why is my welding inconsistent?

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afbill

afbill

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I started welding in a trunk pan and half of my welds look really good and the other half burn holes right through the sheet metal.....what up with that????:banghead:

No, I'm not concerned about settings and all that. I say that because I use the same 'technique' as far as I can tell, but sometimes I get burn through and, well for lack of a better term, I'm vexed as far as what is going on.
 
No idea, maybe you are using THIS for a welder?

P1070373.JPG.jpg


What ARE you using, gas, mig, tig, stick, JB weld, ??
 
uuhhhh....how'd you get a picture of my welder????????


mig....although as frustrated as I'm getting I'm considering going the JB weld route.....lol...JK.

It's not that big of a deal, I am able to fill in the holes, it's just frustrating.
 
I've had trouble with mine things as simple as the tip all goobered up, clean it and the outer shield.

AND as simple as getting a sort of "kink" shall we say, in the cable. Seems to cause the wire to EFF up. Just take the cable, give it a shake, and turn it to "test" for the best "lay" of the cable.

Out in the weather, WIND can raise havoc on a mig.

And don't forget you are welding on rusted old metal which even if ground to clean metal, is probably changing thickness over the length of the panel.
 
I would say power is too high and you are moving too slow. Wire speed will cause splatter and popping. Turn the power down to about a third of what your machine is capable of. Adjust the wire speed until it sounds like a consistant bacon sizzle. I also like to keep the tip at a 30* angle to the welded surface and push the weld not pull like the old stick welders.

If you are installing a trunk pan you should be using plug welds. Then seam seal all the joints.
 
oh, push the weld....never thought of that. All I've ever done is stick welding. Also, I've just realized that what I was practicing on was pristine metal, not old crusty stuff. I guess I just need to realize that this is just part of the 'fun' of restoring a car....lol.
 
Yes panel thickness will vary a bit due to rust etc, also as you weld you carry more and more heat as you go. The method i use takes a little longer but i use it for 100% penetration (looks like a bead on both sides), and to eliminate burn through which causes more work etc. I run my welder a touch on the cool side, not so cold as to get a cold lap type weld, slightly starved on wire speed (too much wire can push right through the puddle) to compensate on thin sheet metal, and start and stop as the puddle dictates. If the puddle cools reasonably fast, stitch it again. If its hot wait for the orange glow to fade a bit and off ya go etc. I prefer to pull the weld on sheet metal, gun angled toward the seam welding towards yourself. Its easy to see the puddle this way. With a little practice you can watch the puddle and know when to stop/start. You want to be stitching before it cools too much or it'l pile up each time. I can use either .023 or .030 on 22ga steel with just a small change in heat/wire speed. Solid wire with gas is the best route to go, C-25 will give you more control and less spatter than Co2.
 
The better prepared the metal is the better the weld will come out. I use a wire wheel on a grinder to strip everything off before welding and it makes a huge difference. If theres rust your weld can almost turn and try to jump back at you kind of as in it doesnt want to penetrate and sink in it just sits on top
 
afbill said:
I started welding in a trunk pan and half of my welds look really good and the other half burn holes right through the sheet metal.....what up with that????:banghead:

No, I'm not concerned about settings and all that. I say that because I use the same 'technique' as far as I can tell, but sometimes I get burn through and, well for lack of a better term, I'm vexed as far as what is going on.
Click to expand...

LOL, It can't be our fault..... it is all China's fault because the wire is faulty.
 
You did not mention what welder you are using.
Flux core or gas and solid core?

What are your settings?

Sounds like your temp is too hot if it's burning through Which means you should be concerned about your settings.
Turn the heat down a click and try a sample piece until,you get it where you want it.

Do you have an auto darkening mask?.....gosh I love those things.
 
Couple of things some already said:

1. Clean Clean Clean BOTH SIDES IF POSSIBLE, any contamination will cause problems even if it is on the reverse side.

2. The temperature of the material. Thirty or Forty degrees can have a real impact on the welding. So if the temp of the material starts at room temp and then as you weld is raised from 70 degrees to 110 degrees it makes it a lot easier to burn through.

