Removing clear silicone caulk from exterior fiberglass

[noteven]

I bought a vintage (ok - old) Bigfoot camper that is pretty much in stock condition - as the seller said it hasn't had the Pintrest treatment -

But - the camper has suffered an attack of the Silicone Monster to the exterior - every window, arpeture, access door frame etc has recieved generous globs of clear hardware store variety silicone sealant.

Granted, I think the thing would float - but it does not look that attractive all stuck up with dirt and grime - and my looks standards are not that high...

Anyhoo - I would like to remove the silicone sometime in the future -

Anyone who has done this - what is the best cleaner to remove the silicone residue from the fiberglass gelcoat?

Thanks

[JimK-NY]

Scrap off all the old silicon or other caulk. Then use a scotch pad and gasoline. Then bon ami or barkeepers friend again with a scotch pad. Then mineral spirits and a shop rag. If the surfaces are still slick and shiny, consider a light sanding with fine grit paper. Then use dicor or a similar quality sealant. Inspect annually but no work should be needed for decades.

[frankwp]

That was a good video, but it's concerning that he uses "silicone" as a generic name for silicone sealant. Lexel doesn't even make a silicone sealant.

[noteven]

Thanks Dan I’ll check out Leon’s videos

[dapperdan]

I watched an RV detailer take clear silicone caulk off of a DRV Mobile Suites this spring while attending a DRV rally. The gentleman's name was Leon Kirby, he's known as "The Nomad Detailer". Go on You Tube and watch his videos, he's good at what he does!

Leon demonstrated caulk removal using just regular old Mineral Spirits! The key according to Leon is to NOT be in a huge hurry removing the old caulk! It does take time but is VERY effective! It was amazing to watch him go over and over the seams with the mineral spirits and "soaking" the old caulk. With a plastic knife he removed huge sections (pieces) of the silicone by simply "working" the spirits into the seam!

To do a 40' fifth wheel Leon claims it will take him at least 8 hours and he'll use at least a gallon of mineral spirits! His programm is to let the RV sit over night after removing the old caulk so it has a chance to "off gas", next day is spent caulking the whole rig, which obviously doesn't take near as long to do as the removal.

Watch and learn...... You Tube is your friend!

Dan

[ernie1]

Over countless years of working on cars and now rvs, I've found virtually not much of anything will do a good job of removing silicone caulk except for two things: gasoline and Mechanica Silicone Caulk Remover. I know, gasoline is a smelly flammable material but it works and it's relatively cheap and accessible. Just wet a rag with it and place it on the silicone for a few minutes and it will start to crumble into little pieces and eventually the area cleans up well. The Mechanica is sold at Ace Hardware and works well but is slow and messy

[noteven]

theoldwizard1 wrote:
If it is the silicon caulk designed for bath tubs, you have a fight on your hands !

If it is silicon-ized latex caulk it should come off easily.

If I get time in the next few days I'm going to remove the silicone from the water heater access door thumbscrews (I said "everything" is gooped) and see what we think it is...
🙂

[BarneyS]

Moved to Tech Issues forum from DIY.

[jjrbus]

Silicone has become the generic term for caulk used by too many people. If it is truly silicone none NONE of the products sold as silicone removers will do anything but remove money from your pockets! If they do remove anything it is not silicone!

Now don't take my word for this, take a cutter of some kind and cut some big chunks of it off and put it in cups with recommended removers such as vinegar, WD 40, isopropal alcohol, gasoline, xylene etc and see which one actually works. I found zero.

[GMH]

I bought these for removing my decals. With something like these, you may be able to scrape 99% of it off without damaging the fiberglass. Then maybe a commercial silicone remover solution? If not, naptha may work. They work great, but the edge doesn’t last long, so buy lots of them.

[theoldwizard1]

If it is the silicon caulk designed for bath tubs, you have a fight on your hands !

If it is silicon-ized latex caulk it should come off easily.

[noteven]

thanks for the replies so far

[noteven]

frankwp wrote:
Silicone sealant has become like a plague on humanity. It's great stuff for certain uses, but there is almost always a better choice when caulking is required. Even when using caulking remover, it's very hard to remove all traces of the ****.

You should see me lose my mind when I go to remove a motorcycle valve cover and some DIY person has used it and the crumbs start falling in the engine....

[noteven]

gbopp wrote:
Do a YouTube and/or Google search for removing Silicone caulk.
You'll get several responses.

Ya I have done a bit of that. A lot of presenters seem to call every kind of sealant "silicone"

What is gooped all over this unit is the clearish product found in hardware stores called "Silicone Sealant"

The first inch comes off by mechanical means.

I am researching how to remove the residue so I can go back with urethane. Sikaflex 522 UV

[frankwp]

Silicone sealant has become like a plague on humanity. It's great stuff for certain uses, but there is almost always a better choice when caulking is required. Even when using caulking remover, it's very hard to remove all traces of the ****.