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OT: How to remove all silicone sealant from aluminium?

Spud

Diamond
Joined
Jan 12, 2006
Location
Brookfield, Wisconsin
OT: How to remove old silicone sealant from aluminium?

Removed Aluminium shower enclosure and door frame . Has gobs/strips of old Silicone sealant stubbornly stuck to the Aluminium sides.

Tried box cutter and old style razor blade but thin strips of silicone is still left attacked to the aluminium.
Tried just pulling with fingers but that only works on the thick gobs and still leaves some behind. Tried rough sponge and sandpaper, with the latter marring the paint. Tried thinner also.

So how can I remove all of the old Silicone sealant without damaging the paint?
 
Effectively, you cannot. You can remove the appearance of the silicon best by picking them off with patience and then rubbing with soft rubber. However, it is both my experience and that of many others that there is no known solvent. The consequence of the use of RTV is that paint will no longer ever adhere to the affected surfaces. Probably not what you wanted to hear. Maybe others have a different experience, but I doubt it.
Steve
 
I had a small bottle of silicone sealant remover which was fairly effective on 2 or 3 year old stuff stuck to wood. With a lot of rubbing it seemed to shift the final bits after scraping and pulling off the main lumps. Following up with the usual decorators cleaners and a bit of rubbing down I was able to stain the wood with a good colour match to the main, un-siliconed, part. As I understand it silicone sealers never completely go off except on the outer layers fully exposed to air so there may be a chance of it working even on very old stuff. Sorry I don't recall a brand name.

I think its actually made to clean off accidental applications when you are installing things. Allegedly after following up with sugar soap or other decorators cleaner you can paint over successfully.

Clive
 
I got it off 1 side of the Aluminium enclosure frame with a lot of elbow grease, retractable box cutter, old style razor and the final thin silicone layer with sand paper. Unfortunately I also ended up removing a layer of paint from the sanding, but didn't see any other way to remove the silicone.
 
Try this link.

I have tried a couple of these products and while they don't make the silicone fall off while you sleep, they do work with a little elbow grease - agitate with a nylon kitchen scouring pad for example.
 
Condolences. Silicone sealants are some of the most tenacious substances ever devised by man, and can be very difficult to completely remove. That said, I've had reasonable, but not great, results with a product made by De-Solv-It called “Contractor's Solvent”. It's an “environmentally friendly” formulation that's the most effective of a dozen or so other things I've tried. The longer you leave it on the better it works – I'd recommend up to twenty-four hours if necessary. It's distributed to all the major national DYI, paint, and construction materials outlets, but may be hard to find in some locales.

De-Solve-it Contractors solvent

Some aviation maintenance acquaintances have mentioned RPM Technology products for removing silicone, but I've not personally used them.

RPM Technology has products to remove cured silicone RTV and polysulfide (PRC) and next generation cleaning products

~TW~
 
Trichloroethylene is the only solvent I've ever found that removes cured silicone, it makes it swell up so it can be easily scraped off.

"Old school" brake cleaner has tri in it or you can get it at a chemical supplier.
 
I have tried to use TCE to remove silicone which used to attach a solar cell cut from a solar module onto a metal plate with many small round holes, under a heating condition of 60-70C for 4 hours. but it couldn't work out. Is there any right way to achieve this without breaking the solar cell?

Trichloroethylene is the only solvent I've ever found that removes cured silicone, it makes it swell up so it can be easily scraped off.

"Old school" brake cleaner has tri in it or you can get it at a chemical supplier.
 
About the only way I know of to get cured RTV off is mechanical. If you can tolerate the damage, an electric wire brush is the fastest.

There are a number of chemicals that will attack silicone, but it make take time and most are not available to Harry Homeowner.

Do a search for silicone rubber digestant. Such a material is Prosoco – Dicone NC9.

https://smartbuildingsupply.com/product/prosoco-dicone-nc9-1-gallon/?v=7516fd43adaa

Tom
 
I actually used to work for a company that needed to remove silicone from metal on a regular basis. This was in the late 70s. We built a sealed room, with complete air recirculation to the outside- big exhaust fans, and a hood with fans, over a fiberglas tank, about 4x8 x 1 foot deep, filled with heated triclorethelne. It worked- turned the silicone to jelly, which fell right off. But I am amazed we didnt all get cancer of the eyeball, testicle, and toenail all at once. It was so obviously toxic and dangerous that nobody ever wanted to work in there.

I find that rubbing it with your fingernail actually works almost as well.

These days, I try to stick with citrus based cleaners- I figure I already spent 8 1/2 of my lives.
 
After I have razored most of it away I have used a magic rub eraser to get it off. At least that's how I remember it! May have been the white one for velom.
 
The Audi technical manual shows using a nylon bristled wheel brush in a rotary power tool. (A drill motor) for removal of gasket sealing compound (Silicone) from alu engine parts.

I bought one of those wheel brushes at the hardware store last trip into town just because I had never seen or used a non-abrasive charged synthetic fiber flap wheel. (I had used the type where the fibers contain grit of one sort or another). I haven't used it yet. but it should work. I just wish it was a good brand so I would trust the bristles not to fly out as I expect from this Chi-com example. Wieler offers a selection of nylon brushes.

Product | Weiler Abrasives

I have
 
I have tried to use TCE to remove silicone which used to attach a solar cell cut from a solar module onto a metal plate with many small round holes, under a heating condition of 60-70C for 4 hours. but it couldn't work out. Is there any right way to achieve this without breaking the solar cell?

Ordinary gasoline turns silicone to jelly, perhaps that would be enough to get the cell off?
 
You might try a very strong solution of salt water. The reason I say this is because before I knew any better, I used 100% silicone on my boat which is stored on the Chesapeake bay. This was used in areas above the water line such as portholes. All of the silicone turned to mush after a short while and just fell off. I have since gone to Life Caulk which holds up very well. I have talked to other boaters and they say the same thing about silicone. Don't use it around salt water. May or may not work for you but I think it might be worth a try from what I have seen.
 
It's been seven years, I'm thinking the OP has either gotten the silicone off, or replaced the whole thing by now.

For what it's worth, lots of the chemicals suggested will degrade the physical properties of silicone, but a huge factor of this whole thing is time. It's true that nothing will really dissolve the stuff, so the only thing you can do is make it swell and degrade its physical properties. More exposure = more degradation, so the problem just becomes a 3-way balance of time, chemical harshness, and elbow grease.
 








 
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