First efforts at Silicone Molding - Assembled Coot!

Did you seal the plug first? If I am going to use a foam Herters body as my plug, what do I do to it to prepare it? Will the release agent sprayed on be sufficient? It is an aerosol, so concerned it will eat the foam?
 
Dave, I spray the plug with 3 coats of release agent for birds I am using still in my rig, like this one-Ease Release 200. IF its a mantel bird I am casting off, spray lacquer applied at the same layer of applications. IT's that thin first layer of Rebound 25 that captures all the surface texture, so you want to pop any air bubbles that form and keep lathering it up onto the body from the moat of liquid that accumulates in the space inside that clay retention strip oval.

Did you get my PM on the Blick Art components sale?
 
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Great progress last couple days....

I painted a total of 3 coats of latex on the plug. The last coat was white, so when I sprayed the lacquer on I would see that I got full coverage!


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I then coated the plug with gloss black lacquer, which should release from the silicone without the use of a mold release....fingers are crossed.


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The plug was hot glued to the plexi glass, and a clay moat was formed. I used Smooth-on Rebound 25, a trial kit was just the right amount for this first lesson.

1st coat:







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2nd coat:





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After the 4th coat, the kit was used up!


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I will let the silicone cure over night and tomorrow try to peel if off the plug and the plexi. More to follow I am sure.
 
Nice work! Love that plexi-glass sheet, maybe if I get "Messier" to visit Lakeview Arena I can get the building manager to release some shards!
 
Looks good! If you are using urethane, .I would suggest plywood behind the Plexi. I have cracked plexiglass when not using it.
 
So far, I have cast 16 bodies, enough for the 16 heads I cast previously. I think I will get about 24 bodies out of the foam I had on hand. I am using some 4lb foam that I bought off CL, several years ago. It was left over from a flotation project they guy was doing, and I used it on the Burdick Scull (which was then all removed as soon as the next owner got it home! I could have made a whole bunch more decoys with that!

I took the bodies to my 6x48 belt sander and got a couple birds done before the motor stopped starting. I hope it is the capacitor... pulled it to bring to the Maint guys at work to check for me.

Anyway, got far enough to float test and assembly a couple...



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This foam it tough, I can not depress it by hand. I have no experience if this is typical of 4lb foam, or maybe it is just old. I am not getting the full 15x expansion, but am seeing at least 10x. I have both parts in water bath in crockpots on low, like I do with my epoxy too. I am getting a decent routine going and get a body per hour or so.

I will titebond III and wood flour restle coat these later this week. I am using a paintable/food grade release, and feel nothing on the bodies, so fingers crossed.
 
Very nice! Congratulations!

I agree, since it is the catalyst component that drives the reaction for urethane foams, determining expansion rate, bubble size and consequent density, you're likely getting an end-product that is denser than fresh 4lb foam would generate.

IF you want to fill-in the decoy bases to minimize adhesion of "marsh stuff" ( Aufwuchs, or attached community is the limnologic term), flat black Rust-Oleum applied at three to four coats will work well.
 
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Dave, I should have mentioned this earlier...you can mount a piece of softwood to the underside of the Plexi-glass plate with a screw-eye via a hole drilled through from the outside of the plexiglass plate when using a foam <8lb density, to function as a mounting site for the weight and decoy screw-eye. When Steve and I were molding his sleeper bodies, I initially hot glued these in place prior bolting the plexi-glass plate onto the bottom of the mold, but had trouble getting them to hold due to the mold release residue, so I just drilled through and mounted them centered, pinned with the screw-eye.
 
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Rick, Tom Rowe had advised the same to use the PT block to have a mounting point and save some foam. Next time I may try that. I also thought about embedding the weights, like the Herter's original. I think these will work OK. I used construction adhesive on the weights and the heads, and a couple SS screws. I will restle over the entire body with a couple coats of titebond III and wood flour. Though I have epoxy on hand too so could use that also.
 
Phil, the old coot I got from Frank was used as the plug for this project. I imagine I will stick the plug on the back shelf, and not bother to convert it back to a working decoy.
 
Rich, trip home was easy after the trip north on Friday! Got home, power was back on, house was warm. Friends had emptied the refrigerators and freezers, so I took a few hours Sunday night clean them all real good!
 
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