Taping down a solar panel on a PAINTED fiberglass roof?

[Naio]

I learned the hard way that I have a pretty extreme allergic reaction to fiberglass dust. I had a pin hole in the roof of my van, and remediation cost me thousands of dollars and a year of camping.

I'd been thinking that this meant solar was not an option for me, because tying down the panels would involve drilling holes in the roof. But then I read here about a couple people using extreme sticky tape to hold down solar panels. I wonder if that might be an option for me.

The catch is, my roof has been painted with rustoleum.

The roof is also slightly curved in both directions, so I would need supports under the edges of the solar panel. I could screw the panel to the support, but I would need to tape down the supports.

Do you think this is reasonable for me to even consider, with a flat 1 x 2 meter panel?

There's somebody in the place where I am right now who bought a bunch of them for a house and is selling the extras, so I could get a good deal.

Thin film solar might be more practical in conforming to the roof, but I understand it has problems with cupping and overheating. And of course it is quite a lot more expensive.

I'm not sure whether I would be willing to risk having someone remove the paint from the places where the panel supports would tape down. Maybe with a liquid paint remover, the van emptied out and closed up tight, posting it down thoroughly afterwards before opening any doors.... Do you think taping to the rustoleum would work?

I'd love to hear your folks' thoughts on this before I leave the area where the guy has the cheap solar panels :-).

[2oldman]

Naio wrote:
I don't think fiberglass and resin are on the menu for allergy testing . have you never had it done?

I thought they could test just about anything. I've never been tested, but I know I'm allergic to a certain weed, tree pollen, and mold/mildew. Learned that the hard way too. I sneeze constantly between April and July.

[Naio]

2oldman wrote:
I would have thought OP got professionally examined to see exactly what he's allergic to.

I don't think fiberglass and resin are on the menu for allergy testing ;). have you never had it done? They have a set of things that they test for, and it's mostly tree pollen and mold and things like that.

Anyway, it was irrelevant at the time. All that mattered was that I was allergic to something that had gotten in the van as a result of fiberglass repair, and I had to clean it out so that I could use the van.

I was present when the repair was done, so I knew that nothing was used other than a blow dryer, epoxy, and hand tools. No weird chemicals. I knew the allergen was particulate rather than a vapor, based on the way it transferred from item to item.

Sometimes it just makes sense to do your own detective work.

[2oldman]

I would have thought OP got professionally examined to see exactly what he's allergic to.

[landyacht318]

I've removed plenty of 3m5200 from properly prepared surfaces.

It's strong and resilient but hardly impossible to remove.

I know some people have bad sensitivity to the hardener used in epoxy resin, and some develop sensitivity to the point they can't come in contact with it even fully cured.

But Van tops are made with polyester resin, not epoxy. Perhaps it is the styrenes Naio is allergic to in the PE resin, not the actual glass fibers.

Glass fibers itch, but rarely has it lasted more than 36 hours in the worst case I can personally remember.

[Veebyes]

If you are going to use an adhesive 3M 5200 is about as nasty as it gets. Once it cures nothing moves it. As a boater I am familiar with the stuff. My weapon of choice is 3M 4200. Not as strong as 5200 but once cured still very strong.

Good thing I don't have your nose. I have been in the process of re decking a small boat for the past couple of months. Lots of fiberglass work involving cutting, grinding, drilling, mixing & laying.

[Naio]

landyacht318 wrote:
...if one sands a greasy/contaminated surface they push those contaminants into the valleys which will inhibit the bonding of anything laid atop.

Good point. Thank you for this and all the other info about fiberglass.

[Naio]

naturist wrote:
Here’s the thing: the last thing you need is for the sail that is a solar panel to blow off the roof and decapitate the poor devil behind you. Since the frames of the panels need to be mounted with an inch gap between panel and roof for cooling, you really need to screw them down.

I think there are a couple of people on here who attatched the brackets to a roof with adhesive 10 or 12 years ago, and haven't decapitated anyone yet.

If I'm wrong about that, I definitely want to know!

For what it is worth, it isn’t likely that your allergy is to the glass. It is very much more likely you are allergic to the resin. Early in my career, I was a plastics chemist in the electrical equipment industry where we had people developing allergies all the time. It was always to the resin, not the glass.

Hmmm...that is bad news, from the point of view of wanting to remove the paint from the gel coat and tooth-up the gelcoat a bit :(.

