Peeling exterior finish on Ford RV exterior

[mike19920926]

Hi everyone, I noticed the exterior finish on my Ford RV is starting to peel off in several areas (see attached photos). I'm looking to DIY a repair to stop it from spreading and keep it watertight. What’s the best way to sand and touch this up? Should I use a gelcoat repair kit or just sand and paint it?
Thanks!

 

[Professor David]

I would sand (feather in any edges), prime, paint and clear coat. Not sure any point in restoring the gelcoat at this point though someone might have a good reason for doing so.

 

[mike19920926]

I would sand (feather in any edges), prime, paint and clear coat. Not sure any point in restoring the gelcoat at this point though someone might have a good reason for doing so.

Thank you for your suggestion.can you tell me what i need buy so i can do prime, paint and clear coat.

 

[bigbAZ]

It would help to identify just what we are looking at.

Is it just a clear coat that is peeling off the gel coat, or is there a (base) color coat? Gel coat doesn't peel like that so whatever it is must be on top of the gel coat. Clear coats applied on cured surfaces don't generally hold up too well, a clear coat is applied at the same time as the base coat as soon as the base coat flashes, so it melts in and adds durability to the base coat. (The clear coat is catalyzed but the base is not).

If it's only clear over gel coat, you could remove it all and keep the gel coat waxed but if there is a base coat it gets more complicated. You can try sanding and applying a new clear coat but I wouldn't expect it to hold up very long, especially if parked outdoors.

 

[mike19920926]

It would help to identify just what we are looking at.

Is it just a clear coat that is peeling off the gel coat, or is there a (base) color coat? Gel coat doesn't peel like that so whatever it is must be on top of the gel coat. Clear coats applied on cured surfaces don't generally hold up too well, a clear coat is applied at the same time as the base coat as soon as the base coat flashes, so it melts in and adds durability to the base coat. (The clear coat is catalyzed but the base is not).

If it's only clear over gel coat, you could remove it all and keep the gel coat waxed but if there is a base coat it gets more complicated. You can try sanding and applying a new clear coat but I wouldn't expect it to hold up very long, especially if parked outdoors.

Thanks for the insights! To clarify, the peeling layer feels very thin almost like plastic wrap (Saran wrap).

It is a transparent/clear layer coming off the surface. Underneath this "plastic-like" film, the surface still looks white. Based on what you said, it seems like a clear coat or some kind of protective film was applied over the original finish by the previous owner.

Given it's peeling like plastic wrap, what would be the best way to strip the rest of it off without damaging the layer underneath?

 

[bigbAZ]

Thanks for the insights! To clarify, the peeling layer feels very thin almost like plastic wrap (Saran wrap).

It is a transparent/clear layer coming off the surface. Underneath this "plastic-like" film, the surface still looks white. Based on what you said, it seems like a clear coat or some kind of protective film was applied over the original finish by the previous owner.

Given it's peeling like plastic wrap, what would be the best way to strip the rest of it off without damaging the layer underneath?

I think you may have to experiment. It could even be floor wax that a lot of RV owners put on the roof and swear by it. If someone applied a clear paint finish directly to the cured gelcoat they didn't do you any favors.

Does it have any smell to it, like paint or wax?

 

[bigbAZ]

Out of curiosity I Googled it and there are some marine polyurethane clears that you can spray after sanding. The sandpaper grit recommended varies from 320 to 600.

Google Search

On the other hand it might be a wipe on product like Poly Glow or DiamondFinish and I'm not too familiar with those but someone here might be . You could contact Poly Glow and ask if there is a way to tell.

 

[mike19920926]

出于好奇，我上网查了一下，发现有一些船用聚氨酯透明漆可以在打磨后喷涂。推荐的砂纸目数从320目到600目不等。

Google Search

另一方面，它也可能是一种类似 Poly Glow 或 DiamondFinish 的擦拭型产品，我对这些产品不太了解，但这里或许有人了解。您可以联系 Poly Glow 公司，询问是否有办法辨别。

thank you sir

 

[Gary RV_Wizard]

The subsurface is almost surely filon panels. Technically not gel coat (which is the very hard, colored finish layer in molded fiberglass), but a still a fairly hard finish. Filon doesn't have a gloss finish and is intended to be painted with at least a clear-coat to give it a shine. It is, however, waterproof without painting.

What you are seeing is peeling clear coat, a result of poor quality paint preparation. It's a cosmetic problem only. Yes, you sand and re-paint it.

 

[Professor David]

Buy the best automotive primer, paint and clear coat u can afford. Prep work is key. Sand down grits (100 to 220) and then wet sand down to about 400 to 600!grit. Use your finger tips to feel for any remaining edges. Best tool for this is actually your finger tips. If u can’t sand sufficiently, use a thin coat of bondo and sand flat. Once you prime, see if there are any imperfections…priming usually reveal imperfections. Sand those down and then prime any spots that have gone down to the base or fiberglass. Spay color coat…at least 2 coats…better to spray 3 to 4 light coats. If you use white then less coats are likely needed. Let each coat flash off and then spay another. Clear coat at least two coats. Then buff out if u know how or learn how to buff. Buffing really finishes or smooths the surface out for a mirror finish.
Are u painting the whole rig or just a section? If just a section and the rest of ur rig is dull, then u may not want to buff out the fresh section so it doesn’t stand out???

 

[Kirk]

We had a white fiberglass cap that began to lose the gelcoat in an area on the top of the front cap, but it was not flaking like you have. It was more like chalking in appearance. I had an RV & boat fiberglass repair worker look at it and his recommendation was that I clean it thoroughly and then use an automotive clear topcoat spray on it, but mine was up on the top of the cap where you couldn't see it from the ground. That was also about 15 years ago so there may be better answers now.

 

[RV_Lee122]

That looks like peeling clearcoat or a wrap coming off. Is the RV full body paint???

 

[John From Detroit]

I wonder if a prior owner used ZEP wax or some such.

But for a job that big.. I would not DIY. THe flip side of hiring it done is $$$$$

But then I know a good body and paint guy who works cheap.

 

[Gary RV_Wizard]

We had a white fiberglass cap that began to lose the gelcoat in an area on the top of the front cap, but it was not flaking like you have.

A front cap is a molded fiberglass part and does have actual an gelcoat surface layer. The gel top layer of a molded part is pre-colored and very hard, so if thick enough it can be polished to a shiny finish without requiring painting or a clear coat. It may oxidize and fade over time and thus lose both shine and color, but it doesn't peel. However, for cosmetic reasons the front cap on an RV may be painted or clear-coated anyway, e.g. to match a color scheme in full body paint, or because clear-coating a thin gel coat is faster & cheaper than a quality polishing job on a thicker gel layer. So at the high end you may find gel-coated molded pieces that have been painted and/or clear-coated for looks while at the low end it may be done simply for economy.