Welding Advice

[MikeC]

I know that it is difficult to comment on this because you are not here to see and really give advice but I have a novice level (maybe) in my welding ability.  
I am welding 16ga. and 18ga. sheet metal on my body.  I have been practicing and I either get a burn-through or a puddle of weld.  Looks like "chicken-s--T".  I have watched experienced welders and "know" the sound I am looking for.  It is a 110 wire feed with 25-30# gas pressure (25-75) & .023 wire.  
I want to be sure to get good penetration but also want the wire to flow.  
Can anyone give me an idea what I am doing wrong here.
Thanks
MikeC

[cyberrodder]

mig or oxy, I think its mig. especially with the those pressures?

[MikeC]

mig or oxy, I think its mig. especially with the those pressures?

[Mr Cool]

mig or oxy, I think its mig. especially with the those pressures?

It HAS to be MIG as he has stated wire size and feed rate.
I have no idea what youre doing wrong without actually seeing the job, Im no expert but I can weld OK.
All our stuff here is in metric not imperial, so I cant help you.

[cyberrodder]

ah sorry oxy expert dont even own a mig.
The only thing I can reccommend is turn down the settings and work up.
Same thing happen when I learnt oxy and arc I was too high come from a low settings then build up. I use a arc welder to do the bulk of my welding its all in the settings and hand work.

good luck, it will happen its one of those techniques that just fall into place and bang its plain sailing from there on.

[EMSjunkie]

Wire speed too fast or too slow, maybe :?

Vance

[chris spokes]

mike what i find best is to get someone to play with the wire feed settings till you hear that sweet sound your looking for, hope this helps
chris

[enjenjo]

First, make sure everything is clean, clean, clean!! Second, make sure you have a good fit, grind the edges as needed to make it fit. Third, clamp the joint good to keep the edges from moving. Now we;re ready to start.

To get good penetration, you have to heat the metal all the way through to a molten state. But on thin material, if you hold it too long, a hole will magically appear. So the process you use is called stitch welding. A stitch weld is just a bit more than a tack weld, then stop. One method that works for most people is to tack a weld every inch or so all along the seam. Then go back, and do another short weld along side the first all along the seam. You keep this up until the seam is welded solid. Done right, this will look like a TIG weld with many overlapping welds.

One cause of many problems, a lot of novice welders think it has to be a continous process, it doesn't. If you blow a hole, stop. If the edges become misaligned, stop. I like to do tacks all round the piece, hammering and dollying as needed. Then I go all round again with a hammer and dolly to stretch the welds slightly, before doing the whole process over again. If you blow a hole in it, hammer the metal back flat, this will help close up the hole, and grind both sides back to near the original surface before starting to weld again. this not only allows the metal to cool, it gives you a chance to evaluate how to fix the hole without making it worse. If the hole is large, and sometimes they are, back the hole with a copper chill to allow you to fill the hole. Stitch, cool, stitch, cool, until the hole is filled. A chill can be made from 3/4" soft copper pipe flattend on one end. and bent into a curve if needed.

One mistake we all make is to make the patches too small, trying to save as much original metal as possible. Evaluate the repair honestly, and if the original metal is thin, cut it out and replace it, you will be better off in the long run.

[dpsmith]

[

quote="enjenjo"]First, make sure everything is clean, clean, clean!! Second, make sure you have a good fit, grind the edges as needed to make it fit. Third, clamp the joint good to keep the edges from moving. Now we;re ready to start.

To get good penetration, you have to heat the metal all the way through to a molten state. But on thin material, if you hold it too long, a hole will magically appear. So the process you use is called stitch welding. A stitch weld is just a bit more than a tack weld, then stop. One method that works for most people is to tack a weld every inch or so all along the seam. Then go back, and do another short weld along side the first all along the seam. You keep this up until the seam is welded solid. Done right, this will look like a TIG weld with many overlapping welds.

One cause of many problems, a lot of novice welders think it has to be a continous process, it doesn't. If you blow a hole, stop. If the edges become misaligned, stop. I like to do tacks all round the piece, hammering and dollying as needed. Then I go all round again with a hammer and dolly to stretch the welds slightly, before doing the whole process over again. If you blow a hole in it, hammer the metal back flat, this will help close up the hole, and grind both sides back to near the original surface before starting to weld again. this not only allows the metal to cool, it gives you a chance to evaluate how to fix the hole without making it worse. If the hole is large, and sometimes they are, back the hole with a copper chill to allow you to fill the hole. Stitch, cool, stitch, cool, until the hole is filled. A chill can be made from 3/4" soft copper pipe flattend on one end. and bent into a curve if needed.

