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Discussion Starter #1
I am having some problems putting in some body panel replacements. Right now I am working on a friends S-10, but need to get better at this because my 65 Chevelle quarter panel is next.

Am I correct in assuming that when doing a butt weld on a panel I need to leave a slight gap between the two panels in roder to get penetration in the gap. I think the last panel I did was too tight. I got it seal welded up nicely and then ground the high spots off with the edge of a small cut off wheel and then flattened with a sanding disc. The problem is when smoothing out sometimes the edge reappears and then I get the parent material too thin. When I go back to reweld some pinholes it is soo thin it just blows out. This is very aggrevating. So I think that I need to leave a little gap and then maybe use an aluminum or copper backing plate for welding these up.

Any help is appreciated. Everything goes real good until I get the weld ground down and then it goes to pot.
 

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until you get the hang of welding try putting a 1" metal strip under your weld. Plug weld to each panel [which means drill some 5/16 holes in the top panels and weld though to the strip under them]. Leave about a 1/4 gap between your two panel you plan to butt weld together.This way you you have metal under your weld so you don't blow holes and you end up with a stronger weld.
 

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Make sure that the tip is not pointing straight at the butt joint, place it on an angle. If your tip is directly straight it will blow right through.
 

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No gap is best for less warpage, turn your heat up and hold the nozzle within 1/4"-3/8" from the panel and do a spot weld, keep spot welding untill the weld is complete. Also watch the accuracey of your grinding-do not thin the parent metal or this will cause a weak spot along the edge of your weld. Knock the majority of the weld down with a hard stone at slow rpm then switch over to a disc sander to finish to a flush surface.

Using a copper backer will help to avoid blow through, and if you do need a gap for total penetration make sure it isn't any larger than the thickness of your metal- equal to 18-22 guage.

Do some practice on scrap before you tackle the patchwork again-this will help determine what welder settings are needed, trigger timing, and gap if necessary.
 

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I believe the problem you are having is due to shrinkage along the weld seam that has caused the welded area to sit lower than it's surrounding metal causing you to have to grind down that adjacing metal to far in order to create a invisable weld. Try to strech the weld by hammering on dolly in order to raise the seam to the desired level and reverse the warpage that has occured. Then touch it up with a sander making sure to only remove the bead and nopt remove excess material.
 

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If you use those clamps, in my opinion, you will have too large of a gap. Most patches are not perfect parellel edges, therefore may be bigger than the .040 gap provided by these clamps. Too big. Keep them tight (Butt tight) as you might say. Grinding skill is as important as the welding skill. Go easy, concentrate only on the weld spot. We tend to grind hard and fast and get into the surrounding metal. Slow down. you can warp a great, carefully done, welding job with aggresive grind-down. It takes a while to get the weld technique down. Just because you get three in a row right on your paractice piece won't get it. You will have HUNDREDS before you are done with some patches! you can't do that without blow thru until just about the time you have learned to fix them and back them up with copper.
 

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58Chev said:
I came across these little tools to help keep the sheet metal at the right distance for butt welding.



Found HERE
YIKES! If you have a Harbor Freight retail store you can get these for under 10.00 for about 6-8 clamps. I haven't been able to locate them at their online store...probably not searching with the right term...

Anyway - on butt welding...you are going to have a completely different experience welding your friends 65 chevelle quarter as opposed to the S10.

Personally unless I was customizing the S10 welding on the newer alloy metals is not the same.

The metal in the 65 is thicker and a different make-up and with rust, undercoating and who knows what else the welding experience/process is different.

Are you using a Mig or Tig welder?
 

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Brian_B said:
rambo: Do the HF stores sell a version of the "cleco"? I need some of them for body work and I am cheap.
Those I'm not sure, great tools to have...I can probably pickup really cheap used ones locally at the Boeing Surplus store, but not sure when I'll get down there again...
 

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Discussion Starter #11
I am using a mig welder. I am sure that the metal on my 65 chevelle will be much better to weld. I was cutting new cab corners on the S10 and the replacement panels were much thicker than the original sheetmetal. I think that you are dead on about the panel shrinkage and trying too hard to get the perfect looking weld grind without hammer and dollying the area first. Overall we were able to get it done pretty well with using an aluminum backing strip for welding the blow throughs.

As stated above, would it be best to weld a little hotter with a slightly lower wire feed speed than a low setting at a higher wire speed. The initial welding went real well the problem came into play after I ground the weld down.
 

