Just bought a Second hand Arc

[Stinka]

Well I might do, mate wants £50 for it, it looks like a beast and is early 90's

Want to make some rock sliders for my 4x4

Anyway, any one know what it is ? and what all the knobs and terrminals are/do etc

Cheers

The big nob in the middle seems to turn but not stop turning ...

 

[rtbcomp]

Welcome to the forum.

The big knob in the middle adjusts the welding current. As you turn it you should an indicator in the window on the side move.

I've moved thread this to "Welders and Welding Machines" as it's more about the machine than welding.

 

[Stinka]

Ah i see, so am i best off on the 70v terminal on my domestic supply ?

And keep amps to 120a max ?

want to weld up 50mm square box with 3mm wall thickness, also weld plate to chassis on end of sliders about 5mm thickness

 

[Stinka]

Anyone ?

 

[the snooper]

yes you could go a little higher but eventually the fuse would blow

 

[Country Joe]

Ah i see, so am i best off on the 70v terminal on my domestic supply ?

Some rods will want a higher voltage than others - it would say in the specifications on the box.
CJ

 

[SiPMerlin150]

Ah i see, so am i best off on the 70v terminal on my domestic supply ?

And keep amps to 120a max ?

want to weld up 50mm square box with 3mm wall thickness, also weld plate to chassis on end of sliders about 5mm thickness

Doesnt matter, the 50v an 70v are what you get on the tip of the electrode, some rods, wont run too well on 50 volt, so use 70 volts. You'll be best getting a bag of 13 amp fuses and start from low current and keep upping the amps on the welder until you determine what maximum current you can get before fuses begin to pop. Remember, fuses are meant to blow to keep things safe, and my welder has munches through 10 or so fuses until i got a proper supply for it.


Thinnest rods can be used at 50volts and thicker ones 70 volts. Depends on what you will be welding,

In your situation, 3.2mm 6013's @ 95 or 100 amps will do, or make used of the 70 volts and get some '7018' rods (They pack much more penentration, if the job is a critical one)

Have you welded with an arc welder before?

 

[Ragnarok]

the power draw from the socket will be about the same on 130amps 70volts as on 180amps 50volts, so running it on 70v won't stop you blowing fuses.

 

[Stinka]

Doesnt matter, the 50v an 70v are what you get on the tip of the electrode, some rods, wont run too well on 50 volt, so use 70 volts. You'll be best getting a bag of 13 amp fuses and start from low current and keep upping the amps on the welder until you determine what maximum current you can get before fuses begin to pop. Remember, fuses are meant to blow to keep things safe, and my welder has munches through 10 or so fuses until i got a proper supply for it.


Thinnest rods can be used at 50volts and thicker ones 70 volts. Depends on what you will be welding,

In your situation, 3.2mm 6013's @ 95 or 100 amps will do, or make used of the 70 volts and get some '7018' rods (They pack much more penentration, if the job is a critical one)

Have you welded with an arc welder before?

Cheers for the replys guys

This is a great reply thanks, And I've not welded for 15 years since i was at college doing my btec in mechanics so I'm a noob basically

But I've watched the youtube vids and I'm going to get some rods and some steel and just practice a bit see how I go on

 

[SiPMerlin150]

We have a small but detailed guide here, put together by a few guys on here, just click on the arc tutorial in green at the top of the page, and follow the guide, its good, and i wouldn't of got to where i am right now without it

I'd say, personally, go for it, for £50 its not much of a loss if it doesn't do what you want it to do...

Arc is good, very good, but if you try to weld anything less than 2 or 3mm then forget it, so any type of MOT bodywork or patch panels for automotive work is out of the question, as the arc vaporizes the thin steel right before your eyes

A mig welder is quite versatile, being ok for up to 6 or 8mm thick steel, right down to 1.6mm steel for bodywork, but trying to find a decent mig for less than £200 is rare.

What your mate has there is a fan cooled AC (i think) transformer based Arc welder. Duty cycle could be amongst its downsides, (time welding vs. cooling) alng with its portability, as it looks heavy!

With all that said, if its for occasional use on smaller jobs, you may aswell buy it, as they rarely go wrong unless serious abuse has been done to it.

 

[Stinka]

Well it works fine, but I am shocking

Blew 2 fuses just doing this, rod kept sticking, was at about 100 amps on 70v with a 4mm rod

Anyway, will get some rods and steel plate, and set myself a bench up at a decent working height (2 plastic tresels and a bit of wood, outside in case it goes up lol) and practice striking an arc and doing some nice steady lines

Holding the mask with one hand is a nightmare so might have to invest in a proper helmet. What are those cheap speedglass copys like on ebay ?

Also, any advice on welding butt joints in 50x50x3mm box section ?

Also, is it safe to hold the rod with your spare left hand to steady (if long enough so as not to burn me) ?

 

[rich r]

If you're running off a 13A plug, forget 4mm rods. You generally need about 140A-160A for 4mm E6013 rods, which you just can't get from a 13A supply.

Try with 2.5mm rods at 80A until you get the hang of arc welding. Then 3.2mm rods at 100A (which you'll find easier than 2.5mm, but you need to master the art of controlling the arc length and speed, which is more apparent with 2.5mm in my opinion).

Definitely get an autodarkening helmet - the £25 True-Fusion ones are reckoned to be quite acceptable. That'll give you both hands free, and the autodarkening means you never have to take your eyes off the job.

And yes - it's fine to steady the rod with your other hand. Most of us do it when trying to be accurate with a boingy long rod. Once the rod's down to 20cm or so, it's not so necessary...

 

[Stinka]

If you're running off a 13A plug, forget 4mm rods. You generally need about 140A-160A for 4mm E6013 rods, which you just can't get from a 13A supply.

Try with 2.5mm rods at 80A until you get the hang of arc welding. Then 3.2mm rods at 100A (which you'll find easier than 2.5mm, but you need to master the art of controlling the arc length and speed, which is more apparent with 2.5mm in my opinion).

Definitely get an autodarkening helmet - the £25 True-Fusion ones are reckoned to be quite acceptable. That'll give you both hands free, and the autodarkening means you never have to take your eyes off the job.

And yes - it's fine to steady the rod with your other hand. Most of us do it when trying to be accurate with a boingy long rod. Once the rod's down to 20cm or so, it's not so necessary...

OK, brilliant cheers mate.

Got the rods from the engineering place in town, just asked them for a few and some scrap steel to practice on, as i wanted to make sure the welder worked first before I shelled out on any consumables.

Will get some decent 2.5 s then and stick with them, as they will do my 50x50x3mm box section sliders I assume.

 

[rich r]

Yep - 2.5mm rods are much better suited to 3mm steel than 4mm.

 

[Stinka]

I gave my mate £40 for this in the end, bargain imho