, but it’s not the same color and I want to make sure the color match is right, and that I’m using stock that has consistent grain and ray-flecking:
Back to the lumberyard today for more wood.
So yesterday I spent another 4 hours (total time: 70 hours) on the ent. cent. I didn’t do much but cut the tops to final length and sand, sand, sand. If you’ve ever wonder why the iPod was invented, it was so woodworkers could stand for three hours in one place while sanding.
Speaking of sanding, I always wear earmuffs and a face shield, but I can’t use the inexpensive filter that I bought several years ago. It’s really uncomfortable and since I have a beard, it has small gaps around my face that let the dust in anyway. I’ve been considering the purchase of a much more expensive and effective dust hood but can’t quite bring myself to pull the trigger on it. After all, there are better things to spend the money on (like, say, nothing at all), but I figure that I can spend a few hundred dollars on this now, or several tens of thousands of dollars later on when I get chemo for the lung cancer that’s brought on by inhaling fine wood dust for a few decades. Or maybe the Hodgkin’s disease. Oh joy. (cough, cough). I do my best to keep the exposure to a minimum by sanding outside with the wind behind me, but there’s only so much I can do.
Yeah, yeah. I’ll probably just buy the stupid thing. It’s a new product and I’m waiting for the first round of reviews to hit. Dropping almost four Benjamin’s on a ventilated face shield isn’t my idea of fun, but neither is an arm full of bleomycin.
Back to the shop. Today’s I start on the face frames. Then more sanding…
This is becoming a (very enjoyable) habit. Yesterday (monday), I spent 6 hours in the shop, and pulled another 7 today. 66 hours in total on the ent. cent, and it’s starting to look like a piece of furniture! I think I could probably speed things up by at least 50% if all of my machines and stationary tools had permanent homes. As it is, the table saw is the only thing that lives in one spot. Each of the other major tools (band saw, planer, jointer) have to be moved to one particular spot in order to be used. I only have one tube from the dust collector so if I want to use the band saw I have to move the planer out of the way, or if I want to use the jointer, I have to shift the planer aside. It makes for a whole lot of moving and shifting, and a piece of wood might have to visit every machine before it gets glued into place. Then the whole dance has to start over again. I’ve gotten pretty good about looking ahead and doing as much as I can on one tool, but I often have to complete one piece of wood before I can move on to the next.
I love my shop. It’s a nice big 2 car garage. I’m not complaining. Indeed, I have a friend who works out of a very small 1 car garage. It’s ridiculous how little space he has in there. Still, one of these days I’m going to build me a big place where all the tools can be bolted to the freaking floor, never to have to move again. With their own dust collection and outfeed tables.
What the hey, as long as I’m wishing, I want a pony.
It’s 57 degrees and rainy. My absolute favorite weather (except for the wind- I really don’t like wind). What in the world am I doing inside?!?
Time to change back into the grubbies and go find something I can do in the shop with the door closed. I can’t work the main machines when it rains because they’re right next to the garage door. If the cast iron tops get wet they’ll rust in about ten minutes. No kidding- 10 minutes. You can almost stand and watch it happen. Only the most generous and frequent application of paste wax to their tops keeps them from turning red and flakey from rust. So if it’s raining I can’t use the table saw or planer (the two machines I need to use to finish the ent. cent. top).
But I’m sure I can find something else that needs to be done. It’s too cold and rainy to stay inside. I’m off!
UPDATE: 4 hours in the shop. The rain quit and I got a bit done-mainly a glue up on the bookcase tops, plus a lot of standing around cogitating on future problems to be solved. There’s a lot of ‘em. Tomorrow is the main top glue up and… more sanding! Yay! 
Another 9 hours in the shop today working in the ent. cent. I’ve got the main carcasse glued up. Thanks to neighbor James for helping move the beast off of the work table, and for the ant killer in the yard. 
I had to rout out a groove in the back for the back piece, then plane and joint more wood for the top of the center and two side book cases. I had all the wood for these tops all laid out and ready to plane (6 pieces each 7 inches wide and 60 inches long), and realized that it was over $130 in lumber! Don’t screw it up.
I screwed it up.
