Installing Weld on Door Patch panels

[WES1977]

OK I now have my real steel weld on door lowers, and I can't find a lot of people talking about it. It comes in two pieces inside and out. This will go on my 1977 FJ40 front doors.

I've read this is a no brainier but i want to make sure the job is done as best as i can do.

My plan for my front doors:
1. place new outer piece into position and draw the horizontal line.
2. carefully cut out the old outer piece.
3. spot weld in the new outer piece.
4. place new inner piece into position and draw the lines to cut out.
5. carefully cut out the old inner piece.
6. spot weld in the new inner piece.

I would like to see other people's work, inside piece especially. Suggestions are welcome. inside lower panel seems like it's going to be the hardiest.

 

[WES1977]

 

[peteinjp]

This guy has got it down!

81 BJ42 - I have to bring it home and pass inspection

 

[gcrump01]

I would suggest you hang the door & make sure the gaps are correct when you tack it. then pull it off & weld it solid.

 

[peteinjp]

Yes- hang them and check for sure. I know a guy that overlaps the panels and tacks them- then he cuts through both panels with a jigsaw or really thin disk. That way he gets perfect gaps and perfect alignment with less fussing around. In this case you'd have to get the seams cut to fit perfect first then overlap, tack, cut and weld the longer sections. Those thin sheet metal clamps that slide in the weld gap would probably be a great help.


Pete

 

[handcannon]

Pete, I like your idea of placing the new piece over the old, tacking together, then cutting. I've never done this in metal, but coming from a cabinetmakers background I really like your idea. Any wobble in one piece would be matched with a matching opposite wobble in the other piece. Makes for a perfect fit for welding (or gluing for wood) together.

Don

 

[jm599]

Flat metal is so easy to warp when butt welding. Maybe why auto panels are usually curved.
Go very slow. Use heat sink.
I screwed mine up and created small disaster shrinking. Had to skim coat filler thicker than I would have liked.

 

[snaggletto]

However you do it, use a straight edge to check the flatness of the patch with the top of the door while you are tacking the patch into place. Also, be careful grinding the welds down. I have found that grinding the welds down so that they disappear into the sheet metal was to deep. Use the straight edge to find the tallest welds and be selective when grinding. Body filler will have to hide the rest. Also, maybe cut and fit and tack the patches and take the doors to somebody with a TIG welder.

 

[peteinjp]

When I welded a small patch on my truck I left a bit of a gap and did a series of overlapping spot welds with my mig instead of running a bead. Practice on some spare sheet for sure.

I also read about a method where you do a spot every inch or so and then you put a dolly behind each spot and hammer them down supposedly countering the shrinking of the weld itself checking with a straight edge as you go. Then you grind them all down and do the next set adjoining them. I figured you could get one door done in less than a few weeks....

Seriously a lot depends on how concerned you are about the looks/use of filler. Personally (though many would hate it) i might even consider a lap joint (a strip that overlapped the old and new panels on the interior surfaces) with a 3m body adhesive for the flat sections and just weld the bend/seam areas. I mean how much less "pure" is that than 1/4" of filler over a weld? That 3m stuff has replaced a lot of welds and rivits on everthing from 18 wheeler trailers to- well any modern car probably and would likely outlast much of the overlapping sheets spot welded together on the truck.


Pete

 

[WES1977]

Great advice. Thanks. I'm debating on getting a small plasma cutter.

 

[Nottajeep]

Just curious how this project ended up

 

[DougAustinTx]

I have strong doubts about the tacking of the new patch over the existing metal, then going back and cutting the excess and then welding. Since you will only be able to get to the outside of the joint, you'd have to use a zip wheel or something like that, which would leave about a 1/16" gap that you'd have to weld up. Any time you weld a gap, rather than a tight fit-up butt joint, you are going to have SUBSTANTIAL shrinkage at the joint which will be very visible no matter how quick and small you make the spot welds.

 

[Tin basher]

Depends on how you cut it I don't tack it I use small sheet metal screws to attach the panel over top
The lower piece is already cut off about 1/2 inch longer than where the final cut will be
Then I cut it with the thinnest zip cut you can buy
Holding the Zip disk on a 45deg angle so it cuts under the new panel I get a perfect fit for tig welding
Without filler rod or very little o35 mig wire as filler rod
Or 0.23 in the mig do hot tacks several inches apart
Then a tack between every tack let it cool
Then another series of tacks till I have about a 1/4 inch between tacks and then carefully grind all the tacks down then go through and weld between all the tacks moving around so you don't do two welds next to each other
I try to stick close to body lines if at all possible
Much easier to control warping
On a door if it's not rusty above the body line I would trim the patch panel down to avoid going that far into a flat panel