welding quarter panels

[alb_accord]

ok from the other thread i learned that to weld the quarter panels you need a tig welder.

but how do you weld the two parts together?

body shops,,,, they just get a big piece of the quarter panel and they just cut in on the trunk edge/rear window edge etc etc basically in places where you can hide the weld job.

but what about the smaller patch panels that you can buy for $80 or so. how do you weld and hide the weld?
do you put a piece of metal between the two pieces that you are welding????

so who ever has done or has seen this process enlighten us.

this is the part i am talking about.
http://www.rustrepair.com/repair_pan....htm?r=ru&p=sm

[foamypirate]

I forget what the tool is called, but when you cut out the old metal, you leave about 3/4" of extra metal overlapping the new panel. The tool then puts a little fold in the metal on the car, which you place the patch panel into.

I'll try and remember what the tool is called.

[starchland]

a lip maker

[foamypirate]

I love the tool industry. Their tool names make sense!

A pedestal grinder is...a grinder on a pedestal.

lol.

[tommi]

http://www.cb7tuner.com/vbb/showthread.php?t=9368

the patch panel i used came from a cb7tuner member by the name of noxidea, a good friend of mine.

[Camurai]

You DO NOT absolutely need a TIG welder. A MIG welder will work perfectly fine for welding in a patch panel as has been stated many times in the previous thread.

We can do DIY's on welding sheet metal until we're blue in the face, but there's no substitute for doing it. You won't learn welding by reading about it. Every machine is different and you'll have to fine-tune the heat and feed settings until you get the one you're looking for. Practice on some scrap sheet metal before welding your car. Remember, prep is key. Have all the tools you'll need close to hand. For starters:

Welder (Duh.)
Tip cleaner
Spare tips (you never know)
Assortment of wrenches and screwdrivers (you never know when you'll have to take the torch apart to fix a kinked wire feed)
Metal brushes
Slag hammer
A good grinder
Welding gloves
Welding jacket (Don't know about you, but I'm not a fan of getting burned by slag)
Welding shield (Do yourself a favor and don't do the "turn away" or "closed eyes" methods. You'll end up with sunburn, risk of skin cancer and possibly blindness.)
Good music (A large part of welding is being comfortable and smooth, good music will help get you into a "groove" and your work will improve, trust me.)

Prep the area first. Get everything flammable out of the area and make sure it's clean and uncluttered. Clean your workpiece and make sure there isn't any oxidation on it. This will greatly increase your chances of inclusion in your welds, and ruin your work. Set your piece together. Make sure your connections are solid and your machine is working properly. Put on your protective gear and test everything by doing a spot weld on a scrap piece, or in an area that won't be visible. When everything's ready, put the hammer down and go to work. After you've welded in the patch panel, use the grinder to knock the bead down and CAREFULLY blend it into the surrounding panel. You probably won't get much better instruction on this site than that.

P.S. - I probably forgot some things because I'm not a welder. This will give you a good head start, however.

P.P.S. - The best way to weld in a patch panel is to tack it in first, then weld it in small sections. Move around the perimeter of the piece, tacking it every 1" or so. When it's tacked in, weld a single 1" section at a time, then move to a different portion of the panel to allow the area you just worked on to cool. This will help to prevent heat warping on the panel.

[benji]

I don't know about a lip maker, but every time we've (my dad and I) had to do patchwork, all we did was put the piece in (we aim to have it just barely fit inside the hole), tack it on, make sure it will be even around the sides, then weld around it. If you can do this from the back side, then that is the best so you aren't adding to the height of the panel.

Once it is all welded in, we use a hand held grinder (lightly!) to remove the obvious ridges and stuff, then sand (with a sanding block) everything as smooth as we can get it, starting with a 100 or 80 grit, and then moving down to a 320 or higher grit to polish it more.

To finish off, we use a little bit of bondo to smooth everything out further and mask any sanding marks. Multiple passes can help, with sanding in between. The better you are, the less bondo you will need.

Just be sure to do it in good lighting, and look at it from as many angles as possible to see if you still are high in places. Try not to add much height to the panel. Be sure to primer everything when you are done to prevent rust.