Well, to be fair, I really didn’t, but the results are sub-optimal. I wanted to leave as much of the inch thick lumber remaining so the top could be very thick. As thick as possible, preferably 7/8ths of in inch. I feel that this thickness balances the heft of the rest of the piece. Unfortunately, the wood has to cooperate. If you’re planing 4 pieces of 7 inch wide wood that’ll eventually be one solid top, you are limited by the maximum thickness of the roughest piece of wood. Put another way, the lumber comes from the yard very rough, and you have to run it through the planer and jointer until both sides have no imperfections. If there’s still an imperfection (a saw mark or a low spot), you have to run them ALL through until they match the thickness of the thinnest piece. My thinnest piece ended up being almost exactly 3/4 of an inch (1/8th inch less than I had hoped). So by the time I caught it I had already hogged off than extra 1/8th inch from all the boards. It’s not a catastrophic deal by any stretch of the imagination. It only means that the top of the entertainment center will be 1/8th inch thinner than I had designed. Still, it rankles. I turned 1/4th of my $130 pile of lumber into sawdust getting everything smooth. That’s a trash bag full of $33 in shavings and dust. Ug. That’s woodworking, though: turning large pieces of wood into small pieces of wood.
Next step is to joint and glue up the tops. One of the boards I worked today had the most spectacularly rayed grain I’ve ever seen. It’ll be my showpiece board in the best position (closest to the door). The other bookshelf has a serviceable grain, but nothing to write home about. The top of the center section is very nice, but I have to do some creative grain matching since I went ahead and used a new board in place of the too-thin one I described above. I’ll still use the too-thin one for trim (got just the place for it), so it’s no loss.
In the last three days I’ve put over 20 hours of work into the entertainment center. I can now put all three basic carcasses next to each other and get a feel for the size of the piece. It’s wide but not too tall. Nice proportions. I told Erin today that I fell like 1/3rd of the time spent on any project is the basic structure build, 1/3rd is spent detailing, and 1/3rd is spent on the finish. The detailing (trim, face frames, ebony inlays, doors) will start as soon as the tops are done (another couple of days).
Incidentally, I found this site tonight while looking around for design ideas. I wasn’t surprised to find out that this craftsman charges up to $9000 for some of his work. Next time you look at a hand made piece and wonder if it’s really worth 10 times what you could buy a cheap dept. store version, just remember that I (a much less qualified and talented woodworker) just spent 40 hours doing a basic carcasse build. I aspire to that level of quality some day and certainly don’t begrudge him what he charges. It’s beautiful work.
Got a glorious 8 hours in the shop yesterday (1-9pm). Pretty sore today, but I have a lot to show for it.
Two days ago I went to the lumberyard and got 2 more QSRO boards to make the right side of the main carcasse. Pretty panful to the wallet. Each board was 7 inches wide, 10 feet long, and about $35. In all, it took 4 boards just to make the 2 sides of the main carcasse, for a grand total of $140 in lumber! It would have cost about $80 if I’d have made it out of ply, and I would have had enough left over for all of the shelves, but this is a once-in-my-lifetime project. If it ends up costing more to use the very best lumber, and if it looks correspondingly spectacular, it’s a price I’ll gladly pay, especially since it’ll still be cheaper than buying the thing new.
Anyway, I came home and planed/jointed/glued the panels up and let them sit overnight, then yesterday I spent 2 hours standing in one place sanding, sanding, sanding the two main side panels. This, dear friends, is why God invented the iPod. The thing saved my sanity (thanks again, Tim! It’s running like a champ!). I gone through literally hundreds (probably over 1000) podcasts while in my shop. It’s a great way to keep up with what’s going on in the world. It’s also nice that I can make a custom, for-Jason-only audible “newspaper” that covers the topics I’m interested in. Tech, woodworking, science, etc. Right now I have 632 podcasts waiting to be listened to, and I’m sure I’ll eventually get to them all.
So after the sanding (sanding, sanding, sanding) was done I spent the next several hours carefully measuring and cutting the dados and grooves for the cross-pieces in the center section. Unfortunately, I messed up one of the cuts (DOH!), but luckily it was in a place that’ll be virtually invisible in the finished project (inside the cabinet area). Plus, I think I’ll be able to fill the dado with a piece of wood so that it’ll be much less obvious. WHEW. That was a close one. If I’d have screwed up on a more visible area I’d have been kicking myself.
