Fiberglass roof repair. Help!

[Troutter]

Just came in for lunch and thought I'd give those of you who are helping me an update on my progress. I decided to work from the outside first because working above my head with 2 1/2 foot long piece of mat didn't seem like a good idea for a newbie. I got the surface clean, then cut the fiberglass to the right size, mixed up the resin and decided to paint some resin on the trailer and lay the fiberglass on top of that. Then pour and paint the resin on the fiberglass paying close attention to getting the fiberglass well saturated along the way. I was working fast and thought I had the resin/catalyst mixed correctly, maybe I didn't. It said on the container I would have about 12 minutes before it would start to set, but the sun was out and I'm guessing that made it set quicker. Holy smokes, maybe 5 minutes into the application it started to gel up on me! I was probably another 1-2 minutes from having the mat completely saturated and being done. Well, needless to say there were some air pockets and the mat didn't get completely saturated in a couple areas.

The resin cured rock hard and tack free in a little over an hour. I sanded out the weak spots and will reapply to those areas after lunch.

Even though my first attempt wasn't a total success, it wasn't a total flop either! I'm satisfied that this is the kind of repair I can do my self and it will actually look good when I'm done!

Now I need to start thinking about the seam that goes down the middle of the trailer. Any thoughts?

[FRED SMAILES]

Hey J, ya the sun makes things happen pretty fast,,,,,
I went back to look at the seam pic,, there isn't quite enough detail to give an accurate accessment of options.
It appears the top of the seem has gaps, if that is the only issue, maybe grind a
length ways groove, not too deep, shread some mat, pour resin in the grove and fill with fibers. Put masking tape down each side a little higher than the ridge to create a dam to stop the material from running away. tape off the inside so the resin can't enter the cabin.
Ther go get busy!! LOL
Fred
MY typing is so slow I could do it faster than type it lol

[Troutter]

Fred,

You have been so helpful! I just came back in for the day because I guess it's my night to cook. haha. Anyway... before I came back inside I took the dremel to the seam on top. It's been filled with bondo which I'm sure is why it's cracking. I got in there with a putty knife and the bondo comes right out. This all makes me a little angry because the guy I bought it from said, "He properly repaired everything, painted it and nothing leaks. I also noticed a small crack on the side of the trailer where the vent for the stove hood used to be. The last time it rained I had a puddle on the floor there also. I tore into the wall he had put up. Sure enough... there was a hunk of wood stuffed in the hole with a little woven fiberglass cloth around the edges. I'm sure the thought was, get it filled, bondo, then paint. I spend half my time just standing next to the trailer shaking my head. lol

Anyway... Yes, the plan will be to remove all the loose material and bondo from the seam. Then fill with resin and mat. I plan to do this fix tomorrow, and after tomorrow it's supposed to rain off and on for the next 3 days so the new seam should get tested!

thanks so much for the help! I'll keep you posted!
Jason

[Westcliffe01]

I am in no way connected to anything in the composite industry. Gentlemen, when the trailers are built in the factory (or boats for that matter) the hull starts as a sprayed on coat of gelcoat in the mold. This becomes the outer part that we see. Then fiberglass mat or chopped roving is applied on the inside. Nobody cares how rough the inside is, since it is ultimately hidden under the insulation.

The repair job Trouter is doing is on the outer surface. It will be nearly impossible to get a material like mat to fair with the outer surface. Without using a LOT of filling compound one is going to end up with a protrusion on the outer surface. Even if you pile on the filler, anyone with an experienced eye will be able to spot it.

Cloth is much thinner than mat and you can do repairs externally without anyone being able to tell. Yes, epoxy is more expensive than Vinylester resin but we are talking about $30-40/gal. A gal of epoxy will do a LOT of repairs. Why penny pinch particularly when one does not have a lot of experience ?

Once one has the outside closed in and tight, then you can lay up all the mat you want on the inside, where you will not have to fair it.

Sorry, but the comments above are very short sighted, unless the repair is done exclusively from the inside.

The kayaks below have a layer of glass cloth over the wood. Can you tell ? Try that with mat...

