fiberglass tear repair help - Boler B1500

[AKSCAMP]

Hi friends, so I'm trying to get the 15' Boler mostly restored before the snow flies, and that means finally doing the fiberglass roof repair. I've done plenty of searches but haven't seen any info on the method for repairing a "tear" in the roof like this. My questions are:

supplies?- can I use the "fiberglass repair kit" from the auto store or do I need a certain type of mat, etc.?

Do I grind away the previous owners attempt at repair and get down to the original? How far back into the tear do I grind?

When ready to lay glass, do I build and screw a wood template on the backing side to bring the tear together as close as possible? Or just get it close and fill in the extra?

[Westcliffe01]

The "standard" handbook for any work that does not involve a mold is Burt Rutans "Moldless Composite Sandwich construction" handbook. Cheap to buy and currently in print. Moldless Composite Sandwich Aircraft Construction: Burt Rutan: Amazon.com: Books

See a video of a part being "loaded" here Foam/Fiberglass strength demonstration - YouTube

Take into account that they are describing building parts which will keep you in the air and the engine and wings attached (any of which will cost your life if it fails).

Another write up on composite repair. Great place to order all non hazardous supplies too.
Fiberglass and Composite Repair | Fibre Glast

The key thing is to get down to undamaged material to bond to and that all surfaces that you want to bond to need to be roughed up and dust free and all traces of oil, wax and silicone removed.

Even though more expensive, use an epoxy system like West System and not boat building resin. The boat building resin that is made for laying up will not produce a non tacky surface unless a wax additive is included. This is very complicated for a repair. Just stick with a good epoxy.

Then when the repair is done, and faired with some of the light fillers, it will ultimately need to be painted with a paint system that blocks UV. The gelcoat which is put in the mold serves that function, but I know of no way to apply gelcoat to a repair. If no UV blocking topcoat is applied, the resin will become embrittled and finally crack and fail.

For the repair of an awkward shape like the one you are dealing with, it might be best to make an insert out of PU foam, which you can order at Aircraft Spruce POLYURETHANE FOAM from Aircraft Spruce
The reason PU foam is recommended is because it can be easily sanded into any shape. Final shaping is often done with another piece of foam and a bit of sandpaper. Then do the external layup, then shape the inside, then do an inside layup and then only the external finish needs to be done. This will produce a very strong repair which will also have insulating properties (don't know if a core was used on these trailer shells, does not appear to be the case).

[Westcliffe01]

Fibre Glast - YouTube

Considerable number of videos on different aspects of composite construction at that site

[Terry G]

I'm not a specialist at repairing fiberglass but I've done a little. If it was up to me, I'd clean the inside as well as possible and try to repair it from there first with some thin mat and resin. Once you get the rip physically secure, then it should be a lot easier to fill and sand the repair from the top.

It's hard to see what the previous owner did for a repair. it looks a little like cardboard. I would definitely remove as much of it as possible.

[AKSCAMP]

THank you very much! I feel better about attempting the repair already.
The PO used some sort of heavy duty glue to attempt to join the sides.

[deryk]

The west system which is kinda expensive, but a good set of products....they do have video's on their site and dvd's showing repairs...might be worth your while to take a watch. Also check out youtube its amazing how much information is out there.

My last sailboat after purchase found a bunch of stress cracks in the keel... water was dripping out of them. I read a book, watched some video's and cut open drain holes in the keel to help dry it out and 5 months later reglassed it back together with layers of matting and cloth and she floated nicely for 2 years till hurracaine sandy put a hole in her bow. Fiberglassing is not difficult but there are things you need to know. Do a little reading and the job is doable.

good luck!

[Bob Miller]

Do some more searching on the fiberglass boat sites where this kind of damage is common due to docks suddenly jumping out in front of unsuspecting boaters. (LOL)

Another source would be fiberglass vehicle repair where everything from Corvettes to Dune Buggies need similar repairs.

A few months back we had a member with a "Cracked Egg" with a collapsed roof that looks like it came out OK. You might look that thread up as well for some tips from the OP.

As far as UV protection... from the looks of things you will be doing a complete repaint anyway and that will take care of that issue. For that I suggest checking out Interlux Briteside marine paint, it's the best, albeit a bit pricy.

[sheephills]

i would check out a channel on You tube called boatworks today. Its a fiberglass repair Channel. He deals with boats but its all about fiberglassing and all the same techniques would apply for the boler repair. by the way its very very detailed instruction Preferably the videos on "theres a hole in my boat".

