engine and drivetrain Stitch welding engine bay

[djm1968]

Hello,

Motor is out of my car, awaiting time/money for my s14 build. In the meantime, I am focusing on the engine bay and steering. Since my car will have an s14 and will be tracked, I'd like to stitch weld the seams. Question is: where are the key areas to attend to? All seams? Or only certain areas? How far apart do you make the welds?

Thanks!

DJM

[bmw1602.com]

on my build blog...

you can do like so... about 1.5"- beads every 2-3 inches....or whatever pleases your eye.

and also recommend the cabrio brace from the firewall to the frame rail...

or you can use some retangular mild steel tubing.....

Im sure someone can post a pic...

[Nate.Vincent]

First make sure that you torch and scrape all the under coat off the back sides of the seam to be welded. If you don't the welds will pop and burn through as soon as you get some heat in them.

Second you can make a cabrio brace very easily with some 18 gauge steel. One simple 90 degree bend and cut it to fit.

Third the places I would seam would be the frame rail to wheel housing, Wheel housing to fire wall, and A pillar and windscreen area to wheel housing.

Best of luck,

Nate Vincent

[djm1968]

Great info -- thanks! Any pics of the cabrio brace?

What is your preferred method of stripping the paint? I was thinking wire wheel on a drill, but maybe you guys have other methods that work bettter? Chemicals + wire wheel?

Thanks,

DJM

[tjones02]

There's some very nice detail pics of the cabrio brace here at Matt McGinn's Sports Car Restoration site. http://s94994139.onlinehome.us/gallery/1973-BMW-2002-Restoration/P1010003_005

Some 18ga sheet, a vice mounted brake and a small bead roller from Eastwood. Anyone could do it. Installs in minutes, no tools required.

If your rockers happen to be off.... the Voll Cab's also have a square tube section added inside the rockers, among other reinforcements.

[Nate.Vincent]

There's some very nice detail pics of the cabrio brace here at Matt Mcginn's Sports Car Restoration site. http://s94994139.onlinehome.us/gallery/1973-BMW-2002-Restoration/P1010003_005

Some 18ga sheet, a vice mounted brake and a small bead roller from Eastwood. Anyone could do it. Installs in minutes, no tools required.

If you don't have access to a bead roller and or a brake both of these tools functions can be replicated with normal workshop tools.

For the break you can use a vise, find two pieces of steel or preferably aluminum stock with a straight edge 1/2 or thicker and as wide as the piece being worked. Clamp the piece in the vise at the desired bend. Then use a rubber mallet to work the piece over the edge creating the bend. Using the mallet and aluminum will stop the steel from being crushed and stretching.

As for the bead roller I would suggest finding a groove or a rut in a solid steel piece (or make one clamp two pieces of steel together). Clamp the work piece on the grooved block. Using a body hammer (small ball peen will work) hammer through the groove creating a groove in the work piece. We use this more often then most would think even though we have a bead roller.

Here is a great write up on sheet metal fab from my boss at SCR Matt McGinn.

http://www.sports-car-restoration.com/forum2/index.php?topic=14.0

As far as removing paint sand paper, sand blasting, or a cookie on a die grinder are your best bet. Chemicals I have found not to work very well.

For under coat you need to physically scrap off the rubber. I would use a propane torch and a inch wide metal scraper. Heat the scraper very hot and it will cut through the undercoating and seam sealer. Beware that the undercoat will catch fire but is easily put out.

Good luck,

Nate

[bottlerocket]

This sequence might visually explain some of what Nate spoke of...an inner wheel well repair made by clamping a piece of rounded edged sqare stock and a steel block together. A chisel punch was used to drive the form into the sheet metal. A modified version of this process would work fine to bend and form the ribbing in your cabrio brace. Only a few simple found tools required.

[djm1968]

Guys,

Awesome info, pics and links! I have done some work with my homemade "brake" using Al flat stock clamped in my bench vice. Love the homegrown bead roller as well.

Another question for you: cutting metal. What do you use for 18 sheet? Tin snips? What do you guys use when you need to cut thicker metai -- for example, when you need to cut plate steel for brackets etc? I'd sure like a plasma cutter, but cost is a bit prohibitive.

Thanks again for all the excellent info guys!

Cheers,

DJM