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View Full Version : What does silicone caulking not stick to?



Elninio
02-20-2011, 09:47 PM
I want to apply it at the back of a tile that I use for sharpening things, I will be applying it with a credit card, but I want the surface to be flat. I will be pressing it onto a flat surface, and don't want it to stick to that surface.

SGW
02-20-2011, 09:58 PM
I think I would lay down a piece of plastic film food wrap on your flat surface and press your piece down on that. I think you should be able to peel it off when the silicone hardens. A preliminary test would be a good idea, as this is pure conjecture on my part.

A coating of soapy water on the plastic film to act as a parting agent might work, too.

Elninio
02-20-2011, 10:01 PM
Sounds like a great plan with the soapy water, will apply it now. (Can't believe I didn't think of it !)
Edit: Just tried it, the soapy water helped, but it wasn't as perfect as you'd think. I mixed soap and water with a brush (this way its consistently mixed), and applied a bunch. I had to keep the tile moving on the soapy water film to prevent it from sticking (circular pattern). Once it was flat, I left it stuck in its position; I assumed it would not stick at all with the soapy water film. I was generous in the amount of soap I used, too.

smalltime
02-20-2011, 10:37 PM
Waxed paper

Jpfalt
02-20-2011, 10:40 PM
Silicon caulk will not stick to polyethylene sheet. Silicon caulk cures in contact with moisture, so dampen the tile with water before applying the silicon caulk. Then squish it on a flat surface and peel the polyethylene when the caulk is hardened.

What I have done in this situation is to glue mousepad to the bottom of the thing I want to be non-slip. I use gorilla glue to do the attachment. The gorilla glue also cures in contact with moisture, so I dampen the base with water, apply the gorilla glue and weight the item on top of the mouse pad. When set, I trim the edges with a sharp knife.

AiR_GuNNeR
02-20-2011, 10:41 PM
I've done just that using a glass plate that I sprayed with PAM cooking spray

Andrew_D
02-20-2011, 11:03 PM
I've always found the silicon caulking will not stick to the joint between my bathtub and the shower/tub surround.

It will however stick to my skin, hair, clothing, the bottom and sides of the tub (but not that darn pesky top-rail), walls, etc.

Andrew

P.S. Hey, someone had to say it!

Mike Burdick
02-20-2011, 11:11 PM
Here's some info on getting it to set up as well as what to use as a release agent...

http://www.myheap.com/book/chapter-07/siliconecaulkmolds.php

Dragons_fire
02-20-2011, 11:16 PM
waxed paper works great. I make gaskets from RTV coated coffee filters. I lay a sheet of wax paper on a sheet of glass, then RTV, coffee filter, more RTV then another layer of waxed paper and then Glass. I weigh it all down with a bunch of lead. Then when its cured, i just peel them off and cut to the right shape.

Elninio
02-21-2011, 12:56 AM
i'll try the wax paper now, the caulking stuck the thin transparent plastic sheet to my granite surface. I have no idea how this happened, i didn't press it that hard so the tile would come in contact with it!

Bruce Griffing
02-21-2011, 01:51 AM
Silicone will not stick to Delrin worth a darn. Not much else will either.

metalmagpie
02-21-2011, 10:12 AM
A trick from the BBQ guys: use some parchment paper from your kitchen. Works much better than wax paper. It is impregnated with silicone, presumably different formulation from the silicone caulking.

ptjw7uk
02-21-2011, 10:49 AM
thanks for that heads up Andrew_D as I have found many times to my cost, it wont stick to what I want but will to what I dont!!
Still I supose thats life!!
Also happens with so called super glue thats why the videos used to show them gluing a freshly cut o-ring back together!!
Peter

gary350
02-21-2011, 02:37 PM
It will not stick to polyethylene.

NSB
02-21-2011, 03:48 PM
Why not just use normal paper, allow the silicone to set, then soak until the paper can be removed easily?

Elninio
02-21-2011, 07:26 PM
Why not just use normal paper, allow the silicone to set, then soak until the paper can be removed easily?
It doesn't stick that well to the tile to begin with, and it would be slower. Additionally, to achieve the flat surface would require some moving around, and without sliding this will offset the caulking ont the tile-side. It's really a pain, even the soapy-water way produced a poor result, and took about a day and a half to dry due to the water.