It was amazing that six cuts (well, twelve, but I ganged the pieces together and cut both at once) took so long. It was almost three hours between start and finish, but I’m absolutely perfectionistic about these cuts. Since I’m making grooves on $140 worth of wood panels, it’s really important that I get it right.
Today Erin and I are going back to the lumberyard to get wood for the top of the cabinet. This has got to be the most beautiful and flawless wood I can find since it’s right on top where everybody can see it. Then I’ll come back and start assembling the center section from all these random pieces. I have to connect five large shelves of plywood (52″ x 21″) to the solid wood side pieces (60″ x 21″) in such a way that the solid sides are free to move with humidity, but still hold everything together tightly. How is this done? With buttons, of course. The idea is that you cut a small groove on one surface, then connect something solidly to the other surface in such a way that the perpendicular planes are held together in one dimension, but are allowed to slide in the other dimension. Here is a picture of a metal “button”. I’ll be making mine out of wood because it’s more authentic and because I can customize them to my needs. Here’s a better pic.
After the center carcasse is assembled I’ll spend another day planing and gluing up the three top pieces, then cut and sand (SAND! SAND!) it. Once it’s fastened on I’ll start in on the face frame. Lots of detail and work to come. I’m probably not even halfway there yet. Racing the summer heat.
Had a rather long night last night with a bout of insomnia from 4-6:30am. No matter, though, because I was able to get some good mental design work done on the telescope. I have a good rough idea of the case that I’m going to build for it. It’s roughly modeled after a beautiful paduak and curly maple briefcase I saw. Still have to figure out a way to do the inlay work, and the exact design/materials for the inlay.
Speaking of inlay, I’ve come to a decision about a spectacular detail on the tube of the telescope, but I’m going to keep that one under my hat. Grin.
It may not look like it, but “work” is proceeding on the design. 99% of it is mental at this point (in more ways than one), but once I get the design figured out in my head and go through a virtual imaginary assembly, I should have most of the build issues worked out. That’ll save me grief and time once the construction begins. I still anticipate that it’ll be 4-5 years until the whole project is completed. It’s been a real joy to just be able to spend months thinking and incorporating different ideas that I see into the design. No rush to commit to anything or start building immediately- I’ve got plenty of other stuff to build in the meantime.
Speaking of which, time to go to the shop this afternoon. The sides of the ent. cent. are almost finished (except for the trim and doors). Next step is the center case, then I’ll go back and face frame the whole thing. Then build doors. Construction stalled this past week because of other commitments, but it should get back on track this week.
I think I found another “someday” project. Swoopy, on this page. Wow.
Erin and I watched Die Hard 4 tonight (Live Free and Die Hard is the actual name). Pretty fun, if you’re willing to suspend your disbelief by a razor thin thread, then have that thread repeatedly thrashed by very sharp blades. At one point during the film we paused the movie and both burst out laughing because Hollywood had stepped over the line of believability so far. Not only were we calling the major plot points out thirty minutes before they happened, but seeing one Bruce Willis endure punishment that would have put Bruce Banner in the ICU, then walk away and crack wise, was a bit much. I mean, how much punishment can a human body take?
I found out a small amount of the how much in my shop yesterday, actually. I have been working on the entertainment center and was gluing together some boards. I reached for a clamp hanging on the wall and one of the clamps next to it fell off, pirouetted through the air, and landed sharp side down on my forearm. Didn’t break the skin, but I thought I had maybe fractured the bone or cracked something. Turns out I didn’t, but there’s a nasty deep bruise in the spot.
If I were John McClain I’m sure I’d just laugh it off and make some clamp-related pun. Fortunately, I’m only Jason and so am far too unclever to think of any.
Progress on the ent. cent the last couple of days. I sorted through my pile of QSRO and picked a bunch of boards to match for the sides and shelves. Lumber comes in varying thicknesses that are organized in 1/4 inch increments. You can get 1/4, 1/2, 3/4 and (wait for it)… 4/4. You can also get 5/4 and 6/4. The next step is 8/4 for the really thick stuff. There’s probably a good reason they do this, but I don’t know it.