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Those clamps are fine for thick gage metal but like 58 said,they have too big of a gap for sheet metal. We used them to line up a cab corner on the 56 and it sucked up BIG time and even after pounding the shemp out of the bead,still have a ditch to fill up.Some stretching of the piece with a slapper & dolly "should" help but I've learned my lesson with those. Now, I've been tinkering with making some with a thinner gage insert but have not had the time to work up anything positive yet.
I use the flap disk sanding wheels to remove the majority quick as they run a lot cooler than the cut off's or grinding one's. They cut fast and quick so some care is needed to keep out of the parent metal. Then i use the 2" Roloc grit disks to finish for plannishing.
Another gizmo I picked up at HF was the 1/2" wide belt sander adapter for the 4 1/2" ele grinder. I figured it was a POS and a "gimick" but this thing really works and can get into some weird areas inaccessible with a ele or die grinder.I think they have the cleco fasteners in the welding "cabinet" with the hoods.Check this out.
grinder
 

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rcm800 said:
I am using a mig welder. I am sure that the metal on my 65 chevelle will be much better to weld. I was cutting new cab corners on the S10 and the replacement panels were much thicker than the original sheetmetal. I think that you are dead on about the panel shrinkage and trying too hard to get the perfect looking weld grind without hammer and dollying the area first. Overall we were able to get it done pretty well with using an aluminum backing strip for welding the blow throughs.

As stated above, would it be best to weld a little hotter with a slightly lower wire feed speed than a low setting at a higher wire speed. The initial welding went real well the problem came into play after I ground the weld down.
Double check your wire size I use .023 wire size when welding sheet metal.

You can get over zealous when grinding and actually cause problems.

These clamps work really well, but I use them only to set the panel in place with spot welds - then I take them out to finish the welding.



Again patience...if you don't do solid welds then take your time and dolly - as needed, as you go...the reward will be on the other end

You said you used a piece-o-aluminum to prevent blow thru - copper works better IMHO try it out, see what you think...

There are anti heat clay-like compounds. I use Anti-Heat from Eastwood tools (sure there are others) that you place around the areas to weld and the compound absorbs the heat...the trade off is there is a little bit of clean-up - but the compound is re-useable...

 

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Brian_B said:
rambo: Do the HF stores sell a version of the "cleco"? I need some of them for body work and I am cheap.
You can make your own out of pipe and bolts,Take the head of the bolt and cut a line on the top and get some banding strap,weld banding strap to the cut. Drill a hole the size of a nail in the strap abought a 1/4 to 1/2 inch down from the bolt head. Weld a washer on top of the pipe the size of the bolt,and insert the bolt and use a nut or wingnut and there you have it. the nail goes on the underside of panel,and when done welding, unscrew the nut some and take out nail to remove. :thumbup:
 

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I've got a dozen I made out of thin walled square tubing and banding steel but I do not like to have a gap so they don't get used very often.
 

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I don't weld much, but would it be possible (and worth it) to grind or file some gaps/indents in the sheet metal where those clamps will go, so that the remainder of the butt joint is gapless?

Then, you remove the clamps and the only gap you have to weld across is where the clamps were and it would be no thicker than what you would have had across the entire weld seam without the clamp indent.

If you had a flat file about the same width as the strip in the clamp, seems like it wouldn't take all that much time to cut a quick indent on the edge of one or both panels. Would take more planning though, but if a gapless weld is better/easier, might be worth it.

Just an idea...
 

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That is what I love about these forums, you "don't weld much", but you have a great idea. I have never thought of that, and it IS a great idea. Thanks!

Brian
 

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butt welding

I tell you what,I've learned more in the past 5 minutes reading this discussion than in a whole year of burn thrus. So does anybody have any idea what good a panel crimper is ?It seems the butt weld is cleaner, easier to line up. I get all kinds of warp using a crimper and its impossable to get into tight areas.
 

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ckucia said:
I don't weld much, but would it be possible (and worth it) to grind or file some gaps/indents in the sheet metal where those clamps will go, so that the remainder of the butt joint is gapless?

Then, you remove the clamps and the only gap you have to weld across is where the clamps were and it would be no thicker than what you would have had across the entire weld seam without the clamp indent.

If you had a flat file about the same width as the strip in the clamp, seems like it wouldn't take all that much time to cut a quick indent on the edge of one or both panels. Would take more planning though, but if a gapless weld is better/easier, might be worth it.

Just an idea...
The problem without an air gap is that the weld material builds up too fast and can easily lead to...

1) not allowing adquete penetration of the weld
2) extra material requires more grinding and actually leaves a very thin weld which in my experience doesn't last or behave as well.

With a gap the weld is the bridge and therefore doesn't just "sit" on top of the sheet metal - hoping you made penetration.

Take a couple of test panels and play around with it a little bit, I think you'll see what I mean...also, think about how you would weld 5/16 mild steel...you would bevel the edges to allow the weld to penetrate and spread across the valley...kinda the same thing with leaving an air gap with sheet metal patches...
 
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