One mistake we all make is to make the patches too small, trying to save as much original metal as possible. Evaluate the repair honestly, and if the original metal is thin, cut it out and replace it, you will be better off in the long run.

[/quote]
Good advice
Also would be a good idea to get some offcuts of similar material from your local sheetmetal shop (even if they have to make some scrap pieces ) and try different settings.
Start by setting your amps on the lowest setting and your wire speed low as well and then give it a go.
If that doesn't work try increasing the wire speed a setting at a time and have another go.
If you run out of wire speed settings then increase your amps to the next setting and your wire speed down low and try again.
Keep repeating this until you get a setting that you are happy with.
The best thing about this is you don't make a mess of your good work.
Good luck
David

[348tripower]

I would like to add one very important note to this welding forum. Just last week a young man here at work stopped by my house. (for a cold beer) He was welding some OSHA mandated guarding on our molding presses. He said he has having a very hard time with the lincoln mig welder. He said the wire feed was jumpy and * causing poor welds. I suggested a look at the gun liner and the gun itself and told him to see me in the morning. He came over the next morning and asked me to look at the junk welder. I walked over, fired it up and yes it welded like crap. I checked the liner, the rollers the drag on the spool and found nothing. I suggested an electrical problem and went to grab the manual from the bottom of the cart and there it was      :oops: !!!!!!!!!! About 50 foot of 18 gauge extension cord!!!!!!!!!  
I then explaind that his problem was with that extension cord. Get about a 10 gauge cord and it will cure the problem. So gentlemen, watch the use of extension cords on your equipment.
Don

I know that it is difficult to comment on this because you are not here to see and really give advice but I have a novice level (maybe) in my welding ability.  
I am welding 16ga. and 18ga. sheet metal on my body.  I have been practicing and I either get a burn-through or a puddle of weld.  Looks like "chicken-s--T".  I have watched experienced welders and "know" the sound I am looking for.  It is a 110 wire feed with 25-30# gas pressure (25-75) & .023 wire.  
I want to be sure to get good penetration but also want the wire to flow.  
Can anyone give me an idea what I am doing wrong here.
Thanks
MikeC

[Fat Cat]

So gentlemen, watch the use of extension cords on your equipment.
Don

When your born with the right equipment you have no need for extensions and the ladies love you for it.

[cyberrodder]

Boy Stitch welding sounds like a pain in the proverbable. But then I have been speaking to tig welders lately (I was looking in purchasing one) and and several had said they would interested going back to oxy to sheet metall (non ally work) in the end I'll stick with my oxy. I can weld to the cows come home and not have any problems like what you guys mentioned.

thanx for explanation of stitch welding enjenjo I never new why ever time I see tacks like this this is what they were doing.

now I wish I could do a fillet weld with my arc and all my prays are answered.


back to practicing.
cyber.

[jeffa]

Being a relative novice at mig welding, I can't add much, except make sure your wire feed speed is constant. Listen as it feeds: does it sound like it's feeding at a constant speed? Are the feed rollers round and not eccentric? Is the wire diameter constant? I find gasless wire tends to vary in diameter causing erratic feed speed. One minute you have a nice weld running and the wire will either speed up and poke a hole in my nice weld, or it will slow down and the arc goes out. It helps to have a "quality" machine that offers good speed regulation.

[spark]

I have been doing some welding with the MIG on 18 gauge I have the wire feed set at 4-5 and 20 gas flow. I pulse weld sheet metal- that is to say- weld- stop- weld, I weld a bit longer than a tack (about 1/16 th )  then off the trigger then back on a second later. With a bit of practise you get so the next tack is done before the last on loses its colour.

Long runs on sheet =  distortion and too much heat so it blows through.  I use .08mm wire.

I have also used the MIG on 30-31 Ford panels with a low heat setting 2-3 wire feed, I usually have some off cuts to have a practise on and get the settings right. I will set up were I'm going to be working, have the practise run and straight on to the job.  

Sometimes you will have to tack and move to another part of a panel – tack one end and move to the other end and do a tack, next do one in the middle of the panel and then in between the end and the middle tack. keep doing tacks in between until all the tacks join together.
  The trick is to take your time and don't put too much heat into the panel, every 5 or 6 tacks stop and wait- if you can run you bare hand over the work area, its safe to start  doing more tacks.
 This takes longer to do but you get a better result with less distortion.        

Hope this helps.

[Anonymous]

When your born with the right equipment you have no need for extensions and the ladies love you for it.

Gees Mate, been listening to too many of those Aussies