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Old 08-05-2009, 03:10 AM   #1
John Pasinski
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Welding question

I'm trying to repair the cab inner fenders on my '72. Like most others', mine are torn, and the one on the right side is missing the section that formerly was positioned under the battery box. Here's the dilemma: These fenders just WILL NOT accept the weld! No matter what settings I use (setting "A" wire speed 2 1/2, too weak, setting "B" wire speed 3-4, burn through). I have a Lincoln 3200 (from Home Depot). I'm using .025 steel wire with argon/CO2 gas. I have double checked the polarity (it's correct). I have changed the gas pressure from 15, up to 40#. I'm getting gas as I can hear it when I pull the trigger. I have cleaned, and reconnected the ground cable and clamp. I have cleaned (using a grinder and disc sander) the fender to shiney metal at the grounding connection, and as best I can at the welding points. Any attempts, and the arc is "weak" and comes out like looking like I used no gas at all. It looks like bee bees, or bumpy and blotchy (is that a real word?). So I suspected the welder itself. I've used this welder for 5 years now. So I happened to need to weld a unit number on a handle to another machine. Perfect time to test the welder itself. Well it welded perfectly! Conclusion; the welder is working fine. Yeah....I could buy new fenders, but jeepers, they want so much just to ship the things (LMC $225.00 each). Beside that, just for my own self respect I can't let this thing beat me! Any suggestions from anyone? I sure will appreciate them. Thanks.
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Old 08-05-2009, 06:54 AM   #2
mrein3
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Re: Welding question

A couple of things to look at.
First, set your gas at 20 and don't use it outside. That gas is a shield and needs to protect the weld puddle. If you are outside the slightest breeze will blow the shield away leaving the molten metal out in the atmosphere on its own.

Second, you can't weld metal that has rust or paint on it. You may have to cut back further to better metal and clean the paint off of it. The little pits in the metal from rust contain ozidized metal which will screw up your puddle.

Most welders I have used have a little chart under the door where you change the wire. Start with what it suggests for voltage and wire speed. Make slight adjustments from there.

Your ground isn't a problem. Either it completes the circuit or it doesn't. If you are getting an arc, your ground is ok.

If you are attempting to do this outside, go get a spool of flux core, reverse the polarity of the machine, and be prepared to do a little extra clean up work.

I hope this helps.
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Old 08-05-2009, 09:52 AM   #3
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Re: Welding question

Try using the higher setting "B" in your case....turn up the wire speed a bit and then DO NOT run continious weld beads....Just use a series of tacks to create a complete bead....letting the metal cool a mili-second in between tacks.....and as mentioned before, the area must be very clean and free of rust.....
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Old 08-05-2009, 10:04 AM   #4
ebfabman
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Re: Welding question

show some pictures
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Old 08-05-2009, 10:36 AM   #5
dwcsr
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Re: Welding question

Try backing up the joint with a piece of copper.

Last edited by dwcsr; 08-05-2009 at 10:37 AM.
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Old 08-05-2009, 07:10 PM   #6
PanelDeland
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Re: Welding question

If all else fails I always go here to read what they have done to make it work.

http://millerwelds.com/products/
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Old 08-05-2009, 09:58 PM   #7
my67c20
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Re: Welding question

I presume that yours kinda look like mine did. I thought just like you and i figured $10.00 for a piece of steel and if i screw it up too bad i can always buy new ones.

My welder same as what you have, same gas set to 20, welder at A2 ish. Spent alot of time creating the patch panel. I backed it up with a piece of copper pipe i hammered flat. Also get the wire as short as possible.

If you don't have an autodarkening helmet get one as well.

Tried B2 too much heat on that thin material.

Was it easy, no. Is it burning thru, yes. Do i need to practice patience, yes.

I was doing mine in the garage. As you might be able to see i made alot of small blob like tacks but with good penetration. I will need to do alot of grinding and likely have to back weld to smooth it out. Some areas that it burned out i just tack,wait,tack,wait and so on.

Found that my small right angle air grinder (harbour freight $10) works best. Takes some time, but no engine i have plenty of time.

Also what works good is to have a cooler of beer or a fridge full of beer. Encourages patience.
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Old 08-06-2009, 02:44 AM   #8
John Pasinski
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Re: Welding question

I really do appreciate all advice, & suggestions. I read through each reply. Believe it or not, I have, or am doing all you've said. Heat, wire speed, not outside etc. The one thing I haven't tried, was the copper back-up trick.
67C20; you've given me the encouragement to keep on keepin' on. I'll try your technique of "tack & move". I've been on the Miller website. I love that site. Lots of great projects, ideas, & suggestions. It's better (in my opinion) than Lincoln's site. In my little world, any day I can weld; is a great day! Thanks everyone; ~John~
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