Can you use tube silicone to add details to existing silicone mold?

[NsMar42111]

I couldn't find this on a search...I have a silicone mold thats the right shape and size for a project but I need to add some detailing to it. Trying to figure out if the silicone in a tube would work? Has anyone tried this? I'm reluctant to toally mess up a mold...although I may have too .

 

[steffamarie]

I'm a new soapmaker so I can't speak from experience, but I would imagine that that would probably work. I would be worried about the tube silicone not adhering well to the mold and either letting soap seep underneath or being pulled off as the loaf was unmolded. If the first, I think you could clean up with a sharp knife depending on the level of detail. If the second, it would likely be easy to peel off the stuck bits from the loaf but it would mean that it could be a one-time-use design. I say give it a shot! Try it on an old one or a cheap one that you don't use often...or go whole hog and dive right in!! You win some, you learn some.

 

[Lin19687]

You mean like the Caulk stuff, correct ?

I don't think it will adhere to the mold Or if it did, not sure it would survive the soap process ?

back when I first started the IKEA small drawer set of 9 was a big thing. I was lazy and tried to use Bath Caulking in it as a Perm liner.
It didn't go so well and didn't want to come out - at- all.
This was HP soap so that is why I wonder if CP would be too harsh/hot/lye-ish

 

[earlene]

No, I am pretty sure that's not going to work.

I have made molds with caulking silicone. There are a plethora of videos on how to make silicone molds using caulking silicone. But NOTHING on how to attach new to old or already set-up silicone, probably because it just doesn't work.

Silicone has to set-up, dry, lose moisture. Once it has done that, it's pretty much finished.

Some drawbacks to using caulking silicone is the odor and how long it takes to go away after making a mold. Also there are a few different ways to make it. The liquid soap method works. The powdered cornstarch method works. Adding naptha (a solvent) works, too, but I would not recommend this method for a soap mold! The strong silicone odor takes a long time to dissipate and in fact, for a sensitive nose, may remain (while fading) as long as the life of the caulking silicone mold before it starts cracking and is no longer useful as a soap mold.

The shelf life of the caulking silicone molds I have made (I made several small ones in 2016) is much shorter than any I have purchased. I won't be making them again using caulking silicone.

 

[Obsidian]

@earlene did you use 100% pure silicone? When I hear the word chaulking I think of the chalky white stuff used in bath tubs. I can't imagine it would work well.

I would be tempted to try pure silicone, see if there was anyway to get it to adhere to a mold. I'd experiment on the outside before trying in a single cavity mold.

 

[NsMar42111]

I tried the white version that claimed to be 100% silicone on a cheapo walmart ice cube mold, that's a no go as it peeled right off .

earlene, I was reading with interest the DIY molds, did you use the clear stuff? I don't care about vinegar smells LOL.

They don't make what I have in mind or I would definetly just buy it! I did find a lace mat that's close, I may have to go try the lace mat technique....

 

[zanzalawi]

i was reading up on this same thing this weekend
i came upon so much conflicting information
the one thing i'm still pondering is like a silicone epoxy type material- putting down something to prep the surface so the new silicone will stick

 

[NsMar42111]

Hrm, haven't seen anything like that zanzalawi...and nowhere in home improvement forums have I found any advice for coating old silicone other than peel it off LOL

 

[earlene]

@earlene did you use 100% pure silicone? When I hear the word chaulking I think of the chalky white stuff used in bath tubs. I can't imagine it would work well.

I would be tempted to try pure silicone, see if there was anyway to get it to adhere to a mold. I'd experiment on the outside before trying in a single cavity mold.

Yes, it was 100% silicone caulking (clear as well). NOT the white stuff. Not partially silicone. 100% silicone caulking is not the same as the the rubber or latex or acrylic or even the siliconized acrylic caulking. It's 100% silicone and is labeled as such.

I tried the white version that claimed to be 100% silicone on a cheapo walmart ice cube mold, that's a no go as it peeled right off .

earlene, I was reading with interest the DIY molds, did you use the clear stuff? I don't care about vinegar smells LOL.

