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Unibody rust weld repair

Posted: Sat Jan 13, 2018 4:49 pm
by LandShark
I will load the pic soon but I have a rust hole above the front jack point. The jack point is weakened but mostly intact.

Peek-a-boo, wire harness.
ImageUnibody rust hole above left front jack point. by Matt Squirsh, on Flickr

Im making some patterns out of 1/16" (1.5mm) steel to weld up 3 unibody rust holes in the area under the left wing. Im familiar with the risks of doing this and have access to a quality MIG setup. Any tips for this repair?

Re: Unibody rust weld repair

Posted: Sat Jan 13, 2018 11:33 pm
by olympia57
That's not the jacking point , that's on/in the sill ( rocker ) .
I believe that the square pad in your photo was used to transport the shell during prep/painting at manufacture .
The pad serves no purpose and providing you are not seeking to preserve the 100% originality of the car , can be removed. They allow the build up of road dirt leading to rust ( as you have found out .....)
If you wish to retain it I'd remove the carpet and underlay ( most important :wink: ), cut out the rot and replace with fresh metal , fabricate a new pad and then weld back onto the new metal underneath .
I removed both pads from mine when I restored the car A) to remove a source of future corrosion and B) to give the Lokari liners I fitted, a flusher much better fit.
'Bye the way , that circular plug to the right of the rusty area is the sunroof drain tube exit . I presume you have no sunroof on your car , if you do it's draining into the sill cavity :shock:
Good luck .
Don

Re: Unibody rust weld repair

Posted: Sun Jan 14, 2018 9:34 am
by wattsmonkey
As Don says. I've had this argument with E28 owners having learned the hard way that this is NOT a jacking point, even though it's labelled "lifting pad" on real oem.

I have removed them from my M as part of the restoration along with the jacking points on the sill. Instead, I've welded reinforcing plates onto the chassis rails and carry a small scissor jack in the boot.

Re: Unibody rust weld repair

Posted: Sun Jan 14, 2018 2:54 pm
by LandShark
Golly, its such a convenient jacking point (I use a rectangular piece of wood in there). I think I'm just going to cut the rust, clean it up, treat the underlying metal and reinforce it.

Re: Unibody rust weld repair

Posted: Sun Jan 14, 2018 3:06 pm
by LandShark
I see that the "frame rails" are the appropriate part to jack on. Mine are dented pretty good (that's the condition they were in when I acquired the car) #-o

Re: Unibody rust weld repair

Posted: Tue Jan 16, 2018 1:52 am
by LandShark
I'm using POR 15 on the peripherals here. The fender is obviously rotten to the core, but I have this idea of working chain/bar oil into the seam to to treat the unseen . But then top coating it for aesthetics will be difficult.

http://www.type2.com/library/body/baroil.htm

ImageRotten at the crease by Matt Squirsh, on Flickr

Re: Unibody rust weld repair

Posted: Fri Jan 26, 2018 2:51 am
by LandShark
On this episode of this old Saab... nah just kidding. Stitching 16 gauge wasn't too bad. I used a Hobart MIG welder with 100% CO2 mentioned in another post. Just some cheesy plates mainly to reinforce that square so I can continue to use it for my "jacking pleasure".

Image20180125_161540 by Matt Squirsh, on Flickr

Image20180125_161343 by Matt Squirsh, on Flickr

Image20180125_133901 by Matt Squirsh, on Flickr

Re: Unibody rust weld repair

Posted: Wed Jan 31, 2018 4:18 pm
by tschultz
Is that your personal garage!!?? :D

Re: Unibody rust weld repair

Posted: Thu Feb 01, 2018 2:32 am
by LandShark
That's Jeffs Saab Shop. Although my dream garage would have a 2 post lift. And an espresso machine.

https://www.google.com/maps/place/Jeff' ... 06.5256959

Re: Unibody rust weld repair

Posted: Fri Mar 02, 2018 3:26 pm
by SenorShark
LandShark wrote: Thu Feb 01, 2018 2:32 am That's Jeffs Saab Shop. Although my dream garage would have a 2 post lift. And an espresso machine.

https://www.google.com/maps/place/Jeff' ... 06.5256959
Gotta get some 'fuel' aka coffee somehow...Also, working on a lift is so much better than laying on the ground.