Here's the first patch installed:


Heres the next section to be attacked (lower at running board) note multiple previous repairs. Unseen is doubled doubler inside! Second wider one between rusted out original and brazed on outside patch.


Will do a complete tutorial including forming the patches using hammer forms, using shrinking disk, metal finishing.

 

Awesome! This will come in handy

 

Can't wait for more!!! Thanks for the help from us non body FTErs

 

I'm ready to make lower fender patches. I have a brake available to make the lower lip. I have made my curved templates from plywood. How do i form the patch? Can I shrink them with hand tools?

Thank you!

 

I also am interested I read the welding thread over and over thank you ax

 

It depends on what part of the fender needs replacing. The most common area on the lower part is below where I just patched on the upper fender or around the frame opening where there is the doubler. Can you post or send me a picture of what you have? Put something white behind it to better show the rust thru if possible. Yest you can shrink by hand hammer work with some practice or by cutting the lip like fringe and rewelding, but a shrinker makes short work of it and is much easier to control. If you go too far the companion stretcher can be used to fix it. If at all possible get some 19ga cold rolled "aluminum killed" (also sometimes called "deep drawing") steel sheet.

 

I just bent mine over my thigh until they had the right shape (simple curves-no componds). For the lower edge, I did as AX said and cut a few slices, bent them over, then rewelded the seams. They were fairly straightforward (never done body work before). Followed some of AX's previous tutorials and all worked well.

 

Ax,

Can you show us step by step, fronts and backs, etc.....

The issue I keep having is I cannot get full penetration (nice little bubble on the backside) with my mig. I either blow thru and have to weld the holes up, or go to the backside and spot weld it as well.

It creates a lot of extra work.....really need to learn to gas weld.

 

I too will be needing to do this. Next month I plan on dismantling my '47 1/2 ton and the 4 fenders are the worst parts on it. I have six front fenders in all, and 3 rear fenders. None are great, but I'll have lots of metal. Someone once showed me an 'english wheel', and he was excited about making compound curves with it. Is this something that's common in the body restoration shops? Maybe too expensive for us common folks with a hobby? Looking fwd to your tutorial AX, thanks for all the help on this forum.

 

Have you read my mig welding tutorial? What equipment are you using: machine, shielding gas, wire size and type, seam fit? It's not difficult, a little testing to dial in the machine and technique. NEVER try to make up for lack of penetration by working from both sides! That should never be necessary or does it improve the weld strength. Bubble gum on the front and more bubblegum on back is still bubblegum. I showed Gary how to do sheet metal tack welds in a couple demos and he did most of the tacks on the patches we did yesterday.
Here a couple shots of the front and back of the welds:
Front



Rear showing proper penetration:

 

Have you read my mig welding tutorial? What equipment are you using: machine, shielding gas, wire size and type, seam fitmetal thickness clean of rust and/or paint? It's not difficult, a little testing to dial in the machine and technique. NEVER try to make up for lack of penetration by working from both sides! That should never be necessary or does it improve the weld strength. Bubble gum on the front and more bubblegum on back is still bubblegum. I showed Gary how to do sheet metal tack welds in a couple demos and he did most of the tacks on the patches we did yesterday.
Here a couple shots of the front and back of the tack welds:
Front



Rear showing proper penetration:


Tacks are about .25" in diameter, flattened button shape slightly smaller similar shape on back, heat affected zone (dark color area around weld) is about .5 - .62" in diameter. You can't run beads on thin sheetmetal! The technique is to make a series of tacks about 4" apart with no two consecutive welds placed closer than 6" apart. here the first tack was placed near the top, second about 6" below after making sure patch seam alignment was perfect at the pint of the tack. This was continued until I reached the other end of the seam. Last tack was place about 1/2" from end. Once panel had cooled completely alignment was adjusted again and a second series of tacks was made between the previous ones.
Note the definition of a weld in the tutorial says that the parent metal must melt and flow together at the junction. If the gap between the two pieces is any wider than the thickness of the filler wire (0.23" in this case) you cannot make a true weld! I spent between 1-2 hrs perfecting the patch fit before I ever attempted to weld it. The next phase in completing the weld will be to add additional tacks between the ones shown skipping between pair so I am not welding closer than 6" apart then allowing to air cool completely before adding any additional tacks, repeating the process until the seam is completely welded.

 

It is a Hobart 210. .030, 75/25

The welds are not "bubble Gum" They look just as yours do, it is just when you flip it over you can still see the seam. So I spot weld the back sides and finish it down same as the fronts......pita.

This is not always the case, prep work is key, no gaps etc........

There are several issues....This cab was sandblasted by the P/O. It has tiny pits that I cannot get the primer they used out of which interferes with the weld some. The other thing I am wondering is if it is due to the older metal being slightly thinner than the new???

 

Are you using the ESAB easy grind in this tutorial?

