new to mig which welder to buy

[jefty]

Hi: I'm new to the forum and to mig welding. I have been wanting a small mig ( 175amp) for sometime. I want to be able to weld mid steel, and am planning on buliding stainless steel water tanks for my boat, but I also need to do some repairs to my bullworks which are .250" alum. Today I went into a local welding shop and they implied that even if I weld prep and use multi-passes I could not weld on 1/4" alum. with less than a 250amp unit. Is this this right or were they just trying to sell a more expensive unit.

[Guest]

Hi Jefty, welcome to the forum... haven't done any aluminum with a 175, but I think they were right. I'll let someone else chime in here that has done it. There's lots of experience here to draw from. There's no dumb questions only exchanges of information.

[jefty]

Seems more confussing all the time. Under articles on the Lincoln Elelectric web site, they say a 175 should be able to weld 3/16 alum.or even 1/4 with pre-heating, although not for production. Since most of my work will be with steel Lincoln is claiming with the right feed setup it will work for me??????

[Hobart Expert Kevin]

jefty,
Under the right conditions a 175 unit will be able to do 1/4" aluminum but you will be running it at absolute max giving you a very short duty cycle and the results may not be what you want. I would recommend looking at least one notch up in equipment. The Millermatic 210 is very capable of welding 1/4" aluminum and will give you a big jump in duty cycle compared to the 175 units. If you plan on doing lots of 1/4" aluminum then a 250 amp unit is the way to go.
Hope I didn't add to the confusion...

Kevin

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[jefty]

Thanks guys for your input. The problem is this unit will be used on my tug. It is 80 ft. and 3 decks high which means I have to carry it in and out hatches and up and down ladders, plus hoist it aloft for any rigging work. The one big project is new water tanks which will be stainless steel and I think the 175 will be fine. All the rest of the work will be small repairs, mostly mild steel. Any alum. work will be short duty cycles not over 12" at atime. I could spend the money for a 200-250 but I think the size and weight will be a real problem. The best might be an inverter, but I just can not spend that much at this time.............. Any more thought are welcome.:

[Bill H.]

Would a spoolgun be an option?

Jefty, I'm still in the learning stage but wondered if the spoolguns I've seen in catalogs would be able to solve your problem. I believe they come in a long enough length to reach from one deck to another. If so that might save you from some of the weight and portability issues. -Bill

[dekker]

For maximum portability you could use a small inverter (e.g. Maxstar 140) and a Readywelder spoolgun. The Readywelder is a voltage sensing spoolgun and works well with a stick/TIG welder.

This combination works well for steel and aluminum over 1/8 inch thick. For thinner material the Readywelder works with two or three 12 volt batteries.

Ernie Leimkuhler posted a long review of the Readywelder to sci.engr.joining.welding and rec.crafts.metalworking last year.

The thread with the review is:

http://www.google.com/groups?hl=en&lr=&ie=UTF-8&oe=UTF-8&threadm=ernie-01F807.22121522052002%40news.mindspring.com&rnum=13&prev=/groups%3Fq%3Dreadywelder%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8%26selm%3Dernie-01F807.22121522052002%2540news.mindspring.com%26rnum%3D13

Comments on the thickness limits with a CC powersource:

http://www.google.com/groups?hl=en&lr=&ie=UTF-8&oe=UTF-8&threadm=82b24195.0206211830.2321bb7b%40posting.google.com&rnum=4&prev=/groups%3Fq%3Dreadywelder%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8%26selm%3D82b24195.0206211830.2321bb7b%2540posting.google.com%26rnum%3D4

A google search will turn up more threads on the Readywelder and there have also been a couple here.