Why are my silicone molds warping?

[janesathome]

Hey friends; I’m just 2.5 years into my soapmaking journey and, as we seem to do, I’ve acquired a whole bunch of different molds. The ones I go to most are the first molds I bought- an inexpensive pair of loaf molds in wooden boxes from Amazon. They’ve been great until just recently - I had a 2 month hiatus from soaping and last week I noticed that both of these moulds have developed divots in their bottoms, when I wasn’t watching. I hoped the weight of the soap batter would even it out but nope! I have divots in the bottom of the loaves I just made . Anyone else experienced this? What’s going on? I don’t soap hot, I CPOP most batches.

I’m a hobby soaper but I do make quite a few small batches - don’t really want to buy very pricey replacements (and my CDN $ doesn’t go very far for anything imported from the USA) - but wondering if anyone has a recommendation for good molds that won’t go wonky on me!

 

[AliOop]

Awww rats, that's such a bummer, @janesathome! My vote would be that the heat from CPOP'ing is causing this. What temp is your oven when you put them in?

This is one reason I do prefer the heating pads for gelling my soaps. It keeps the temp low enough to avoid warping, although some cheaper (but super cute) cavity molds did end up with permanent silicone rash from the added heat.

 

[Ford]

Hi, put a flat board inside the mold. Then put weight on top of the board. On a flat surface. See if that doesn't flatten them out. Do they leave dimples in the soap. As they are now?

 

[janesathome]

Hi, put a flat board inside the mold. Then put weight on top of the board. On a flat surface. See if that doesn't flatten them out. Do they leave dimples in the soap. As they are now?

Thanks, I will try that - although the silicone appears to have stretched so I’m not sure it will resume its original shape. I’ve got some weights that will fit nicely.

Awww rats, that's such a bummer, @janesathome! My vote would be that the heat from CPOP'ing is causing this. What temp is your oven when you put them in?

This is one reason I do prefer the heating pads for gelling my soaps. It keeps the temp low enough to avoid warping, although some cheaper (but super cute) cavity molds did end up with permanent silicone rash from the added heat.

Yes, could be the many CPOPs over time. I turn the oven on to its lowest setting and turn it off when the soap goes in. (I MAY have forgotten to turn that oven off once or twice for about 30 minutes ) I’ve sometimes CPOPED in a large cooler with a couple of warm bricks - that may be the better option going forward.
The weird thing is that the distortion appeared over the summer; the moulds are stored at room temp in a cupboard.

 

[Ekuzo]

Warm bricks sounds like a nice idea if you don't have heating pads.

I have the same molds, but I got them on AliExpress - and one of them deformed a little on one side, now it looks wavy. Meh, I won't bother fixing it, I think it adds a cool effect to the bars. And I love those cheap molds.

I guess the quality of the silicone is not that good and it happens often by itself, even if no pressure is applied - just by sitting somewhere. I hope you manage to fix that!

 

[AliensrReal]

It’s the heat that causes silicone to warm. Some people are luckier than others with silicone molds. I have yet to experience warping of my molds, but my oven does go down to 170F and I turn it off 30 minutes before placing in the oven.

 

[janesathome]

Warm bricks sounds like a nice idea if you don't have heating pads.

I have the same molds, but I got them on AliExpress - and one of them deformed a little on one side, now it looks wavy. Meh, I won't bother fixing it, I think it adds a cool effect to the bars. And I love those cheap molds.

I guess the quality of the silicone is not that good and it happens often by itself, even if no pressure is applied - just by sitting somewhere. I hope you manage to fix that!

I like the warm bricks as no electricity is required, once I’ve warmed them in the oven I do have a couple of heating pads but they get good use to heat my bed over the winter
I am sure you are right; cheap silicone can warp. I have used each of the moulds at least 50 times so I guess they don’t owe me much. But I hate to add to the volume of garbage we throw to landfill.

It’s the heat that causes silicone to warm. Some people are luckier than others with silicone molds. I have yet to experience warping of my molds, but my oven does go down to 170F and I turn it off 30 minutes before placing in the oven.

Good idea to turn off the oven a while BEFORE putting the soap in! I’ll change up my routine. Thanks for the tip!

 

[Mobjack Bay]

I have't had warping quite like that, but I removed waviness along the side of one of my purple liners like yours using hot water. With the liner in the wood mold, I filled the liner with hot water (probably 170-180 F) and then let the water cool off completely before I drained it off.

 

[Ekuzo]

I like the warm bricks as no electricity is required, once I’ve warmed them in the oven I do have a couple of heating pads but they get good use to heat my bed over the winter
I am sure you are right; cheap silicone can warp. I have used each of the moulds at least 50 times so I guess they don’t owe me much. But I hate to add to the volume of garbage we throw to landfill.

Mine wasn't even used when it became like this, I guess it was just my luck

I have't had warping quite like that, but I removed waviness along the side of one of my purple liners like yours using hot water. With the liner in the wood mold, I filled the liner with hot water (probably 170-180 F) and then let the water cool off completely before I drained it off.

Sounds like an easy thing to do, maybe I'll give it a go, thanks

 

[janesathome]

I have't had warping quite like that, but I removed waviness along the side of one of my purple liners like yours using hot water. With the liner in the wood mold, I filled the liner with hot water (probably 170-180 F) and then let the water cool off completely before I drained it off.

@Mobjack Bay Thanks for the tip! I tried it, following your process. No change in the warped bottoms. Oh well -
Maybe one day I will decide that the insanely pricey silicone moulds are worth it; in the meantime, I guess it’s another Amazon purchase.

 

[Ekuzo]

How about using the same wooden box but with freezer paper lining? I've never tried it, but it always sounded cool to me and I know lots of soapers love it

 

[janesathome]

How about using the same wooden box but with freezer paper lining? I've never tried it, but it always sounded cool to me and I know lots of soapers love it

@Ekuzo i may try that sometime as I now have 2 spare boxes! I have freezer paper but I’m all thumbs when it comes to folding. (I LOVE soaping but the wrapping is no fun for me. So if it turns out that I like the folding of freezer paper to make a precisely sized liner I’ll be pleasantly surprised! )

 

[Ekuzo]

You never know, you may be a freezer paper natural

 

[Ekuzo]

Check this out - short and simple, you may find it useful

 

[janesathome]

Check this out - short and simple, you may find it useful

@Ekuzo thanks for sharing the video! Yes, I “may” be a natural - and I “might” turn into a naturally tidy person one day too!
I do appreciate the video - I may give freezer paper a try next week when I make my next soap

 

[Ekuzo]

@Ekuzo thanks for sharing the video! Yes, I “may” be a natural - and I “might” turn into a naturally tidy person one day too!
I do appreciate the video - I may give freezer paper a try next week when I make my next soap

All's well that ends well - make sure to share how it goes!