[D White]

As I stated, the repair should have been done from the inside, but mat is the preferred material and the veil you used on your boats has no place on a fiberglass trailer done by a rookie...however, I do not intend to get in a how to do it match with someone who hasn't done it much...I stand by my advice from my experience and I hate to see wrong information given to someone wanting advice...my advice wasn't followed...however, I won't argue with someone who obviously has no experience with the op's original question, and will vacate this thread...I should have stayed out of it entirely...sorry to the original poster....I wouldn't know what to believe if I were in your shoes....

[Westcliffe01]

Perhaps I was not clear in my original post that cloth could be used to seal up the external surface and make it weathertight. Then lay up either more cloth or mat on the inside to build the strength up to where it needs to be.

The only reason mat is used is because it is cheap and it develops bulk fast. Laminates produced with mat are heavy and relatively weak. Its no secret that all modern high performance boats and other composite structures use cloth on inner and outer surfaces, and core material in the middle. The chopped roving was just another step in getting it even cheaper and having a process that could be automated with robots. None of this is about quality, strength or finish. Just the almighty $ and a higher profit for the manufacturer or the ability to stay in business against competition from low labor countries.

[FRED SMAILES]

After pm discussions with DWHITE I realize his way to repair your situation is best.
Post # 16. I have tried but there is no way to delete my posts.
I hope people reading this post in the future will use DWHITE's procedures for this type of repair.
Fred

[peterh]

I'd have to agree with D White, too. That said, I have a fiberglass repair I'm working on now . . . as in one of my patch layers is curing as I write this . . . in a wheel well. It was hidden under several layers of badly done repairs, including some huge 3/4" thick blobs of silicon caulk that basically covered the inside walls of the damaged corner of the wheel well.

I've been taking pictures of the repair process as I move along, and will post a thread showing the steps I took to repair it when I finish up tomorrow or the day after.

Here's what the damage looked like, inside and out, after I stripped the silicon gunk out and ground off the layers of repairs that had been applied to the surface gelcoat.

[Troutter]

I have a repair very similar to the one you just posted to do myself. Keep us posted on the progress of your repair! Good Luck!

[Richard Hayes]

Nice boats!!!

[Kenny Strong]

Hi all

I just spent 50 hrs. doing a glass repair to the rear of a 72 Boler. a car caved the rear into the seating area. the space between the seats. Internal damage was to the short back wall between the seats. When the impact occurred the upper curves above the rear window on both sides was bend in and cracked (fractured ) the surface a foot wide and about two feet in height. I cut out the rear panel at the bumper height. ( bumper cut off). I ordered glass mat and resin. I ground the outside surfaces on an oval with the center almost cut thru. I bought an electric grinder from harbor freight it worked great very little sanding. To fill the areas in I started with a piece of mat one third the size of the oval ground out area. I didn't wait for the resin to set I cut another oval piece of mat half the distance of the first piece to the ground out area edge and placed it over the piece first laid up, and a third one over this one. I pulled the mat edge of the last piece to form a 1.5 inch feathered edge one the finished piece, that extender about an inch plus beyond the ground out area It brought the surface almost up to flush with the Gel coat surrounding the ground out area. The glass was so thin in the center of the fractured curves that it almost went thru. I fit the inside rear floor piece in place, I put an 8 inch backer on the inside of the rear shell at the hole, I screwed the back panel to a wooden form, that had glass mat, on top of wax paper, it was 1/4 inch piece of plywood, ( that was removed each time the resin set and a new layer of wax paper and mat attached so that it would bend when screwed onto the cut out shell piece and to the shell that remained in place. I screwed the cut out piece, on and off 3 times giving me 3 layers of mat 4 inches in on the trailer shell and 4 inches to be a backer for the cutout piece, that then had resin applied to it and it was screwed back onto the 1/4 inch plywood, with 3 layers of mat attached to it. ( the screws were removed when the resin was set)...I agree with DWhite in all respects. I put 2 layers on the inside of the fractured curves . I worked in my garage when the temperature outside was in the teens. I could heat the garage to 60 degrees. The hardener Can be added at a much higher ratio if the temp is below 70 degrees. A very few drops at 100 degrees. The resin is as hard as a rock and when it was painted the painter said the glass job was very impressive.

Later Kenny

[peterh]

Originally Posted by Troutter

I have a repair very similar to the one you just posted to do myself. Keep us posted on the progress of your repair! Good Luck!

The thread with my repair narrative is here.