Welding Question, what am I doing wrong???

I just bought the Millermatic 175, the 230 volt mig. I'm using .030 flux core wire and we're trying to weld up some exhaust pieces. The problem is that with the amperage on the lowest setting, it still burns right through the exhaust tubing, even the thicker stuff we have.
We keep turning the speed up, it is at about 60 or so right now. Any suggestions. We've gotten it to work, but every now and then it still makes a hole. It's very particular.

 

flux core wire is weird stuff sometimes

Turn down the wire speed and use a bit more wire stick out. On thin stuff you may need to "pulse" the trigger to keep the heat down.

0.023 solid core wire with straight CO2 would be better for welding thin stuff.

 

If you are welding on Rusty old pieces of exhaust Tubing, you can expect blow throughs....

If its nice, new exhaust tubing, you should be able to set the Welder where it will run a nice smooth bead around it. I have never been a great fan of Flux Cored wire though, and it does tend to burn a little hotter, so if all else fails, do like ELpolacko said and pulse it in there.

I think the .030 would be fine if it was solid wire and you were using 75/25 gas. Co2 would work too, I just happen to like Mixed gas better.

 

flux core sucks for thin stuff...
convert to MIG...

if ya must stay with the flux core- take your time... weld a bit, then stop... let the metal cool down... weld a bit more, then stop...

 

You invested in a good machine, so why not spend a litte more to get the whole setup that much better?
I use .23 wire for almost everything ( only go thicker for the really heavy stuff ) And mixed gas.
When you are in my neck of the woods again, you can run a couple of beads with my machine, and I'll give you pointers.

 

Flux core burns through paint and rust pretty well but switch to regular wire and a bottle of argon for that thin clean stuff much less cleanup too.

 

flux cored wire has its place,,, and that is in a small portable wirefeed that is outdoors,,

i am with the others on this, i have used mig with argon, co2/argon mix, and straight co2, as well as flux cored wire


you have picked an excellent machine and have it set up in the poorest manner possible, connect the thing to gas,, and get some solid wire,,

wire is another thing that people skimp on,, dont do it... get the best alloyed wire you can get,,, i have used the common steel wires which are good for production welding on clean and new steels. Get the upgraded alloyed wires and you will be amazed at the difference when welding old/rusty steel.

also for thinner sections use a mix gas such as the 75/25 co2/argon gas.. it will produce sound and clean welds with little spatter.. use pure co2 on dirtier higher amperage appication, but you will have a bit more spatter.
there is no need for pure argon gas is steel welding and it is about twice the price of the mixed gases and 3 times that of the straight co2

surface prep is important also on thin sections as rust will interupt the arc in low amperage ranges causing a strutter and blow holes... so be sure to clean the weld zone, sand or grind it smooth and clear of rust... on heavier sections you can weld thru alot of crap,, on thin stuff you cannot as easily.

i used to use linde 86 wire, which costs about 20 percent more than the common linde 82 wire that was the generic stuff that everyone used,,,, with superior results...

esab has taken over the linde name several years ago,, but they continue with the same wires or equivalents. i am sure you local supplier can get you hooked up with a good wire, just dont settle for the run of the mill stuff, the difference in price is small, about 15 bucks on a 44 lb roll. which is enuf wire to build 20 hotrods ground up!!


you have bought an excellent machine,, now go out and buy the best alloyed wire you can get, and a co2 argon mix gas to weld with... you'll wonder how you ever got buy without it!!

buy good products to go with your machine,, and watch how well things go together.

bob

 

Yeah, I know, I was under the impression that the flux was just as good, and I really didn't feel like adding another C-note to the bill, so I didn't get the gas. I will, most get it very soon.

I was not doing this work, it was my buddy's car and he has taken a class in the past, so, rather than have me ruin the limited pieces we had, he was doing it. I'm glad that he was blowing through the shit, too, I didn't feel so bad.

The stuff is all new pipe. The Pulse advice worked really well. I guess I'll have to spring for the bottle when I get back from New Hampshire next week. This Jackson auto darkening helmet is the cat's ass! Just gotta remember to turn it on.

 

I'm in your neck of the woods, probably minutes away. I'd be happy to give you a hand any day. Been burning lots of wire over at MCC in the welding lab for the last six weeks....

 

I haven't even played with it yet, but I will. What is MCC? Sure, when I get back from NH, you'll have to stop by and give me some pointers, that would be appreciated.

 

Get the gas! your welding will improve 50%

I started out with core flux and thought I had wasted my money getting a MIG, got the gas and I'm welding stuff like thin sheet with good results. get the gas!!

 

It's been a long time since I used any flux core but if I remember right, it is hard to see what the puddle is doing which is important to keep from blowing through! I like to run mig hot, and do one zap at a time overlapping to make a good solid weld. I use the trigger a lot for heat control. If you try to run a continuous bead on thin stuff, the machine starts to run you instead of you running the machine. I prefer gas-welding for all thin stuff.

John www.ghiaspecialties.com

 

Flux core wire burns hotter, and is better suited for structural welding, like your chassis.

With the solid wire even though it is not the intent the gas has a tendency to cool your weld. I normally use .030 for just about everything, including sheet metal. But for the thin stuff you might try .027.

With .030 solid core and gas ( I use an argon mix I think 70/30) and a little practice you should be able to do about anything on your car.

A side note, solid wire is not intended for cast steel or iron. You should either stick weld it or buy the appropriate flux core wire. say 7018 or 8018 for cast steel, and an alloy for cast iron.

if it don't make ya dirty it aint yours