Welding technique is important. Be sure to spread your heat over as much area as you can, and don't spend too much time in one area.

As an aside, you don't have to have a MIG/TIG welder, it's just that those kinds of welders (wire feed) are really really easy to use and can give even beginners clean welds. For delicate stuff like fenders, it is best to either use a wire feed or acetylene torch. We don't have a MIG, so we've always used torch. It takes a bit of skill, but you can get very clean welds using a torch.

[Camurai]

Oxy/acetylene welding is probably second only to TIG in accuracy. It takes a steady hand and a good amount of skill to do it well. And a typical TIG machine doesn't have a wire feed. Those types of machines tend to be exorbitantly expensive. Wire feed is much more common in the MIG process.

[alb_accord]

hmmmm how come no one said anything about the thicknes of the wire for the mig welders.

after researching and asking a few welders it is better to use a thinner wire (.6) to weld thinner metals(car panels) with a mig welder

[steelbluesleepR]

As an aside, you don't have to have a MIG/TIG welder, it's just that those kinds of welders (wire feed) are really really easy to use and can give even beginners clean welds. For delicate stuff like fenders, it is best to either use a wire feed or acetylene torch. We don't have a MIG, so we've always used torch. It takes a bit of skill, but you can get very clean welds using a torch.

how do you avoid warping the panel with a torch? it is hard to avoid it with a mig welder (which is why you are supposed to do lots of little dots spaced out instead of one long bead). i have never even heard of anyone dong professional-level sheet metal welding with anything but a mig welder (except when welding small pieces made of aluminum sheet, then they used a TIG welder)

[Camurai]

how do you avoid warping the panel with a torch? it is hard to avoid it with a mig welder (which is why you are supposed to do lots of little dots spaced out instead of one long bead). i have never even heard of anyone dong professional-level sheet metal welding with anything but a mig welder (except when welding small pieces made of aluminum sheet, then they used a TIG welder)

You've never seen oxy/acetylene welding. The torch isn't like any torch you've ever seen, trust me. The flame is typically about the size of a cigarette lighter flame, but hotter. It's a very delicate type of welding, more like TIG. I've actually watched a professional patching body panels on a 1937 Chrysler Business Coupe with an oxy/acet setup. I was amazed at the pinpoint accuracy of it. Back before MIG and TIG were invented, this was how they had to weld thin metals. When done by an experienced professional, an oxy/acet weld practically indistinguishable from a TIG weld.

[C91BLX7]

From what my friend has told me;

1. Arc Welding: Don't even think about using it on thin metal.
2. Mig Welding: Works good, a bit easier than TIG.
3. Tig Welding: It works good just harder to do than MIG

[customchord]

Tig isn't really that hard for what you would be using it for its just trying to find one.

[steelbluesleepR]

You've never seen oxy/acetylene welding. The torch isn't like any torch you've ever seen, trust me. The flame is typically about the size of a cigarette lighter flame, but hotter. It's a very delicate type of welding, more like TIG. I've actually watched a professional patching body panels on a 1937 Chrysler Business Coupe with an oxy/acet setup. I was amazed at the pinpoint accuracy of it. Back before MIG and TIG were invented, this was how they had to weld thin metals. When done by an experienced professional, an oxy/acet weld practically indistinguishable from a TIG weld.

interesting. i have welded with oxy/acet before, but it was really thick steel plate and the entire thing glowed orange. that was during a manufacturing processes lab, though. my professor told me that oxy/acet was vastly inferior to tig because the ratio between the heat affected zone and the heat applied was so huge. in his mind, oxy was just for welding big things to big things when you couldnt get electricity (like in the middle of a field or something on a farm). thanks for clearing that up

[Camurai]

No sweat! My father was a professional welder for 40+ years, and I also got to spend some time with a metal shaper in Sturbridge, MA who used both TIG and Oxy/Acet regularly in his work. Between the two of them, I've got a pretty good theoretical knowledge base in most of the ways to bond metal. Unfortunately, I don't have a lot of practical experience yet.