Author Topic: What’s wrong with this weld?  (Read 1042 times)

Offline dxhall

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What’s wrong with this weld?
« on: May 16, 2021, 06:46:39 PM »
This is the modified side stand on the Eldovert.  When I started the weld, the .250 rods from the original stand were about .250 proud of the small flat plate.  The idea was to put a blob of weld over the stuck-out rods.  But my blobs look like crap.  Is this a gas problem with my mig?





Offline JC85

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Re: What’s wrong with this weld?
« Reply #1 on: May 16, 2021, 07:33:55 PM »
This is the modified side stand on the Eldovert.  When I started the weld, the .250 rods from the original stand were about .250 proud of the small flat plate.  The idea was to put a blob of weld over the stuck-out rods.  But my blobs look like crap.  Is this a gas problem with my mig?






Guessing that ".250 proud" is a typo, and I'm not sure what you mean, but it looks to me like you pulled in contamination from the painted surface. With very few exceptions, all welding processes have trouble with painted surfaces. Hard wire, especially, which is what I'm guessing you're running. Always grind or sand the paint off of the base metal at least 1/2" back from the weld area, before welding.
 
« Last Edit: May 16, 2021, 07:42:23 PM by JC85 »
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Offline dxhall

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Re: What’s wrong with this weld?
« Reply #2 on: May 16, 2021, 07:46:27 PM »
By “proud” I meant that the rod of the old stand was sticking up from the surface of the small plate about .250 inch.  I thought about making it flush with the plate, or maybe below the plate, but it seemed that the weldment would be stronger the way I did it. 

I wire brushed the paint off the rod part of the original stand before I welded it.  I ran a few test beads on scrap before I did the stand, and the test beads looked fine.

Offline JC85

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Re: What’s wrong with this weld?
« Reply #3 on: May 16, 2021, 07:54:15 PM »
By “proud” I meant that the rod of the old stand was sticking up from the surface of the small plate about .250 inch.  I thought about making it flush with the plate, or maybe below the plate, but it seemed that the weldment would be stronger the way I did it. 

I wire brushed the paint off the rod part of the original stand before I welded it.  I ran a few test beads on scrap before I did the stand, and the test beads looked fine.

Wire brushing takes off some of the surface paint, but it doesn't get down into the pores of the base metal. There was most likely still paint residue in the base metal, which caused the contamination. If you're still questioning, simple way to tell if you have a problem with a shielding gas leak: shut off the gas tank; if the regulator doesn't start dropping, your gas is fine.
« Last Edit: May 16, 2021, 08:08:39 PM by oldbike54 »
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Re: What’s wrong with this weld?
« Reply #3 on: May 16, 2021, 07:54:15 PM »

Offline guzzisteve

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Re: What’s wrong with this weld?
« Reply #4 on: May 16, 2021, 08:31:40 PM »
It's on the wrong side for a foot.
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Offline jrt

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Re: What’s wrong with this weld?
« Reply #5 on: May 16, 2021, 08:50:28 PM »
Common reasons for porosity are contaminates (paint) on the base metals, rust on the base metals or running too hot.  You don't have to see paint or rust for it to be there.   
I have read about too much gas on MIG, but that never made a  lot sense to me (it's a shield, right?).  If you are working outside, the shield gas might be blown away without doing its job.  I have done that before and it results in similar to what you are seeing.
Might be any or none of these?
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Offline dxhall

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Re: What’s wrong with this weld?
« Reply #6 on: May 16, 2021, 09:47:04 PM »
Thanks for the replies.  I was getting a lot of popping during the weld, so it seems like contamination was the problem.  Fortunately, I have a good supply of discs for my side grinder.

Steve - it’s a left handed Eldovert.  It will work.  The stand is from a Breva, with stops at the milling machine and band saw.

Offline Chet Rugg

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Re: What’s wrong with this weld?
« Reply #7 on: May 16, 2021, 10:03:01 PM »
a welder always grinds where the weld is to be. thats how you know if the guy is for real.try tiggin on a dirty piece of aluminum same deal. live and learn in the welding world :thumb:
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Online Ncdan

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Re: What’s wrong with this weld?
« Reply #8 on: May 16, 2021, 11:17:18 PM »
Major rule in any type of welder. Globing weld on top of weld never makes a stronger weld, just a blob.
Second lesson- Never attempt welding, gas or electric, on a painted or otherwise contaminated area.
Any weld must have three metals melting simultaneously, the two metals being welded and the welding material. This method does not include brazing.
These principles has always worked for me on non professional required projects.
If this helps good if not, there’s no change 👍

Online Ncdan

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Re: What’s wrong with this weld?
« Reply #9 on: May 16, 2021, 11:19:14 PM »
Major rule in any type of welder. Globing weld on top of weld never makes a stronger weld, just a blob.
Second lesson- Never attempt welding, gas or electric, on a painted or otherwise contaminated area.
Any weld must have three metals melting simultaneously, the two metals being welded and the welding material. This method does not include brazing.
These principles has always worked for me on non professional or certified welder applications required projects.
If this helps good,if not, there’s no change 👍

Offline MMRanch

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Re: What’s wrong with this weld?
« Reply #10 on: May 17, 2021, 12:14:44 AM »
Not clean and temp to low .  We all do things a little different so good luck with it !
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