Wasn't sure where to put this post! Made a rear wishbone for my midi tonight. some welding went really well, other bits less neat - as shown here. Penetration appeared good. Any clues to what is happening? Cheers!
Rescued attachment HPIM0235.gif

Too fast, not enough amps or an unsteady hand, possibly a combination of all 3.

Do some more practice on some scrap if I was you...IMO

David

looks similar to some of my welding. More amps is often the solution, i have trouble setting current on my welder due to a lack of finesse in the machine (i know, a poor workman who blames his tools ).

there are several professional welders on the forum, one will soon come along with full details and tips

Less wire speed, it looks like you afraid of burning holes in the thinner tube and hurrying, which equates to lots of weld on top of the job.

Try and work the molten pool from the thicker plate across, slow down and weave the torch more evenly.

Its just practice. burning a hole merely indicates full penetration !

I'm left handed so if your right handed try the opposite, I hold the gun in my left hand and steady it by resting it on my right hand bit like a sign writer would do, make any sense ? I find it much easier too "weave" the torch like this.

More amps less feed speed.

Ill second (or third? ) the too much wire speed opinion.

id try just going a little slower with less wire rather than adjusting wire and ampage at the same time, just try changing one at a time that way youll get a better feel for how the two settings interact and in the end you'll be able to feel exactly setting is which is to high or too low.

You wont be on your own Joel, many hobby type welders are almost impossible to coax a decent weld out of, erratic arc being a big problem, even with a pro holding the torch, for once you can blame the tool.



Originally posted by JoelP
looks similar to some of my welding. More amps is often the solution, i have trouble setting current on my welder due to a lack of finesse in the machine (i know, a poor workman who blames his tools ).

there are several professional welders on the forum, one will soon come along with full details and tips

Yep yep yep yep and yep!

all good advice so far!

Wadders you are dead right, that's why my Clarke 150 TE went and the big machine that I have now got bought.

Slow it all down. Practice on some scrap and just keep trying to go slower and slower until you're welding takes perhaps 7 or 8 secs per inch (as a guesstimate)

This is very slow for mig, but when you have perfected a setup that will give a smooth weld at that slow rate, it's dead easy to speed the wire up and knock the amps up a setting then to speed things up.

As everybody else said, you have too much wire and not enough heat to melt it at the moment.

Keep welding scrap until you can get it right consistently with all types of weld (corner fillet, butt weld etc) as welding round tube to things neatly is not the easiest task (as uncle Ron showed with some of the pics in "the book"!!)

I (trumpet out!) am a pretty accomplished welder, but I will never start a weld on something I am making until I have verified the setup of the welder on a piece of scrap first, so don't think you're the only one who needs to! It's just good practice.

Lastly, with a lot of hobby machines you will find that they spend most of their time on one setting. My Clarke 150 amp used to spend nearly all it's time on setting 5 (actually "2-High" ) which was 1 setting down from full power. I used this on everything from 1mm through to 2.5mm, which was most of what I welded at the time (still is probably) and just varied the torch speed and wire feed to adjust the weld.

Keep practising, that's the key!

[Edited on 23/2/06 by NS Dev]

quote:

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Originally posted by Wadders
You wont be on your own Joel, many hobby type welders are almost impossible to coax a decent weld out of, erratic arc being a big problem, even with a pro holding the torch, for once you can blame the tool.



Originally posted by JoelP
looks similar to some of my welding. More amps is often the solution, i have trouble setting current on my welder due to a lack of finesse in the machine (i know, a poor workman who blames his tools ).

there are several professional welders on the forum, one will soon come along with full details and tips

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But thats the point i was trying to emphasize. Most people on here wont be "good workmen'"when it comes to welding, they are only novice learners, and as such will blame themselves if the results are poor, never suspecting the machine they are using is pants and that even a pro would struggle to lay down a nice weld with it.


A good workman would still not blame the tool, they would just do like NS Dev and get the right/better tool instead. [/quot

Very true. It was only working in a prototype fabrication shop for a while with "proper tools" that put my hobby stuff in perspective.

Are you working towards yourself or away. Turn the power up and push the gun away from you.

Not enough heat (amps), too fast on the wire...would suspect that the penetration is not too good from the shape of the bead.

