what to use
baller/dickbutt#69
Joined: Nov 2002
Posts: 16,059
Likes: 0
From: hampton
Re: what to use
whatever you use it will crack eventually....fiberglass or urethane
your probably doing it because the kit fits like shit...
they all do!!!
to make it fit right you will have to find your high/low spots and remove/add material to make it fit better
but if you REALLY MUST mold it....
aluminum rivet the fuck out of it...get some fiberglass if thats what the kit is and grind down the fenders and start laying glass
if its urethane glue it on with windshield urethane
let that shit dry and mold it from there...
urethane flexes much more than fiberglass and WILL CRACK ..
they will all crack eventually...so just dont do it
your probably doing it because the kit fits like shit...
they all do!!!
to make it fit right you will have to find your high/low spots and remove/add material to make it fit better
but if you REALLY MUST mold it....
aluminum rivet the fuck out of it...get some fiberglass if thats what the kit is and grind down the fenders and start laying glass
if its urethane glue it on with windshield urethane
let that shit dry and mold it from there...
urethane flexes much more than fiberglass and WILL CRACK ..
they will all crack eventually...so just dont do it
Racetracks
Joined: Nov 2002
Posts: 15,668
Likes: 0
From: How long is a piece of string?
Re: what to use
Fiberglass is about the only thing that can properly reinforce and spread the load at the area where the body kit meets the sheet metal. The body kit flexing isn't really a problem, it's the fact that the body kit will flex where the joint is that becomes the problem. If you just Bondo over the joint, you're adding rigid body filler between rigid sheet metal and the flexible body kit. Therefore you'll get cracking wherever the Bondo meets the body kit. Add in the difficulty of getting good adhesion between Bondo and the body kit material, and you have more problems.
The trick with using fiberglass is that if you fiberglass over the joint between the body kit and the sheet metal, the fiberglass spreads any loads over a large area and keeps there from being a big difference in flexibility right at the joint. There are special flexible urethane products that can be used with fiberglass cloth that work very well for this, and there are also special plastic mesh sheets (they look like window screen kinda) that are made for similar things too.
So basically you need something to tie the two things together (body kit and sheet metal) while covering the joint and spreading any loads which try to flex the joint.
Oh, and if you get the right products (talk to a big, professional body shop, they know where to get what you need) you can bond the body kit on instead of riveting it. Riveting is fine, but I hate to punch holes in sheet metal if I can just bond it instead. I'm not much for molding body kits but I love molded fender flares. And I'm an adhesives and composites nut.
The trick with using fiberglass is that if you fiberglass over the joint between the body kit and the sheet metal, the fiberglass spreads any loads over a large area and keeps there from being a big difference in flexibility right at the joint. There are special flexible urethane products that can be used with fiberglass cloth that work very well for this, and there are also special plastic mesh sheets (they look like window screen kinda) that are made for similar things too.
So basically you need something to tie the two things together (body kit and sheet metal) while covering the joint and spreading any loads which try to flex the joint.
Oh, and if you get the right products (talk to a big, professional body shop, they know where to get what you need) you can bond the body kit on instead of riveting it. Riveting is fine, but I hate to punch holes in sheet metal if I can just bond it instead. I'm not much for molding body kits but I love molded fender flares. And I'm an adhesives and composites nut.