RPS
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 posted on 23/3/04 at 09:00 PM |
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Welding Problems- Help please!
I have been welding for 26 years, done all types, all positions, even taught basic welding for a while and never had a problem. Then I came to weld
my chassis! After studying the welding threads, I decided that I could use my arc welder, with 2mm electrodes to make sure that I get adequate
penetration without excessive heat.
Now I have never used 2mm rods before, never needed to (I work mainly with larger machines -agricultural), I bought myself a pack and started welding
and here's the problem. As soon as do any fillet welding, the result is crap! The weld just sticks to either piece of metal, or both, but will
not flow into a nice neat fillet. The weld pool just does not run like it should, you can see the flux getting in the way all the time. Directing
the arc is difficult and you have to adjust the rod position to try to get it going in the right position.
I have tried every conceivable angle, amps setting, arc length, position and I can't get a decent weld. As soon as I revert back to 2.5mm its
ok, perfect welds. I bought another pack of 2mm from a different supplier to see if that would work, as I have noticed that the flux was often
burning away unevenly. This has made no difference, they seem to be the same.
My questions are:
1. Is it me or the rods?
2. Can I use the 2.5mm rods for the fillets and the 2mm rods just for butt joints (or will this cause too much distortion)?
By the way, don't suggest I buy a MIG welder, because I can't afford one!
I would appreciate your help before I spend another night wasting rods and metal.
Many thanks,
RPS
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Peteff
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| posted on 23/3/04 at 09:22 PM |
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Sounds like you are using an AC welder and can't get the power down low enough. I never had any luck with arc on anything thinner than 3mm even
with 16g rods, too fierce. You could try one of those attachment rod holders that pulses the current if they still sell them but I don't know
who has them nowadays.
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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David Jenkins
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| posted on 23/3/04 at 09:41 PM |
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I was using 2mm rods last night, for a little job where I couldn't get either my MIG or TIG into the space.
The result was 'orrible! 
I don't claim to be a good stick welder, but I can usually turn out something respectable when using 3mm rods from BOC. This time, 'bird
droppings' would be a suitable description...
Taking Pete's comments - I was using my DC TIG as the power source, so the current was electronically controlled... didn't help any...
Doesn't answer your question, but you have my sympathy!
rgds,
David
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Mark Allanson
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| posted on 23/3/04 at 09:55 PM |
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What sort of welder do you have? If it is a baby air cooler transformer (not inverter) the OCV will be about 48V. This will cause you problems, but
not insummountable.
Try to weld uphand if you can, the flux will flow away from the weld pool, decrease the angle of the rod (normally bad practice as it reduces
penetration - but it sounds like you have too much already!)
Try splitting your earth lead and earth both sides of the work at the same time
Try 2mm Satinex 6013 rods from BOC, the smoooothest rods available, if you use 1.6mm it will increase burn through as less of the power is used to
melt the rod.
Keep the rod as close to the work as possible to reduce the arc length, when it is working right, you can press the rod against its flux coating onto
the work. The longer the arc, the higher the power.
Tyr warming the rod on a piece of scrap first, it will not stick as much
Sorry if it sounds like teaching Granny to suck eggs, but I don't know what else you have tried
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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David Jenkins
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| posted on 23/3/04 at 10:08 PM |
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My 3mm rods are BOC Satinex - made a huge difference to my stick welding, especially when I remember to store them in my airing cupboard until I need
them... so easy to use.
rgds,
David
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Mark Allanson
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| posted on 23/3/04 at 10:46 PM |
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Using the next size up on rods on thin metal is fine, it effectively reduces the heat of the arc as more energy is needed to melt the rod. If 3mm
(1/8"?) rod work - use them, arc is much stronger than mig in all cases due to the width of the arc.
Satinex really are the best, arn't they 
Try using 8mm rods with 400A at 110 OCV. Fillets as big as your finger in one pass, flat as Holland and a beautiful kipper skeleton patern. Might even
give up this bodyshop stuff and go back to welding - I really used to enjoy it
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 24/3/04 at 09:53 AM |
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when I remember to store them in my airing cupboard until I need them
We used to store them in a wooden box with a light in it and a 60w bulb which was left on permanently. It was surprisingly efficient and kept them in
perfect condition for very long periods. I used to find it easier to use thinner rods if I cut them down in size, I know it's wasteful but it
worked for me.
