stephen_gusterson
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| posted on 4/4/03 at 11:01 PM |
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between you two guys, you ought to be able to give us some definitive advice on welding - like write a short course and post it here - dispel some of
the myths and stress some of the good advice.
I have seen Viper's welding - we use it in most of the machines my company produces and its leak proof even when holding a vat of thin oil.
atb
steve
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PerspexIt
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| posted on 5/4/03 at 08:03 AM |
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Hi All!
Thanks all your answers, i had some busy days at office, we have a demo the next week and the program need tests... like my welding. 
Hopefully i'll be back home early so i can try again.. the next week i'll buy a digital camera.. so i'll post my horrible welds!
Have a good weekend!
-P
[Edited on 5/4/03 by PerspexIt]
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craig1410
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| posted on 5/4/03 at 09:15 PM |
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Hi,
This is mainly a question for Mark due to his use of a Clarke welder similar to mine but anyone else feel free to answer too:
I wondered if you might be able to give me a bit of advice on power and wirefeed settings appropriate to welding 2mm thick SHS (25mm sq) (Note 2mm,
not 16swg)
It is a 120 Amp Clarke and I am currently using full power and between 6 and 7 on the wire feed. I always feel like I'm too rushed when welding
because the pool piles up too quickly but penetration seems to be variable. If I get a hot start (short stick out) then I can get good pen. but if I
use a half inch stick out as I think most people recommend then I just get an initially lumpy weld before it starts to penetrate.
I also quite often get little craters at the end of a weld sometimes where it seems like air is bubbling out and causes a void.
Final point is regarding the welding electrode and gas cup relationship. One other thread on this forum said that the gas cup should be positioned
such that the electrode stuck out by a few millimeters and this does seem to improve penetration but my electrodes keeping fouling up. What is
recommended here? Should it stick out or stay within the gas cup?
Thanks for some useful tips already, I hope you get a chance to answer the above too.
Cheers,
Craig.
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Mark Allanson
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| posted on 6/4/03 at 08:54 PM |
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I use the full 140 amps and a wire setting of just under 4 using .6mm wire. I have the contact tip exactly level with the shroud.
The 'piling up' at the begining of the weld sounds like wire feed too fast or the earth is a bit dodgy, check the clamp still has good
tension in the spring, and that the earth cable has a good connection to the welder, this is often overlooked. The hollow at the end if the weld
sounds like you are stopping the feed too soon, watch carefully at the end of the pass and watch the weld pool swell, basically pause for about 1/2
second at the end of the weld.
I have a pressure guage fitted after the regulator, the gas pressure on my set works best at 10psi closed which equates to 2psi when the gas is
flowing which I find ideal.
If you are using .8mm wire, get some 250 amp tips, these are much bigger and do not expand as much when they get hot, this causes snagging of the wire
and unpredictable welds. If you have the wire feed set right, the amount of wire sticking out of the contact tip should be about what you started
with, 10mm.
Hope this helps a bit, do not go by my settings as gospel as we have different machines, and even identical machines work differently due to
manufacturing tollerances.
Mark
[Edited on 6/4/03 by Mark Allanson]
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craig1410
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| posted on 6/4/03 at 09:00 PM |
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Mark,
Thanks for that, I will try a few settings to see how I get on, I think my wire feed is indeed too fast. I think that I should be using less wirefeed
and taking more time instead to get a nice flow.
I should have said that I'm using CO2 just now for tack welding but hope to move to Argomix for seam welding. I know CO2 is usually said to give
better penetration but would you expect this to require different settings on the welder when I make the change?
One final clarification, when you say "you use the full 140 Amps" is this for 16 swg or were you meaning this is what you would use for
2mm?
Thanks again,
Craig.
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Mark Allanson
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| posted on 6/4/03 at 09:28 PM |
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Both, always use the maximum power you can handle without getting any undercut, or massive ditortion
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craig1410
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| posted on 6/4/03 at 11:17 PM |
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Cheers m8, I'll give it a try tomorrow night.
Craig.
ps. Is 120A enough for 2mm tubing?
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RoadkillUK
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| posted on 6/4/03 at 11:22 PM |
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Try this file, I can't remember where it came from but it's a good read 
MIG Welding Document
Roadkill - Lee
www.bradford7.co.uk
Latest Picture (14 Sept 2014)
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craig1410
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| posted on 7/4/03 at 07:36 AM |
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Hi,
I found this document a little while back (Liam's guide to welding). I think it was on the other list in the files section. Thanks for reminding
me though because reading it again is useful.
Craig.
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Gremlin
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| posted on 10/4/03 at 10:28 PM |
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This seems to be the place to ask any welding questions.
I have a 150A welder and am only using it at about half power if that with a slow wire speed and slow movement just allowing the welding pool to move
slowly along and this seems to have ok penetration. If i turn the welder power up i just end up with big holes yet everyone else seems to have welder
set to as high as possible.
Is this wrong? or are you all just moving torch quicker?
[Edited on 10/4/03 by Gremlin]
EZy GreMLiN
"The only way to get rid of temptation is too give in to it..!"
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craig1410
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| posted on 10/4/03 at 10:44 PM |
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Hi Gremlin,
I'm no expert but will reiterate something I read elsewhere.
Be aware that just because you have a nice weld pool running into the area between the metals to be joined might not equate to good penetration in
itself. This scares me a bit because a good looking weld might not be strong at all! Very worrying!
The advice I found was to practise on two bits of steel butted together and make sure that you actually see full penetration by looking from behind
and seeing a little bit of drop through and even "blue'ing" of the metal on either side.
HTH,
Craig.
ps. It's a bad sign when I give welding advice so hopefully one of the resident experts will elaborate and/or tell me to shut up 
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Gremlin
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| posted on 10/4/03 at 11:01 PM |
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Have done and seem to. Perhaps because im moving quite slowly to the weld pool has time to heat through material properly?
Thanks for advice i may go away and try slightly higher power.
I have tried braking appart a couple of pieces of material i have welded and the material tears around the weld where the material is weekend by the
heat but the weld has held no problems.
Any other thoughts?
[Edited on 10/4/03 by Gremlin]
EZy GreMLiN
"The only way to get rid of temptation is too give in to it..!"
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PerspexIt
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| posted on 22/4/03 at 10:28 AM |
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MUCH BETTER!!!!!!
Hi, i had time for do other tests in the last days, the result with square tubes it's much much much better.
Was a mix of mistakes, i changes the kind of wire, i rented a big bottle of gas instead the small disposable one.. and now is not the "cream of
the cream" but it's not so bad, and very important, it's STRONG. I can jump up and down on the welded parts without cracks.
Now.. any hints about weld round tubes? I tried, but i got other "disappointing welds"
Many tanks and best regards,
-P
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David Jenkins
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| posted on 22/4/03 at 10:43 AM |
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I hate welding round tubes - never managed to get a pretty result.
It's the combination of keeping the correct angle, moving across the work, AND trying to go round a radius that messes me up.
I'm afraid the 'P' word is the answer again - practice!
cheers,
David
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elewayne
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 posted on 22/4/03 at 02:18 PM |
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Welding test
Hi,
What size wire are you using? I'm getting good results with .25 or .o25 what ever it is? Non flux coated. I've had to take a couple things
off and even tacked they were hard to remove. Even after I cut the tacks with the grinder.
I like the slight zig zag motion myself.
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