Well, I got my corners in from Carpenter last night. I held them up to the respective corners and the match looked pretty good. I was a little worried about what I may get from some of the threads I've read. Anyway, while I was matching them up I started thinking what the best approach to cutting and fitting these to the cab.

My question is does anyone know of a thread or have advice on approaching the cutting, measuring, and fitting for welding of the new patches. I plan on butt welding them also. From my practice welding I've done I realize that the fitting is very important to getting a good clean weld with out blowing holes.

This will be my first real fitting and welding I've done (the practice is over now it's time for the real test) on the truck so I'd like to be as prepared as possible and you guys are great on the advice.

Thanks!

 

you are right you want to get the best fit as possible. and do slow. you didnt mention what you had to weld with. dont know of any threads on here im sure theres some in the search with some good information. you might want to check out metalmeet.com there tons of info on there about prep, welding, and weld finishing.
when you weld you patches in you want to get it fitting tight then go around and tack it skiping around till you have it tacked about every inch or so. you liable to have to grind the top off the tacks and strech them as you go to keep your patch from warping from the welds shrinking. after you get it tacked every inch go through and weld in between two tacks grind the top off the weld and hammer on dolly to strech the weld then repeat between two more tacks. skip around to keep from getting to much heat in one area. theres lots of information on metalmeet.com on this subject and if you going to be doing much body work its definatly worth checking out. hope i didnt confuse you.

 

As to your question on fitup, how I do it depends on how much the patch has to cover. The cab corner is very difficult to do because of its compound shape. It is a harder fit if the patch has to reach over the vertical stiffening rib area on the back of the cab. If your patch can stop short of that area, you'll avoid the mismatch problems many have encountered. If you have to incorporate the rib area, a slice and reweld of the patch has been necessary. Basically, the patch will wind up being in two pieces, as it is a longer reach between corner edge and rib than the cab is. I would use a measuring tape dim from the door rear jamb to the stiffener to find out if you are in the ballpark. If your patch does incorporate that rib, cut the patch vertically, fit the rib area, then the corner, and marry the two patch pieces at the cut seam.

First, measure the patch and transfer the dims onto the cab corner, so you'll know the max dims of the patch. Then determine how much of the corner you need to replace and transfer those dims onto the patch. Cut the hole in the cab and finish the hole edge. Trim the patch oversized, maybe 1/8-1/4 on a side. Trial fit and trim the patch to fit a clean-edged hole until you have about an .040 gap all around. You'll find that trimming the patch to get your final fit is a lot easier than messing with the hole. If you're lucky, the trimmed patch will fit inside the cab so you can transfer the hole outline onto it making the sizing easier. I like to mark a witness line across the patch and the panel vertical and horizontal so I always realign the patch the same when checking the trim. This whole operation takes a while. Take your time. If you over trim it, you'll need another piece to patch the patch.

59's tips on welding are good ones. That is the basic method. The hammer-dolly work as you go is critical to eliminating most of the shrink caused by heat. The cab corner isn't too hard to get to both sides of, either. Although usually, you have to work "wrong-handed". If you are right handed, it will be the right corner that needs patching, so the right hand is the one holding the dolly. This problem is only solved by hanging from the rafter while hammering. (LOL).

AXracer swears by "Esab Easy Grind" weld wire for your MIG. It is very forgiving and hammers out and grinds easily.

Good luck.

 

yes, .025 Easy Grind wire. Use a piece of copper sheet pressed tightly against the back of the seam to keep from blowing holes. Don't weld over 1/4-3/8" at a time keeping each tack at least 6" from the last one. Once the patch is tacked in place grind each weld bead down nearly flush, hold the dolly pressed hard against the back like you are trying to push the panel outward and tap GENTLY with a slightly curved faced body hammer in a circular pattern starting with the bead and covering the heat colored area. You should be able to see a pattern of overlapping slight circular marks of the hammer and hear a distinct metallic ringing sound that tells you you are hammering "on dolly" which will stretch out the heat shrinkage until the rest of the panel fits correctly again, then add another short bead between each of the previous ones, but never closer than 6" to the last (hot) weld. Continue the pattern of tacking, grinding and stretching until you have finished welding the entire perimeter. If you take your time and work carefully, by the time you are done you will need little to no plastic filler to finish it off. If you try to do it all at once, you will create and then lock in warps and oil cans that will be very difficult to remove or require a lot of filler to cover up. I'd also highly recommend buying Ron Covell's great video "Basic Techniques for Working with Steel" www.covell.biz words alone cannot begin to teach you what you can learn from that video on repairing old tin. It's a MUST for anyone getting into body work.

 

Thanks for all the great advice. I would have certainly done this the wrong way after reading the replys.

I tried to do a search for "Easy Grind Wire" and didn't find anywhere selling it. I even went to ebay or Upay as it is referred to here. Do you know where I could order this from?

