Mark Allanson
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| posted on 28/2/04 at 04:03 PM |
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Unbelievable Welding Problem :(:(:(:(:(:
Brief description of the gas system on a mig.
Gas cylinder connected to the regulator, low pressure gas runs inside the welder to a solenoid valve so it is controlled by the torch trigger, gas
then free to exit at the torch - simple?
I added a guage (0-60psi) between the regulator and the solenoid valve, so I can see the pressure with the torch at rest (usually 10- 20psi), and the
torch actually welding (2-5psi). This has worked really well for about 11 years on this welder (Clarke 140 E Mk2)
The problem I have now is that the pressure between the regulator and the solenoid valve now creeps upto 90+psi and eventually blows the low pressure
pipe off the regulator. It also buggers up the weld.
Easy I thought, the reg is buggered, so I put another one on, but I get exactly the same problem - Either both regs are up the swanny (bit of a
coincidence!!) or something a little more sinister is going on.
Help me out guys, I wanna weld up my fuel tank today
[Edited on 28/2/04 by Mark Allanson]
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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Mark Allanson
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| posted on 28/2/04 at 04:21 PM |
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I have just dug out my third and last regulator out of my toybox, the pressure is now controllable between the reg and the solenoid valve, but now
when the torch is live, there is a short puff of gas from the nozzle and then nothing, the guage goes to zero, and then builds up again when the torch
is off again - I cannot get a constant stream of gas out of the nozzle.
I can only assume that the 3rd reg is allowing the pressure to build up correctly, but not allowing any volume of gas to flow - blocked pipe?
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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Hugh Paterson
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| posted on 28/2/04 at 04:31 PM |
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Mark, you sure the solenoid valve is opening and closing correctly? Could also be the trigger on the torch has an intermittent contact and is not
opening the solenoid correctly.
Shug.
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theconrodkid
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| posted on 28/2/04 at 04:35 PM |
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had a similar ting on my old reg,diaphragm had split,piece of old innertube fitted and still working
who cares who wins
pass the pork pies
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Mark Allanson
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| posted on 28/2/04 at 04:45 PM |
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I have taken the main (number 1) reg apart, and all looks as it should be.
The solenoid valve is definitely shutting OK as there is no gas leak with the torch at rest. I cannot see how the solenoid valve would affect the gas
pressure increasing between it and the regulator, when the torch is live, it is allowing the gas to flow, albeit at increased flow rate with regs 1
& 2, but not at all with reg 3, but reg 3 holds the pressure steady with the torch at rest.
GETTING FED UP, ALL I WANT TO DO IS WELD THE FRIGGIN' TANK !!!!!!!!!!!!!!!!!!!
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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Alan B
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| posted on 28/2/04 at 05:23 PM |
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VERY ODD
I agree with your initial diagnosis....Set up works for 11 years....then control of pressure is lost.... can only mean regulator fault....seemingly
However, the same "fault" with reg number 2 would suggest no "fault" at all.....hmmm??
I would have been suspicious of the gauge...but blowing the pipe off does suggest a high pressure....hmmmm?
Reg 3 with a very low volume does suggest a blockage...but where...???
Do you have a different gas bottle to try?...does the current bottle blow off freely when cracked open a little?....
It really is very odd...do keep us informed..
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Mark Allanson
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| posted on 28/2/04 at 05:34 PM |
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I think reg 3 has a fault (probably why I stopped using it 10 years ago?). I think reg 1&2 are OK, as you say Alan, I am now suspecting the gas
bottle. I tried 'sniffing' the bottle valve to check the was no foreign body in the valve head, but it does not blast off as it should, 1
1/2 out it is blasting, but not on 1/4 turn as it should.
I have a CO2 adaptor, so I am off to the pub to beg/borrow/steal a CO2 bottle to test the theory.
If it is the Argon bottle defective, it will be the second one in a row, the first would not seat and had to be exchanged.
Thanks for you help Alan, I was really at the pulling hair out stage
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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Mark Allanson
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| posted on 28/2/04 at 05:45 PM |
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Just a quick shot to explain about the pressure guage I added all those years ago
 
Rescued attachment WelderGuage.jpg
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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type 907
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| posted on 28/2/04 at 06:31 PM |
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Hi Mark
just to comment on the 1/4 turn bit:
Some bottles now have a "soft seal", no longer brass on brass, but a soft washer or something, maybe ptfe. When cracking open nothing
comes out for another 1/2 turn or so. You can hear it pop or feel the spindle move sometimes. These can be over tightened when turning off.
My BOC argon is like this.
As for the prob you have, my money is on the reg.
Good luck Paul G
Too much is just enough
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Peteff
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| posted on 28/2/04 at 06:46 PM |
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Opening the bottle fully.
There was a thread a while back where someone was worried about the spindle coming out of his bottle if he opened it fully. I have to open the one I
have now at least three turns for the pressure to register properly on my regulator. Have you got a two stage reg that shows your bottle pressure as
well as the flow rate and is your reg suitable for the bottle which is probably filled to a higher pressure than they were when you bought your
reg.
yours, Pete.
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Mark Allanson
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| posted on 28/2/04 at 06:51 PM |
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jjjust% bene dvwn the PPub, borrowed a CO2 bottle, complete with reg from Pte the landlord, he's putting a BMW aircooed twin into a 2CV!!!!
Fitted my number one reg to the CO2 bottle, same problem, fitted Pete's reg to his CO2 bottle - perfect
Type 907 and Peteff are probably right - I have 3 duff regulators, coincidence - well the jury's still out on that one.
Just going to surf Machine Mart to find a replacement - unless anyone here knows a better place to try?
thanks for everyones help
Mark
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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type 907
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| posted on 28/2/04 at 09:06 PM |
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Hi again,
On the subject of regulators I prefer to use a flow meter (or two).
They are so much more accurate than the flow gauge on a regulator, down to the last 1/2 litre / min. It can save money on gas! (I'm a tight
git) 
Paul G
 
Rescued attachment reg 003s.jpg
Too much is just enough
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malcolmstoddart
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| posted on 29/2/04 at 12:14 PM |
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dunno what it is with british oxygen (or air products)whatever their name is now, but they put a recall notice out on acetylene bottles with a certain
code on, phone your branch for details..I had one with defect code.
and to add to this new bottle of argon once opened won't seal off properly and hence now empty..so its going back to air products.
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Mark Allanson
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| posted on 29/2/04 at 02:25 PM |
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Thanks for the warnings.
Syd, what problem did you have with your bottle?, I use BOC size W
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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Mark Allanson
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| posted on 2/3/04 at 08:04 PM |
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Problem solved, and for less than £30, talking to the welding rep, the new gas cylinders are now between 230 and 260 bar, hence the simultaneous
destruction of my regulators - not a coincidence!!
The new reg is rated to 300bar and as it is an oerlikon (20mm anyone?!), should last a long time
Thanks for everyones help
 
Rescued attachment Regulator.jpg
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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Peteff
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| posted on 2/3/04 at 08:11 PM |
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That's what I said earlier.
I was advised of the problem a few years back when the lower pressure was being phased out but my reg stood up to the new 200+ bar cylinders so I
didn't need to swap. That's not a bad price for a quality reg.
yours, Pete.
[Edited on 2/3/04 by Peteff]
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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