Home Improvement → Is there anything that dissolves silicone?

In some not exactly sane moment, I used silicone caulk to fill some voids. Now I'm trying to get rid of it because the whole thing need to be painted, but completely removing the dried caulk is a royal *PITA*.

Yes there is, and it's called silicone solvent, possibly sold under an array of different brand names.

As far as I know there are no chemicals/solvents that can be bought by anyone to actually dissolve cured silicone from what I've been told, but if I'm wrong someone please do point them out, the only ones I've found for uncured silicone (aka silicone solvent as TheMG said)

I found that denatured alcohol worked ok for softening cured silicone up, and then using a wire brush or a razor to scrape it off, and then using a rag wet with denatured alcohol to rub lose the film left over.

...I found this out after I caulked my bathroom, only to find out 1 of the "new" tubes I purchased that day was expired by over a year, the caulking did not cure properly and I had to remove it.

What type of surface are you removing the caulk from?

»www.omega.com/pdf/tubing ··· rt_5.asp

Wood

I have actually tried xylene (marked with "D" on that list) and while it did soften silicone, it did not dissolve it. Many of the chemicals marked with D are not practical for one reason or another.

Have you tried a propane torch yet ?

Try "Stoddard Solvent" (aka White Solvent Paint Thinner)... You should be able to get it at your local Paint Supply store.

It won't Dissolve Silicone, but it should help to soften it up a bit, and make it easier to remove... It may darken/raise the grain in the wood, but since you're going to be painting over it anyway, that shouldn't be an issue.

-Tursiops_G.

I think a scraper and elbow grease is going to be your final answer. Since silicone is already soft, I don't think softening it up is going to help. To me, I think that would actually make it harder to remove.

I'd pa-ruse the paint aisle and see if you can find a scraper with the shape(s) for your application. Is this wood cedar siding? Petrified logs? Oak floor? Coffin lid?

Does this help?

»cool.conservation-us.org ··· 007.html

quote:

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REMOVAL OF SILICONE ADHESIVES
David Erhardt

REMOVAL OF SILICONE ADHESIVES is a problem which conservators are encountering more and more often. Silicones are thermally stable and difficult to dissolve. Mechanical removal is one possibility. For certain substrates, chemical degradation of the silicone can also be considered.

Silicone resins are decomposed by strong acids such as sulfric or concentrated hydrochloric acid. Decomposition can be accelerated by swelling the resin, which can be done with polar organic solvents. Swelling and acid attack can be combined by mixing an alkylbenzenesulfonic acid, which is comparable in strength to sulfuric acid, with non-ionizing polar organic solvents such as dichloromethane, toluene or xylenes. Alkylbenzenesulfonic acid in non-ionizing solvents is rather unreactive to many metals but aluminum, iron, lead, copper and tin are slowly etched, probably due to traces of water which allow the acid to ionize. Stainless steel seems unaffected, as are the glasses and ceramics we have tested. Some glasses or low fired ceramics which contain carbonates may react, although the mixture can be applied to limestone with no visible reaction unless water is added. Plexiglas, Lexan, Mylar and polyethelene show no effects after contact, although one suspects that the solvents could cause effects like delayed crazing. The mixture should not be used on porous, acid sensitive materials like paper or textiles.

Either organic solvents or water can be used to rinse off the degraded silicone. Water works because the alkylbenzenesulfonic ion is a good surfactant which serves to emulsify the mixture. The choice of rinse will depend on the substrate. Water is the best choice on materials like Plexiglas, but solvents should be used on acid-sensitive materials like metal and ceramics.

The following formula has been used in this lab to remove old silicone repairs from glass objects:

* 10 mL dodecylbenzenesulfonic acid, available in kg bottles from: Pfaltz and Bauer375 Fairfield AvenueStamford, CT
* 8 mL dichloromethane (methylene chloride)
* 5 mL toluene
* 18 mL xylenes

The fumes should not be inhaled nor the liquid be allowed to contact skin.

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A sharp knife/scraper would be far safer and easier to get.

If you can get ahold of those chemicals, be VERY careful and read the MSDS on them. The quote was about LAB use. You'll also be labeled as a suspected terrorist or running a drug lab in your garage. I knew someone that was sent to the hospital after exposure to one of those chemicals.

I've only ever scraped, but I've seen a Dap product called silicon-be-gone which is a sulfuric acid and some type of organic solvent. Similar to but much much safer then that lab formula. It might be worth a shot. I don't think it will really dissolve it, but it's supposed to soften and loosen the bond.

what about a heat gun? or in a pinch a blow dryer. seems heat would make it a bit softer too.

I didn't try heat gun, but I'll do when it stops raining....

Silicone-be-gone is also a good suggestion, though I'm not sure how it will effect wood.

Easy cleanup for silicone is alcohol, of the isopropyl vintage...

For the dried and fully cured variety?

isopropyl alcohol will do nothing to cured silicone..

denatured alcohol will soften/loosen it up, but you still need elbow grease to get it completely off.

I would be wary of Silicon-Be-Gone, looks like it could stain the wood/cause bleed-through in the paint:

»docs.google.com/gview?a= ··· 6001.pdf

Ideal for Use on:•Porcelain•Ceramic Tile•Fiberglass•Stainless Steel•Most Plastics•Glass•Formica •Concrete •Granite •Chrome Plated Brass

Note: Always test in a inconspicuous area prior to use. Will damage nylon. May damage or discolor some metals, painted and synthetic finishes or treated wood surfaces.