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Old 05-16-2009, 10:07 PM
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powerrodsmike powerrodsmike is offline
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Quote:
flow about 25 CFM
You mean 25 CFH.

I don't run that much, but it will work.

In addition to what MikeH said, a poor technique can also cause voids and pinholes, no penetration will wind up being pinholes after grinding..


When I weld thin gauge sheetmetal, I use the same wire and gas, but have found stitch welding piles up on top some, and does not lay smoothe without pinholes unless I do a little backwelding motion.

For stitch welding using single spots:

Instead of starting at the previous bead, and advancing in the direction of the weld, try starting your bead about .050" or.060 ahead of your last bead, and welding back towards the previous bead..this takes advantage of the heat buildup, and will blend the bead into the previous bead, getting them both flatter.

You can use the same backwelding technique for longer stitches, and it is fairly well known that it will reduce warpage on long welds.

Showing direction of weld, direction of stitch, angle of torch and start point.



Finish point of stitch.


You can stand the torch up some if you want, I lay it down so I can see better. When MIG welding,I also use a straight line motion, advance some then back up a little, advance some more then back up a little.

Backwelding on .035" with .023 wire with about a .4" -.5" stitchlength. No backup metal was used.


The backside of the same weld.


after grinding.


Some guys trim the ball on the end of the wire off after every stitch, it does make a cleaner weld, and better penetration at the start, I don't. It helps keep me from burning through at the start.
I don't use anything less than 20 gauge in the shop. 24 gauge is tough to weld, and too flimsey for the old stuff I work on.

Hope this helps,
later, mikey
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Last edited by powerrodsmike; 05-16-2009 at 10:28 PM.
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