A small amount of mold release agent from any hopefully local place that works in lay ups should get you by. You need so little they would probably give it to you.

You also may be able to put the aluminium mold into hot water so it expands a little before trying to release the molded part. Most resins and plastics will probably tolerate 180F degrees. You will need something molded into the part to pull on as well and cut off later I suspect. Hopefully epoxy resin shrinks a little as it cures. I have tried various ideals as separation barriers. Things like hard waxes seem to be attacked by some of the resins to some extent.


This may not have any relevance or use. When I want a plug or cork shaped object. I take a piece of hard rubber and drill into it with a hole saw. With the drill removed of course. You get a tapered plug to extract from the hole saw. If say you want a one inch top and a 3/4 inch diameter bottom type of thing 1 1/2 inch long it works well for me.

I used to pour waterproof concrete containers like very large septic tanks on location. To keep the plywood forms separated I used 1/2 ID hard plastic pipe. This with a 3/8 inch threaded rod through it and the plywood sides. After curing and pulling the rods and plywood forms. I Drove the plastic tubes out of the concrete easily. Then drilled all the rubber plugs required and drove them into the smooth bores. I figured they would last almost forever in that service and they provided a pretty absolute hole seal.

Really upset the inspectors although they could not fault the tanks in any way. It did enable good two and three thousand gallon holding tanks to be poured in place very economically. Usually for about a tenth of the retail cost plus an average days labor in total. So not for the first time with me they changed the regulations to require only csa or ul approved in America type certification tanks. Actually mine were better. The regulations at the time stated the manufacturer of the tank was responsible for the tanks integrity until they changed them. I knew at the time my areas large concrete and pre cast tank supplier was politically well connected and I thought that this is where all my attention was originating from.

After I had poured the sides and bottoms in one pour and removed all of the forms except the one on the very bottom. I would form the top and pour it and the access hatch cover . Go inside a couple of days later and remove the top support form. Also these tanks were reinforced with 6X6 wire mesh. They did want to know where I sourced those rubber plugs from. They were kind of questioning that I was able to drill them after examining one. I knew they were wondering how can he drill a smooth tapered rubber plug? I also sized them so they were a bare start into the holes and you really had to drive them in.