bonding FG to steel

clutchdust

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I'm seriously considering making new flared fenders for my 240 project car, ala Porsche 944 style. The main reason is because the left rear fender is rusted so bad that a proper repair would mean finding a donor car, cutting and welding in a new body panel. I do have a good car to use as a model and could produce a fender with a 1 to 2 inch flair pretty easily. But the question is, if I do that, can I just cut away the old fender lip and then bond the FG to the steel panel and have a secure bond that won't delaminate?
 
Thanks. I know I probably have some structural sheetmetal that will need to be replaced. The nice thing will be that I can build in a little flare and make the structural repairs underneath, it won't matter what they look like just so long as they're strong.
 
I bought mine from one of our local paint suppliers several years ago.
It was around $50 - $70 at the time. The only label I can still read
on the gun says, "Motor Guard Corp." made in Taiwan.
 
Thanks Saudi those look like they're work. The last time I used 3m 8115 was about 5-6 years ago and the paint store loaned me a gun. What ratio are you using it at with metal to glass bonding? If I recall the ratio is determined by the replacement tips correct?
 
Thanks Saudi those look like they're work. The last time I used 3m 8115 was about 5-6 years ago and the paint store loaned me a gun. What ratio are you using it at with metal to glass bonding? If I recall the ratio is determined by the replacement tips correct?
No probs mate. The cartridges are already a 2:1 ratio with a sort of figure 8 cross section that fits into those special guns. The tip is about 3 inches long and all the mixing is done actually in the tip as you squeeze the stuff out. If I only wanted a tiny bit, I wouldn't screw a nozzle on ($9 for a pack of six), I'd just squeeze a bit out and mix it with an "ice block" stick then spread it where I wanted it.

Where I used it to attach metal to glass, I just laid a bead and clamped the parts together. Where I used it to splice panels in, I also (at Smyda's suggestion) laid some fiberflass "dry wall" mesh in the 8115 and coated it in.
 
Another question, I don't recall doing anything but cleaning the surfaces between the steel and 'glass. Did you or anyone use a primer of some sort? As far as I know the bonding is still good but that was my only experience with this product.
Thanks
 
Be carefull with where you attach metal to the FG. I have some issues with my header bar, starting to created dimples where I put screws through both of them and refilling the holes afterwards. The holes keep on showing through the prime because of some kind of shrinkage...PITA.
 
Be carefull with where you attach metal to the FG. I have some issues with my header bar, starting to created dimples where I put screws through both of them and refilling the holes afterwards. The holes keep on showing through the prime because of some kind of shrinkage...PITA.

Through the primer?? jeez, even mine was not that bad....it waited until the 'finish/color' coat was on, THEN it shrunk up ......
 
The guys were talking about bonding with adhesive, not screws. There shouldn't be any sort of deformation with that 3M stuff - I sure hope not as half my car's glued together with it :crap:
 
The guys were talking about bonding with adhesive, not screws. There shouldn't be any sort of deformation with that 3M stuff - I sure hope not as half my car's glued together with it :crap:

It all comes down to how close you're looking. BTW : the 3M stuff is great, but I'm under the impression our cars originally were not all in all that great.
 
The guys were talking about bonding with adhesive, not screws. There shouldn't be any sort of deformation with that 3M stuff - I sure hope not as half my car's glued together with it :crap:

I used to screw to get the header bar back to its original location. For the rest it is glued on.
 
The guys were talking about bonding with adhesive, not screws. There shouldn't be any sort of deformation with that 3M stuff - I sure hope not as half my car's glued together with it :crap:

I used to screw to get the header bar back to its original location. For the rest it is glued on.

Screw holes cannot be "filled". They need to be dished out deep, and reglassed...just like a regular repair. Treat every screw hole like a crack in fiberglass.
 
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