I have. On one door, I replaced the inside door bottom with a patch panel. On the other door, I made my own patch panels where needed (rust through). Both doors had small pinholes through the exterior skin at the bottom (showed up after media blasting). the rust was from the inside. I used a brass backing "paddle" and welded up the pinholes. The holes will open up immediately upon hitting with arc, but stops once you hit "good" full thickness metal. The backing paddle keeps the weld from building up on the inside of the skin. Its tedious, but can be done.
If the metal is so bad that welding just caused the hole to grow and grow, its time for a patch.
Right now most holes are less than 1/16 of an inch and I could probably spot them shut.
Would leading the doors give a better result? The bottom sill is rusted, and starting to pin hole... so that may also need redone.. but for now its 'good enough'.
Are the patch panels available from the typical vendors good or is there one that has 'the best'?
The problem with using the patch panels is the welding part. It is very difficult to weld this part of the truck without warping. It certainly can be done, its just difficult unless you are really good at welding sheet metal. You will likely have to use some filler to make it perfect after welding. I would clean up what you have to shiny metal inside and out and try to build up the pinholes. A tig works good for this. I have not tried a mig for this, but I'll bet it would work too.
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
For pin holes it's easier with MIG, TiG can be used but it's more work. For welding panels Tig is easier to control, either way you have to be patient weld hammer weld hammer. Practice on some 18 or 20 ga sheet metal. First thing is to get it good and clean then you can plan you repair.
I am getting two sets of patch panels (inner and outer) from TCS Coachworks (price is right) and it seems from his web site that he give you enough outer patch to weld up to the middle support . That should help.
For my better set of doors I plan to lead the holes shut. Just not a fan of bondo. On my worst set I plan to patch them... if they turn out good enough they'll go on the truck.. if not, ebay!
I fear welding across a door skin, no matter how good you are. Metal warping/oil canning for me would be a sure thing. Then it gets ugly fast. I agree that Bondo (or any other plastic filler brand) should not be used to fill pinholes. Plastic filler absorbs moisture and will cause additional rust in time...especially on a door skin that sees moisture every time it rains or you wash the truck.
Never thought of using lead, but it should work ok, I guess. Just remember that the metal around the pinhole is very thin at this point and will remain so even after leading (assuming you lead from the outside and the rust was from the inside).
It will not warp if you do one spot at a time (MIG), blow air on it until cool to the touch then do another. This will take a long time. If you can't bring yourself to do that, it will warp. If you can, it will not. When you grind, it is JUST AS critical. Small amounts at a time with air or it will warp. It's the only way on large flatish areas on a MIG. You can get some 3/4 inch copper tubing and flatten it. Make some long and short ones and bend to reach in behind and push against back of weld to prevent burn thru. It provides a temporary plug while filling hole. The MIG wire will not stick to copper/brass. If you can get behind, a small metal backer behind hole will weld in place as you fill the hole. Tape it in place if you can reach in, then weld from outside. If it starts to warp, as in: wrinkle and bulge....you are cooked, as in, screwed.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
One thing I've found that helps in welding up holes is to take a piece of copper pipe, split it and flatten it out. I clamp this in behind the hole and then mig it up on the outside and grind the weld then....
... I used a brass backing "paddle" and welded up the pinholes....
Yep, as I said previously. But, the paddle is copper, not brass (I misspoke). The "paddle" is easy as it has a handle and thus does not want to burn you through the glove. The flatten copper pipe/fitting will get very hot very fast.
I had the same issue on one of my doors. I found a length of steel flat strap about 1 1/2" wide and long enough to span the width of the door. I cut the rusted metal strip out to match my flat strap and mig welded the strap in place. I went slow but not extremely slow. It worked out great, cant tell I did anything. Had I read all these threads before hand I probably would have been too scared to try it. Sometimes ignorance is bliss.
