Making molds

[Kittish]

I have wondered the same, about painting the inside with silicone. Logically, it seems like it should work, but I wonder how easy it would be to get the soap out? (If the mould doesn't have any removable pieces, that is.)

I find that if my silicone pieces fit together very neatly with no gaps, it's hard to get the soap out of a straight-sided loaf mould. When I use the fractionally larger mould, there is a 1-2mm gap where the liners don't meet, and it is much easier to get the soap out. (To clarify, I have two wooden loaf moulds, but one is about 2mm longer than the other.)

If the mold doesn't come apart at all, then I'd think it would be very hard to get soap out of a silicone coated mold. Need to be able to break the airseal to let the soap out. I'm kind of thinking of painting each piece individually, so that there is overlap on the silicone coating at the corners when the mold is assembled. I think I'd also carry the silicone up over the top edges, so it makes a lip. I'm kind of thinking silicone might not stick well to the wood of the mold, so you'd need some way to stabilize it and one or both of those might work.

With the one small silicone liner I cut and tried out, I was able to pull a couple of pieces of the liner out ahead of removing the soap from the mold. Soap slid right out once I had those liner pieces out. Just pulled straight up on them. I think if I cut any more silicone liners, I'll leave a little bit of a lip that extends up past the top of the mold, to make it easier to grab.

 

[jcandleattic]

I have wondered the same, about painting the inside with silicone. Logically, it seems like it should work, but I wonder how easy it would be to get the soap out? (If the mould doesn't have any removable pieces, that is.)

You would most likely need to freeze it and bang it out of the mold, kind of like people do with PVC pipe...

 

[bathgeek]

I have wondered the same, about painting the inside with silicone. Logically, it seems like it should work, but I wonder how easy it would be to get the soap out? (If the mould doesn't have any removable pieces, that is.)

I find that if my silicone pieces fit together very neatly with no gaps, it's hard to get the soap out of a straight-sided loaf mould. When I use the fractionally larger mould, there is a 1-2mm gap where the liners don't meet, and it is much easier to get the soap out. (To clarify, I have two wooden loaf moulds, but one is about 2mm longer than the other.)

I hear you. My idea was that the sides of the molds would fold out, so you would unlatch, fold down, and slide out the soap. Of course, to ensure the soap could be removed, I guess all four sides would need to fold down, but it's nothing hinges can't fix... ^_~

 

[earlene]

Would silicone adhere to wood? I don't know. When I have used silicone to caulk tile and tubs, it does eventually peel away fairly easily, but that's with a smooth porcelain finish. Wood is much more porous. So I decided to do a search on the topic. Apparently you'd have to glue the silicone to the wood if you want it to adhere to the wood. Doesn't seem like the best way to go in my mind, but if you want to try it, go for it and let us know how it turns out.

Here are some links on the topic:

http://silicone.co.uk/blog/how-does-silicone-stick-to-different-surfaces/



[ame]https://www.youtube.com/watch?v=zNpfGhtzZLI[/ame]

For mask making, we painted the silicone/naptha mixture onto a smooth surface, waited for it to dry and it peeled off quite easily. Getting the right consistency for painting and for it not be too thick or too thin takes a bit of practice as well.

The other issue I see is that painting on the inside surface would be problematic as the liquid silicone tends to travel with gravity, therefore it I think it would slide down the insides and want to pool at the bottom.

 

[penelopejane]

So here's a question... why don't we just paint the inside of wooden molds with silicone? I'm thinking of making a box with a front that flips down, and if I coat the whole thing with silicone on the inside then once I flip the front down I can theoretically slide the whole thing out the front, then just wipe down the mold and reuse.

The soap doesn't actually fall out of a silicone mold. You have to pull the silicone mold away from the sides of the soap then you can push the soap away from the bottom of the mold by turning it upside down.

So you would have to have all four sides folding down to remove your soap and you would have to be able to lift it off the base.

Then you would have to work out how to get a very smooth finish to silicone after you worked out how to get it to stick to the timber - maybe with a special silicone type adhesive/sealant that would act like silicone.

Would silicone adhere to wood?

Earlene,
Sikaflex sticks to wood. It is a polyurethane adhesive/sealant that's very similar to the characteristics of silicone.
You probably have something similar in the US. I am not sure if it is safe up to 250*F as silicone is.
http://aus.sika.com/en/solutions_products/02/02a024/02a024sa08/02a024sa08100/02a024sa08104.html