best way to fix hairline cracks in fiberglass?

[Options13]

these hair line cracks are pissin me off!, how do i get rid of them? i googled and people were saying to make the crack worse so you could actually fill it, but that won't work in my case since there is like 20 cracks in 1 tiny area, i don't want to sand past the top gel into fiberglass, cuz i know i'm going to get deep dips and not fill it in right, its in an awkward spot on my rear bumper..


what if i just used 2k build primer on it, sanded it, then shot it again with like 3 coats of 2k, would that work?

heres a pic of the fun stuff..

http://i17.photobucket.com/albums/b90/timberlando/IMG_1654.jpg

resin!!

http://i17.photobucket.com/albums/b90/timberlando/IMG_1658.jpg

[JDMStanced]

i have those hairline cracks too.
have you fixed it?

[jr_ss]

Those cracks look like they are in the gel coat and not necessarily in the fiberglass. I'd skim coat it with bondo and sand it down. The only problem is that they can and probably will return. Use a dremel and open them up slightly if you have to. Anytime you stress that area, it will crack again...

[jparker7]

You have to sand past them to get rid of them and then refill

[theboy]

yup, grind the cracks til they are gone (dont get carried away, maybe an 1/8" deep). Clean the area very well with a thinner or spirits (reducer works very well). Then apply your favorite flavor of bondo. Let sit up then block sand it smooth. Re-paint it, then remember to not hit what ever it is that you decided to run into.

[godrifttoday]

The term "bondo" is a brand whxh Autozone sells... U want to use body filler which will work with fiberglass...

[jr_ss]

Bondo is body filler....

[s14silvia10]

For small repairs you might want to use polyester glazing putty works better, bondo or body filler are used for bigger repairs.

[Prime]

I'd go with glazing putty or Bondo Ultimate-Cote. Stuff is a bit more flexible, lessens the chances that it cracks later. Also, use a good epoxy primer/sealer. It tends to flex a bit better than the urethane does.

As for the whole "Bondo=/= Body filler" nonsense... Bondo is to body filler what Kleenex is to tissues and Windex to glass cleaners. Get over it. Considering the vast majority of body fillers are made of the same type of resin as the majority of fiberglass parts, the odds of you getting one that "won't work" with fiberglass is ridiculously low.

[jdizzle9]

As for the whole "Bondo=/= Body filler" nonsense... Bondo is to body filler what Kleenex is to tissues and Windex to glass cleaners. Get over it. Considering the vast majority of body fillers are made of the same type of resin as the majority of fiberglass parts, the odds of you getting one that "won't work" with fiberglass is ridiculously low.

and Coke is to all soda/pop :rofl:

[Prime]

and Coke is to all soda/pop :rofl:

Kleenex - Definition and More from the Free Merriam-Webster Dictionary (http://www.merriam-webster.com/dictionary/kleenex)
Coke - Definition and More from the Free Merriam-Webster Dictionary (http://www.merriam-webster.com/dictionary/coke)

Not really. For that matter, Windex isn't the best example. But I've made my point.

[alwyzDTF]

I sanded down a few hairline cracks and a few half inch nicks and threw some "bondo 3M Glazing & Spot Putty" then primered it. on my way out to the car the crack opened up and the half inch nick cracked where the bondo was. anyone know of something a lot more flexible then this product because I was told that this was "the good stuff" maybe I could get some fiberglass resin and mix the 2?