I had the same issue on one of my doors. I found a length of steel flat strap about 1 1/2" wide and long enough to span the width of the door. I cut the rusted metal strip out to match my flat strap and mig welded the strap in place. I went slow but not extremely slow. It worked out great, cant tell I did anything. Had I read all these threads before hand I probably would have been too scared to try it. Sometimes ignorance is bliss.
Exactly what I did Trip, bent it in the vise with a MFH and trimmed the door to fit making sure I cut out enough to be able to reach inside from below as long as I was at it. Worked out great. Since then I've about finished off a nice CPU cover recylcling it into panel pieces
Just welded one of my doors up. Given that mine rusted from the outside I just cut a strip of 20 gauge and just stuffed it inside the door tacked it in place and just welded the holes up with the MIG.
Took about 2 hours to grind it smooth, nothing warped. Just need to paint the inside with POR15 so it doesn't get any ideas about rusting from the inside.
I like to bush some on the lap joint to the skin to get the capillary action to pull it up between the skin and the rest of the door.
Most of the rust on two of my doors is at the bottom sill... so a patch is not really an option... but need to replace the inner lower sill and bottom skin.
I got two sets of patch panels from TCS Coachworks and will be giving it a try shortly.
Just welded one of my doors up. Given that mine rusted from the outside I just cut a strip of 20 gauge and just stuffed it inside the door tacked it in place and just welded the holes up with the MIG.
I plan on fixing my apron panels (bed to running board) in this manner as the metal gauge is too thin to weld up properly. However, I decided against that method for the doors as the backing metal is a place for moisture to collect and cause rusting between the two pieces of metal. Especially in a door that sees a lot of water. On the aprons, I can seam seal perfectly due to unlimited access.
"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir "When we tug a single thing on an old truck, we find it falls off" ~ me Some TF series details & TF heater pics
I am just about finished with one door. The bottom sill was close, but not an exact match. One flange was 1/8th to short (forget to add bend allowance??) and the ends were not recessed to allow the door frame to sit flush.. so the inner panel now has a slight bow to it.
Warping was minimal but I did have to add a skim coat of bondo which I am not to worried about. For the cost its a great part, but the next set of doors I do I will modify the bottom sill for an exact fit.
I have not seen the parts that Jim Carter sells, but they are 3x the cost... if they correct the issues with the TCS part I would buy them. But for a daily driver door (not a restoration) TCS's parts are great.
Most factory sheet metal is 19 ga, which is challenging to find. Given the manufacturer's tendency to roll out the steel on the lower end of the tolerance, 18 ga is not too much thicker than what the factory 19 used to be. You will find that body crossmembers, Big Bolt fenders, and running boards will likely be a bit thicker. If anyone does need some 19 ga CRS, I have some cut to about 24 x 48, and some game board Flat Rate Pri mail shipping boxes...
I was able to get 2 4x8 sheets of 20g from Nivert steel in WilkesBarre PA. $75 total. The one door panel I have is definitely thinner than 20g. But the door looks to have been 'repaired' before... lots of weld bead where there should be none so its been worked on before.
I have 3 more to fix. The dolly work is quite easy, and I am surprised at how close I can get it with just beating on it. Still need some filler... but not much more than a skim coat.
This approach worked very well for me. I made a copper heat transfer bar from an 100amp electrical dist. panel copper buzz bar. once cut to length you can drill or machine a flat bottom hole and epoxy a rare earth magnet and the backer heat bar will hold itself in place behind the area being welded. No handle required.[IMG]http://i150.photobucket.com/albums/s107/vickraft/weldingjigs/weldingjig4.jpg[/IMG]
All videos are down at the moment... I deleted my youtube account. I had a radio playing in one of the videos and they tagged me for copyright violations... for a radio in my garage.
So till I get them posted again on my site they will be down.
All videos are down at the moment... I deleted my youtube account. I had a radio playing in one of the videos and they tagged me for copyright violations... for a radio in my garage.
So till I get them posted again on my site they will be down.
Dang it, I just about had that music downloaded and ready to sell on the black market. Copyright violations?! Really?! Come on!
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
recylcling it into panel pieces 
