Sun/heat damage to fiberglass?

[pindraak]

I am living in Florida now. I haven't been able to work on my Bigfoot 17 for months and I have been letting it sit out in the sun. I am currently replacing a roof on a house, and it got me to wondering about how wise it is to just let it sit out like that in the Florida sun at 90 degrees plus for months on end. The surface of the fiberglass is old and oxidized, so they tell me. I actually like the flat look, so am not concerned about cosmetics, just about structural damage or deterioration of the fiberglass shell, delamination, etc... Any ideas?

[Bill K]

Don't take this the wrong way, but how many fiberglass boats are there in Florida that sit out in the sun year around ?

Bill K

[pindraak]

Yes, and there are also lots of roofs that sit out in the sun year round... and those roofs wear out about twice as fast as they do up north. In general, plastics do not respond well to UV exposure or heat. I don't know anything about fiberglass boats. Perhaps people who really take care of them maintain and reapply protective coatings or something.

[cpaharley2008]

There is a whole thread on Poliglow and Red Maxx Pro floor polish and the effects on the fiberglass, if you can not cover it, I'd at least coat it with one of these products. For $15 you can make look like new and protect it.

[Darwin Maring]

It seams gelcoat gets small hairline cracks in it as it ages on any type of fiberglass product that is used outside. Campers, Boats, Cars (Except Corvettes) Don't know why, just know it does. Corvettes are painted so that may be why they don't.

Investing in a cover may be the answer.
DR

[pindraak]

I just took it to a covered storage unit and will leave it there until I can get around to addressing the finish. Good thing I did, too. I was storing it tilted slightly forward, due to driveway slope, and when I tilted it back a lot of water poured out of the drainage hole just in front of the door. I could see no signs of water or leak stains anywhere on the interior, so there must be a hidden leak along the mid seam or front access hatch.

I looked at some fiberglass boat sites, and they recommend repairing the oxidation by polishing it with grit, then using a fiberglass cleaner and then adding wax or polish. I'm a bit skeptical though. Grit polishing is actually going to grind/sand off part of the surface, and I don't see how thinning the surface is going to be beneficial to any purpose other than making it look shiny, which I don't care about.

[Donna D.]

Ken, I was able to track down a website that I remembered being posted here on FiberglassRV (pre HACK) about Florida and fiberglass boats. I have NO personal experience, but you may want to check out this website: Pictures of boats using the Vertglas Gelcoat Restorer

Hope this helps!

[pindraak]

Thanks. It looks like Vertglas is an acrylic, and the only real options are wax and acrylic and paint.

I have looked through a lot of ads and opinions and have yet to see anything but a few vague, bald assertions that any of these products actually protect the fiberglass from deteriorating or eventually leaking - nothing resembling a convincing explanation for how they accomplish actual protection, or what is wrong with just leaving it oxidized, aside from the look. Almost all the talk is about the aesthetics of making it look shiny, whereas I actually like the flat look it has now.

All 3 options seem to require periodic maintenance, some even every few months, and even with maintenance, they eventually get ruined and require some kind of ordeal of stripping and starting over.

Worse, almost everyone talks about sanding or polishing. Basic physics says this will thin the material, which is exactly the opposite of what I am looking for. Even chemical stripping seems like a move in the wrong direction. It seems to me that, unlike any of the 3 coating options, the oxidation that is already there is quite durable, with little or no tendency to flake off, and since it is already oxidized, is already providing a better barrier against further oxidation with little or no loss of material.

From what I know about the oxidation of metal, it is only a problem if the products of oxidation (rust) are not well bonded to the base material and flake off. This is why rust is a huge problem with steel, but not aluminum. With steel, the oxidation flakes off exposing more steel to oxygen and the metal keeps getting eaten up. Perhaps surprisingly, aluminum is actually far more reactive with oxygen than steel. If you sand or polish it, it develops an oxide coating instantly in air. The surface cannot be clean, pure metal in the presence of air. However, since the oxide sticks extremely well to the metal and provides a barrier to further oxidation, aluminum seems virtually rust-proof for practical purposes.

