Mig Welding 101

[silentdub]

I have a wirefeed mig welder, without gas,
I am using .35 wire while on the lowest setting.

I warp sheet metal most of the time. I can weld 1/8 inch with no trouble and get a really nice weld.

If I were to tack it, wait 15 minutes and then again, fine, it works, no warpage, but I am welding in a piece approx 4X10, I can't wait until I am 65 to get the job done. What do you guys do? If you had to wait like me, you would either have to charge $1000.00/hr or go out of business.

I can fill a little warpage, no big deal, but I should work at getting better.

If you are patching a piece, do you get a bead around the panel or do you tack it here and there and fill over it?

I am trying to get a bead around the piece, so maybe that is where I am messing up.

Any tips or ideas? Thinner wire maybe?

[silentdub]

http://www.jalopyjournal.com/forum/archive/index.php/t-8057.html

found some good stuff there.

I'll try backing up the area with a piece of copper or something.

[casey]

Yup copper will help , also most welding shops carry some type of heat sinking paste / dough that you can put around the weld area.

Your using a fairly heavy fluxcore wire and that makes things more difficult on sheetmetal , ideally you would use .023 solid wire and an argon/CO2 gas. Harris makes a nice fluxcore in .030 , they call it "Twenty Gauge" and it does pretty well on sheetmetal, if you can go down to a .030 wire it will help some but as long as you're not getting burn throughs it's not a must.

As for technique , you should go around the patch and make a series of short welds far enough apart that you're always welding on cool metal, don't try to run a long bead , do a bunch of half inch long beads spread around the patch and then let it cool and clean up your flux off them for the next batch. Always snip a clean end on your wire between each spot , helps start a clean weld as soon as wire hits metal instead of sputtering. You can blow some air on the patch to help cool it between welds. Careful when cleaning up , grinding can warp as bad as welding.

Ray

[Roch_Greg]

The Harris Wire named "Twenty Gauge" isn't a Flux Core wire. They have a product called "Ten Gauge" that is.

With the thin sheet metal used on cars you won't be welding a continuous long bead. Surprisingly enough even 1/8" thick sheet metal is considered thin in the Welding world I've learned.

Gas (Argon/CO2 mix) runs cooler than using just Fluxcore wire so I am lead to believe.

Most Autobody welding is "blind" where you don't have access to the backside of the panel. This makes it difficult to get a good "heatsink" behind the weld area. Or should I say getting it back out.

Eastwood Company (among others) sell a Fiberglass Weld Backing Tape (http://www.eastwoodco.com/jump.jsp?itemID=21225&itemType=PRODUCT) I'm going to try this week. Seems one of the manufacturer's is in the next town up from me and one of the local welding shops was able to get me a few feet of samples.

Eastwood also sells 4 and 8 inch magnetic Copper Butt-Weld Backer set (http://www.eastwoodco.com/jump.jsp?itemID=21231&itemType=PRODUCT) which I've been meaning to try.

I have some of that heat sink paste being talked about and it does do what it says it'll do.

In your case I would drop down in wire size as already suggested. MIG welding in the autobody world isn't one of the fastest things going. MIG welding claim to fame is that even a novice can get decent welds but it won't be lickty split.

I use panel bonding adhesives where I can

Greg

[casey]

Yup , you're right Greg , Ten Gauge is flux and Twenty Gauge needs gas, the Ten Gauge does come in .030 if you can't or don't want to switch to gas. I haven't burned much of this wire , but they were supposedly developed for thin sheet welding. Other companies do make flux core in .030 , but not every welding store carries the small stuff.

Ray

[silentdub]

Thanks for all the tips.

I'll look for a thinner wire and basically slow down. I do burn through the metal at times, but I learned to get around that by very quick tacks, basically a bump of the trigger, when that cools, then I can tack it better.

Is there a flux thinner than 30?

[Roch_Greg]

I'm not sure, have a look see at the Harris Ten Gauge (http://www.harrisproductsgroup.com/consumables/alloys.asp?id=12) wire we've been talking about. The solid wire version "Twenty Gauge" is really good.

A few more tips (not that I've been welding that long mind you).

1) Check your Amps and Wire Feed Speed (IPS).

2) The are two angles when welding, the angle of the gun to the panel and the angle of the tip in relation to the work.

Most will get the 90 degree angle to the panel right but your tip should be at a 10 to 30 degree angle to the weld puddle

Which direction will depend on if your "pushing" the weld puddle or "pulling" it.

3) Check your fit up. I find I only blow holes when my fit up is poor or there is a gap between the panels

Check out the Welding Resources over at Miller Welding (http://www.millerwelds.com/resources/improving-your-skills/mig/). They've got some pretty informative guides to help tell if your setup right and sections on troubleshooting common issues like blow through.

Greg

[Ron H]

Going to the .023 wire really made it easier for me to keep from blowing through. I also angle my gun toward the panel I intend to start my weld on and roll the gun toward the other side. It seems to draw the puddle accross the gap better than trying to push it accross the gap. I use small tacks and just keep going around the patch. Like earlier mentioned panel fit seems to make a big difference for me as well. Serge helped me out by suggesting to use a piece of tig rod on areas that have a greater than desirable gap. I use an argon/co2 mix also. It takes me along time do my patches (along with everyting else I do) but I am afraid of creating additional problems while trying to fix another. Regards Ron

[Stanger]

It is really a waste of time without .023 and C25 gas. Perfect metalwork will elude you for a long time if you continue to use .030 flux core.
Grant

[Roch_Greg]

It is really a waste of time without .023 and C25 gas. Perfect metalwork will elude you for a long time if you continue to use .030 flux core.
Grant

That's a pretty definitive statement. It would involve accounting for every person (regardless of skill level) that's ever or is presently welding sheet metal with flux core wire on the entire planet.