I bought all my lumber in the 4/4 variety because it comes rough and you have to plane it down smooth. Planing obviously takes off material, which is why the standard furniture thickness is 3/4. The 3/4 stuff is is thick enough to be strong while still giving you enough wood left over after you’ve planed off the rough spots and smoothed things out. You can buy pre-planed wood from a big box store like Lowes, but the cost for that service almost doubles the price of the wood! So if you have the tools and the time you’re much better off doing it yourself.
Also, really good handmade furniture often doesn’t comply with this 3/4 standard. So I decided to make my carcasses and shelves out of wood that’s a bit over 3/4. This more closely matches the whole Arts and Crafts style I’m aiming for. The other reason is that I can’t stand spending several hundred dollars on lumber, lugging it home, and then immediately turning 1/4 of my investment into sawdust. Even at the current thickness -about 7/8ths of an inch- I’ve got a trashcan full of some expensive oak sawdust. Such is woodworking.
I pulled the boards out and carefully rough cut the pieces I needed, then sent them all through the planer and jointer. Just for the boards that make up 4 of the “walls” (the two side bookshelf walls) took several hours of work. Planing is pretty noisy and boring, so I put the iPod on and work my way through podcasts while I’m doing it. A planer is a fairly safe piece of machinery so I feel comfortable doing this. Whenever I’m on the table saw, though, It’s Total Concentration Time.
Anyway, after grain matching the wood for the best look I jointed the edges and glued them up into the 52×16 panels (four of them) an left them to dry. Today I did the same thing except with the six interior shelves. I’m starting to realize just how heavy this beast is going to be- solid wood is dense!
I also went to pick up a piece of 1/4 inch oak plywood for the back of the bookshelves. The lumberyard had a piece of beautiful 4×8 ply that had a severe ding in it on two edges. Fortunately, I won’t need that much wood. The guy at the yard sold it to me for ten bucks. Nice. I’ll have to carefully work around the ding a bit, but I’m glad to save the coin.
Next step is to go back and get a really nice piece of 3/4 oak ply, then measure and cut a couple pieces. I’m trying to limit my plywood usage because I want to be able to say the thing is made from solid wood, but I figure putting a few pieces of good 3/4 oak plywood in a few invisible spots won’t ruin the authenticity too much. Besides, there’s a big difference in the cost, and I’d hate to waste money on buying beautiful quarter sawn red oak only to hide it where it’ll never be seen. To give you an idea, I could have easily gotten all 6 of my shelves out of a $45 piece of 3/4 ply with enough plywood left over for 12 more shelves. I calculated the value of the solid QSRO that’s going into the shelves today: $85. So I’m all about saving money where you won’t see it. That way, what you do see can be even more beautiful.
Once the plywood is cut I’ll have all of the raw pieces for the bookshelf sides glued up into panels. Then it’s sand, sand, sand. I’ll probably spend two days doing nothing but annoying the neighbors sanding in the driveway. My hand gets numb holding the sander so I’m thinking I might use some kind of padded glove. Anyway, after that comes the stressful glue-up, then then interminable detail stage. I decided to incorporate ebony somehow, but I think I might do it in the doors. Depends on a couple things that I won’t know until things are a bit farther along.
Once the side shelves are done I’ll start working on the big center piece. It’s a scaled up version of what I’m doing now with a few major modifications. Still trying to work a few things out. Then I’ll have to get the final pieces of lumber for the three top caps (more planing/jointing/glue-up/sanding). Then the finishing, which will probably take a couple of weeks.
Long way to go.
Just got back from the lumberyard. I filled my truck with beautiful quarter-sawn red oak (QSRO) to use on the new project. I can’t wait to get started! I still need to get a little bit of plywood (a couple sheets) as well as some more QSRO, but I think I’ve got 75% of the lumber I need. What is it? Well…
Take a look:
It’s an entertainment center! I designed it in Sketchup to compliment Erin’s music cabinet in the piano room. Oh, how I LOVE Sketchup. I also modeled the rest of our living room to work on overall dimensions and proportions. It was neat to be able to stretch the piece out until it looked “right” in the space, then take those measurements to the lumberyard and buy wood. You can see the subwoofer I built a year ago as well as a coffee table and couch. The rest of the room isn’t visible in this picture.
Here’s another pic of the ent. cent. In this picture I’ve exploded the piece to get accurate measurements.
(Sorry, the proportions of the pic aren’t working out right now. This looks too tall and stretched. I’ll fix it later.)
