Oxford Oil Immersed Welder issue

[Mannyroad]

Hi,
I have a trusty old Oxford Oil Immersed Welding Machine that I've used for a good 40 years now, off and on. Don't use it for arc welding anymore but it's great for using the brazing torch to heat up steel etc. for bending steel etc. However, tried to use it today and its stopped working. Tested fuse in plug. Tested continuity of flex to the welding machine, all good. Unbolted the lid and lifted it up to bring out the transformers from the oil and all the rigid metal connections from the flex terminal point to the transformers etc all look good, intact with no breaks. So I can't figure why it should suddenly stop working just when I really need it. Anyone out there who know these machines and can give me any pointers? These things are so simple there's nothing much to go wrong.

 

[Misterg]

Try a different socket?

 

[Parm]

How do you use an arc welder as a brazing torch?

Have I read this wrong?

 

[oldbikedavey]

How do you use an arc welder as a brazing torch?

Have I read this wrong?

Carbon arc....

 

[Fazerruss]

How do you use an arc welder as a brazing torch?

Have I read this wrong?

Carbon arc torch.
It's a torch with two carbon electrodes connected to the welder. Works like an arc light

 

[Fazerruss]

How do you use an arc welder as a brazing torch?

Have I read this wrong?

 

[voipio]

What is the resistance between the transformer terminals? The ones to which the mains power goes? Does the welder hum when powered up?

 

[piman]

Hello Mannyroad,

check the contacts on the current controller?

Alec

 

[Keith 66]

If its built any way similar to my old BOC set, that went intermittent then stopped working at all, there are two sets of contacts one for coarse control one for fine, basically a ring of heavy copper 3/8" dia rods on a paxolin base with a central spring loaded contact that bridges any two making a circuit. The bridge contact is a spring loaded roller. After many years of work arcing had burnt the contact roller away & also the contact rod surfaces facing the centre. The central roller resembled a burnt thruppeny bit & didnt make contact on an intermittent basis.
Remedy was to turn a new roller up out of copper & undo the main contacts from their base plate & rotate them 90 degrees so the burnt surface didnt touch the new roller. Everything now works fine.

 

[Dragnet]

I second Keith 66. As you say there's very little to go wrong on these, and you don't mention a great fireworks display of chaotic failure so it's very likely to be something simple such as that last little bit of arcing being the straw that broke the camel's back. With the transformer hoisted up it's possible to see the contact faces with a bit of peering. Checking the continuity will guide you.

 

[fizzy]

Carbon arc torch.
It's a torch with two carbon electrodes connected to the welder. Works like an arc light

A mate had one of thee when he was 14
We had no clue how to use it properly so we had great fun burning and melting things - he replaced the fuse in his Dad's garage with a pair of compasses

 

[Mannyroad]

Try a different socket?

I did that. I'm not sure it's the supply. This was my dad's welder and he stuck a 3 pin plug on the end of 3 core 4mm2 flex. Yes, I realise it needs a 32amp supply but to be honest, it has worked like this for years and no fires, haha.

 

[Mannyroad]

What is the resistance between the transformer terminals? The ones to which the mains power goes? Does the welder hum when powered up?

I don't have a meter to check that. Will borrow one. But what should I be reading, ohm-wise?

 

[Mannyroad]

Hello Mannyroad,

check the contacts on the current controller?

Alec

Do you mean the end within the oil, that slots into the radial sprung metal contacts? If so, then it seems fine (visually). Pretty robust actually, and you can feel the tang/spade (whatever it's called) pushing the sprung contacts apart properly.

 

[Mannyroad]

If its built any way similar to my old BOC set, that went intermittent then stopped working at all, there are two sets of contacts one for coarse control one for fine, basically a ring of heavy copper 3/8" dia rods on a paxolin base with a central spring loaded contact that bridges any two making a circuit. The bridge contact is a spring loaded roller. After many years of work arcing had burnt the contact roller away & also the contact rod surfaces facing the centre. The central roller resembled a burnt thruppeny bit & didnt make contact on an intermittent basis.
Remedy was to turn a new roller up out of copper & undo the main contacts from their base plate & rotate them 90 degrees so the burnt surface didnt touch the new roller. Everything now works fine.

No, it's not quite like that. The current controller is a rod with a tang (a bit like a mortise lock key) that is sprung and is forced down into a series of radial sprung metal contractors.

 

[Mannyroad]

What is the resistance between the transformer terminals? The ones to which the mains power goes? Does the welder hum when powered up?

Interesting question. It's a good while since I last used it but I think I recall it used to hum. Now, when I plug it in, it's silent.

 

[voipio]

The silence, when the welder is plugged in, would suggest that the path for the mains current flow, from the live mains plug pin, through the primary, and back to the neutral mains plug pin, has gone open circuit somewhere. If the open circuit location is inside the transformer itself, then a rewind will probably be necessary, which may prove not to be cost effective.

 

[brightspark]

The silence would suggest that the path for the mains current flow, from the live mains plug pin, through the primary, and back to the neutral mains plug pin, has gone open circuit somewhere. If the open circuit location is inside the transformer itself, then a rewind will probably be necessary, which may prove not to be cost effective.

specialy when people cant give them away on here possibly the primary coil as above

 

[voipio]

I don't have a meter to check that. Will borrow one. But what should I be reading, ohm-wise?

The DC electrical resistance of the primary, as measured using a multimeter, will be just a few ohms. Not quite a short circuit, but close.

 

[Misterg]

This was my dad's welder and he stuck a 3 pin plug on the end of 3 core 4mm2 flex. Yes, I realise it needs a 32amp supply but to be honest, it has worked like this for years and no fires, haha.

My dad's was like that too! (With a 'Farmer fuse' )


All the lights in the house used to flicker when he was welding.