Validate my assumptions!

[Llama]

Hi everyone,

Been lurking a while, but have recently acquired a BOC 180P with a CO2 bottle, and a very generous pile of scrap flats to stick together.

Have just been running lap and butt joints to get the settings tuned, and think I have a few things figured out.

-I had cases where (using the settings from the sheet) it would splutter as I was running, even though my stickout was quite tight (I was bumping the nozzle into the pool quite often). I turned the voltage up 1-2V above recommended, and that seemed to help. Is this because I'm using CO2 rather than the recommended argoshield? I was planning on getting a rented bottle once I had something more than scrap to weld.
-What happens with too much voltage? (aside from too much heat input)
-Low inductance causes lots of splatter and a rough weld, too high inductance causes ???
-Just because the metal isn't glowing, doesn't mean it isn't hot!

I can post pictures if you like.

Thanks in advance.

 

[Carsten S]

Hi and welcome.
The settings on the sheet is a startingpoint, nothing more. On some machines they are a little to the cold side, on others a little to the hot side. You will allways need to tweak the wirefeedspeed or the voltage to get it going perfect.
If the voltage goes way too high, the wire burns back in to the contact tip.

Does your machine have inductance-outputs to the groundcable, or is it a dial you can tweak?
On most older transformermachines the inductance outputs are related to wiresize. Ie. output a = 0,8-1,0 mm wire, output b = 1,2 mm+

For most hobbyists CO2 will do just fine. You won't get into spraytransfer, but thats more for production.

 

[Llama]

Hi, thanks for the reply.

You will allways need to tweak the wirefeedspeed or the voltage to get it going perfect.

Well that's the funny thing, my machine only has a "fast/ slow" rocker switch for wire speed, which (according for the manual) corresponds to 0.6 and 0.8 or 1.0mm wire respectively.

If the voltage goes way too high, the wire burns back in to the contact tip.

Ah. Then you get melted contact tip? Haven't managed this yet, must be a good thing

Does your machine have inductance-outputs to the groundcable, or is it a dial you can tweak?

It's a dial, ranging from 0-10. No mention at all is made at all in the manual.

 

[shenion]

Sounds like the 0-10 dial would be an adjustment for the wire speed.

 

[mike 109444]

Sounds like the 0-10 dial would be an adjustment for the wire speed.

Would agree with Shenion it does sound like you have the wire and power controls mixed up?
Post a pic of frount of machine would help and if you have it a pic of the inside.

 

[Tino]

Sounds like an unusual machine. Most have much more wire speed adjustment and a lot less inductance control. To much inductance will reduce your penetration.
Pictures are always good.

 

[Llama]

Pictures as promised!

The Machine

These are lap welds on 3mm steel. 16.5V, 75A, 0.9 wire on "low speed" and the inductance written above the weld.

The flattest of the welds (although not by much). Very little splatter

Splatter central.

Bad hand positioning you can tell as I dipped the nozzle into the weld a bit

I plan on attacking the welds with an grinder to check penetration when I get the chance.

 

[Llama]

Oh doh, forgot the inside. Will get one for you folks tomorrow.

Cheers!

 

[shenion]

That control panel makes no sense. On MIG you have a voltage setting, the current is set by the wire size and speed.

I guess it could be adjusting the wire speed to reach the current setting of the knob.

 

[Llama]

I guess it could be adjusting the wire speed to reach the current setting of the knob.

Yeah, that is what I was suspecting too. It was and older model BOC are trying to get rid of cheap I think.

 

[pedrobedro]

There's a manual for it here and it describes the voltage control as the wire speed and the inductance as infinitely adjustable.

 

[Llama]

Ah. That is slightly unintuitive, but I guess it makes sense. Thanks!