[David Tilston]

As my neighbor says, there is nothing fibreglass that can't be fixed. If you make a mistake, and put down fibreglass wrong, then grind it off and try again.

Since the inside of the tear is accessible, grind both sides so it tapers down to a paper thin wedge. The grinding should be about 4" from the sharp tip of the wedge, to undamaged fibreglass. If the tear causes the trailer to sag inward, I would support it from the inside, to as close to the shape you want as possible. Use wax paper to keep the resin from sticking to what you are supporting the inside with. Or use cardboard, or Styrofoam that you carve to the correct shape. Then grind or sand it off the inside later. Then glass the outside to hold the shape. When it sets, take off the inside supports, and glass the inside. your new glass should cover all the fibreglass that you exposed with the grinding.

After that, smooth the new glass to blend with the rest of the shell, then paint.

Easier said, (typed) then done. But if you mess up, grind and try again.

[captsteve2002]

Remember if you use epoxy resin for the repair, it will gve you the best bond, you will be able to use polyester on top of the epoxy for fairing or aditional build up of glass. Don't try to use epoxy over new polyester as it won't bond very well if at all. Also remember that glass cloth with make the strongest repair, mat will conform the easiest but not as strong. The cloth is the hardest to work where you have compound curves.

If you start on the outside and need to pull the parts into aliengment, you can park it under a tree, drill a small hole in the glass, and tie a small piece of line from the tree through the hole and pull it to the position you want. This will leave you with only a small hole to patch after you make the major repair.

[andrew78]

i still working on my roof i have never fiberglass until this project that i'm on.

the west system is simple and worth every penny. i found the best way was to cloth the inside first with a couple of layers then start on the outside. i found you don't have to feather as much on the curve of the roof and keeps its looking original. this way you can much wider than the tear on the inside and it will be covered by the interior covering

good luck

[Westcliffe01]

The Rutan manual goes through the different types of cloth and when to use what. You want BID cloth with what is called satin of crowsfoot weave. It will conform the best to the curves. You can actually stretch it into different shapes by pulling on the edges. Just remember that your patch is going to BOND with the original material. The best way to prep the surface is to use a disc sander with a coarse grit of sand paper and rough it all up, then vacuum then wipe with acetone.

I will say that working with epoxy in low temperatures is a real pain. When one gets below 60F it seems like one has reached absolute zero with some epoxies. So remember to figure out a way to keep the epoxy, hardener and the workpiece warm. Also be very careful about getting glass cloth wet. The fibers are coated with a product called "sizing" which helps with wetting it out and water does a lot of damage to sizing and significantly affects the strength of the laminate.

I suspect that what one sees in the crack is probably bondo or old fashioned body filler.

[Richard Hayes]

Here's a few things I've learned working with epoxies around kayaks and sailboats...some the hard way...

All surfaces must be scrupulously clean and absolutely dry. Lots of sanding, followed by a tacky dust rag, followed with a final wipedown with an acetone-soaked rag is tedious, but it sure beats having to tear things out and redo them...

If you use epoxy in multiple layers, beware of amine blush...a waxy substance that forms on the surface of some epoxies as they cure. If you don't get it off, the subsequent layer is trying to bond to wax...and it won't...

I use only glasscloth with epoxy - besides random-fiber mat being hellish to work with (a million little wild hairs clinging to the roller and everything else you don't want it on) many are held together with a binding powder that inhibits good epoxy saturation of the glass fibers themselves. The result - little air pockets, which weaken the layup and can trap water...

I've learned, the hard way, to clean up any construction drips and blobs as I go - trying to sand out cured epoxy layups is right up there with bleeding as a fun activity, so get it while it's wet or buy lots and lots and lots of sandpaper and elbow grease. BTW, semi-cured epoxy (up to several weeks) dust is toxic stuff - I use a good respirator, not a paper nose mask, if I do have to sand it...

Finally, there are low temp epoxies available - Cold Cure is one - I've never used them, but they do work. Rumour has it they are more prone to amine blush...

Alaska - lucky dog! Newfoundland is God's country for sure, but I had a chance to spend some time in the Yukon last year, and it's right up there with this island of ours as one of the Last Best Places. Both of us live in places that most trailer owners dream of as the trip of a lifetime...