Seems to me if someone was, say a "master welder" if such a thing exists. Has all his certifications and union cards, been welding like forever, he could do damn near anything he wanted to with whatever he chooses to use.

Like any other Master of their craft, they don't need a certain setup to make the magic happen, the magic is happening because of them.

Greg

[silentdub]

That's a pretty definitive statement. It would involve accounting for every person (regardless of skill level) that's ever or is presently welding sheet metal with flux core wire on the entire planet.

Seems to me if someone was, say a "master welder" if such a thing exists. Has all his certifications and union cards, been welding like forever, he could do damn near anything he wanted to with whatever he chooses to use.

Like any other Master of their craft, they don't need a certain setup to make the magic happen, the magic is happening because of them.

Greg


I don't need to be a master welder, I just need to make it work. A little grinding and filler corrects all. The less the better.

I know some of you guys can weld so good to a point where filler isn't needed.

I don't mind using a little, I just don't want to have a total mess.

[fortyfords]

You need the the smaller wire and gas ,set your amps accordingly ,then play with your wire speed that effects your amps in a fine way to keep from burning through.plus gun angle and gas flow.
But you have to weld short 1" welds or less and jump around to prevent warpage.

Been doing this for along time.
Rich

[silentdub]

Thanks for all your tips, hopefully this helps other people too.


I just tried it at a smaller angle.

About 15 to 30 degrees and didn't burn a hole at all, I was able to lay a 1/2 in bead with no burn through and no warpage.

I was holding it at about a 70 degree angle, and this would punch a hole, then I have to fix the hole, that adds more heat, and the saga begins.

This made a major difference already. I will go to a thinner wire and see if it gets better.

[Lost in NJ]

The most mis-understood aspect of welding.

Warpage is caused by metal shrinkage. ALL welds cause metal shrinkage!!!

Some my think they do not get any warpage, the truth is on some panels you may not be able to detect the warparge. If you look up on how to weld parts onto a huge I beam you will find there is a special technique to minimize the distortion from welding.

It is not hard to learn how to correct the shrinks and fix the distortions. You may find you can put in panel substantially better than before if you take some time to learn about how metal behaves.


Follow the link to my website for some more thoughts.

My blurb on metal working (http://home.comcast.net/~68c/Metalworking.htm)

[nickp]

Ron,

what size TIG rod do you sue with the MIG?

nick

[Ron H]

Nick, Here is the thread where I got my info from. http://autobodystore.com/forum/showthread.php?t=7497 Hope this helps. Regards Ron

[drizler]

I have a wirefeed mig welder, without gas,
I am using .35 wire while on the lowest setting.

I warp sheet metal most of the time. I can weld 1/8 inch with no trouble and get a really nice weld.

If I were to tack it, wait 15 minutes and then again, fine, it works, no warpage, but I am welding in a piece approx 4X10, I can't wait until I am 65 to get the job done. What do you guys do? If you had to wait like me, you would either have to charge $1000.00/hr or go out of business.

I can fill a little warpage, no big deal, but I should work at getting better.

If you are patching a piece, do you get a bead around the panel or do you tack it here and there and fill over it?

I am trying to get a bead around the piece, so maybe that is where I am messing up.

Any tips or ideas? Thinner wire maybe?



I don't know how you can manage anything that small with .35 Go here and buddy up with these guys as they live and breathe welding. http://www.hobartwelders.com/weldtalk/
Seriously though I would look for the thinnest innercore you can find if you don't have gas capability or you will have nothing but headaches. The only other solution if you can get at the back is to tack on a nice long stretch of heavy backer like 3/4 x 1/8" and hook that back up under there. I did that with my Silverado fender arch and it worked good using an arc welder. Still it isn't much of a way if you can avoid it, just a way to make it work. Mig isn't all that easy to do on modern panes as they are too thin and hard so practice and patience is the way to go. Better yet use the right wire unless its a $$$ issue and save yourself the headaches.

[Stanger]

That's a pretty definitive statement. It would involve accounting for every person (regardless of skill level) that's ever or is presently welding sheet metal with flux core wire on the entire planet.

Seems to me if someone was, say a "master welder" if such a thing exists. Has all his certifications and union cards, been welding like forever, he could do damn near anything he wanted to with whatever he chooses to use.

Like any other Master of their craft, they don't need a certain setup to make the magic happen, the magic is happening because of them.

You are right. That is why it would elude him for a long time. It will take a good while to be come a "master welder" so he shouldn't be looking for perfect metalwork out of .030 flux. Since he is a beginner he would get much better results and be much less frustrated with .023 and C25. You are also right that it is the man behind the mask, not the welder. In this case the weldor is a rookie and could use some help from the welder. I still suggest dropping the .030 flux and moving on to .023 and C25. Flux is only for conditions that prohibit the use of gas or for welding metal that is on the edge of the welders capability. Flux is hotter and will get better penetration in those situations. It is not for sheetmetal.
Grant