Buying arc welder for structural supports in residential project

[ejo4041]

I have looked through the site a bit and see all of the nice tutorials. I need help picking a welder for this one job and then just for fun after that, nothing serious. Could I get away with a cheap $100 setup from Harbor Freight?

The project is a 5"x4"x 5/8" steel rectangular tube connected to two 3 1/2" sched 40 steel pipe supports, then those connected to 1/2" steel base plates. So, 4 welds total. I just need them to stay together, doesn't need to survive a tornado or anything, they will be stationary for their entire life.

I'd like to do it myself since the first estimate I got was $560 for a 4 hour minimum. I'd like to keep it in the $100-$150 range and have a fun toy to mess around with after the project is done.

 

[mike os]

if these are structural and you are asking this, you really should not be doing them, and with those kinds of thicknes it is hard to see them any other way...

 

[CRB]

Rooves are stationary too, but the snow loading is tremendous.

You need to think very carefully about the uses this structure will encounter, before 'doing-it-yourself', especially in your litigious society.

 

[ejo4041]

The design for the structure of it was already approved by a structural engineer, accounting for snow loads specified by the county.

 

[Justme]

The design for the structure of it was already approved by a structural engineer, accounting for snow loads specified by the county.

But with the joints welded by someone that:-

A, knows what they are doing & is possibly coded for structural work

B, with a welder that is up to the job

Not some one just having a go with a hobby class welder.

 

[mike os]

not trying to be nasty or put you off ejo, but these kind of welds need to be done right, i have welded on & off for 30+ years ( OK I have tried to weld stuff together for 30+ years ) but will not undertake structurally critical welds... because i dont have the experience to know 100% that it is up to the job every single time.

This steel section has been designed with the preconception that it will be assembled by someone qualified and experienced enough to to the job required and that it will not only look right, but also be right.... just sticking it together is never a requirement for 5/8 steel section in buildings, 1/8 maybe but even then in structurally important areas the work needs to be to a certain standard... thats why welds have a coding.

if you were making some gates or something that would be an entirely different matter

 

[ejo4041]

No, that's fine, I get the point. I was really just trying to guage whether I could do this myself. Sounds more and more like it is not a DIY job. I think I will leave this to the pros. Thanks for the advice everyone.

Got a few more estimates in the $300-$400 range.

 

[mike os]

bit better.... its a fair bit of work on each of those

dont let it stp you getting a little welder & having a play though

 

[shenion]

Looking at The Horror Fright site, they have only a few arc welders.

The $79 70 amp arc welder is near useless. too low a current
They have an 80-amp inverter for $149, better but will not run rods big enough for structural work.
There is a 225 amp buzz box for $189. That will do (requires 220v)

You will not be able to do anything on 120V. You will need 220/30A outlet. To run 1/8" rods, you will need 160 amps or more available.

Even with a decent arc, it will require multiple passes.

If you need to do this on site, a generator/welder will be needed.

Check Craigs list. You often see 200+ amp arc welders for about $100 or so. I see the Lincoln AC225 for usually around $200. A decent arc welder will last forever, mine is 35 years old.