The cabinet will be solid wood (with a very small amount of plywood in the hidden areas) with ebony inlays. Arts and Crafts style. I think I’ll add doors to the side cabinets but that’ll be a detail that I decide on later once it comes together. Got a really nice design idea for the doors.
Fedex just now delivered the mount for the flat panel HDTV. I designed the ent. cent. to hold our new TV with no cables showing. I’m also going to cut a hole for the center channel to slide into so the front of the speaker is flush with the TV. The whole thing will be finished in the same finish as the bookshelf, which is astonishingly pretty. Hand-rubbed shellac top coat. I’m designing this and building it in my normal fashion: overbuild and make it out of nice materials. I figure I’m probably only going to build one really great entertainment center in my life, and seeing how our current one is a piece of particleboard garbage I bought for $15 from my college roommate 15 years ago, this’ll be a step up. I’m only going to build one and I wanted to make it out of the best wood I could find, so the raw stock cost is fairly expensive. Here’s the kicker, though: go out and price a low-quality particle-board entertainment center. You’re easily in the $750-$1000 range, and the thing is going to fall apart in a few years. It’s not something you’d want to pass on, and it definitely isn’t made of good materials. Now go price a solid wood one. Handmade. You’d easily pass the $6000 mark.
The best thing about having my own shop is that I’ll be able to build a solid wood handmade piece that’s custom designed around our 46″ TV and fits our style exactly… for a bit less than the price of the low-end piece of garbage. That’s why I don’t mind getting the good wood (QSRO is $6.37/bf as opposed to $2.50/bf for “normal” oak…but oh, the difference).
I’ll keep you updated on progress with pictures. I figure (hopefully realistically this time) that it’ll take me about 2 months to build if I work on it a bit every day.
(And yes, we got a TV. No comments from the peanut gallery, please. We still like watching movies. Got it for half of what Best Buy was asking, too! 46″ 1080p LCD. We’ve had it a few months and love the thing… especially plugged into the Mac Mini with the big TB hard drive full of movies.)
Warning… long and maybe boring post with lots of detail. I decided to document my procedures and what I’ve learned over the past 3 weeks, so skip this post if you’re not interested in that kind of stuff.
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I’ve always enjoyed model building and came across a site a few weeks ago that discussed mold making and casting. I thought it might be interesting to get some experience making my own blocks for modeling (like making your own Legos), so I embarked on some self-education about room temperature vulcanizing rubber (RTV), sculptural clay, and casting replicas in different kinds of plaster (Plaster of Paris, Dental plaster, Hydrostone, etc). It’s ostensibly so that I can add another Maker Ability to my library of skills, but it’s mainly because it looked like a lot of fun. Maker Faire had a booth dedicated to creating your own prototypes, and the idea of making something and casting it in plaster, plastic, or even pewter kind of blows my mind (the guy at Maker Faire had made a prototype pizza cutter out of polyethylene). There’s a whole dedicated community online that casts their own building blocks for amazing Medieval castle and LOTR constructions, so I’m using that as a template for making my own. In fact, I’m trying to replicate this mold:
Once the initial mold is made you can use it to pour dirt-cheap plaster (100lbs for $30!) to make as many blocks as you want. I used the mold pictured above as a template but added a few extra pieces and subtracted a few others. Bruce Hirst, the owner of the site sells these molds for about $30 each, but they’re VERY worth it if you don’t want to spend hours making your own perfect master blocks. I’ve got to hand it to him. These things are hard to make. Making one block that’s approximately 1″ x 1/2″ x 1/2″ is fairly easy. Make it accurate to a thousandth of an inch is demanding. Now make a couple dozen of them to those tolerances and I can almost guarantee you a case of eyestrain. And if you don’t have access to a few thousand dollars’ worth of tools, you’re in for a frustrating experience. But I do, so I decided to spend three weeks and quite a bit more than $30 to make my own mold. Hey, it’s the journey, right? I spent days trying to figure out the best way to make the blocks accurate and after much trail and error, I had my basic blanks. I had to devise a few jigs from wood, cram Sculpey clay into them, bake the whole thing in the oven at low temp (good thing the wooden jigs didn’t burst into flames!), then cut on my band saw and sand on a belt sander with a custom jig I built and measure with calipers until they were accurate to 1000th of an inch. After the sanding was done I spent several hours with a magnifying headset and sculpting tools carefully texturing and detailing the bricks. They have to look detailed and interesting, but also interchangeable and kind of “bland” so that you don’t have one specific pattern on one brick that repeats itself. The idea is to cast hundreds of bricks from a few originals (9 on my final mold), and you don’t want one specific brick to stick out. Anyway, I’ve made 30 or so different bricks (and floor tiles, and cobblestone road bits, and brick wall sections) and have picked the very best ones to go in my mold. If I have leftover RTV I’ll cast the rest in a second mold.