Fiberglass seems a lot more like aluminum than steel. Unless I can find better justifications for coatings, I'll bet just covering it when not in use is the best strategy for longevity, and the coatings are largely irrelevant, or even counterproductive if stripping, sanding, or polishing are involved.

[cpaharley2008]

I guess he already knew the answer, I certainly did not know of any of that information..

[mcbrew]

What you are dealing with on the outside is gelcoat, nit fiberglass. Yes, it will oxidize, but it will become chalky. If you wipe your hand on it, your hand will be white. This is stuff coming off.

The fiberglass is very tough, and can take more sun than florida can throw at it. We sail in the Caribbean, and the boat rental companies don't use any protective coatings. These are $70,000 to $800,000 boats. They don't stay in the rental fleets too long, but when they "retire," they usually stay in the area. Many of them end up in smaller rental fleets for many more years.

The sun will not make fiberglass leak. It will, however, damage many other things, such as plastic vents, rubber molding, and sealant caulk. Keeping your trailer out of the sun will prolong the life of these other parts of your camper.

[pindraak]

Thinking about it more, and my experience with finishing steel sculptures...

Given the fact that the surface is oxidizing and it does get worse over time - though slowly - wax, acrylic or paint could indeed protect the fiberglass from further oxidation, provided the surface was coated well enough to provide an oxygen barrier.

To get a rust-preventative coating on steel with wax, it is necessary to really rub it on hard several times for smooth surfaces, or use heat to melt it on for uneven surfaces, using hard paste wax. However, no wax coating will prevent rust for long at all outdoors. Both sun and rain wear it off in no time.

Paint, lacquer, or polyurethane will protect steel from rust much longer, provided you can get it to stick well in the first place, which means scrupulously cleaning all particles and oil residues off of the surface immediately before application. Maybe acrylic is a little more like poly or lacquer than wax. This would explain why people say it often lasts a couple years instead of a few months. However, anything clear is probably not going to block UV rays, which is not an issue with metal.

This all leads me to guess that a fully opaque paint coating is probably the ultimate way to protect the fiberglass, as it would presumably block out all light, including UV, and oxygen. With any coating, if the goal is protection and not looks, I doubt you would want to do any sanding, polishing or stripping with chemicals that could eat into the fiberglass itself, unless the coating will not stick to the oxidized surface. The surface of mine only seems very slightly powdery, so I would probably just wash the surface with soap, then coat.

However, it doesn't seem like the surface has actually deteriorated, thinned or pitted much at all, and my trailer is 23 years old. Given all the hassles involved in coating, I wonder whether the protection is significant enough to be worth it.

[Donna D.]

Ken, I also have a 23 year old trailer. The thing I've found that protects the finish (from UVs and lots of scrubbing in the Spring!) is to keep it under cover... a carport works for me!

[pindraak]

Good to know about the boats mcbrew. I was using "fiberglass" to refer to whatever is there on the surface, minus user-applied coating. I've often wondered why the common name emphasizes the glass and not the plastic. I thought heat might deteriorate it faster due to the fact that heat usually speeds up chemical processes.

[pindraak]

A carport is exactly what I did, Donna, except that I am renting space under someone else's. My situation here is too temporary to get my own. I think it is also a good idea in terms of leaks. Direct exposure to the kind of violent rain we get down here almost every day in summer certainly isn't doing any seals a favor.

[Donna D.]

Ken, we get the same rain except it's fall/winter/spring rain. Turns the outside of a fiberglass trailer different colors... red/black and green. I didn't realize mold came in so many colors! Best of luck to you!

[rabbit]

Originally Posted by pindraak

A carport is exactly what I did, Donna, except that I am renting space under someone else's. My situation here is too temporary to get my own. I think it is also a good idea in terms of leaks. Direct exposure to the kind of violent rain we get down here almost every day in summer certainly isn't doing any seals a favor.