I'm laft handed like Jon and am a two handed welder. Makes those hand held masks a waste of time. I'd reccommend an auto darkening mask, helps you start in the right place. It took me ages to 'see' the weld pool, thought it was just something gas people talked about, turned out I was moving too fast. Slow right down look for the melt pool (darker ring around weld) and move this along the workpiece. I've never had better welds!!

Marcus

A cheap MIG I used many years ago tended to overheat after a few inches of weld. I couldn't get it to work properly until it cooled down. When overheated, the power dropped and the wire feed speed became eratic.
This made learning to weld very dificult - I kept blaming myself for the weld quality - I could produce two or three inches of nice weld - then bird droppings.

quote:

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Originally posted by Marcus
I'm laft handed like Jon and am a two handed welder. Makes those hand held masks a waste of time. I'd reccommend an auto darkening mask, helps you start in the right place. It took me ages to 'see' the weld pool, thought it was just something gas people talked about, turned out I was moving too fast. Slow right down look for the melt pool (darker ring around weld) and move this along the workpiece. I've never had better welds!!

Marcus

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I use a hand held mask while I tack stuff up, then I use my head mask with the "nod" facility (slacken the screws off). I fitted a sponge bung where it drops down so it hits my chin and doesn't go too far, the wonders of gaffer tape technology

One way of getting a farily good weld without a lot of practice is to do lots of short runs.

Turn the power right up then cut the blob off the end of the wire, position your torch and wire end, holding the torch and supporting the nozzle with your fingers. This ensures a steady hand, do not try to weld in mid air.

Now just do a short squirt of weld. The high power will ensure good penetration and the short squirt ensure you do not burn through. Just do a lot of these short bursts moving the torch and cutting off the blob each time.

When you get better you can make each run slightly longer.

Top welding machines have a pulse facility which basically does the above for you as you weld. It means you can run high power with time between for the weld to cool.

John

Thanks guys. The frustrating part is that practise welds on scrap were going well - guess I've made another piece of interesting shaped sculpture (sell on e-bay??!!).
I'll try again, slower, steadier, more current, less wire. Watch for results next week!!!!

theres nothing to stop you grinding it back, and welding over the top once you've perfected your technique. shame to scrap the whole thing.




Originally posted by JC
Thanks guys. The frustrating part is that practise welds on scrap were going well - guess I've made another piece of interesting shaped sculpture (sell on e-bay??!!).
I'll try again, slower, steadier, more current, less wire. Watch for results next week!!!!

Another thing that hasnt been mentioned (but I have only skimmed throught the thread...) is it is worth 'shining up' the metal in the general weld area first, as well as the earthing point. The metal may *look* clean, but a quick rub with some emery cloth etc will make quite a difference, especially with a hobby MIG...

Hi i would guess your using co2 try using Argon / argo shield (argon oxygen mix)
It makes a big difference

Gareth

Yes (agreed as we used to use argoshield in the fab shop) but I only use crappy CO2 "at home" and get results easily as good as with Argoshield, except I seem to get more spatter with C02. Anti-spatter spray is cheap tho!!!

quote:

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Originally posted by JC
Thanks guys. The frustrating part is that practise welds on scrap were going well - guess I've made another piece of interesting shaped sculpture (sell on e-bay??!!).
I'll try again, slower, steadier, more current, less wire. Watch for results next week!!!!

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Hi All,

Firstly I must point out that I don't own, or have never used a single phase Mig from,
how can I put this, the cheap end of the market, so I may not understand the problems
involved in setting one up, so feel free to ignore anything I say.



A successful setting, (that sound of frying bacon), is a question of a perfect balance between volts and wire speed.

Every welding machine is different but you may have a rotary switch (say 1 to 10) for wire speed, and another rotary
switch or stepped settings, (hi/lo 1 2 3 4) for volts.

Wire speed = amps
Volts = power

Too high a wire speed and it will feel as if the torch is being pushed away from the metal.

Too high on the volts and the arc gap will be to long, to the point when it will burn back to the tip.

To set up...
select a voltage setting, say 75% (if you have 1 to 4, then No3)
Set the wire feed at 75% (if you have 1 to10, then 7.5)
Try it, then turn the wire up and down and find that middle position where the sound is a nice even crackle, (frying bacon)
You've now found a setting for a given thickness of metal. On a 180amp machine this might be, say, 4mm to 4mm.
On a small machine this might be 16g to 16g.

Repeat, starting with a lower voltage setting, then again with a higher one.

Try to end up with a range of settings for your machine that will cope with a range of thicknesses.