Here’s a few pictures of the process:
Here’s me detailing the pieces. You can see one of my makeshift jigs in front of me (the Home Depot paint stirrer sticks)
I didn’t take any pictures of the building process, but it was a long one. Probably 15 hours total to make all the bricks. Here’s a sample of the flat floor tiles I made, all accurate to a thousandth of an inch:
Here’s a brick wall section after detailing. I ended up not casting this one (yet) because it was a first try. Looks like a tiny section of brick wall, though.
After a lot of research I decided to use an RTV called Oomoo 30 from Smooth-On corporation. They make all kinds of industrial and commercial rubber and plastics. Their website is amazing. I had no idea what you could do with this stuff. Oomoo 30 is a very viscous 2 part epoxy-like substance that hardens into a smooth shell over your originals. Technically, it’s a tin-cured silicone but it’s supposed to be pretty beginner friendly. The more expensive platinum cured silicones are stronger (to avoid tearing) and last longer before the finished mold dries up and cracks, but the platinum-cured products are harder to use. The platinum cured RTV also requires you to mix much more accurately and benefits from a vacuum degassing process. With the Oomoo 30 you don’t have to build a bulky and expensive degassing system to get the bubbles out as long you use a few tricks. So I ordered the smallest amount of Oomoo 30 I could (2 lbs) and waited. I always seem to order things at the worst possible time, and this time Christmas got in the way. My order took an extra week! Oh well. That just gave me time to prep the Master blocks. I actually dropped a few of the master blocks and chipped them very slightly, so I had to remake a few. A couple also didn’t make the final cut to go in the mold because they had odd irregularities in them that would have been annoying if they had been replicated 100 times on a project.
Once the masters were done and detailed and the Oomoo arrived I was ready to pour. I was pretty nervous about it since I didn’t want to make any mistakes. Not only is the RTV very expensive ($22 for 2 lbs, or approximately 1 quart!), but if I really screwed something up I’d end up destroying my original masters and that would be a tragedy. At this point I’ve got too many hours of learning and creation in those little blocks. Bruce Hirst makes them just like this but gets to sell his molds over and over. I was only doing it once just for me. If I want to build anything different in the future I’ll spring the $32 for one of Bruce’s molds. He uses the platinum-cured RTV so his molds are higher quality. Some of the platinum stuff retails for a couple hundred dollars per gallon. Yikes! If I were doing this commercially like Bruce does I would figure out a way to have the master blocks cast in some kind of metal. Even if it cost more, pouring many master molds from the master blocks would probably eventually destroy the master blocks themselves.
So anyway, tonight was pouring night. I got out all my pieces, did a test layout, and cut the MDF base for the mold box. Next, I blew off the pieces with compressed air then dunked them in Future floor wax for a few seconds. This step seals the baked ceramic and acts as a lubricant so the final RTV will release without shattering the masters. I took the pieces out of the floor wax and dabbed them with a paper towel. Once they were dry I superglued them into place on the base with exactly 1/4″ between them all, checking to make sure that the bottoms made a very smooth seal with the MDF. If you let the RTV seep under the pieces it can entomb them in the mold. This Is Very Bad. Don’t do this. Then I cut some foam core and made a wall all the way around the 7 1/2″ x 4″ mdf base to contain the RTV. I taped the foam core to the bottom of the MDF, and ran a bead of Sculpey along the inside of the box to keep the silicone from seeping out.
I then measured 1/2″ above the highest block and made a mark on the inner surface of the foamcore wall so that I’ll have a nice thick “floor” of silicone under the block casts. Then I filled the cavity with sushi rice (hey, it’s what I had around) up to the mark.
Wait… say what?!?
