Not enough penetration

[gjkathome]

Hi I have bought a second-hand Clarke 135TE Turbo. I have done some rudimentary maintenance; cleaned it, new tip, new shroud, adjusted wire tension. I'm new to all this.
I have been practising on 1.5 mm mild-steel sheet using CO2. The welder has two switches labeled 1-2 and Min-Max respectively. Following advice in the manual I have set these to 2 and Min with wire-speed set to 6. This seems to get me close to the sizzling bacon sound but there seems to be no penetration - the weld just seems to sit on top of the sheet, I do not get the equal-sized bulges top and bottom as illustrated in the tutorial (https://www.mig-welding.co.uk/power-setting/mini-sectioned-welds.jpg).
I have tried playing with the wire speed, welding speed and height of the shroud above the work. I seem to be able to get bigger beads but still no penetration. I have tried setting the second switch to Max. On a couple of occasions this has resulted in some penetration but I have found it very easy to blow holes.
Any advice please?

 

[Matrixx]

Can you put some pics up? sounds like not enough voltage?

 

[gjkathome]

More info. I have measured the voltages at the various settings:
1 MIN 9.5v
1 MAX 13.2v
2 MIN 11.0v
2 MAX 16.4v

Seems odd as the manual suggests that 2 MIN should be higher than 1 MAX.

 

[Rrobson]

Is polarity correct?

 

[a111r]

More info. I have measured the voltages at the various settings:
1 MIN 9.5v
1 MAX 13.2v
2 MIN 11.0v
2 MAX 16.4v

Seems odd as the manual suggests that 2 MIN should be higher than 1 MAX.

Those OCVs are way out. For a similar Clarke model (90, 100) they should range from 18 v to 28 v.
They are renown for corrosion on the crimp to the inductor and earth, causing high resistance. There a picture of this on a fairly recent Clarke thread of mine.

The TE models are all fixed polarity, torch positive.

 

[a111r]

https://www.mig-welding.co.uk/forum/threads/another-deal-clarke-im-perplexed.100987/

Cut off the crimp and replace with a large screw terminal block.

Some of their manuals are wrong for the machine, the rocker switches can work differently:
1 min, 2 min, etc... instead of 1 min, 1 max.

 

[gjkathome]

https://www.mig-welding.co.uk/forum/threads/another-deal-clarke-im-perplexed.100987/

Cut off the crimp and replace with a large screw terminal block.

Some of their manuals are wrong for the machine, the rocker switches can work differently:
1 min, 2 min, etc... instead of 1 min, 1 max.

Thanks very much for that I'll have a look at the connection in the morning.

 

[MattF]

The thread title sounds like the story of my life, these last couple of years.

 

[Nick DV]

The thread title sounds like the story of my life, these last couple of years.

 

[eddie49]

The low open-circuit voltages could also be due to one of the four "effective" diodes in the bridge rectifier going open-circuit.

 

[gjkathome]

I've opened the welder but I don't see anything quite like the crimped connected discussed in the thread above. I have measured the OCV at two points as indicated photo.
I got 16.4 volts at the red cross, 21 volts at the yellow. I have no idea what the mechanism in this photo actually does.
If it is something wrong with the bridge rectifier what do I do?
Thanks.

 

[a111r]

That's the half-wave bridge rectifier. You can see 8 diodes on the two alloy heat sink plates.

If your meter has a diode test function, you can test them individually, easily, in-situ.
They will conduct one way, giving a reading around 0.5, whilst the other way they should give no reading at all with no conduction.

I think you will have the crimps, on the wire from the yellow X (the DC -ve).
Take another side-on photo?

 

[gjkathome]

Right, first the apology. Having now learnt how to use my multi-meter properly I think the voltages are OK.
1 Min 19.7v
2 Min 23.0v
1 Max 27.4v
2 Max 33.8v
So, sorry for introducing red herrings. Still, at least I have now tested the diodes (0.46 in each case) and have checked various connections. I also know that the manual I have has the middle two settings swapped.
The images below are my efforts on 1.5mm mild steel, with settings 1 Max (27.4 volts) and wire speed as follows:
1 5
2 5.5
3 6
4 6.5
5 7
I was using 86% argon and 14% CO2.
Top image is as it looked when I finished. Second is with some of the brown sooty stuff rubbed off. Third is from underneath (flipped so the numbers correspond correctly).
I have not been getting the sizzling bacon sound as well as I did with earlier attempts. More like a sizzle with the occasional loud pop. I wonder if the wire feed is not consistent?

 

[a111r]

The machine's OK then. 1 and 2 are the best.
Did you try using setting 2 Min for that thickness?

 

[gjkathome]

Thanks. I'll try that.

 

[DavidL]

It is my limited experience that the wire feed on a Clarke is as you describe, from new. Despite faffing about with liners and eventually replacement with a euro socket and (short) torch, I could never get a spot on consistent feed on mine. Either (occasional) pops or judders, which I'd for a long time assumed was a setup or technique problem.

It was only when using a different welder (also very cheap, but a Sherman) with a very different feed mech (on the same short euro torch) that I concluded it must be the Clarke feed - those cheap plastic wire feeds just seem a bit marginal.

Not terrible by any means; works ok ish but not very consistent - and off-putting when learning!
This said, it (well, mine!) seemed to weld ok if you ignore the odd noises and press on regardless. Well, as "ok" as I could manage. No doubt an expert could weld perfectly well with one

 

[gjkathome]

Thanks everyone for your input. Here are some images using the 2 min setting (23v). Wire feed settings are, from left to right 4.5, 5, 5.5, 6. I think 6 my have been too high as I seemed to keep welding the wire to the tip.

 

[backpurge]

They are all too hot, you are burning right through the plate. Penetration is something completely different

 

[Munkul]

turn the wire feed up.

I'm getting sick of saying this.


Wire speed = amps = penetration

volts do not equal penetration!!!

 

[outofthefire]

turn the wire feed up.

I'm getting sick of saying this.


Wire speed = amps = penetration

volts do not equal penetration!!!

It's not just turning the wire speed up though is it, it's a balance between the control's especially on a hobby machine. You can't adjust the wire feed too far before it either starts burning back or hitting the metal before it's arced. Personally on a hobby machine I turn everything to full, adjust the wire speed till it's welding right. If I burn through I dial back the wire speed, and drop the power a bit to suit, or move quicker. If you're sick of repeating yourself just ignore the posts.