 

There are a few KEY elements to making good welds that MUST be followed before you can call yourself a welder rather than a bubblegummer/hack.
First and foremost you MUST be able to see the puddle. (Note the major emphasis on this point), I can't emphasize this enough!!!! Most novices and ALL bubblegummers/hacks weld by wrote. The point the torch in the general direction of the place they want to weld at near arms length away like they are lighting a fuse on an explosive, pull the trigger and see nothing but a bright light. They then stop and check to see if they were lucky enough to have put down some bubblegum near where the seam is. If not (which is more often than not the case) they go back and add even more bublegum over around or after what they just did in hopes of doing something that holds or else they stay in one spot so long the metal overheats and burns thru.
If this is how you (general "you" not anyone in particular) weld, STOP right now and learn to be a WELDER:
The proper gear is essential!!!!
1. a self darkening helmet (the ones Harbor Freight regularly offers for 35.00 on sale with a coupon are perfectly serviceable! If you can't afford one maybe you ought to take up a cheaper hobby like knitting.)
2. a "cheater" magnifying lens (+2.0 diopter)for inside the mask(<10.00 on ebay) be sure it fits your helmet. Set the controls for shade 9, medium sensitivity and minimal delay.
3. long sleeved, high neckline, 100% natural fiber shirt or jacket.
4. MIG welding gloves (typically all treated suede with heat resistant lining)
Now you are completely protected better than a bomb squad from the MIG welder, so you don't have to be afraid to get up close and personal with what you are welding!

Next you need to be in the proper position:
1 Get comfortable!!! use a welding table or other fixture to hold what you are working on steady with your hands free.
2. Use plenty of clamps to hold everything solidly in position, It's near impossible to weld a moving target! You cannot have too large a quantity or different types/sizes of clamps. if you bump what you are working on and it moves, don't try welding it.
3. Sit down if at all possible. An adjustable height desk, drafting chair or stool is worth it's weight in gold! Check out larger thrift stores they usually have dozens of used ones to chose from and often sell for < 10.00. pick one the as the largest height adjustment range, is small and lighter weight and with good size easy rolling casters if your shop has a smooth hard floor. 2 or 3 different height stools would be a second choice. You need to have both hands free and be able to brace your non dominant hand.
4. set up some practice metal. 4- 6 or more pieces of flat, clean 16 ga steel plates about 4 x 6" is ideal. Welder should have 0.30 solid core wire and Ar-CO2 shielding gas.
5. arrange yourself (with the welder off) so you can look straight down on the plate that is fixed in place (clamped flat to a welding table) with the face plate of your helmet between 8 - 12 " (NO FURTHER!!!) from the surface to be welded. You must be able to hold the end of the torch 90* front to back and pointed in the direction of travel about 60*. The wire stick out should be about 1/2". The torch should be supported near the bend by the non dominant hand (that is resting on a fixed surface) and you should be able to make several slow simulated confirmation passes across the plate while the torch tip remains at it's original height and angles.
6. Set the welder as per directions on the machine, and turn on.
7. make a test bead across the test plate, concentrating on seeing the puddle (the dark red area around and ahead of the arc) and watch it move across the plate. DON'T fix on the arc itself, only the puddle! Keep practicing making additional bead passes until you are seeing the puddle clearly and can control it's size and direction from side to side of the plate. you want to see/make a continuous 1/4" wide even puddle/bead. Take your time, it's not a race! Once you are sure you are seeing the puddle and can contol it's direction by watching it move, verify by making several circular beads about 1.5" in diameter. Finally butt two practice plates against each other an run a continuous bead down the seam by watching and directing the puddle down the center of the seam.
Once you can do this consistently by watching the puddle, congratulations you have become a welder!
Now when you make your tacks (tacks are done with the torch held perfectly vertical) on the lighter sheet you can watch your puddle develop so it is exactly over the seam and just the right size.

 

First, Sorry, if you can still see the seam on the back, it is indeed bubblegum not a weld, the filler wire is just sitting on top.
Yes, I am using ESAB Easy grind 0.023 wire. 0.030 wire is too heavy for sheet metal work, other common steel wire is not suited for body repair (too hard, brittle) to stretch out the seam shrinkage. If you don't want to use the correct wire I can't offer you any advice. It's theoretically possible to do body work with a sledgehammer and a rock but why punish yourself. sorry.
The metal needs to be as clean as possible without thinning. I use clean and strip disks (looks like a 6 x 1" dark grey plastic steel wool on a mandrel to mount in a drill, available at home depot or lowes, and or 2 or 3" quick change 320 grit scotchbrite disks on my air grinder. The metal should be at least bright. Fine pitting is OK but if deep likely means the metal is thinned by rust. All paint needs to be removed. If you get smoke, sooty appearance and/or flames at the weld site you haven't cleaned or cut back enough. Be sure you are welding to solid metal. Better to cut back too much than not enough. NEVER try to weld up rust holes, cut it out and replace with new metal. You should be doing body repair with 18 or 19 ga (higher the ga # the thinner the metal) cold rolled sheet steel (We have been using 19 ga aluminum killed deep drawing steel on Gary's truck and it's a pleasure to work with, matches the OEM body metal thickness. His truck was sandblasted and epoxy primed by the PO as well.