Advise please

[Jasetheface]

I have brought a cheap mig to learn some basics, i have a question, i have opened up the torch to find that the liner is bolted through to the swan neck, and the gas connects into the switch, my question is does the gas fill up the torch and diffuse through the holes in the swan neck? If i blow through the tube the gas is always open. All torches i can see now have all pipes terminating on the gas valve in the gun... Is mine just an old design, should i replace with this type.......

 

[Wedg1e]

Presumably then there's a gas solenoid (valve) inside the welder? Which is the 'professional' way to do it...

 

[Jasetheface]

No the gas connects into a plastic mechanical valve, when you push the trigger it activates the valve and pushes through to make contact with the live feed bolted to the swan neck, similar to a clarke setup but the swan neck is separate to the valve. The gas seems to fill the housing as there are two seals and diffuses into the swan neck through the holes in the barrel of the swan........ideally I would like to buy a new torch handle with swan neck and valve and connect to my existing pipes?

 

[Wozzaaah]

The plastic pipe normally goes into the gas valve, the gas then flows up through the swan neck and out of the diffuser.
If you can blow through the pipe and it's coming out of the diffuser then the gas valve is probably stuck open or faulty. You should be able to take it apart easily enough and as long as it's all there, clean it.
Failing that then a new valve or torch may be needed.
Here's the torch page of Weldequip's shop, email him and he may be able to tell you what parts might fit your machine.

 

[Jasetheface]

My swan neck is seperate to the gas valve albeit both inside the handle, i think buying a clarke replacement would be easier.

 

[Wozzaaah]

Any chance you can post a pic of the torch innards?

 

[Jasetheface]

Hope this helps

 

[Wendelspanswick]

Could be that the valve needs the higher pressure of a gas bottle to hold the valve closed, it could be that blowing in does not supply enough pressure to form a seal.
Have you tried it with a bottle yet?
Should be fairly straight forward to change the torch to a Clark or Sip valve in torch type if you want to but I would try it as it is if funds are tight.
If the valve still does not seal when it's on a bottle and if you cannot clean/repair the valve then I would replace the torch assembly.

 

[Jasetheface]

I have taken it apart and cleaned it up and it works........ haven't checked with gas yet but the valve will now shut off, the last person had used silicone to seal the gun........ will get some gas and try, I assume the flow rate would be better on the Clarke style gun as the gas is fed through the swan neck as opposed to mine diffusing into the swan shaft.?

 

[KemppiFrog]

I have taken it apart and cleaned it up and it works........ haven't checked with gas yet but the valve will now shut off, the last person had used silicone to seal the gun........ will get some gas and try, I assume the flow rate would be better on the Clarke style gun as the gas is fed through the swan neck as opposed to mine diffusing into the swan shaft.?

Not quite sure about that.
My eurotorch feeds the gas in at the machine and it wanders up along with the wire to the torch. I suspect there is a bit of leakage where the wire enters the nozzle at the wire feed, as there is less resistance than the 3mtrs up to the torch. The original Kemppi torch worked the same way.
So your system feeds the gas in pretty close either way.