Hello Fellas. I am just getting ready to replace my rotted out Model A fender/wheel wells with some nice patch panels I ordered. The big question is should I leave a little extra metal on the back and do a slight overlap weld and use filler or should I do a precise cut and butt weld it? I am afraid to warp the hell out of it. Added note. the parent metal is pretty dented from a rear ender years ago. I hammered it pretty straight but it will need filler for sure. I'm not exactly skilled or talented in the world of body work. Actually, 100% rooky would be more accurate. Any words of wisdom would be greatly appreciated. Thanks,
I always prefer to butt weld in body work. Small tack welds spaced an inch or two apart, then let the second weld overlay the first by 1/3-1/2. Then go to the next of your first welds doing the same with each. This helps hold down heat warpage and allows for corrections in allignment. Yea, it's slow but it works. You'll eventualy fill in all the gap in the butt between the two panels.
Im sure someone knowledgeable will chime in.... If you can butt weld it do it. That way you can get 100 penetration before grinding off the welds. Lap welding leaves that tiny lap for moisture to get into and cause more rust in the future. Thats what I'd do, but I'm no pro bodyman, just what I've been taught/caught on to from watching others.
Oh yeah, what he said. DO NOT do one solid weld. spots, then more spots, then more spots until you get the whole thing welded.
I have been doing patching on my 50 and the metal is thin on the car and warping happens very easy. I would say not to butt weld do to your experience and to avoid as much warping as possible. Sounds like you need filler anyways, if you do it right filler is just fine to use. I purchased a cheap flange tool from harbor freight and it works great.
Learn how to weld sheet metal first....maybe find some other metal to practice on, to get the hang of it. Butt welding is tricky, it's easy to warp the panel. But lap welding is also easy to warp if you get it too hot or don't fit it right, and it's really difficult to fix a lap weld without cutting it apart.
Butt weld for sure! Here are some reasons... 1. You can't body work a lapped joint 2. lap weld looks like crap on the inside What welding process are you using? That will make a huge difference in your method. No matter what process you use you will have distortion. The art is learning how to manage it and metal finish it out. If you have it available to you TIG or OXY/ACYY is king! Start leaning the right way from the start!
butt welding is the correct way to do it. you will be welding real metal so warping really shouldn't be an issue if you move around. do a couple practice pieces to get the settings right and find a comfort zone. it's only metal and any screw ups can be repaired if you don't warp the shit out of it. just take your time and you'll get the hang of it real quick. good helmut, good gloves, a mask, and no flip flops are also key. go git 'em.
that is a very difficult task, welding replacement inner fenders on the rear of a model a because it is curved in a couple directions. If you don't have a lot of experience i would do a lot of practicing. Butt welding flat and straight panels on a bench is tough but when you get down on your knees and start doing curved surfaces is a whole different animal. Butt weld is the best method - and to do taht you need to have a perfect fit, no air gaps between the panels. So you have to be very fussy when cutting and fitting the panels. They have to be very clean, the rust will mess with the weld. You can use the original bolt holes for clamping, i bend sheet metal to form a 'bridge' and bolt thru the original fender bolt holes with the bridge on the inside and tighten the bolt from outside and that is what holds everything together and aligned for tack welding. I think you'll only need 4 or so. I might have one layin around so if you are stumped about what they'd look like shoot me a pm and i get you a pic. I tig weld and i bet you're migging it so i can't offer advise there. Good luck, there is no easy way to weld those pieces.
I am no welder, I AM an awesome grinder! Seriously though, when I started repairs on my Rivi I tried both methods on my floors. I prefer butt welding now that my skills improved (there was a ton of welding) Go slow and learn as you go.
I prefer to use a lap weld of about 1". I drill small holes every 4" through the outside panel and plug weld first. I make sure that the out side patch panel is over the original panel, this prevents water from running down between the two panels on the inside and causing rust between the panels. After welding the outside 100% I work the metal so that it is smooth and flat, showing only a seam on the inside. That seam could be welded if you are realy conserned about rust and/or looks, or you could just seam seal it. I find that I get much less warping and have a stronger panel as a result. I also find that by using 16ga. metal, it acts as a good heat sink that prevents warping. It also does not "oil can" the panels. I use a mig with .023 wire. This may or may not be the "expert" way to do it, but it works well for me especially if the inner panel can not be seen. I fully form the panels on an anvil or other tools before welding and often "pick and file" them after welding.
Butt weld if you can, lap weld if you can't or if the metal is too thin. You can also use a flange tool to help. That's what it was designed for. The inside is not that important. Most times it is hidden anyways. If you can't body work a lap weld then you shouldn't be doing body work...period. Gas weld is not the right way, it is old school and is an inefficient way to work with panel replacement. Too much heat even if you are good, too large an area is heated in most cases. I know you can wet rag the spot but it still ain't the right way...
Butt weld is way better. Lap weld is way easier to fit and weld. Want the best of both worlds? Fit it up as a lap joint, use cleecos or rivets or screws. Get it as nice as you can , massage it, tweek it, adjust it however you want. Cut thru both panels in a few places for tacks. Thin cutoff wheel works good, even a dremmel cut off wheel. Carefully tack those areas as a butt joint, maybe every 6" or so. You may have to open the top piece cut off to get at it but its easy. Finish cutting thru both panels connecting the dots and tacking as you go. Can use a body saw now. The joint will be perfect no matter how crooked you cut it. Cut a bit, dolly nice tack repeat. That really makes things go quicker for me. Fitting compound curves in a butt joint is just no damn fun.
Butt ...it takes some practice but well worth the effort to become good at...I keep the air hose handy and cool the welds ...helps reduce the chance of warping, if you are uncomforatable its time for some practice!
I'm going to have to respectfully disagree. Even though the lap is hidden, its still there. Its a dead give away an inexperieced body man was at work, hurts re-sale value. When I say body work, I mean metal finish (maybe skim coat filler), primer, paint, not sling tons of mud. I used to think the exact same thing about gas welding. Ancient method, not worth using. Google David Gardiner or Peter Tomasini, what they do with a gas torch and hand tools will blow your mind. Both of them hang out on here too. If you really want to get in depth visit Allmetalshaping.com Tons of info over there. I was imediately humbled.
Somebody should tell Bill HInes that gas welding is inefficient and old school. Actually I would love to have Bill Hines answer this thread. He has been doing this for about 70 years, as he just turned 90. I would bet money he butt welds using gas, and that is what he has done all his life. Valley Custom sectioned cars using gas.
Learn to gas weld! Hammer welding is NOT that hard to learn. The results are well worth the effort. Once you do you will NEVER mig another patch.
Good idea and food for thought, thanks. I've got some old lap welds on an OT car to deal with, and repairs right close to it that are needed. The existing lap was bent in a low v-shape and bondoed over. Couldn't tell it was there until I started stripping paint. So I planned to hire someone to fix it all at once but so far I'm two for two of guys that say it's OK and want to fix the other spots with a lap weld too. Hopefully I can find someone cut it all out and butt weld it, if not it'll just sit until I work up the courage and practice enough to just do it myself
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