I have half a mind to ask someone to do a small spot, create a little dust, and then I snort it. My allergy, although quite bad (when I tried to sleep in the van after doing what I thought was an extremely thorough cleanup, I had to use a month's worth of allergy meds in one night), did not involve anaphylaxis. It was a big hassle, but not life-threatening.

[naturist]

Here’s the thing: the last thing you need is for the sail that is a solar panel to blow off the roof and decapitate the poor devil behind you. Since the frames of the panels need to be mounted with an inch gap between panel and roof for cooling, you really need to screw them down.

For what it is worth, it isn’t likely that your allergy is to the glass. It is very much more likely you are allergic to the resin. Early in my career, I was a plastics chemist in the electrical equipment industry where we had people developing allergies all the time. It was always to the resin, not the glass.

[Naio]

pianotuna wrote:
ndrorder,

Panels are heavy. Everything gets heavier as I age. The OP is handy but not strong. Muscling panels in and out would be a night mare for me.

True. Also I am usually not near the rig during the day, and I wouldn't want to leave panels out where people could get them. I thought about flexible panels for this -- I've seen posts where people just unroll them when they're going to use them -- but I figured they would disappear.

[pianotuna]

ndrorder,

Panels are heavy. Everything gets heavier as I age. The OP is handy but not strong. Muscling panels in and out would be a night mare for me.

[ndrorder]

Why not leave the panel on the ground. Parts to make you own system are now readily available online. You have a source for the panel. The rest can be spec'd by folks on here. It also gives the freedom to place the panel where the shade is not?

[valhalla360]

bgum wrote:
I suggest you forget the whole thing. Your allergy is the controlling issue.

As far as DIY...if you allergy is that bad, don't even try it.

If you have a pro do it, they should be able to rough the surface up and epoxy mounts to the outside surface. This process doesn't need to go through the roof.

You still need to get the cabling down to the batteries and an openable window doesn't make sense. It's going to be very inconvenient to climb up on the roof every time you want to connect it. The big advantage of solar is you install it and it just works.

[pianotuna]

Naio,

Extend the wires down the side of the RV and then drill up from below.

I don't think having wire enter through the window would work unless you are drilling through the metal frame. Even then sealing may be an issue.

[landyacht318]

Gel coat does not contain any glass fiber, but its thickness is highly variable, depending how much wore away, compared to how much was originally sprayed into that part of the waxed mold when it was built, 20 ...30 years ago?. HOw much was sprayed depends entirely on the mood of the guy working the gel coat gun at the time, and the quantity of resin fumes he had already breathed that day. It's a thankless, toxic task, spraying gel coat in a mold.

It is pretty easy to see when one has sanded through the gel coat into the greeninsh or perhaps brownish polyester resin which was used to saturate the fiberglass matt/cloth laid atop the gel coat inside the mold. The gel coat's bond to the fiberglass is usually as good as a bond gets, but if the gel coat was cracked badly then the paint used to fill those cracks, all bets are off.

The paint's bond to the gel coat is entirely dependent on how it was prepped before the paint was laid atop, AND the adhesive ability of the paint used. Regular rustoleum enamel bonds poorly, the Rustoleum MArine yacht enamel is several fold better in adhesion and resistance to UV and abrasion.
I have lots of experience with BOTH, and regular rustoleum enamel deserves ridicule.

Any VHB tape's or #m 5200 or other adhesive's bond will only be as strong as the paint to the gel coat and this can be quite weak depending on the surface preparation before that paint was laid atop.

Getting things to bond well to bare fiberglass requires mechanical tooth, Sharp valleys and mountain tops to increase surface area and this sharp sandpaper needs to be used after the surface its thoroughly degreased, as if one sands a greasy/contaminated surface they push those contaminants into the valleys which will inhibit the bonding of anything laid atop.


Loose solar wires into a window is a horrible idea, no matter how you decide to adhere them, you'll never seal that entry and it will leak right in the worst possible place for it to leak at the worst possible time for you to be able to do anything about it, but to curse the horrible original idea of using the window for the wire entry to begin with.

Employing a strong vaccuum when drilling/ cutting fiberglass is by no means an impossible task. Taping a bag to the ceiling to catch any dust can work wonders, so can positive pressure by having blower motor on high with all windows and doors closed.

Household panels are usually 24v.