bondo shrinking?

**edmund** · 06-23-2005, 07:56 PM

Has any one experienced bondo shrink after painting.
I heard that using bondo and having it in really hot weather will make it shrink in like a week, so you need to add more.

has anyone had this problem with there fab projects??

Thanks

**team canada** · 06-23-2005, 08:10 PM

If you put it on too thick, then yes, it can shrink or cave in once it's dry. Apply it in thin layers and let it cure in the right temperature range, and you'll be fine.

**kingvitamin** · 06-23-2005, 09:33 PM

I'm going through the same problems. I recently "finished" my screen mounting/finishing. Well, today it got up above 90 degrees, and with the windows up it was pretty damn hot in there. I was happy witht he finish I accomplished, but now the bondo is cracking. I'm loosing faith in bondo, and plan on going with a almost total fiberglass mounting, and on rely on bondo for very minor final finishing. Live and learn. No matter how much you read about this kind of stuff, experience and experimenting is the only way to get the results you want.

P.S. Is Bondo-Glass a good product to use for shaping, or will it crack too?

Thanks,

Chris

**xdjxklusivex** · 06-23-2005, 09:41 PM

you can put fiberglass hairs into bondo to make it stronger i do that when i have thin pieces on the side and they are flexy it holds well

**edmund** · 06-23-2005, 09:54 PM

hmm. thanks for the replys.. I'm afraid that when it comes winter here (-30).. my bondo will crack..

what do you guys think..

**xdjxklusivex** · 06-23-2005, 09:57 PM

reinforce it with fiberglass hairs!

**edmund** · 06-23-2005, 10:13 PM

to late.. already ready for primer.. it's smooth as glass now.. but I just thought about this problem now... :S

**xdjxklusivex** · 06-23-2005, 10:16 PM

ehhh give it a shot
it prolly wont crack i havnt had mine crack and ive got bout 1inch thick of bondo

**edmund** · 06-23-2005, 10:21 PM

ya mine is about an inch thick.. so it shoudl be all good.
Cheers guys!!

P.S should regular primer work with bondo or should i get different stuff. I have..KRYLON Primer

**Altimat** · 06-23-2005, 11:03 PM

The bondo itself usually doesn't crack, but the materials expand at different rates with temperature changes causing the bondo to lose adhesion with the plastic. Make sure everything you apply it over is well sanded, and reinforce the backside as well as possible.