I thought welding in a patch would be easy....

More of an art than a science - discuss metalworking and welding here.



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PostPosted: Mon Oct 13, 2014 4:00 pm
Bump, well everything's welded, the panels are a little low but I should be able to get away with a small amount of filler.

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PostPosted: Tue Oct 14, 2014 11:39 am
Good job! Looks like it eventually turned out. Most people would have given up and outsourced it.

I am learning just like you and by no means have I perfected the "art" of welding in a patch. I taught myself how to weld by reading sites like this and watching youtube vids. But do have some tips, take them or leave them.

Fitment and prep will make or break the job. You mentioned in a previous post that you were having difficulty fitting the patch and asked how people do it. In my opinion, there isn't any one way. Sometimes I get it close and grind a little at a time. What I have been doing lately is laying the new patch over the old metal, clamping it down or even tacking it in, and cutting both pieces at one time with a 4 1/2" grinder with a thin cut-off wheel. I really like this method, even over using a plasma cutter.

Also, a lot of people suggested leaving a small gap for the weld to "fall" into or "fill". I used this practice initially. However, I found that no gap worked much better for me. I was able to turn the welder up and get a much better and more consistent weld without blowing through.

Here is a picture of my last patch fitment.

Image


Here is the start of my welds.

Image


And as I progressed….

Image


What I do is hammer on dolly the welds to stretch the metal that was shrunk from the heat caused by welding. I do this after a few welds.

Like I said, I am new just like you so take it for what it is worth.

Great job and keep it up. Don't be afraid to try other techniques. What works for someone else may not work for you or visa-versa.



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PostPosted: Tue Oct 14, 2014 1:53 pm
Vdubber wrote:Good job! Looks like it eventually turned out. Most people would have given up and outsourced it.

I am learning just like you and by no means have I perfected the "art" of welding in a patch. I taught myself how to weld by reading sites like this and watching youtube vids. But do have some tips, take them or leave them.

Fitment and prep will make or break the job. You mentioned in a previous post that you were having difficulty fitting the patch and asked how people do it. In my opinion, there isn't any one way. Sometimes I get it close and grind a little at a time. What I have been doing lately is laying the new patch over the old metal, clamping it down or even tacking it in, and cutting both pieces at one time with a 4 1/2" grinder with a thin cut-off wheel. I really like this method, even over using a plasma cutter.

Also, a lot of people suggested leaving a small gap for the weld to "fall" into or "fill". I used this practice initially. However, I found that no gap worked much better for me. I was able to turn the welder up and get a much better and more consistent weld without blowing through.

Here is a picture of my last patch fitment.

Image


Here is the start of my welds.

Image


And as I progressed….

Image


What I do is hammer on dolly the welds to stretch the metal that was shrunk from the heat caused by welding. I do this after a few welds.

Like I said, I am new just like you so take it for what it is worth.

Great job and keep it up. Don't be afraid to try other techniques. What works for someone else may not work for you or visa-versa.


Thank for the tips! Next time I'll try to fit it a little better and try to have access to the back to hammer it back up.

I'm in the process of stripping the door down and I'll epoxy it and then put filler on because I thinned out he metal and I have a couple pin holes that I'm afraid ill blow through if I try to weld.



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PostPosted: Thu Dec 04, 2014 11:12 am
You can use a copper welding backer (just a small piece of copper plate if you don't wish to buy a fancy one from Eastwood or what not) to put behind the holes. You can't weld to the copper, so it allows you to fill the hole while having something to absorb some of the heat.

The other way I've done it, a bit messier and requires some more experience, is to just tap the torch ( mean pull the trigger VERY quickly and pull away) at the outside edges of the hole almost pointing the torch somewhat inward towards the edge itself. Even if you can just lay a dot of weld there, you can build up on that to thicken the metal so it won't burn through and work from that point out. Once you get a decent weld chunk going there, start from a few degrees around the hole and do the same, working to connect the two points.The goal here is just to build up a little thickness on the existing metal to help absorb the heat/strengthen the edges for when you start filling the hole. Once you get it down, it is really pretty easy. I have filled some big gaps on very thin sheet metal like this. The copper spoon/backing piece would require less finishing work though and much less chance of warping the metal if it is a long, flat panel being that you won't have to actually weld to the metal as much to fill the hole, and the copper will absorb much of the heat.



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PostPosted: Thu Dec 04, 2014 11:15 am
http://www.harborfreight.com/welding-spoon-66785.html

Cheap one from Hobo Freight.



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PostPosted: Mon Dec 08, 2014 11:05 am
How does one weld in a patch on a quarter panel that doesn't have anywhere to clamp the ground cable? Weld a bolt onto the patch panel and then clamp to that? Also I'm a little worried about how I'm going to hold the patch in place, but I do have magnets.

Anyone ever plug weld in metal strips behind the panel where the patch is going to be in order to have something to line up the path on? I've seen this in one of eastwoods videos but I'm a little worried if you could visually see where it was done due to sunlight heating metal up at different speeds due to the extra thickness?

Thoughts?

Thanks
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