Softening Silicone Adhesive

A cabinetmaker seeks help with loosening a silicone joint. July 31, 2009

We did some showcases that had glass tops. A couple of the glass tops have to be redone. They were done with a glass to glass joint and water clear silicone between them. We cannot even get a razor blade between them to cut the glass loose. Is there anything anyone knows of that would soften the silicone? What about heat? I am thinking that maybe a heat gun would soften it enough to separate it. Any ideas would be welcome.

Forum Responses
(Cabinetmaking Forum)
From contributor R:
There is a product called SolvoPlast. You should be able to find it in a pharmacy. I believe its purpose in life was to remove adhesive left on the skin from bandages and the like. It's the only thing I've ever found that will remove dried silicone.

I was tipped off to it by my father-in-law. A pretty fussy fellow, and they used it to remove the excess silicone from a less-than-perfect caulking job on the windows in their new house. I've used it successfully when other products have failed - like lacquer thinner, acetone, etc. Don't know how it would work in a situation like yours, but I'd guess if you got the joint wetted and left it for a while, it would soften it enough.

From contributor A:
A few years ago, I bought some solvent that is specifically designed for silicone removal. I needed to get a ton of caulk off a shower surround. I Googled it and I think it was about $35 for a quart.

From the original questioner:
I tried to Google it but didn't come up with anything satisfactory other than some cleaner that is made by 3M and it didn't sound like it would work all that well for the application I am trying to do.

From contributor A:
Has anyone tried vinegar? I've heard it is a solvent for silicone when it is wet, might work after it dries.

From the original questioner:
The problem seems to be that alcohol or items with alcohol in them work well when it is wet, however once it is cured just about nothing re-softens it. I asked a silicone tech line and they said heat has to reach over 400 degrees before it will cause it to degrade. If anyone can get a name of a product I would really appreciate it as I have Googled and have come up with nothing that really works on the cured stuff. I even asked my glass people and they don't know either. They just scrape it off with a razor and then clean the residue with glass cleaner, but that doesn't work to soften the bigger stuff.

From contributor K:
The solvent Xylene will soften silicone (sometimes sold as Xylol).

From contributor G:
The problem with the likes of Xylene and other types of harsh chemicals is that while it may remove silicone, it will also damage what the silicone is on. DSR-5 Silicone and Adhesive remover will remove cured or uncured silicone and adhesive caulks without damaging what the product is on. An example of "harsh" as it relates to chemicals, Lacquer thinner has 49% HAP's (Hazardous Air Pollutants) DSR-5 has less than 1 %.