3. Trim the wire EVERY time you weld. If you look at the end of the wire when you stop welding, you'll see a little ball, this ball is slag. When you weld thick material it doesn't really matter, but on thin sheet metal this can make starting a stable arc more difficult. Which in turn makes you hold the gun in the starting position longer, thus increasing the possibility of burn through.

4. Slow down.

Hope this helps,

Regards,

Joe Dokes
 
calso try holding tip out a bit further away as that sould increase resistance and reduce temp....just dont over do the distance....lol
 
You could use a backer made of copper or aluminum as a heat sink. If you are doing a butt weld copper works real good to bridge the gap and keeps the weld from burning through some. If it is a lap joint clamping a big chunk of aluminum of the side opposite of where you are welding works good to keep you temps down. Mig wire doesn't stick to alum (usually) or copper.
 
Wire feed rate dictates how much heat you're putting into the metal. Make sure the tension on your drive rollers is set right so the rollers feed consistently and don't slip unnecesarrily. Warn out rollers can cause slipping as well. Rollers should be a V-groove, not a U-groove.

I bought a used welder that came with pure argon gas. I couldn't do anything with that stuff. Traded it for a tank of C25 and what a difference.

I also switched to .023 wire which is better for sheet metal.
 
I had a cheap welder that laid great beads until the gun got hot, and then it went to hell. Cool the gun and it was good again for awhile.

Maybe your case, maybe not.
 
are you using flux core wire ? if so you have to reverse the polarity on your welder.if not dont know with out seeing it....Artie
 
well I had much more success today. I actually sped up the wire feed to about 8 (I had it at about 4) and starting cutting the wire before each weld. Thanks for everyones advice. I know I can always count on it!!!!
 
afbill said:
oh, push the weld....never thought of that. All I've ever done is stick welding. Also, I've just realized that what I was practicing on was pristine metal, not old crusty stuff. I guess I just need to realize that this is just part of the 'fun' of restoring a car....lol.
Click to expand...

You should not be pushing a weld puddle with a MIG unless you absolutely need to because of a cramped area or something.

You should be PULLING the weld. For example start the weld on your left and end on your right. The reason I say this is if you are Pushing the weld and have your tip at a 30* angle it will be really hard to see what you are doing and how the weld is coming along.

Stick Welding you Pull the weld.

Tig Welding and Gas welding you PUSH the Puddle......
 
Mad Dart said:
You should not be pushing a weld puddle with a MIG unless you absolutely need to because of a cramped area or something.

You should be PULLING the weld. For example start the weld on your left and end on your right. The reason I say this is if you are Pushing the weld and have your tip at a 30* angle it will be really hard to see what you are doing and how the weld is coming along.

Stick Welding you Pull the weld.

Tig Welding and Gas welding you PUSH the Puddle......
Click to expand...

That's funny. I'm not disagreeing with you Mad Dart, but I've heard EXACTLY the opposite. The rationale being that by pushing into the weld you have better gas coverage. From my own experience, I've found it easier to see and control the weld puddle by pulling the gun.

I've also read on a couple of other welding websites that the push vs. pull argument is BS and you should use what ever you have to, as with tight spaces you will sometimes be forced to push and or be forced to pull. The reality is that you can get a solid structural weld with either technique.

Regards,

Joe Dokes
 
Frankly, being a rank ameture at MIG welding I'm pretty happy with just being able to connect two pieces of metal together, no matter the technique....lol.
 
Joe Dokes said:
That's funny. I'm not disagreeing with you Mad Dart, but I've heard EXACTLY the opposite. The rationale being that by pushing into the weld you have better gas coverage. From my own experience, I've found it easier to see and control the weld puddle by pulling the gun.

I've also read on a couple of other welding websites that the push vs. pull argument is BS and you should use what ever you have to, as with tight spaces you will sometimes be forced to push and or be forced to pull. The reality is that you can get a solid structural weld with either technique.

Regards,

Joe Dokes
Click to expand...

I have no problems doing it either way. If a guy is just starting out on a "Mig" like you are saying they most likely will be able to see better and control the puddle better. Yes it is true you can get a solid structural weld either way.
 
I find it much easier to push the weld for the fact you can see the seam that you are welding therefore not veering off the seam due to the nozzle covering your path. Just makes since to me.

2 more pennies! LoL....
 
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