Will I be able to do much with this?

[Luke Pickering]

Morning - I bought this welder on eBay for cheap.  It might be a load of old bobbins but I just wanted something for welding rebar to flat stock for making knives.  I was wondering if it would be able to do much else?  Welding up a sub frame for a big grinder is one project I have in mind.  Fabricating a solid bench with wheels (I store my stuff away from my work area) is another.  Both projects would be built from about 3mm thick box section.  Will this be much use for that sort  of thing? 

[Smoggy]

It all depends on it's working range and duty cycle, which you haven't provided and I can't make out from the pic, someone familliar with this model may know more but I would have thought it should be ok for general fabrication work and attaching handles to billets.

N/B. Just spotted the 240v domestic UK plug, so assuming you are in the UK then the 110 may not be voltage as I initially assumed. So assuming it's amps then yes should do for light work OK, possibly even a bit more.

( it wouldn't hurt to put a location in yuor profile then folks can provide more accurate answers )

[Kozzy]

Looking at the actual photo rather than the one shown in the thread, it appears to be 50% duty cycle @ 40 amps, 40% at 60 amps and 20% at some unknown...guessing 80A as the logical progression?  100?  Remember that a 50% duty cycle means 5 minutes on and 10 minutes OFF--not that you can weld 50% of the time such as 30 seconds on and 30 off for extended lengths.  It needs that full and long 10 minute cooling period or the transformer windings can degrade.

In any case, that's a bit low in general implication to do any serious welding with.  However, it might be perfectly serviceable for the tack and join here and there.  It'll do the light "fixit" but not so much any heavier fabrication.  Arc starting and maintaining a good arc might be a bit of a chore if the amps are that limited.

The secret to these small welders is practice and experimentation.  Get some scrap and rod and just start playing.  After a while, you'll start getting the hang of making a reasonable weld with it.  As with all welding, the biggest secret is PREP.  Grind surfaces clean before trying to weld (especially important when you don't have a lot of amps to play with) and design your weldments to fit the welder's capabilities.

[WoodnMetalGuy]

9 minutes ago, Kozzy said:

Remember that a 50% duty cycle means 5 minutes on and 10 minutes OFF

I was thinking that a 50% duty cycle would mean in use half the time, or 5 minutes on, 5 minutes off.  And 5 on, 10 off would be 33%.  Am I confused about that?  -- Dave

[CMS3900]

50% Duty Cycle is 5 minutes continuous arc out of 10.

[Kozzy]

Yes...I was typing too fast and stated it completely incorrectly.  What I was trying to get at was not to push these small ones without some extended cool-down.  They don't like to run at the top of their heat range so it's better to give them plenty of cooling time.  Not sure how I even ended up saying things the way I did--brain fart plus about 6 interruptions when I was typing (I'll take that excuse over plain old stupidity).

Grabs dunce cap from shelf, inserts head.

[Marc1]

I have an old transformer welder like that one. I think it's a 180 amps 240/15a supply. I only use it on occasion to take on the truck because my other welders are too large to take anywhere. It welds well but needs a bit more practice than a modern inverter. Up side is that it will probably never break down.

 

[Luke Pickering]

OK so it arrived yesterday.  The 20% is at 90 amps.  I have not used it yet but it definitely looks a convenient little piece of kit.  According to the dials it will cope with 3.5mm on the 20% end of the duty cycle so for my grinder frame it will work, it will jsut be slow and steady (I am likely to be pretty slow at getting things laid up anyway so that should be OK).

 

Thanks for your help.