Welding/Plasma Cutter...

[Eric DeSilva]

Calling all metalhead electricians...

Thinking about expanding capabilities into metal... I'm about to finally get rid of a garage full of furniture, and LOML has OK'd taking over 1/2 the garage for metalworking... Thinking about getting an O-A gas rig (what I'm familiar with), but then also augmenting with a electric welder and plasma cutter. I'd hate to underbuy, and also potentially have some ideas that could require up to 1/4" steel sheet, so I started looking at possible combinations...

If I bought new, I'd probably go MIG--the Miller 211 seems like a good deal. For a plasma cutter, I was thinking about the Thermadyne Cutmaster 39. That should theoretically give me 1/4" capabilities...

Then I got a line on a used but basically new Thermadyne Pakmaster 100XL Plus and a Miller Synchrowave 180SD TIG. Honestly, coming from an O-A gas background, TIG seems more like a natural progression, so this really tempts me.

Here's my issue... My garage is currently wired with a 220V circuit. The breaker is a 20A breaker. The line itself, however, is about 50' of 10/3. I know 10/3 will support a 30A breaker. The factory specs for the various machines are:

Miller 211: 25A breaker, 14ga
Thermadyne 39: 20A, 12ga

Miller 180SD: 60A, 8ga
Thermadyne PM 100XLP: 90A, 2ga

So, the 211/39 combo seems very safe (obviously, only one gets plugged in at a time). But, $3K for the 180SD and 100XLP seems like a really good deal for basically new machines w/gas cylinders and extras... Heck, its probably the same cost for a new 211/39 combo when you factor in all the other stuff (cylinders, gas, consumables needed). If I'm not really going to push the machines, can they be run on a 30A/10ga circuit? The danger here is that if I do push it, it trips the breaker, right? Am I being stupid? Is the nature of TIG/plasma such that I'm going to trip the breaker all the time?

The other consideration is that, in the not too distant future, I am thinking of building a barn/woodshop where I could run 90A circuits, so eventually I could step up to full power.

Any thoughts appreciated.

[Matt Meiser]

I have the Cutmaster 38 and have been happy with it. I don't use it as much as I thought I would, but it does stuff that would be pretty difficult or at least time consuming otherwise. My welder is a Hobart Handler 180 which has been replaced by the 187. Very happy with it as well.

[Charles Lent]

How far away is your main house breaker panel from your garage and how big is your service line to your house?

If you are getting this seriously involved, having a 100 amp or larger sub panel installed in the garage would be the way to go, but your main panel will need to be large enough to add this load and still have enough left for the house. You won't be using more than one heavy current tool at a time, so this should be big enough, unless you have plans to add a helper, buy more tools, etc. With this sub panel installed you could have breakers and outlets sized to match the tools and the heavy line from the house panel would minimize voltage drop when using them.

Charley

[Ralph Barhorst]

Eric

Be careful with the Thermadyne PM 100XLP. I believe that it is a 3 phase machine.

The Miller mig machine would be good and might be a little overkill.

[Eric DeSilva]

Thanks for the responses.

I double checked on the 100XLP and its one of the 220V 1PH versions--I gather they did variations on 220 v. 460 and 1PH/3PH.

My main panel is in my basement 50' (of wire) away. I can get another run of wire to the garage if I need it--or even a subpanel--but I'm not really thinking I'm going to be pushing the limit of these machines and would rather not go to the expense. The 100XLP severs 1.25" steel--I doubt I'm going to do much 0.25". Same on the 180SD side, doubt I'll be welding much over 0.25". But, when I look at shelling out $3K for a 211/39 setup, versus $3K for these machines, its just sooo tempting to get more than I need... esp. given the potential for another shop down the road.

[Scott T Smith]

Eric, if it were me I'd opt for the larger machines and run a new circuit out to your garage.

There have been times in my life where I wished that I had purchased a larger piece of equipment, but few times in my life when I regretted purchasing one that was too large. My present welding equipment includes a Miller Syncrowave 250 TIG, a Miller Trailblazer Pro diesel engine welder and a Spectrum 2050 plasma cutter (along with a suitcase MIG for the Trailblazer, carbon arc equipment, Oxy-acytelene, and a Miller AC/DC crackerbox welder).

One option that is well worthwhile on a TIG is a water cooled torch. Also, if you want to weld aluminum make sure that your tig has the high frequency option.

It's also a good idea to purchase a separate 6" bench grinder and dedicate it for sharpening your tungstens, otherwise you risk contaminating them with debris left over from sharpening other tools.

[Eric DeSilva]

There have been times in my life where I wished that I had purchased a larger piece of equipment, but few times in my life when I regretted purchasing one that was too large.

That was exactly my thinking. But, I'd rather not install a new panel or run a new circuit if I'm never going to pull more than 30A--that's my real question... At this point, I've talked myself out of the 100XLP. So its really coming down to the question of whether its unsafe or stupid to try an run the 180SD TIG off a 30A circuit if I'm not intending--in this configuration--to ever do more than 1/4" steel.

If I get motivated to do more than that, I figure I can add the circuit then, or possibly by then I'll have my real shop with a bigger panel...

[Charles Saunders]

I have had a Miller SD180 for several years. It's proven to be a great machine for material 3/16" and below, but 1/4" steel might be a stretch. You will definitely not be able to run it wide open on a 30A. circuit. I ran #6-3/g wire about 50 ft. from my load center and installed a 100A. sub-panel. I put a 60A. 2-pole breaker in it for the welder and added a couple of 15A. breakers for 115V outlets. The manual says it draws 54A. at full load and a 60A. breaker has worked fine.

I could recommend this machine over a GMAW (MIG) setup for a number of reasons, but the most important are that it is a more versatile machine and it will produce higher quality welds. If you have an oxy-acetylene welding background you can transition to GTAW (TIG) fairly easily. There is considerably more hand-eye coordination needed but there are close similarities to O/A welding. You will also be able to weld aluminum and stainless steel just by changing electrodes and setup. I just use Argon shelding gas for everything. The consumables are more expensive than with GMAW but on the positive side there is little or no cleanup. As a by-product, properly done GTAW welds will be cosmetically superior to anything else.

[Eric DeSilva]

For some reason, I wasn't thinking 1/4" was wide open for the 180SD, but you're right... That's maxing it out. Guess I'll look into the cost of a new 220V circuit... Or maybe just go with the 211 and worry about TIG when and if the new shop gets built.

Thanks for all the feedback.

[Ben Cadotte]

I would highly suggest getting the better machines now. It will be much cheaper to add a new service to the garage than to buy the bigger machines later at a higher price! Heck, you may be able to sell the big stuff and get new medium sized stuff without spending any extra money out of pocket. Just make sure the used machines are in good condition!