Caulk that is soluble with mineral spirits?

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rebar

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Hello folks.

Ive know new silicone caulk will not adhere to old and have avoided it like the plague since then, also considering how difficult it is to remove it.

Which type of caulk can you remove with mineral spirits and elbow grease? If memory serves me right, Geocel Pro Flex did..

Thanks
 
Be very careful using any type of petroleum based solvents. They can ruin the rubber roofing.
Using a hair dryer or heat gun on the lowest setting will soften the old caulking. Use a plastic scraper to remove as much as you can being careful not to puncture the rubber roofing. Then clean it with denatured alcohol.
 
Be very careful using any type of petroleum based solvents. They can ruin the rubber roofing.
Fair enough advice, but way over-hyped in my opinion. Don't pour it on, but it's perfectly safe to use by dampening a cloth with mineral spirits or similar and wiping away residue. Even Dicor, the #1 manufacturer or EPDM rubber roofs suggests that method.

And it doesn't actually ruin the rubber membrane itself either. What it does is penetrate through it and soften the adhesive underneath, breaking the bond to the roof. You can end up with a loose roof membrane if you get too sloppy.
 
Fair enough advice, but way over-hyped in my opinion. Don't pour it on, but it's perfectly safe to use by dampening a cloth with mineral spirits or similar and wiping away residue. Even Dicor, the #1 manufacturer or EPDM rubber roofs suggests that method.

And it doesn't actually ruin the rubber membrane itself either. What it does is penetrate through it and soften the adhesive underneath, breaking the bond to the roof. You can end up with a loose roof membrane if you get too sloppy.
True, but most would try to soak the caulk and let it sit thinking it will work like paint remover. Gently scraping most of the caulk, using medium heat, and then thoroughly cleaning what is really stuck is good enough to reseal.
 
True, but most would try to soak the caulk and let it sit thinking it will work like paint remover. Gently scraping most of the caulk, using medium heat, and then thoroughly cleaning what is really stuck is good enough to reseal.
I hear ya, but you can't fix stupid. The same guys would use a heat gun on High and hone the scraper blade to a knife edge.
 
Thanks everyone.

I have to be honest. I learned about how new silicone will not adhere to old on RV forums.. You have to remove every last smidgen in order for the new silicone to be watertight. So I used Geocel Pro Flex on my old featherlite TH after DAYS of silicone removal, where if featherlite would have used any other caulk, I could have just removed most of it and gone right over what little was left..

The featherlite has been gone for some years now, along with my old job and I switched departments at the U and now do maintenance in the dorms.. We have ongoing water leaks from many of our showers where they used... You guessed it, silicone.. Why? Because its virtually impossible and very time intensive to remove all the old silicone from between tile, so the new silicone wont make a water tight seal. All sorts of fungal growth because it leaks and never dries out.. Don't get me started on how the department needs to remodel all the bathrooms, but they claim there isn't enough money right now.

So I figured, why not ask in the same place I learned about evil silicone, if there was a caulk that when it failed, would be easier to remove, or that if 100% removal was impossible, a caulk that WOULD actually adhere to itself. But I guess that would only be possible after you removed 100% of the silicone, so I guess I'm SOL..
 
In fairness, silicone is an outstanding sealant, i.e. high cling, stretchy enough to tolerate joint movement, resistant to most chemicals, and stable across a wide range of temperatures. All well & good until the need to repair the joint arises...

And if you are working with tile, Formica, Corian, metal, glass, etc, removal of silicone is not that a big deal.

 
In fairness, silicone is an outstanding sealant, i.e. high cling, stretchy enough to tolerate joint movement, resistant to most chemicals, and stable across a wide range of temperatures. All well & good until the need to repair the joint arises...

And if you are working with tile, Formica, Corian, metal, glass, etc, removal of silicone is not that a big deal.


You contradicted yourself.

Removal is very difficult. I tried all the tricks, and what worked was soaking with mineral spirits to make it swell, and then a big eraser. Even a thin remaining film of silicone will prevent new silicone from sealing.

Now thinking back, featherlite used a caulk on the roof that did come off with mineral spirits and a green scrub pad, but the company who installed the living quarters and windows used silicone and I fought window leaks until I finally removed them, removed the silicone and reinstalled with butyl tape which is easily removed with mineral spirits. But not suitable for tile.
 
You contradicted yourself.
Not really; I was describing a different situation. Silicone isn't bad on smooth hard surfaces. The problem comes with vulnerable surfaces like a rubber roof or nooks and crannies like corrugated moldings. For example, silicone is routinely used around RV window moldings, where it can be peeled with a plastic blade and wiped clean with a solvent. No worries. But the same technique is impractical on a rubber roof seam.
 
Not really; I was describing a different situation. Silicone isn't bad on smooth hard surfaces. The problem comes with vulnerable surfaces like a rubber roof or nooks and crannies like corrugated moldings. For example, silicone is routinely used around RV window moldings, where it can be peeled with a plastic blade and wiped clean with a solvent. No worries. But the same technique is impractical on a rubber roof seam.

What solvent wipes dried silicone off?
 
What solvent wipes dried silicone off?
Read the article I referenced. If you can peel the thick part away, even WD40 will work on the residue. I use mineral spirits followed by isopropyl alcohol. Or there are commercially-available silicone softeners, e.g. 3M Adhesive Remover. Lacquer thinner or acetone works too, but can damage plastics or painted surfaces.
 
Been there, tried acetone.

Silicone rubber is a cross linked polymer and cannot be dissolved in anything without first breaking chemical bonds. Since acetone is relatively inert, it will not break any chemical bonds and won’t dissolve it either. Acetone will swell silicone making it stand proud, so you can get a tool under it though.

Like I mentioned, I removed as much as I could and then had to use a eraser in order not to damage the aluminum pained siding.

Have you folks actually tried to remove silicone?
 
Why yes, yes I have. Boat Life caulk around my outdrive for 23 years. Afters pulling/scraping it off wiping with acetone got rid of the remaining residue and left it prepped for new.

Good luck.
Sorry for questioning then.. I just didn't have luck with acetone.. From what I remember, it removed the paint from the aluminum, but that was years ago.
 
Silicone rubber is a cross linked polymer and cannot be dissolved in anything without first breaking chemical bonds. Since acetone is relatively inert, it will not break any chemical bonds and won’t dissolve it either. Acetone will swell silicone making it stand proud, so you can get a tool under it though.
Right. The way to think about it is that some solvents will soften the silicone, making it easier to peel off. Then once the bulk is removed, those solvents are usually enough to wipe the residue away with a cloth. Nobody should expect you can just wipe away pure silicone, no matter what solvent is used.

Let me also add that we are talking about pure silicone; silicone blends are an entirely different matter.
 

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