Hey there. I'm wondering how easily the bondo/putty part of a front lip will crack on a molded lip? I am planning to mold mine onto the bumper, but do not want to do it if the molding will crack when I hit bumps or autocross cones. Thanks in advance.

 

any bump will problaly crack is unless you can use some flexible stuff.

 

even with "flexible" fillers, it will still crack. the only way to get it to be more elastic like the plastic bumper is to do all of your molding with flexible, durable plastic repair materials like some of 3M's stuff or the Crest stuff we use. Crest Code Blue (for flexible bumpers) or even Crest Redline Rigid expoy will work. then just do very minimal filler work and prime it.

like i said though, it will still crack if you hit it or twist it hard enough. curbs and cones > thin plastic bumpers. lol

 

get a fiberglass bumper and lip and fiberglass it

 

still crack and chip with any little BUMP.

 

he said fiberglass bumper molded to a fiberglass lip...

fiberglass bonded to fiberglass, using fiberglass as the bond material with proper prep will not crack. It will become one whole fiberglass piece.

It wont crack where it is molded, but yeah- fiberglass in general can crack if its hit.

 

Will be able to help you with much more certainty if... I know what the front lip is made out of, and what the bumper is made out of.

is it an oem bumper or an aftermarket bodykit made of fiberlgass, frp etc.

is it a urethane lip, fiberglass lip, abs plastic ?

any combination will require a different chemical adherer topped off with a flexible poly topcoat to finish the bodywork before primer. Fiberglass,well, just dont ever mold it. Even with a little bit of body flex or pressure it will cause cracking and seperation at the mold site.