Your test welds will have to be on suitable thickness plate. You won't find a setting for 3mm by trying it on 1.5,
just blow a load of holes.

So you now have a range of settings, say 4 or 5 to try out on various thickness metal.

Tips.

When you find a good setting write it on a piece of masking tape and stick it on the side of the welder.

A setting higher for vertical down, a setting lower for vertical up.

Try not to alter two things at once.

Only pull the torch when going v/down, all other welds push it.

Thick to thin, play the arc on the thickest metal, the pool will flow onto the thin side.

If your welder is on the limit, then set the job up so you weld uphill at 45deg. It will aid penetration.
A machine that will weld 6mm plate will weld 10mm vertical up.


Hope this helps someone.

Paul G

ps. gas mix is argon / CO2 (not argon / oxy) sorry

pps. I assume your welding equipment is in good condition. If not this is all a waste of time.

[Edited on 25/2/06 by 907]

Something often overlooked, but some have mentioned, is the EARTH and the quality of the earth connection and its significance.

The old fella who taught me would NEVER trust one of those spring clamp things. I saw him cut one off the end of a new earth lead, cut back the insulation, and use a G clamp to secure the earth.

This gives a bigger earth area, and a much more secure connection. He showed me the difference between the two methods, and there was definitely no argument as to which sounded better as he welded, and looked better as a result.

When the end gets straggly, just cut back and you have a nice new earth connection! The people he was working for were forever at him for doing this, but there was no doubt that he produced the best work of anyone in the 'shop.

To watch this man weld paper thin titanium in a fish tank was akin to watching a fine artist at work!

Just something else to think about.

Syd.

This topic is extremly interesting.

I've just started welding too, and my trial and a lot of error seems to point to the fact that there are basically 3 variables involved.

Voltage, feed speed and distance the welder is from the material and speed which you mive the nozzle.

I started by setting everything on 50% or so, and destroyed 3 tips in a row before I realiased that the first 5 settings on my welder were pulse settings, so I actually had the wire feed on minimum <doh>

With some practice I managed to run a few OK looking beads on a piece of plate, then tried doing the same on different thicknesses at 90 degrees to eachother and had all the same problems all over again.

I can get the frying bacon sound at a massive range of voltages sat 3 through 7, but I fee rushed at the higher settings, so I've been turning the volts and the feed down, and doing things more slowly. Is this the right approach?

My welds don't look completly horrible, a bit too much material, and I seem to be getting OK penetration.

I'm using 75% argon 25% CO2 as a shielding gas, I just set it at about 17psi and haven't touched it since. Is there a rule of thumb about gas pressure?

[Edited on 25/2/06 by ERP]

Good info and diagrams of weave techniques etc:

HERE


Cheers


G

quote:

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Originally posted by ERP

I can get the frying bacon sound at a massive range of voltages sat 3 through 7, but I fee rushed at the higher settings, so I've been turning the volts and the feed down, and doing things more slowly. Is this the right approach?


[Edited on 25/2/06 by ERP]

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PS apologies for my rather strange post further up, I believe I was rather under the influence when that was "written"

Tried all the things suggested the other night. On a test piece I managed gorgeous welds but when i went to the 'real' thing, much better but not as neat, although a more experienced welder sade that they looked plenty strong enough. I found that with the wire feed set to '2', the wire disintegrated when it touched the weld pool, forming a blob on the end of the wire. The wire then fed down, touched the weld pool and the same happened. With the feed on '2 and a tiny bit' it seemed a bit fast. I also found that one weld would be really nice, then without altering anything, the next would not go so well. Ahhh the joys of self-building!!!!

It's soooo hard to diagnose what someone is doing wrong when your the other end of a pooter.

Are you trying to weld with too long a wire extension.
Get in close. The shroud should almost touch the weld as you progress.

If your liner or tip is restricting the wire feed rate this will have the effect of high volts / low wire.
When you move position to go from test piece to job you may be twisting the lead, making the
wire speed lower. Keep the lead as straight as you can.

The test is to disconnect the earth, (so you don't get a shock) and hold the wire as it comes out
of the tip between thumb and forefinger, pull the trigger, then squeeze the wire. I you can stop it
with ease and make the feed wheels slip, or stop the motor, then somethings wrong.
Try this with the lead out straight and again with it bent, as it would be while welding.

I may be way off here, but it would explain why one weld is OK, the next one poo.


Paul G