Thread: How many amps do I *really* need?

165 will be more than enough

For the sizes your quoting, the 165 will handle that with ease using standard wire with gas. If you start using it for gasless welding, that's where it will start to struggle, especially on long run times.

I just bought this and am more than happy with it..

You will be struggling with 165 amps to weld much more than a couple of mm's thick.
Also, check out the duty cycle, at 165 amps the duty cycle would only be about 10%. ie, weld for 1 minute out of 10 minutes, not real good..

I have a BOC 175 that I have welded up to 10mm with and I find it quite adequate for what I do with it. For the average handyman that size is good enough. Since I bought it BOC have changed the amperage sizes slightly but not enough to make much difference.

165 amp will be flat out with the 2-3mm especially if you have a good run of vertical down. It will be very slow going with 4mm. Having said that if you are only doing small jobs of a couple of minutes welding at a time you may be happy with it.

Well, thanks guys, but your replies (and similar comments that I have seen elswhere) combined with equipment brochure specs still leave me wondering.

Brochures say 6, 7, 8, 9, 10 mm for machines in the 160A - 220/250A range.

Some people (e.g. Bazza) say they use small machines on thick material. Others, like Brickie, say that you won't get a decent fillet without high amps. (Similar un-solicited comment from son-in-law). All this being unrelated to duty cycle considerations.

What is the real story?

Roger

If you are patient Grahame Collins will reply in the thread and you will get the real answer.

If you want to buy one machine buy the right machine that will do all the jobs you will ever need to do.

I think if you buy the 165 amp machine you will be disappointed later on.

Originally Posted by rlincolnh

but I suspect he may be a bit like one of my electrical engineering lecturers of long ago

I just read that bit again.

So why are you asking us, youre the one who should be telling us lot..

Originally Posted by Brickie

If you want to buy one machine buy the right machine that will do all the jobs you will ever need to do.

I think if you buy the 165 amp machine you will be disappointed later on.

I'm going to give exactly the opposite advice - because you can get access thru the SIL to the monster to handle the big jobs (even if you have to ask him to do it), get the 165 for the little domestic jobs you can do yourself. If it turns out that the 165 isn't up to a job, then go and eat some humble pie with SIL.

Thanks guys, useful comments.

Bazza - yeah, I've been waiting with bated breath for a dissertion from Grahame.

Brickie -

If you want to buy one machine buy the right machine that will do all the jobs you will ever need to do.

In an ideal world... As I said in my original post, it's not really so much a matter of money as size and weight. My garage is home to my wife's car, my car, a Bridgeport, a 13 x 40 lathe, a Puma 17K compressor, a beautiful 60-year-old English drill on its own bench, a work bench, a grinding bench, a couple of storage cupboards, and another 7' cabinet with all my brother's boating tools etc (he lives on his yacht, so I'm the work depot). It's like one of those puzzles where there is one spare slot and you have to shuffle all the other pieces through tortuous paths to find a solution

Brickie -

So why are you asking us, youre the one who should be telling us lot

When doing a power budget for a new design, my work sheet goes something like:
Device draws multi (or, gnash teeth, tens of) milliamps - figure how that part can be powered down most of the time, keep thinking/searching for a less power-hungry part.

Device draws tens to a few hundred microamps - ok, but let's not get too carried away

And finally, keep an eye on all the nanoamp leakages - the just keep on adding up

As you can see, anything that draws over an amp is HIGH POWER ENGINEERING. So welding is in the same class as base-load power stations in my book. I couldn't possibly presume to pass technical comment on the process. It's just my curiosity that keeps me asking why there is so much conflict between all the claims and counter-claims.

Grahame, where are you...

jmk89 - good, reasonable advice. But, damnit, I hate pie..

Roger

Sorry, I missed a response:

aussiecollector -

especially if you have a good run of vertical down

Remember, I know zip about welding. What's the significance of your comment? Why does direction/attitude come into it?

Thanks,

Roger

When you are doing vertical down you can turn up the welder and pore the metal on as there is less chance of blowing a hole

I went through this process a few months ago before settling on the machine I bought.

I went and talked to sellers of machines, told them what I wanted, listened to all the bullsheet, compared prices, etc.
Every seller will tell you a different story about the supposed power of the machines.

You can always turn the power down with a more powerful machine, but its a bit hard to turn it up with an underpowered one..

If you only want to weld very thin 1 to 2 mm stock, the machine you are thinking of may do the job, but honestly once you start you will want to weld more and more, and will find the machine underpowered.

Have some gravy with the pie, it helps it slip down a bit easier..