Community Forums

John Stott · 01-20-2021, 09:08 PM

The fiberglass roof of my MH has 2 cracks (6 inch and 4 inch) at the back of the roof top near the ladder mount. I am looking for ideas how to fix it so it doesn't spread. I was think using a fiberglass repair kit or maybe self leveling dicor or maybe both? Maybe something else? Any ideas?

Thanks in advance.

Kraken · 01-20-2021, 09:16 PM

You could clean the area real good then use strips of Eternabond tape on it. Once Eternabond is one there it won't come off. Is fairly cheap, quick, easy and won't leak. Another option is put a piece of fiberglass over the cracks and apply marine grade adhesive under it. If you need to form a radius, you can use a hair dryer to heat the area and it will take a bend, then put it down with the adhesive. If you luck out you might find the same color fiberglass and the repair is not that noticeable.

HarryStone · 01-20-2021, 09:37 PM

I think the primary thing is to find out why it cracked in the first place, otherwise, you will put a patch on a defect that will continue to get worse.

**CountryFit** · 01-20-2021, 11:05 PM

Fiberglass repair kit sounds good. Home Depot and Lowes have it, inexpensive and a permanent fix.

Thewellz · 01-20-2021, 11:08 PM

I would sand and fill the crack with resin and then cover the entire repair with eternabond tape. It gives a clean finnish and it's easy to apply and it will last for years.

VanDiemen23 · 01-21-2021, 12:58 AM

Drill a small hole at the end of each crack. This goes a long way to stopping the spread.

Grind through the gel-coat until you get to the fiberglass do this in a area about 1" beyond the cracks in all directions. Grind it down about 1/8 of an inch.

The fiberglas was probably laid up with polyester resin and a chopper gun. If you just see fibers and no cloth, it was a chopper gun. Normally epoxy would be better, but epoxy doesn't stick to polyester as well as polyester sticks to polyester. Polyester resin is the stuff you buy for bodywork - not the filler, but the resin that comes with most fiberglass kits. The good stuff is here: https://www.fibreglast.com/product/I..._just_resin_90

You will need some heavy fiberglas cloth. If you buy it in a roll that makes life easier. The edges are sealed well and it gives you dimensions to grind to. Something like this: https://www.fibreglast.com/product/W...glass_Tape_217

It helps to mix just enough hardener to cure so that you have more time to work. The more you have, the faster it kicks and the faster it cures, so you want to work small.

Cut the glas to the required dimensions. Mix the poly in a disposable pan and dip the glas unti it is soaked. lay the glas over the cracks. Then take paper towels and soak up the excess. You can also take cheap paint brushes and cut them short to make a stipple brush and apply the resin that way. The resin provides no strength, so you want to get rid of as much of it as possible. Repeat until you have 3 or four layers laid up in there. If you can keep adding layers until you get just below the original surface, al the better.

Fill and feather with body filler, then sand and paint.

Eternabond is flexible. It's not going to do jack to stop propagating cracks.

The advice to try and find the source of stress is good advice, but if you can find it, good luck coming up with a fix. Unless something is broken and obvious, that's going to be a tough one.

Lowflyer1 · 01-21-2021, 05:25 AM

Quote:

Originally Posted by John Stott

The fiberglass roof of my MH has 2 cracks (6 inch and 4 inch) at the back of the roof top near the ladder mount. I am looking for ideas how to fix it so it doesn't spread. I was think using a fiberglass repair kit or maybe self leveling dicor or maybe both? Maybe something else? Any ideas?

Thanks in advance.

I also had maybe a 6" hairline crack in the same area near the ladder. I figured a previous owner must have stepped hard or with a heavy load on that spot.
I was considering eternabond tape but then thought that it would just be a bandaid as it's right around where I step on the roof. It's not meant for structural repairs but to seal joints and such and if I ever need to remove it for new repair, would be a real pain.

So I got a fiberglass kit from O'Reillys and put 2 layers of fiberglass with plenty of overlap. That spot is now stronger than it ever was and won't leak. I can see that it's raised a bit now but since it's on the roof, who cares. And I know it will never crack again.
If those cracks are close to each other, I'd make one big batch to cover them both. In that case a kit may not be big enough and you may consider getting the cloth, resin and hardener separate. For small areas a paint brush works fine but large areas it's much easier to use a paint roller as you really need the resin mix to soak well thru and get all the air bubbles out.

Then I got a can of Rust-Oleum Marine Topside Paint (Battleship Gray) and it was exactly the same color as the rest of the roof.

Dav L · 01-21-2021, 07:43 AM

Van Dieman has it.
All the materials you need are at Home depot in the paint department. A quart of resin / hardner and random strand fiberglass cloth. Just prep the surface, mask where you don't want resin, precut your patches, mix the harder / resin, use a throw away chip brush to apply the resin to the surface, put the cloth on, apply more resin then more cloth. Dry, sand, then cover with eternabond tape to seal and make it look more cosmetic.

One hour of work plus three hours of dry time.

Gary RVRoamer · 01-21-2021, 08:28 AM

First a question: are the cracks in the upper part of the front or rear cap, or in the fiberglass sheet that forms the main roof? The caps are molded fiberglass with gel coat, but the main roof is a thin fiberglass sheet product that comes in rolls. The repair techniques are different.

rangerb3 · 01-21-2021, 10:58 AM

"Stop-drilling" the ends of the crack "is" spot on and a very critical step in your repair plan. This will keep the cracks from propagating further.

153stars · 01-21-2021, 03:33 PM

Locktite marine epoxy is just thin enough to work into thin cloth if you do both sides before laying up. If roof is white no need to paint. I made a near invisible repair smoothing with wet finger shaving with razor blade and sanding smooth . It kind of thin for vertical surface and dries pretty slowly to get vertical to hold as it sets up at last seconds like other epoxies.

TXiceman · 01-21-2021, 03:46 PM

The simple solution is to drill a 1/8" hole at the end of each crack to relieve the stress. The clean the area well and apply Etrnabond tape over the crack. Then caulk the edges when completed.

Ken

Gary RVRoamer · 01-21-2021, 08:13 PM

Id do as Txiceman suggests

hewebb · 01-22-2021, 06:41 AM

If the fiberglass is gel coated, it is possible the crack is only in it not the fiberglass.
You can replace the gel coat only. This typically happens on boats. If in the fiberglass-follow fiberglass repair procedures mentioned in previous post using fiberglass repair kits.
If on any vertical surfaces you can use saran wrap and tape to hold the material in place until it is cured.