What type of fiberglass resin Sunrader

[snail powered]

x

[Davidadro]

I'd try to get Bajadulce's attention or contact him maybe, as he has cut reattached and glassed his awesome custom Rader more than most.

bajadulce

[86rader]

I am in the process of glassing over the leaky wrap around windows of a Sunrader. I am using poly resin. Epoxy resin is recommended for below the waterline boat repairs, so I assume that means it is stronger. The good thing about poly is that it is receptive to a bondo finish. Epoxy is not, so you must use gelcoat.

[waiter]

Bondo will adhere to Epoxy. But, getting anything to stick to epoxy (or poly) the surface must be prepared, this usually means sanding or "peel ply". The bond is a mechanical bond. if the epoxy is not scratched, there is nothing for the bondo, primer paint, or anything else to stick to.

Normally when they use "GelCoat", this is a chemical bond and is actually part of the manufacturing process, i.e. the mold is coated with an release agent, then gel-coat is sprayed (this will become the top layer) then the glass is added, then a peel ply, then absorsion layers to suck up excess epoxy during the vacuum process. If vacuum isn't used, the last step is the peel ply.

(NOTE - We use Bondo a lot to hold stuff together while jigging complex parts, getting ready for glass layups. Nice thing about bondo, its cheep, and cures very fast. and if you need a fast easy mold or complex shape, you can do it and just glass over it. We normally don't use it in a finished part, simply because of it weight (We're talking airplanes)

Either one would be acceptable in the RV application. We use Epoxy in the aviation for several reasons, Strength, workability, and engineering wise, its very predictable and repeatable. If your designing a wing that is going to support 500,000 lbs, your calculations better be correct, and the manufacturing process must be repeatable.

I use epoxy exclusively. it is more expensive than polyester.

I generally use aviation approved epoxy and cloth when doing structural aircraft stuff. but non-structural, I use standard off the shelf materials ( water tanks, aux fuel tanks, fairings, doors, etc. ) . Here's a place I regularly buy from.

US Composites

John Mc

88 Dolphin

[linda s]

Well the best example I have ever seen of extensive fiberglass work on a Sunrader was one guy had his front window area glassed over. He had it done by a boat works company so I think marine application do fit.

Linda

[bajadulce]

Hi Karin (answering your email here in this topic.)

These shells were built with a chopper gun that shreds fiberglass and shoots resin at the same time into a mold w/ a gelcoat . Maybe modern composite core constrution campers use Epoxy to be compatable w/ the foam cores, but these older shells undoubtably used the cheapest polyster resin they could find and bought in huge bulk to be sure.

That being said, I have been using polyester throughout my projects (both this sunrader and an older V8 chinook for several years now). I have used a few different brands from different vendors, but mostly just the cheapo Home Depot gallons as it was the most convenient It's a tad thicker than "quality" resin which would seem to be counterintuitive? Most of my applications have involved a brush (bought those in large packs of cheapo throw away at Home Depot as well) and the thicker globby resin doesn't run down the walls or drip off the ceiling as easily. The few times when I had to use a roller to apply large mats of glass (underside of FRP ceiling, floor, and front windows), Yes, I had to thin the Home Depot resin with some acetone.

Both the V8 chinook and Sunrader have held up for many years now. No signs of any failure due to mix-matched chemicals in any of these to report.

I am in the process of glassing over the leaky wrap around windows of a Sunrader. I am using poly resin

Sounds like a good move. What material are you planning on using to cover the expansive holes? Myself, I used some of the readily available FRP shower panels. FRP panels are pretty flimsy, but added 3 layers of glass matte to the textured side (yes, had to spend a few minutes w/ disc sander roughing up texture) to make for a beefier panel. The beauty of the FRP, is the "backside" is non-textured and thus has a very "gelcoat-like" finish. Used it for the roof as well. Doubt these panels could stand up to the UV punishment of direct sun for very long, but painted, I'm sure they will be fine.

I've seen a lot of ppl over the internet try to use layers of cloth alone for expansive voids rather than scabbing in a section of pre-made panel. The end result is them having to apply a crapload of bondo to try and achieve some sort of smooth surface.

[Derek up North]

I'll agree that what was used was undoubtedly whatever was cheapest. Even on a Sunrader!