Bondo Fiberglass Resin Jelly

[zonaman]

Is Bondo Fiberglass Resin Jelly suitable for repairing hairline cracks on an old (1959) fiberglass boat hull bottom?

Thanks.

 

[Bob_VT]

Re: Bondo Fiberglass Resin Jelly

Depending on how you plan on doing the repair..... yes it could work.

What type of hairline cracks? Got pictures?

 

[zonaman]

Re: Bondo Fiberglass Resin Jelly

Tried taking a few shots but the white hull reflects too much. There are several long, striaght cracks about 1 to 3 feet long running along very bottom of the hull, closer to the stern section. A few of them seem to have a zig-zag pattern others are just straight. They do not appear to be very deep at all.

 

[danond]

Re: Bondo Fiberglass Resin Jelly

I think what you're talking about are stress cracks. Hairline cracks in the surface (gelcoat) of the boat. You have to grind them out to fix them. Gooping over them with anything, doesn't matter what it is or how strong it is, will result in the cracks coming back. Also, you need to fix those with gelcoat, not fiberglass resin.

You either got hit in that spot, have rot on the other side, or have an area of your hull that is flexing for some reason.

Regardless, stress cracks are there because the subsurface is flexing (or flexed once, like if you whacked a dock really hard). Gotta fix that first, then fix the crack. See my site below under the section "fixing stress cracks" for more info.

 

[zonaman]

Re: Bondo Fiberglass Resin Jelly

Thanks. We got new stringers in there so I think we're good to go on the cracks. Your site has great information to walk me through!

 

[danond]

Re: Bondo Fiberglass Resin Jelly

Very cool, glad you found the source of the flexing. Good luck getting the color matched, it's the toughest part. Make it past that and you should be in great shape! Thanks for the compliments on the site.