Looking for hell hole welding advice Options

[AndrewBlyholder]

Launching in my hell hole rust repair. Need some advice on the usual welding technique for patching.

Many of the patch parts have flanges that match the factory stampings. I assume the factory spot welded these things together. Is that correct?

Don't have a spot welder, and probably couldn't reach most of these locations if I did. What's the usual technique then? Drill holes in the flanges and fill with rosette welds? Or just weld the edges of the flanges?

I'm replacing some sections of the main longitudinal tubes under the battery. That tube was a double walled on both the inside and outside faces. The replacement panel I have from AA has the double wall spot welded onto it. But how do I go about getting both panels weld together at the butt joint where the patch meets the original? Grind/cut the outer face back a little bit more than the inner panel, weld the inner first, and then weld up the outer?

Battery tray replacement questions:
- The lower support has three flanges on it. The front and side flange are easily accessible for welding, but the rear flange is turned inward. Do you weld that one too or leave it unwelded? What did the factory do there?
- The easy way to attach the battery tray to the support would be to weld them together first. Is that recommended? But if you do that, then there would be no way to weld the inward turned rear flange of the support.

Thanks for any and all suggestions.

Andrew Blyholder

[AndrewBlyholder]

Ok, been so busy working on this trying to get the car put back together for the autocross this weekend I wasn't taking any time out to post. But the autocross has now been cancelled due to the wild fires around here, so I can slow down a bit and provide some updates.

This corner of the car had already seen some rust repair sheet metal replacement. Among other things, they cut away the top of the outer half of the longitudinal in the area under the battery and welded in a patch, but they only patched half of the whole opened up. They left a big hole in the top of the longitudinal at the low point next to the fire wall:


Maybe they thought they were leaving a nice big drain hole, but that hole drains into the interior of the longitudinal tube! The tube also has small drain holes in it's bottom, but as as a enclosed area, it will be very slow to dry out. And indeed, I'm now fixing the rust this situation caused.

So here's my patch to close the hole:


Did it as a spot weld rather than continuously welded. Will make it watertight with seam sealer.

Where the battery tray attached to the vertical inner fender wall was also completely corroded away. Cut out the bad part and laid it on my new stamping from AA to trace for the replacement patch:


And here's the patch clamped in place:


Love these panel clamps. Another great Harbor Freight buy!

Here it is welded back in:


And just because I'm anal retentive, I ground down all my functional but horrible looking welds and smoothed everything out with a quick swipe of body putty:


Spot welded a new battery tray support into place, then coated everything with two coats of Por-15, then applied Wurth brushable seam sealer to all the seams that needed to be sealed:


A close up of the seam sealer at the low point patch:


The last job is now to patch the outer half of the longitudinal. I did all this work on the upper side of the longitudinal first because I didn't want anything falling into an already sealed up longitudinal. Now that all the top side, engine bay work it done, I can brush and vacuum out the inside of the longitudinal and be assured that it's pretty clean before sealing it up by welding on the outer half patch.

My outer patch was also cut from the same AA stamping I used for the battery tray fender wall patch. But fitting it into place, it became clear that the stamping didn't exactly match my car, so I had to modify it:


And here's the part after welding in a patch for the split. Also welded on the jack tube because once this is in place, there would be no way for me to get a torch tip on the top side of the tube:


And here it is, welded into place and the welds ground down flat:


Now, how do you get the outer jack tube reinforcement plate on? I couldn't put it on the patch before welding the patch because it would have covered over the patch's edge that needed to be welded. And I couldn't have made the patch bigger to move it's edge up above the jack reinforcement because then I couldn't have reached it with the outer fender in place.

So this was my solution:


I cut the reinforcement plate into two pieces, threaded the upper half on, and then I'll weld the lower portion back together. Got it screwed into place temporarily but didn't have time to weld it last night. That's where I pick up today.

Andrew