They don't make what I have in mind or I would definetly just buy it! I did find a lace mat that's close, I may have to go try the lace mat technique....

Yes, I used the clear 100% silicone caulking. But I colored them also. If you use the dish soap method, a colored soap will give the clear caulking the color of the soap. But you can also color it with a bit of artists paint as well.

 

[zanzalawi]

This is one of the links I was reading up on
I found these cute little molds at target and need to block up that hole for the popsicle stick!
http://www.instructables.com/topics/What-glue-can-I-use-to-stick-silicone-to-plastic/

 

[Lin19687]

duct tape


No really, it will work. You just need to use good duct tape and you will just cut off the tiny bit that starts to go out the hole.
Don't make things harder for yourself, make it easier !
I don't even want to tell you what I have used duct tape on, but I SO love it

 

[earlene]

I second the duct tape idea, especially if you aren't pouring at emulsion, but at even light to medium trace. I don't use it anymore, but in the past I have used duct tape on some mold liners I made. The batter at emulsion took so long to set up, that it began to leak through. My conclusion was that the lye softened the adhesive of the duct tape, making it less leak-proof. But with a medium to thick trace, the tape lasted for two or three uses before I felt I should replace it.

But your link looks good and I'd certainly try Devcon if you want a permanent fix. It sure looks costly, but you're not talking about using tons of the stuff, so it may well be worth the expense. And I'd, for one, really like to know how well it works for you.

The Devcon is less expensive than the Silpoxy and gets better reviews.

 

[zanzalawi]

lol! typical me- make it wayyyyy more complicated than it needs to be
THANK YOU!
duct tape it is!
the molds were $1 per package so no point in getting too crazy with them

 

[DeeAnna]

And if you really want a really really sticky duct tape, try the Gorilla brand. For best results, make sure your surface is super clean and bone dry. I used the Gorilla duct tape for the first time a couple of days ago -- it will pull the fillings out of your teeth.

 

[NsMar42111]

DeeAnna, I just pictured you chewing on a roll of Gorilla tape......

 

[Lin19687]

Now see I had a hard time with Gorilla, where 3M was better.
I might have gotten a bad batch.

You could get an Epoxy but that is $ compared to a $1 mold

 

[Mobjack Bay]

I have made molds with caulking silicone. There are a plethora of videos on how to make silicone molds using caulking silicone. But NOTHING on how to attach new to old or already set-up silicone, probably because it just doesn't work.

Silicone has to set-up, dry, lose moisture. Once it has done that, it's pretty much finished.

Some drawbacks to using caulking silicone is the odor and how long it takes to go away after making a mold. Also there are a few different ways to make it. The liquid soap method works. The powdered cornstarch method works. Adding naptha (a solvent) works, too, but I would not recommend this method for a soap mold! The strong silicone odor takes a long time to dissipate and in fact, for a sensitive nose, may remain (while fading) as long as the life of the caulking silicone mold before it starts cracking and is no longer useful as a soap mold.

The shelf life of the caulking silicone molds I have made (I made several small ones in 2016) is much shorter than any I have purchased. I won't be making them again using caulking silicone.

I found a YouTube video where the soaper uses silicone caulk and a piece of pipe to make an individual mold. Is this anything like what you did Earlene? I’m surprised the silicone doesn’t last longer. We use it to repair aquariums and it seems to last forever. Is the lye the issue?

 

[earlene]

I found a YouTube video where the soaper uses silicone caulk and a piece of pipe to make an individual mold. Is this anything like what you did Earlene? I’m surprised the silicone doesn’t last longer. We use it to repair aquariums and it seems to last forever. Is the lye the issue?

Yes, that is one of the methods I used.

Probably, it is partly the lye and partly the heat. But even so, silicone caulking on the juncture of bathtubs and tile doesn't last forever either. And there are different grades of silicone, which is something I had never considered until one of our vendor members discussed the fact that molds made with higher grade silicone lasts longer, while those made with lower grade silicone may not last as well at all.