Cooling an arc welder

[petedut]

Hi,

I have a cheapo 140 amp arc welder, and when you turn the amps down the buzzing gets really loud, is this normal or should I have a look inside to check everything is ok?

If it is normal I was thinking of building a new case for it which would be totally water tight and submerging the whole lot in some veg oil which should have a two fold effect 1, less noise 2, should keep the welder cooler for longer so it wont cut out as much.

I have seen it done with computers and it works well, as long as there are no moving parts it should be ok

What ya'll think of that?

 

[shenion]

The cheap arc welder I had buzzed like crazy. Then again it was only a $0.99 machine, so did not care.

I would look at adding a fan. Will help you duty cycle a little bit. If your are hitting the duty cycle, oil cooling may help, but you are still exceeding what it was designed for.

I'd keep an aye out on ebay for a decent welder nearby. Lots of the old transformer units with higher duty cycles are available.

 

[petedut]

Cheers |Shenion,

I am seriously considering buying a Tig welder, nowt special maybe one of those Rehimann types, I should be able to arc weld with that too shouldnt I? I dont actually weld that much its just for when I get a crazy project in my head I know I will have the equipment to do it

 

[piman]

Hello Pete,


I think your ideal of a double skinned case would make it worse, as it would stop any airflow whatsoever around the transformer, and basically insulate it. Adding a good fan is a far better idea.

Alec

 

[Drains]

Hello Pete,


I think your ideal of a double skinned case would make it worse, as it would stop any airflow whatsoever around the transformer, and basically insulate it. Adding a good fan is a far better idea.

Alec

It's how the Oxfords work piman. I guess you have the thermal mass of the oil, plus convection to move it around. I don't have a clue myself if veg oil would work. I thought you were meant to spend heaps of dosh on fancy transformer oil. Would be great if a bit of sunflower did the job.

Still easier to put a fan on though....

 

[petedut]

If it works quite well on computers it should work on the welder, here is the page where I saw the experiment done-

http://www.tomshardware.com/2006/01/09/strip_out_the_fans/

I have since took the plunge and bought one of the cheapo Tig inverters, which I dont think you can arc weld with now so I might still give it a go as I like Arc welding

 

[piman]

Hello Simon,

no it is not, the transformer in the Oxford is immersed in the oil which conducts heat away from the winding to the case which is then cooled by contact with the air surrounding it.
I maintain that putting a second case around the first and filling it with oil would insulate and not improve heat transfer.

Alec

 

[piman]

Hello Simon,

I think perhaps that I misunderstood the intention. If the windings are immersed then yes it will work, although transformer oil will probably be a better choice of oil.

Alec

 

[Drains]

Hi Pi. I have to agree, if the whole weld set were surrounded with an oil filled case, that would be just silly

 

[^neo^]

Just stick a desk fan behind it when you're welding until you can afford something better

 

[Weldingartisan]

I put a small 240 volt equipment cabinet fan in an old 'buzz box' welder which used to cut out half way round a 4" pipe flange. Could run it flat out for ten minutes after that. W/A

 

[madkayaker]

Id check if cooking oil conducted first. The pic of the computer shows the 230V parts out side. The oil might conduct at a higher voltage. If you know a spark as them to "MEGGER" the oil to see if it conducts. Ill try it when i get my MEGGER back from my mate next week.