Well, the silicone has to be measured in a 1:1 ratio of its two parts, and it has to be accurate. I also wanted to make sure that I used enough, but not too much (remember the $ part?), so I used the rice to estimate the total amount of material I’d need. I transferred the rice to a measuring cup (350ml of rice total), then divided the rice evenly between 2 disposable plastic cups and made a mark on the cups. This will be my fill mark for the part 1 and part 2 of the RTV. Are we having fun yet?
Next, I took the advice of the guy at Smooth-On and gave my masters a couple of light coats of Krylon Crystal Clear acrylic to seal the Sculpey pieces so they don’t stick to the RTV. I waited a couple hours for the Krylon to dry. Then just to be extra sure I gave the pieces a few very light coats of the release agent I bought from Smooth-On (Ease Release 200). Once it’s all dry I plan on using the 2 container mixing method followed by the bombs-away pouring method (explained below) I’ll let it sit out in the garage on a very level surface for five or six hours (around 70 degrees) and then bring it in where it’s warmer overnight. Hopefully when I wake up in the morning I’ll be able to demold everything and have a nice shiny mold. Wish me luck…
I tend to be very slow and methodical learning new things. The downside is that everything takes me three times as long, but the good side is that I rarely make mistakes. Instead, I read about everybody else’s mistakes and try to learn from them. Hope that applies here.
Here are a few pictures of the process so far.
The Oomoo 30 and release spray, next to my mold box:
Mold box closeup. These are the main building block bricks. You can also see a pair of double brick on the bottom row for faster building:
After letting the second coat of Krylon Crystal Clear dry I did a couple of quick coats of the Ease Release 200. Yes, I’m paranoid about my masters sticking to the mold. After the second coat of Ease Release was on, I noticed that the detail on the blocks was somewhat softer than before. I had cut details to look exactly like Bruce’s rough-cut “normal” stone, seen here:
Unfortunately, all the coats of sealer I had applied started to soften the sharp details slightly. Now when I compare my pieces to Bruce’s I have fewer valleys and mountains. If you’ve been keeping track, I have no less than FIVE thin coats of sealer (a Future dip, 2 coats of Krylon, and 2 quick coats of Ease Release). In retrospect, I should have only done the Future and the Ease Release. Live and learn. The details are still very visible, but I wonder how much they’ll stand out when I dry brush the paint on.
So then I laid out all my RTV mixing supplies, poured part A and B into two different cups, and started my stopwatch. Oomoo 30 has a 30 minute “pot time” until it becomes unpourable and I wanted to be pouring within 10 minutes to give myself plenty of working time.
Here’s the pouring setup:
You can see the plumb bob and leveled MDF on the floor. When the time comes I’ll put the mixed RTV in the cup in the edge of the table and pull the tape off the side (it covers a 1/4″ hole). Then the RTV should fall right down the string line (I’ll move the string) and hit the mold in an empty spot to avoid bubbles. The falling RTV should form a very thin string and pop any air bubbles as it falls.
Next lesson I learned: The oomoo comes in 2 parts, a thin blue part (part B), and a HIGHLY viscous bright pink part (part A). What I learned was not to pour the thick pink stuff into a cup and then transfer it to a mixing vessel. The part A was so thick it was very difficult to get out of the measuring cup. I should have used a bigger initial cup for the part A and then just poured the thinner stuff into it. I got most of the pink stuff out of the initial measuring cup I used, but I got a higher percentage of the thinner part B out of its cup. So even though I carefully measured it to be equal parts A and B, due to the fact that I left a little bit more of the part A behind I think I was “B” heavy. Again, it’s not a big deal since I imagine that there’s room for a tiny amount of slop in the mix ratio, and it wasn’t more than probably 2-3% difference, but next time I’ll add the blue stuff to the pink stuff and not transfer the thick pink stuff an extra time.
So, mixing. This stuff is thick. I can’t believe that it’s considered one of the LEAST viscous RTV’s! It took about 3-4 minutes to completely mix, and even then I was paranoid that I wasn’t mixing it thoroughly, so I kept on for a minute or so longer. If you don’t mix it very thoroughly you’ll have gooey unset spots in your final mold. Again: bad. I used a cut off pencil to stir the mix together- round shapes don’t cause cavitation and introduce air bubbles like scooped spoon shapes do. Once it was pretty well mixed, I transferred it to a second container (which I had cut the small hole in and taped over) and scraped out the first container as well as I could. Then I stirred it a bit more until it was really well mixed.
