Silicone Removal from Fiberglass Pop Top

[JCrimson]

I've been very slowly working on redoing my Sportsmobile top and I've come to a portion that I'm unsure of how to tackle.

The previous owner at one time or another decided to use silicone to cover some existing fiberglass threads on the top of the SMB top. I'm trying to figure out a decent way to remove this silicone so that I may repair the fiberglass in those areas.

I'm currently trying a wire-wheel attached to a drill which is working sort of... it's mostly just smoothing out the silicone though.

I'm planning on monsterlining the entire top instead of gel-coating. Are there any solvents I could use to remove it without harming the fiberglass?

Any help is appreciated!

[BCam]

This may help:

https://www.fiberglassrv.com/forums/...val-26489.html

If you want more, Google "silicone removal fiberglass rv boat" and you'll come up with a ton of suggestions.

[JCrimson]

Originally Posted by BCam

This may help:

https://www.fiberglassrv.com/forums/...val-26489.html

If you want more, Google "silicone removal fiberglass rv boat" and you'll come up with a ton of suggestions.

Thanks for the reply! Yes, I’ve actually already come across that thread already and have googled quite a bit.

Some said that Acetone will destroy the gelcoat which I don’t care about, but it does make me question what it will do to the fibers underneath, and I have yet to find a solution for this specific situation.

The heat gun I used previously did a fair amount of work on the larger pieces when combined with elbow grease, but I’m unsure of how interwoven the fibers and silicone are.

I suppose I’ll keep hunting.

[BCam]

Acetone, used sparingly shouldn't be a problem. I used to use it on my boat as a final clean up. Used too heavily it might affect a high sheen gelcoat but shouldn't have any effect on the underlying fibers, etc. You're going to need to scrape and sand the damaged fibers anyway to get a clean substrate. It's possible you might even go all the way through, creating a hole but this isn't a problem. Fiberglass is amenable to repair.

I used to use Marine Tex for relatively small dings on my boat:

https://www.amazon.com/s?k=marine+te...sl_i0fob7grb_e

[BCam]

Don't be afraid to use a Dremel tool to grind things clean. If your roof isn't too shiny, the Marine Tex repair should be enough. If it's shiny, you'll want to get a gel coat repair kit as well.

Your best bet for step-by-step instructions will be boat related sites, including Youtube videos on boat fiberglass repair. The technique will depend on if the repair is simply cosmetic or structural.

[Shadefromtrees@gmail.com]

Razor blade

[REF]

Think a grinder with a flap disc would be too aggressive, but you can try a palm sander with 120 on it, any residual goop comes off pretty easily with goo gone and a rag. You might have to do some fiberglass patching after to make sure things are sealed up before raptor lining.

[moorefc]

When you get most of the silicone scraped off, the final sand should be with fresh, sharp sandpaper...don't smear around the remaining silicone...stuff is a mess to remove. Acetone does nothing to glass fibers, as well as cured resin. You can reglass with polyester, but epoxy is much better, whether in marinetex, or resin with fillers. You can also use seran wrap or wax paper as nice molding surfacing forms....
Sharp knives or razor blades help with the scraping....

[JCrimson]

Thanks for all of the replies!

I wanted to check back in, I've actually got most of the silicone off, if not all of it.

The key was a wire wheel on a drill that removed the silicone clusters pretty quickly. There is some scuffing on the fiberglass from it, but nothing too bad. I will be sanding it with a palm sander, filling the holes with fiberglass patch, and then rhinolining it.