kccampro

Thanks for the document!

atb

What would be the best way to form a 90 degree bend with these fenders. With our without heat? I have a set of Euro-S front fenders that I need to trim the front overhangs to mate up with my S4 front bumper cover. (Why? Because I'm doing rub strip delete and the Euro's are rub strip free and I like the marker light location better) The S4 fender metal has a 90 degree flange where it mates to the bumper cover that I need to copy on the Euro S fender. I was going to make a jig to clamp to the flange portion and bend it 90 degrees, but I don't know if I should apply heat or do it cold. When cutting the fenders I did notice that the aluminum was pretty brittle. Instead of leaving the fine glitter of a steel panel it left noticeably larger particals while cutting. I would be concerned in bending it cold that it my tear. Any opinions?

atb

Sterling,

My passenger side fender crunched so I would need to replace it regardless.
Too late on the Euros, I've already trimmed them, just need to bend they are good to go. Besides, I prefer the placement of the euro markers over the US version.

6.0-928S

Adam,
I trimmed my fenders to the S4 spec. I made some pie cuts, ( the fender has a compound angle there ) & I heated them & bent them under.
Hammer

Mike Simard

My fab guy has a trick for heating the fender material to anneal it before forming which I suspect is important in this case. Use a rosebud equipped Acetylene torch with the O2 off, blacken the area with soot. Then use some O2 for a normal flame and slowly heat the area until the soot goes away.

Kary, thanks! Who would have thought that someone actually did know the alloy

Greg, the welding rod is not as important to a painted part. Maybe if it were to be anodized or left bare matching would be a concern.

atb

You nailed it Hammer. (no pun intended). I'm hoping I can get as good of a line as you did on the mating surfaces. You're right, there is a compound bend there, it's not just a straight crease. I'll have to play around (with some paper stock) and see what needs to be done to replicate the curve before trying it on the actual fender. You don't happen to have a pic or diagram of how you ended up cutting the tab before folding over do you?

Mike, sorry I'm not real familiar with metal work. Are you annealing before bending to prevent damage while you bend the fender, or are you annealing after the bend to give it strength. Heat it up with the acetylene first until its has soot on it, bend it, and then anneal with the oxy added in?, or burn off the soot with the oxy on the proposed crease line, then bend. Sorry if this is obvious to those who work with this stuff on a daily basis, I just want to make sure I get it right.

Mike Simard

Adam, annealing is the process of bringing a metal to a soft state that's more friendly to bending and less prone to tearing, that temperature is some point less than the heat treating temperature. You would want to heat it to it's annealing point and let it cool as slow as practical before working it, the soot burning is just a convenient way of doing that, it may not be as accurate as heating/slow cooling in a big furnace but it's practical and better than doing nothing.

Hammer, nice work!

atb

Gotcha, thanx for the explanation Mike.

6.0-928S

Adam,
After trying to figure a better method, believe it or not, I used a chalk line that followed the rocker moulding line. After all, that's the line you want to follow on a side view of the car.
Thanks Mike.
Hammer

blown 87

The torch trick was one of the questions on my oral exam for the "Airframe" part of my A&P.

How do you anneal something with out a furnace.

The guy that gave me my oral had his original pilots license signed by Orville Wright.

blown 87

I have decided to go all out on my paint job for my 87 after seeing Sterlings write up on putting GTS rear quaters on.
GTS rear quarters, and GTS mirrors.

I am not sure if I should get a fiberglass rear wing and save my original folding wing or not?

Do the fiberglass wings bolt up to the same holes on a S4?

Any suggestions on tire/wheel size?
We will be modding the fenders for max clearance when we have them off the car.

blown 87

Thanks Sterling, and for the link.
I am taking the heads off now, might as well go ahead and do that while I am at it.