fiberglass specifics (2 Viewers)

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ok,
i've asked some questions before on how to fix the fiberglass roof on my newly aquired hard top. today i looked it over and came up with several different senerios i think i will encounter tomorrow. i hope some of you can give me some step-by-steps on how to do this effectively. i'm going to be doing it in a heated garage, but it still isn't really warm in there. i hope this isn't going to be an issue.

senerio #1
long deep cracks, but they don't show up on the underside.
glass1.bmp


senerio #2
long deep cracks that do appear on the underside.
glass2.bmp


senerio #3
multiple stress cracks in parallel (possibly showing up on the underside).
glass3.bmp


senerio #4
a whole
glass4.bmp


senerio #5
busted edges that need to be made true again.
(this is where the roof is riveted to the gutter)
glass5.bmp


thanks for all your input fellas.
 
Lack of heat can be a problem :( The chemical reactions don't go quite right if you're not within the range specified on the resin you have. I know, Ive been there.
I'm not too familiar with the FJ40's, having only had the BJ60's anf FJ55, but I have done a fair bit of firbeglass. My thoughts, without seeing how it works, would be to put another layer of cloth (the lightest you can get) over top and bottom. If you do one side at a time letting it set up between you should OK and clear up all your problems.
Feather out the edges of the holes and cracks prior to starting and lay a strip of cloth or two (depends on thickness of the top)over those areas before covering the whole thing with cloth.
Don't try to fill the weave of the cloth the first time as you'll just create runs all over the place, the cloth will float and the hardtop will weigh more that necessary (it's the cloth that gives strength NOT the resin. The resin just adds weight). Just use a squeege and make sure the cloth is saturated, no more that than.
When you're completely done make sure you paint it in and out as resin is broken down by UV rays.
 
alright.
i was going to post some pics today of my first attempts, but i have failed miserably.
when i'm fixing a crack, how much area around the crack should i remove material?
do i want to use a large area and match it with the mat?

i had tried the top side of the roof and it didn't seem very strong. i'm doing the underside now with more area removed around the crack, and then i think i'll sand down the whole top stuff i did and retry it.
 
Ideally you want to fair the edges of the crack so that the cloth/matt (cloth is prefered for strength [long strand vs. short strand]) can create an effective bridge by bonding with material on both sides.
Is the hardtop in a steel frame of sorts? If so, is it removable from that frame and have you removed it? Support it once it is out of the frame using a jig of some sort from below that it can rest on. Your way easier to fix it and let the glass extend beyond the current edge and trim it later than try to get a clean edge in one go. I still suggest that you fair all holes/cracks/splits and other imperfections one one side first, rough the whole top with a quick go over with sandpaper, cut strips and/or peices of cloth that extend beyond the edge of the cracks or holes (maybe one layer, maybe several, depends on the size of crack and amount of fairing). Lay those peices in DRY. Then cut cloth to completely cover the entire top, lay it over everything, (make sure at this point that all is straight and in order, you can't straighten it once it's wet) and then wet out the whole thing. You may want to use some clips to hold the cloth from sliding around while you're wetting it out with a squeege. Don't over work it, just get the air out. Once the cloth is wetted out LEAVE IT to dry. Don't try to make the extra cloth wrap to the opposite side, it won't do it, and you'll get frustrated. Let it hang over the edge and trim it after everything is finished. DON'T fill the cloth right away, that can come later.
 
Cruiser guy- Do you know anything about applying the gel coat that we will need to apply after we finish restoring the fiberglass? (I'm doing much the same thing, my fiberglass has been seperated from the metal of the top and is just by itself.)
 
I've never done Gelcoat. My fibreglass skills are self taught while making two cedar strip canoes as well as repairing an old fibreglass canoe. I can't imagine it can be any more awkward than working with fibreglass cloth saturated with resin and sticking to everything it comes in contact with though :D. I know what you guys are going through 'cause I've been there. Just take your time and all will be well. Fibreglass is a great hider of mistakes!
 
i have removed the fiberglass top from the entire rest of the hard-top.
i will not be working on it today, but i'll let you know of my progress tomorrow.
what is the best way to remove a lot of area?
sanding and dremel grinding seems to make dust that doesn't bother my skin. a grinder on the other hand (moves material the fastest), but now my arms and neck itch something fierce. i guess i needed to learn that on the hard way?

what are the rasps for i've been seeing and hearing about?
 
but now my arms and neck itch something fierce.

Welcome to the wonderful world of fiberglass work. Temp is definitly a factor do not go outside the manufacturers recommendations on the labels. Speaking of manufacturers...last time around I recommended going with West Systems Epoxy resins...you're not trying to cheap out and use polyester resins :mad: As far as the crack ...definitely buld the strength back on the underside if there is any question as to the depth of the cracks. Grind down the underside enough to get good bonding. On the top side either "V" out the crack and fill with epoxy resin mixed with powdered glass or filling and fairing additive. (all availible from the West Systems folks. If you have a larger are with lots of spider cracks ...grind it down some and reglass with some non woven matt.

As far as application...my 02 is prep all the underside areas that need attention at once. Cut the glass to prefit size and lay them all out. Mix up a good batch of resisn and hardener, lay glass matt on top of saran wrap, pour on some resin and use a paint brush to evenly spread/impregnate the glass matt. Lift the matt via the saran wrap and slap it in place. Once in place carefully remove the saran wrap and let it cure.
 
i'm not sure, but i think it is polyester resin. should i throw it out the window and get the epoxy?
what are the strengths and weaknesses of each?
 
I'd talk with the place you bought it from to find out how epoxy and polyester bond. Your FJ40 roof will be polyester because of it's age. I've only ever used West System Epoxy.
 
Well, shiite...already bought the poly eh. Well lets see...we are talking about a top here not a ground up on a fibberglass car...so poly will work...as cruiser guy says that is probably what was born with. The differences between them (my 02) is that epoxy resins seen to be much stronger, less problems with evil things returning to haunt you.

I would still suggest a trip to your local marine store to pick up some of the West Systems add mixtures.
 

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