Sunday, February 28, 2010

#007 01 Dr. Bank's Office - Casting the Walls

The framing is good.  Not perfect, but acceptable for what I'm modeling.  Looks like Scott needs to get new glasses, so I'll go see the doc next week.

What I want to do is to make molds of both sides so that I can produce more of these and use them as bunk houses.  Since the frame takes alot of long and tedious work, we'll just cast them in plaster.  We'll start with two sheets of .020 acetate since it was handy.  You can use styrene or wood as well.

Next we remove the framing from the paper drawing.  This is rather a pain in the but and I'm not sure I'll do this again.  Next time I'll add a coat of wax paper.

There!  All cleaned up and ready to be mounted to the mold frame.

Here is the acetate sheet.  I like the clear material because it let's me see how well the master and casting dams are mounted, letting me check for gaps and leaks.

Using some 1/4" square basswood boards, I make a pinwheel dam.  This is an easy way to build a dam that doesn't require a lot of accuracy in cutting and can be removed easily.

Done.  Now I'll do the other one and let the glue dry.  Note that Ailene's Tacky Glue was used liberally as wood and plastic don't always stick together.  If the master is not fastened down properly it will float up into the silicone and be destroyed.

While our mold set dries, let's make some clap board.  I'm using S scale 2" x 12" boards which come out to about a 1" x 9" board.  The O scale 2 x 12 looked a little clunky, so I used this since I had it on hand.  First I distressed the wood with a razor saw blade.

There is an exterior side and an interior side.  Each has to be weathered differently.  In order to keep track of sides I put a spot of red paint (or magic marker) on one end on one side.

Next I took a dull hobby knife and scored up the boards, even chopping some parts of the board away.

Damn!  The Canadians beat the US in overtime.  That was for the gold.  Crap!

Here is where I "chunked" the board.

After I got through distressing the board, I gave it a light sanding to get rid of the fuzz.

Next I coated the exterior (red dot) side with Dr. Ben's Aged Driftwood Stain.  This was done rather sloppily in order to get some randomness.

Then I weathered the interior side of the boards using Dr. Ben's Instant Age Stain.  Again, I was sloppy and didn't make the wood too dark as it will be inside.

Once the boards were all weathered I placed them under a glass plate to dry and flatten out (the solvent in the stains will make them curl a bit.)

I sprayed the two masters with Testor's Dullcoat and let them dry.  Later in the evening I came back and mixed up some Alumilite HS3 Silicone Mold Making Compound.  This is a small kit that I keep around but often I buy it by the bucket.

You have to follow the directions carefully or it won't solidify.  I'm kind of worried about this batch since the material is over a year old.  I mixed 5 oz of white and a 1/2 oz of red activator.

The batch was mixed THOROUGHLY and air bubbles were allowed to escape.

I poured the silicone mold maker into the frames very slowly to help air bubbles escape  We'll let both molds cure for 24-48 hours.  This is a thin mold, so 24 should be enough.  We'll take the wood frame out and make a casting to test the mold.

That's all for now!

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