 

this may sound like a no brainer but make sure your doors are on where ya want em to check the gap. heard of people welding them on without doors only to cut em back off because the gap was off. good luck

 

Well, that's something I didn't even considor. My doors are off of the truck. My rust problems are only really in the bottom curve of the corner. I will probably only need to use a little more material above the curve and to the side (back of cab) of the curve of the patch corner.

 

It is made by ESAB, and they list it as exactly that, which throws a lot of suppliers who think every wire must have a composition number.
Any ESAB welding supply dealer can order it for you, if they tell you there is no such thing, or that some other wire is the same thing or try to sell you something else tell them to call their ESAB rep or go here:
http://products.esabna.com/index.html/screen/filler_metals_product_detail/display_id/id4367f2a958f8c3.05458256/category_id/504
The right wire will say "Easy Grind" on the spool label DON'T accept anything else!

When deciding where to seam, think about where it will be easiest to get at to work the seam with hammer and dolly as well as grinder. Put seams in inconspicuous spots or along edges if possible, there will be less chance of warpage where the panel is stiffest. If you must cut a corner into the center of a panel, cut it in a curve instead with the largest radius you can. A curved corner is a much shorter weld bead than a square corner and much easier to blend in. Same thing if patching a hole in the center of a panel, cut out a circle or an oval rather than a square or rectangle.

 

What year truck are the cab corners for? The 48-52 are not even close to correct, Just wondering what year yours is.
Reamer

 

My year is 1954 F100. AX I clicked the link in your post and found some dealers in my area. I'll see if I can pick up some easy grind next week. Thanks everyone for the advice and saving me some headaches.

 

Consider yourself lucky if your dealer stocks it. Mine had to special order it, AFTER he talked to the rep to find out there was such a thing. I bought a spool of the .025 and the .030 but I have yet to open the heavier size. You may also need to pick up a pack of .025 tips if you didn't get any with your welder (likely you didn't) I would also pick up a jar of "tip dip" (not a brand name) tip cleaner. It's like a jelly you dunk the welding tip in every once in a while. It help keep the tip clean which in turn reduces spitting and sputtering from a dirty tip. A jar with last years in a home shop. I keep a pair of thin tipped needle nose pliers with wire cutting section at hand at all times. I clip the end off the wire before each weld (a fresh cut sharp end will start easier and give a cleaner weld), and use the jaw tip to scrape any spatter out of the tip. They are also handy should you need to change a hot tip or pick up a hot piece.

 

Everyone's ideas on here are great. The way I fitted up my corners was first to grind the area to be replaced down to bare shiny metal, because there is always more rust than you think. Then, I used a piece of masking tape to lay out my cut line. I tried to avoid the ribs in the back of the cab (they don't match on the patch), and the door jamb. Unfortunately on mine, I did have to get into the jamb a little.
I then cut out the bad part, trying not to distort it, cutting the spot welds, etc.
Next, I laid the rusty part inside the patch, marked the outline on the patch and cut on that line. This will get you close and you will find that the patch is very close to original in shape, but will need to be tweaked a little.

This is where I varied a little from the previous posts. Now, I cut another strip, about 1 1/2" wide from the patch directly above my previous cut. This gives me a strip that matches the contour of my patch. I then plug welded the strip to the cab, leaving about half of it exposed. Then, with some help, I was able to position the patch on the cab and use Clecos to hold the patch in place. These things are AWESOME, just ask Randy. Turns out that my patch fits awesome, except for the fact that it is about 1/8" too long in the door jamb. Using the Clecos makes it real easy to remove and replace as I get the fit just right. When it is all adjusted, you can plug weld the patch to the strip, remove the clecos, plug them, and do some finish welding.
This method doesn't look as cool from the inside, but for a novice like me, it seems to work.

Good luck

 

I personally usually don't like doubling the metal because it makes it near impossible to stretch out the inevitable heat shrinkage the welding produces which means extra filler to cover the low spots. But if it works for you, go for it. I will be using a backer plate flange around my frenched Cadillac taillights to keep the contour of the body and the shape of the bucket as well as give me extra metal around the edge of the bucket for contouring the corner. I will tack weld the flange to the bucket once I establish the body line before installing the bucket. As of right now I do not plan to weld the flange to the body tho, or if I do it will be with only a couple small plug welds from the inside to stabilize it. Installing the taillights is this weekend's project so I'll be posting pix and info likely tomorrow.

 

Ax I called one of the 4 or so welding supply places here in Houston and the guy on the phone didn't know what I was talking about. He was supposed to call me back because he was busy (end of the day on Friday) with the customers but never did and it was the end of the work week for me. I had to go start my weekend. I will make some calls later today so see if I can locate the wire or get it ordered.

Thanks agin for everyones advice and ideas...I'll let you all know how it turns out.

 

https://weldingsupply.securesites.co...F:OR:terms::PC

Its pretty much all the way at the bottom.

What about bonding? all the tacks and grinding and hammering and dolly work make me wonder if bonding wouldn't be faster and easier. What are the drawbacks to bonding?