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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Terrapin_racing
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| posted on 24/3/04 at 10:19 AM |
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Had this before - it's essential that the rods are in good conditionand perfectly dry. I have recovered rods by baking them in the oven for a
short while. Any moisture in the flux will give you a terrible weld finish. This assumes your using a 240vac arc welder with DC output.
Clean the metal tube of all grease protection and be sure it is dry before welding
Also make sue you have an absolutely sound earth (I'm sure you know this)
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RPS
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| posted on 25/3/04 at 07:12 AM |
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Thanks Guys....
Lots of useful stuff (as usual), some of which I have tried and some of which I had forgotten to try.
I contacted the supplier and challenged him to do a decent weld with them, he is going to call me back with the results. He has blamed my equipment,
I am using a small air cooled welder delivering AC, because my normal welder is a massive one and will not go down to less than 85 amps.
Anyway at least it is nice to know that I am not the only one who has struggled with this.
RPS
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David Jenkins
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| posted on 25/3/04 at 08:44 AM |
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This topic brought up a few memories from 5 or 6 years ago, when I did a couple of 1-day welding courses at the local agri college. The tutor was a
fully time-served welder who REALLY knew his stuff.
We started off with stick welding, using massive Oxford welding transformers - 3 ft square on the base, around 4.5 ft high, with impressive brass
fittings on the front. Mens' welders! It wasn't until I tried welding with a 'toy' welder that I realised that these big
boxes helped the welding so much - I guess it's something to do with good regulation.
Anyway, after a while I asked the tutor whether it was possible to stick-weld thin stuff. He took 2 pieces of thin steel, around 0.8mm, and a sub-2mm
welding rod, and laid down the most perfect weld you could imagine, with slag that could be flicked away afterwards. When I expressed my admiration,
he said "30 years practice, plus setting the transformer to 80 volts, which helps with maintaining a good arc.".
David
P.S. He also did a classic bit of instruction in front of the class - he did a conventional fillet weld into a corner, stood up and said that if he
has done it well, the slag should just curl off as the metal cools - CLICK - and there was the slag barely hanging on to the weld! Underneath was an
immaculate weld...
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M@Triton
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| posted on 25/3/04 at 09:10 AM |
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Stick welding a chassis is not the ideal route as no real control over what is going on........the best way is tig far more control but then takes an
age to do and master properly. But oh so much more satisfying than boring old mig welding.
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David Jenkins
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| posted on 25/3/04 at 09:13 AM |
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I would never consider stick welding anything important - I simply don't have the necessary skills!
David
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Terrapin_racing
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| posted on 25/3/04 at 10:42 AM |
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There's nothing wrong with stick arc welding - if you have the skill and the right equiment. Fortunately working on an oil refinery we were
taught to high standards using arc (coded welding requirements) . I found Gas / MIG and TIG were a doddle after this.
I certainly would not entertain stick welding if you cannot get a perfect weld as the possibility of slag inclusion and a weak joint are too high.
I have arc welded a floor pan in a Triumph Stag many years ago (80's) and it was a smart job. Nowadays I just pick up the MIG because it's
so much easier. No clean up, more control etc.
Then Gas or TIG depending on requirements of job.
Why not hire a MIG for your chassis?
Just a thought.
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David Jenkins
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| posted on 25/3/04 at 11:07 AM |
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Hang on... who are you asking?
The thread was about welding using skinny rods, not chassis building. My chassis has been finished a long time - with MIG & TIG - my car's
nearly finished! (allegedly)
David
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RPS
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| posted on 25/3/04 at 12:06 PM |
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I am confident that you can get more than adequate welds when arc/stick welding, but you do need the necessary skills to do this. I was just getting
worried that I was losing my skills!
I have destruction tested some joints using 2.5 for the fillet and 2 mm for the butt and they are fine. I also know enough to redo any welds that are
less than perfect!
RPS
[Edited on 25/3/04 by RPS]
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Terrapin_racing
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| posted on 25/3/04 at 12:18 PM |
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Great, good luck with the build.
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givemethebighammer
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| posted on 27/3/04 at 07:22 PM |
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quote:
Originally posted by Peteff
Sounds like you are using an AC welder and can't get the power down low enough. I never had any luck with arc on anything thinner than 3mm even
with 16g rods, too fierce. You could try one of those attachment rod holders that pulses the current if they still sell them but I don't know
who has them nowadays.
I've got one of those rod holders that pulses somewhere. My father gave it to me, he couldn't get on with it, I couldn't either. If
you want it U2U me your details and I'll post it to you if you think it will make a difference.
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