Need help MIG welding first time

[Subarub4]

So today I had some scrap exhaust from my old Subaru I will be welding a stainless steel muffler on in a few weeks so I wanted to get a feel of how my welder would do which on the low setting it's about 60 amps or so.

Anyways I set the wire speed to 1 and using .035 flux core and I still get burn in the metal if I leave a gap.. maybe i should leave no gap at all?

I don't think the scrap was stainless steel..

 

[keith19]

Hi Sub, welcome to the forum

If 60 Amp is really your lowest setting that is far too high for that thin metal on that old exhaust. You need to be down to around 25 - 30 Amp, and even then you could get it blowing through.

I'd figure 60 Amp would be too high for your new exhaust too, those things are only around 1 mm thick.

What sort of machine are you using? Seems like your machine is too powerful for that sort of job!

 

[Subarub4]

Well I found if I left no gap when doing the butt weld I did not have any blow through but you still had to be careful of moving the gun at the right speed.. maybe it would also help if I used smaller wire too?

the machine I'm using is here.. not the best..

http://www.harborfreight.com/welding/mig-flux-welders/90-amp-flux-wire-welder-98871.html

 

[aametalmaster]

Yes use smaller wire. Sometime look for a MIG welder and switch to gas you will be glad you did. Since you are in the states watch craiglist in your area. There are some great deals sometimes in your own neighborhood...Bob

 

[Wozzaaah]

The smallest flux-cored wire you can buy here is 0.8mm which I think you call .030, I doubt it would make much difference as the problem is your machine has too much power on it's lowest setting.

I like the blurb which says it's a 90 amp machine which can weld up to 1/2". 90 amps is good for about 1/8" at a push.

 

[Subarub4]

I can try loading in the small wire but it works better as far as not burning a hole if I don't leave a gap.

I did not bring my grinder with me.. If you are careful you can get an OK weld but it's just too much power for so small of metal.

my concern is putting the hangers on the muffler

some of the holes in the picture I just noticed was because I was welding so close next to something I just welded and so the heat was still pretty hot.

 

[keith19]

Sure looks like the machine is too high amps at its lowest setting, but if it butt welds fairly thin stuff, you could give this guy's technique a try:
http://www.youtube.com/watch?v=JohBHzhOyPg

 

[Subarub4]

Yeah that's pretty much what I will have to do.

 

[eddie49]

The scrap muffler that you are testing on looks like aluminized steel ( hot-dip coated with aluminum-silicon alloy ). That coating will have to be ground off before you can weld. I'm surprised that the new muffler does not already have the hangers attached. Since it is stainless steel, you won't be able to weld it with mild steel flux-cored "no-gas" MIG wire. You need a gas MIG, with SS wire and a mostly-argon gas cylinder- or better, a TIG set.

 

[Subarub4]

Why cant I use gasless wire?

 

[octo0072000]

The scrap muffler that you are testing on looks like aluminized steel ( hot-dip coated with aluminum-silicon alloy ). That coating will have to be ground off before you can weld. I'm surprised that the new muffler does not already have the hangers attached. Since it is stainless steel, you won't be able to weld it with mild steel flux-cored "no-gas" MIG wire. You need a gas MIG, with SS wire and a mostly-argon gas cylinder- or better, a TIG set.

Eddie you can weld s/steel with mild steel wire the weld will rust the rest of the system is not s/steel

 

[octo0072000]

welder

Main problem is the welder it's useless for the kind of work he's doing
it's also advertised as being able to weld 1/2 plate do you have lemon laws in your state
i would take it back in the uk (goods not fit for purpose )

as most have said you need a gas mig that goes down to min of 30 amps better still 20 amps for car body stuff the nogas mig is the main problem as it makes it harder to weld in the first place and dam expenseive for the wire too you can use C02 or pubgas as it's know in the uk

try having a look here this is again flux cored as a base model but goes down to 30amps to 140amps this will only weld up to 3/16th of a inch
so you can see the harbour freight one could never weld 1/2 inch plate
anyway have fun here is miller usa site have a look at it no good giving you uk stuff as you are over the pond
http://www.millerwelds.com/products/mig/product.php?model=M00234

 

[Subarub4]

That's way too much money.. I highly highly doubt I will be welding enough to spend that much money on something I might only use 1 or 2 times a year.

 

[Subarub4]

this is what the muffler looks like

 

[Wozzaaah]

Get someone else to do it.

Probably not what you were wanting to hear but the last thing you'd want to do is to make a mess of that muffler so for what it would cost you to get it welded on by someone with more experience and better kit I honestly think it would be money well spent.

 

[Subarub4]

I don't know I think I'm still going to try it but pause and wait method.

I can only get store credit for returning.

 

[Wozzaaah]

With your machine and lack of experience I fear it'll end in (expensive) tears.
If you really must do it yourself then practice a lot more before tackling the job. Good luck.

 

[octo0072000]

I don't know I think I'm still going to try it but pause and wait method.

I can only get store credit for returning.

you should be entitled to a full refund due to the fact this machine can not weld 1/2 inch plate even the miller one only states 3/16 in and thats 140 amps you have been mis sold this take it up with the manager

 

[octo0072000]

U Tube videos

have a look at these might help you learn a bit more and most say dont use the harbour frieght gasless mig wire there are quite a few videos about this welder have fun

http://www.youtube.com/watch?v=tY2nbfQy_Eo&feature=fvwrel

 

[Subarub4]

The scrap muffler that you are testing on looks like aluminized steel ( hot-dip coated with aluminum-silicon alloy ). That coating will have to be ground off before you can weld. I'm surprised that the new muffler does not already have the hangers attached. Since it is stainless steel, you won't be able to weld it with mild steel flux-cored "no-gas" MIG wire. You need a gas MIG, with SS wire and a mostly-argon gas cylinder- or better, a TIG set.

eddie you are right it is aluminized steel