Well, gelcoat is polyester resin containing pigment; the resin component of fiberglass is polyester resin without the opacity contributed by the pigment. Both are catalyzed (pushed to a heat-producing molecular change) by methylethylketoneperoxide so I'd say they are pretty much the same critter. Cloth or mat "wet out" by resin is the "rebar in the concrete".

A rationalization of expense and justification of personal choice is something we all have in common. I am 100% certain that my choice of RedMaxPro as a cosmetic fix for the chalky gelcoat which I cannot abide is the best choice (for me). Will a garage or barn with oversize door or carport protect a trailer from the elements and UV deterioration? You bet! Go for it on your dime.

jack

Come to think of it, and I'm sure all you train drivers out there will arrive at this conclusion, the pigment in marine gelcoat is generally white because of the relatively low heat-absorbing qualities of white objects. Probably also a UV barrier but I won't say I know for certain.

[Night Sailor]

Fiberglass WILL deteriorate in sunlight. But your is covered with gelcoat so you have no worries except that you should polish and wax it every 6 months or at least once a year.

[Carol H]

Originally Posted by pindraak

I looked at some fiberglass boat sites, and they recommend repairing the oxidation by polishing it with grit, then using a fiberglass cleaner and then adding wax or polish. I'm a bit skeptical though. Grit polishing is actually going to grind/sand off part of the surface, and I don't see how thinning the surface is going to be beneficial to any purpose other than making it look shiny, which I don't care about.

Having had or been around boats most of my life and having purchased a fiberglass trailer that sat in the Idaho sun for the first 16 years of its life without a lot of proctection I am a firm believer in 3M marine products.

Yes once the boat or trailer has heavy oxidation the only way to get it off is by using a compound product. 3m makes one called Restore and Wax - you put it on with a wool compound pad - helps if you have a power polisher but doing it by hand is possible using micro cloths - I have done it by hand using micro cloths and its not really all that much more work than using a power polisher but you do get a higher shine with the power polisher. If its a light oxidation they have another product thats called Clean and Wax. Yes using a compond to get the oxidation off will thin the gelcoat a little but if done correctly and not at a high speed and too much presure it should not take much gelcoat if any off at all and you should only have to do that once -the main purpose is to take off the oxidation not the gelcoat.

Once you have done the above you need to put on a ultra permormance paste wax a couple of times a year - to protect the fiberglass.

If you like the flat oxidation look then just the 3m Clean and Wax and then use a good paste wax over the trailer and that should stop it from getting worse.

And yes storing it under cover helps *a lot* at protecting everything - tires, water and electrical connection covers, rivit covers etc.

[Night Sailor]

Gelcoat is pretty thick. I often sand badly stains parts with 100-150 grit sandpaper, and in some cases let it stay dull--like cockpit seats. But the hull, and in your case the exterior, if polished, looks better, prevents staining, allows the application of wax, and is not all that much work to maintain once you get it looking nice.

So feel free to leave it dull. It most likely can be brought back, even years later. And don't worry about thinning if you decide to polish it.

[rabbit]

To put "gelcoat loss" in perspective, my experience limiting abrasion to Barkeeper's Friend and green ScotchBrite by hand is that no cutting thru to green glass occured altho the driveway was stained white by the rinse water. It wouldn't be the end of the world if it did. More than a few older trailers have some nice pink or blue body filler lurking here and there under a rattlecan touchup successfully mimicking the color cast of the gelcoat. I wouldn't be inclined to remove a bit of loose oxidation product starting with even 120-150 grit sandpaper when it isn't necessary. Randy the Shine Bringer introduced us to the cheapest (jury isn't is on the durability but time is passing and I haven't heard much negative) shinola restorer you'll ever see--RedMaxPro floor wax.

jack