Welding Exhaust pipe?

I am new to welding and figured I would google about mig welding and found this site. Very nice write up on the tutorials!

I have a 90 amp mig welder I just bought. I am trying to weld exhaust pipe together. It is really for my innercooler setup on my car. I have tried it on low settings and it don't seem to go through themetal as shown in the tutorials. I have tried it on high and I get blow through.

Now with the gasless mig welder, how do I control the heat? Is it with the wire feed dial?

This is my welder!

90 AMP FLUX MIG WIRE WELDER

NO GAS REQUIRED Specifically designed to use self-shielding flux-cored welding wire, eliminating any need for gas and regulators normal MIG welders require. Self regulating feed control Thermal protection with warning light Carry handle on lid Input: 115 volt, 15 amps, single phase Welding current (2 settings) 63 to 68 amps (low), 79 to 90 amps (high) Duty cycle: 10% @ 80 amps, 18% @ 60 amps Wire capacity: 0.035'' or 0.030''

Originally Posted by BudmannG I am new to welding and figured I would google about mig welding and found this site. Very nice write up on the tutorials! I have a 90 amp mig welder I just bought. I am trying to weld exhaust pipe together. It is really for my innercooler setup on my car. I have tried it on low settings and it don't seem to go through themetal as shown in the tutorials. I have tried it on high and I get blow through. Now with the gasless mig welder, how do I control the heat? Is it with the wire feed dial? This is my welder! 90 AMP FLUX MIG WIRE WELDER NO GAS REQUIRED Specifically designed to use self-shielding flux-cored welding wire, eliminating any need for gas and regulators normal MIG welders require. Self regulating feed control Thermal protection with warning light Carry handle on lid Input: 115 volt, 15 amps, single phase Welding current (2 settings) 63 to 68 amps (low), 79 to 90 amps (high) Duty cycle: 10% @ 80 amps, 18% @ 60 amps Wire capacity: 0.035'' or 0.030''

Hi,
With Gas-Less MIG welders you tend to struggle welding very thin sheet as they don't burn as smooth as a standard Gas type MIG, having a stronger, more unstable arc which causes burn through on very thin metal.
With your machine only having two settings you can't fine tune the arc & it's a case of all (high) or nothing (low). The minimum setting on low on your machine (63 amps) is also way too high - 30amps is typical on most machines which is half yours.
BEST ADVICE - try & do overlap joints if at all possible ie. double the material thickness.
weldequip

So does that mean I won't be able to weld the body panels on my car when I am ready to do that?

If you intend butt welding the existing panels then yes, I'm afraid you will struggle with burn-through. If you are fabricating new panels or patches yourself, use thicker steel & you will have a good chance.
weldequip

That is the only reason I bought this thing. Dangit!

Can someone point me in the direction of welder that will go down as far as I need it. My budget is very limited as of right now.

Don't let me put you off! I'm only talking from experience, but my experience is that the lower the better for a MIG to be able to successfully weld thin car panels - they are tissue paper thin nowadays!
Have a go, but I think you will find that you are constantly blowing holes through the stuff & it may cost you more in the long run with botched panels.
In the UK the Clarke range are good & they are also available in the States.
weldequip

Bud, I have the Chicago Electric 151 220v series and set it up with shield gas. In everything I've read you simply can't do good sheet metal work with flux core wire as it runs too hot. .020 wire with sheilding gas is the recommended way to go from what I'm told (certainly not an expert...but done some reading).

I will look into getting a different welder.

I did go out and give another try, but with no avail. I got the same results. So I put my welder up for sale. And had a friend do the piping that I was working on. I am looking at getting another welder, Just wount be all to soon. I will take my time at buying one now and consider all the pros and cons with it. I have not picked one out yet, but I will. I want to do all the body work myself.

Thanks guys,
Bud

That sounds sensible. 25 - 30 amps is the normal minimum setting for a MIG welder.

A 90 amp max welder would just about butt weld 2mm sheet, and a 130 amp should comfortabaly overlap weld 2mm sheet and butt weld 3mm.

I have a Clarke 100E from Machine Mart and I would say its pretty good with car bodywork.
I taught myself to weld with this machine and then went on to save a "teabag" Cavalier with it.
Also done things like stainless exhausts and brackets etc.... no problem.
Think they cost about £150. Bargain.

Just a small query, but can't you convert the "no-gas" welders to run with gas?