Walmart Epoxy?

[Bluetang99]

Sorry if this is a dumb question but I've never done fiberglass work before. I'm patching some small holes as well as the exhaust vent where the furnace was and I was wondering if any fiberglass Epoxy would work? I'm going to Walmart so I was hoping to just get some there. Thank you.

[captsteve2002]

You might want to go to your local Ace Hardware Store and buy Marine-Tex. It is a two part epoxy putty that is white, waterproof, and won't soak up water. It is very easy to use. If they don't have it in stock, they can order it. It is mostly used on boats, and is a known quality product. Wal-Mart doesn't make any fillers, they just sell them.

[Joe Romas]

Yes it will work.

But are you intending on painting it after your finished?

The reason I ask is some are darker and are not clear.

[Jack L]

Are you looking for putty to fill small holes or are you looking for resin and fiberglass matting to cover a large area ?

[Johnny M]

I did my restoration of a '71 Boler with Bondo Resin and Hardner bought from Walmart, did tons of fiberglass work with it. They also sell the matte cloth and have best prices on both. Check out fiberglass dave's trread here on fiberglass repair, some very good info there.

[Byron Kinnaman]

I think I would use Marine Tex. It's a 2 part putty made for fiberglass boats.

[Johnny M]

the exhaust vent is a large opening, I would use Fiberglass resin and matte cloth for a good strong patch, rivets holes, etc could be easily done with the Marine Tex but if you were going to use that on the vent hole I would still use some type of fiberglass matte, cloth or tape with it.

[Bluetang99]

I will be covering some little holes as well as the large furnace vent hole. I did order pc-11 Epoxy putty, is Marine Tex better and should I buy that instead? I just read that pc-11 is easy to use a syringe with to inject it into the holes which is why I went with that.

Also, yes I will be painting the entire camper in a few days. Does this change anything that I should be using to patch holes with?

[Johnny M]

PC-11 is an excellent and extremely strong and water proof epoxy and is more readily available than Marine Tex in some areas, found at most hardware stores. I used the PC-11 to bond some things on my Boler where fiberglass would not work well.

[Bluetang99]

Originally Posted by Johnny M

PC-11 is an excellent and extremely strong and water proof epoxy and is more readily available than Marine Tex in some areas, found at most hardware stores. I used the PC-11 to bond some things on my Boler where fiberglass would not work well.

The route I was going to take was to patch the back of the accessible holes with a small piece of fiberglass mat and Walmarts 3m resin then take a countersink to clean up the exterior hole and fill with the pc-11. Does this sound about right?

[Johnny M]

Yes that should work fine. On the larger vent you should make 3 pieces of matte, one the size of the hole one a little large than the first and the 3rd even larger. Wet out the area and using a temporary support covering the hole. place the same size patch in the hole, wet out then apply the larger, wet out and repeat again. I repeated the process on the opposite side of the shell to make a stronger patch for the larger holes

[Johnny M]

Make sure you throughly clean the area first and roughing it up helps but is not required. A dirty or oily surface could result in delamination of the patch.

[Bluetang99]

Thanks Johnny, that is very good and clear to understand advice. I will clean up the area with acetone and rough it up before I apply the mat. As for the temporary support, would cardboard with wax paper work fine taped from the exterior?

Should I do anything from the exterior of the large vent hole such as removing some gel coat from the perimeter of the hole and bevelling the edges? Or is that not necessary when applying the bondo/marine Tex?

[Raz]

I've used PC 11 for small holes, 1/4" or smaller with good results. It's sticky, unlike a putty. I would not use PC 11 for a large hole. Bondo is one solution. A trip to a boat place like West Marine might bring better ideas. When I needed to fiberglass a leaking belly band, I got good advice there. Raz

[Bluetang99]

Originally Posted by Raz

I've used PC 11 for small holes, 1/4" or smaller with good results. It's sticky, unlike a putty. I would not use PC 11 for a large hole. Bondo is one solution. A trip to a boat place like West Marine might bring better ideas. When I needed to fiberglass a leaking belly band, I got good advice there. Raz

I did call the boat store but they want $40 for the smallest can of West Marine Epoxy. It's a little too expensive for me since I'm just patching one large hole. I did pick up 3m polyester resin which I will use since it was only $14. To fill the hole I will probably just use bondo.

[Johnny M]

On the large vent you need to use matte cloth, just bondo will not hold. The PO of my Boler "patched" the original 3 way fridge vents, the oven vent and several other smaller opening using Bondo only then painted over it unsuspecting to us when we purchased it. While getting ready to do the reno of the inside I put a little weight on the fridge vent patch and the whole thing popped right out. All the others did the same upon further examination. I re did all his patches with fiberglass matte and Bondo resin and they are now solid as the original fiberglass shell except mine are thicker from doing both the inside and outside. Filler is great for filling voids after fiberglassing but I am not a huge fan of the standard Bondo brand filler, but the resin is great stuff. For the next filler work I do I will use the Bondo glass or Bondo hair fillers and see how they perform. My issue with the standard one is I could never get consistent drying of the filler and it would gum up my sander pads. PC-11 too is good stuff for bonding where you cant or don't want to use fiberglass. I used it to bond the seal of my cabinet inside the door to the contour of the body/door frame...very good stuff and easy to work with. Used it to bond a riser to the roof and it was so strong I had to cut the riser off (I covered the rest of the riser with Bondo filler which delaminated from the wood).

[Johnny M]

I recommend reading Fiberglass Dave's thread located here http://www.fiberglassrv.com/forums/f...ass-52498.html

As far as the support I would use something more solid like a piece of wood, or maybe corrugated plastic if it needs a curve. Aluminum or tin would work well too. Screw it in to the body and after the repair remove the screws and fill the holes. I read about the beveling of the edges somewhere but I did not do that, I sanded down into the gel coat, made my patch, filled it in, then sanded, sanded, sanded and sanded until smooth, did I forget to mention sanding? Start with a 60 or 80 grit to get the contour then work your way up to around 300 or 400 grit. When you prime it any imperfections will show up and you can touch those up then apply more primer then top coat. Any by all means wear a good quality mask made for sanding and fiberglass particulates, your lungs will thank you

[Bluetang99]

I'm definitely using a mat not just bondo over the hole. What I think I'm going to do is cut out a piece of cardboard in the shape of the hole, put wax paper over it and put that onto another bigger piece of cardboard. Then I'll tape this to the exterior of the scamp creating sort of a "plug" for the vent. This will allow me to lay fiberglass down in the back without it bowing forward.

Then I will cut a few pieces of mat the shape of the hole and lay that into the hole from the outside until it's of a decent thickness where I won't have to use much filler.

As for the comment about better alternatives to bondo the only reason I mentioned it was because I was under the impression that it's easier to paint? But if kitty hair or the bondo glass stuff paints just as good without having to add gel coat I will get that instead.

[Johnny M]

Sounds good to me. I can't tell you on the other products though, I have not tried those yet.

[Jack L]

I would not use waxed paper. Smooth plastic works well. Some plastic package sealing tape would work. The wax could leave residue that would be hard to remove.