At this point I was only about 7 minutes into the mix but thought that I could detect it starting to thicken up, so I used a small brush to paint a layer of RTV onto all of my pieces. This first layer will hopefully keep air bubbles from the final mold. Next, I put the mold on the ground on the piece of leveled MDF, put the cup on the edge of my workbench, and pulled the tape from the hole in the cup. Bombs away! I had set up a string with a plumb bob so that I was sure that the first stream of RTV would hit a blank spot on the mold. It worked! The 35″ that the RTV had to fall made the bottom of the stream VERY thin, and I could see air bubbles popping in the stream all the way down. I estimate that the stream thickness was slightly thicker than dental floss by the time it hit the mold, so I feel very good about not having any air bubbles. Who needs a vacuum degasser when you can let gravity do it for you? Say it with me: SCIENCE!
I had to sit and babysit the falling RTV for the ten minutes or so it took to empty out of the cup (my hole in the cup was only about 1/4″ in diameter). I gradually tipped the cup up as the RTV oozed out and used the pencil stub to push leftover material toward the hole. Once it was all done I had a very neat rectangular puddle of RTV in my mold box, perfectly covering my 21 mold pieces 1/2″ over their tops.
I let it sit out in the garage for a couple of hours and firm up a bit, but it started getting down into the mid 60’s and the instructions on the RTV say to not do any molding under 65 degrees, so I made a level spot on the kitchen counter and moved the mold box inside to harden over night. There’s a 6 hour waiting time to demold, which is technically around midnight tonight, but I think I’ll play it safe and leave it until tomorrow to take the mold apart. If colder temperatures affect the vulcanizing time then I’ll give it more time to make sure. At this point I’m willing to be patient.
Hopefully then I’ll finally get to do the fun part- cast plaster and build!
I have to say this whole process of making the masters in Sculpey clay to 1/1000th of an inch tolerance, carving and detailing with sculpting tools, making a mold box, sealing, and pouring RTV has been a real adventure. I’ve learned a lot of new skills and it’s been fun. But now the silicone is sealing and it’s time for bed…
*LATER*
It’s done! I got up this morning and successfully demolded the pieces after they had been curing for 12 hours.
Cured RTV
Removing the box:
Moment of Truth (drumroll):
Success!
I very carefully broke the seal at each of the corners and worked off the edges, then popped off the middle. The RTV came off very easily (thanks to those 5 coats of different sealer/release) and I’m very happy about it. The white line around the mold is the Sculpey sealer that I lined the box with. It peeled off the RTV just fine. You can see some slight raggedness on a few holes where some of the RTV crept under a couple of pieces.
The cavities took some careful trimming with a very small, very sharp pair of scissors, but other than that they’re perfect. My master is also in good shape. I’ll wrap it up and store it someplace safe for when this first mold breaks down and I have to re-cast a new one. Three years is the estimated “library time” for Oomoo 30 RTV.
There was also a small bit of tearing on a few undercuts. I had asked Erin to make the gargoyle piece and it ended up having a lot of detail and deep holes. There were also some pretty sharp undercuts on the piece, but I decided to try it anyway. Most of it came out okay, but there’s a small bit of RTV left on the master sculpt in a few of the deepest spots. Not sure how it’ll affect the final cast pieces yet. I’ll make my first cast later on today.
After this experience I now have the skills needed to replicate whatever I can imagine using silicone RTV molds. It’s possible to get high-temp RTV and use it to cast pewter or even brass (hmm… focus wheel for the telescope?) It’s a surprisingly easy process. Well, the molding part is. The actual creation of those tiny pieces was a pain. But I could easily copy and cast any small flat object. It’s also possible to make 2 part molds to replicate a 3d object (like if you wanted to copy a chess piece or star wars figure), and I’ve even seen molds that are elephant sized… literally, of elephant statues. It’s pretty amazing what you can do with this stuff and I’m glad I took the time to learn. I don’t know what I’ll use the skill for, but it’s good to know I have it. Thanks for reading along!
Oh, and if you came to this page via Google sometime in the future and this 3500 word article was helpful, please drop me a line or leave a comment. You can email me at jasony3131 and the domain is yahoo dot com.
