when to change from .8 to 1mm wire

[arther dailey]

So whats the general rule on changing up from .8 to 1mm mig wire, machine runs up to 200 amps, is it dictated purely by amperage or material thickness(m.steel).
I am guessing there is a guide on here somewheres but havent found it. thanks Arther.

 

[Fife]

You will get a quicker build up of weld with the 1mm wire on higher settings so it better for thicker material 10mm or more. I just use 0.8mm and weave it if welding thick material.

 

[mike 109444]

This manual may help a bit (page 13). Not exactly what you asked but a good guide and page 9> on "modes of metal transfer" explains where you are heading with that size of wire and current.
Quite a good read/guide

 

[arther dailey]

Cheers Mike, quite a good guide that eh.

 

[Omniata]

Just remember, your MIG is going to be running constant voltage, not constant current

For 0.8mm it'll tend to run out of dip transfer, through globular (messy) and into spray when hitting about 24V or over, right on the upper limit of your machine by the looks of things...
For 1.0mm it'll drift more towards dip transfer, so better for anything that isn't horizontal , but on the upper end if you run into globular it'll be messy...

Edit: Sorry, specs were read from the manual posted by @mike 109444

 

[anto]

I bought a Camarc 200c and it had a roll of 1mm wire in it.
It only appears to be 150amp max going by the data plate, is it "man enough" to run the 1mm wire or would it be better off with 0.8mm?
It'll weld with the 1mm but would it weld better with 0.8mm?

 

[Omniata]

I bought a Camarc 200c and it had a roll of 1mm wire in it.
It only appears to be 150amp max going by the data plate, is it "man enough" to run the 1mm wire or would it be better off with 0.8mm?
It'll weld with the 1mm but would it weld better with 0.8mm?

On "full tilt" it depends on the voltage, not the current, more than likely you'll be in low end globular transfer and there'll be splatter everywhere... You'll be moreso in dip transfer with 1.0mm and it'll be a lot cleaner...

 

[arther dailey]

Interesting,I did a voltage test on machine when I got it, I think voltage with wire speed flat out and max volt setting was 33volt,dont quote me on that though.
So would it be best welding say 5mm with .8 or 1mm?

 

[Omniata]

Interesting, I did a voltage test on machine when I got it, I think voltage with wire speed flat out and max volt setting was 33volt, don't quote me on that though.
So would it be best welding say 5mm with .8 or 1mm?

That'll be the OCV, or open circuit voltage, you need to measure the max voltage whilst welding to determine the output voltage being supplied to the wire, you'll need to test both with 0.8mm and 1.0mm.
The only way you're really going to know is to test, best to cut off some pieces of 5mm flat bar, prep, and try...

 

[arther dailey]

Gotcha, that makes sence, will have a go when I get the chance and thanks to all for advice.Arther

 

[Mee]

I find that anything over 150/160 amps requires a change up to 1mm wire.

 

[HughF]

I have run .8 up to and around 25-27v with 80/20 gas quite successfully. Never felt the need to step up to 1mm for the small volume of welds I was doing at those power levels.

 

[arther dailey]

seems there is a personal preferance which I geuss is also possibly down to machine perfoemance ,when I get some time will give it a go, i just wondered if there is a benchmark thickness of material that would generally be considered changing point.Thanks guys

 

[Omniata]

It'd be interesting to see the results

There is a bit of overlap with some machines, a lot of the time wires are changed to avoid mucky globular transfer that sits between dip and spray.
Whilst spray is incredibly fast and hot, good for thicker sections, it is only really useful in the horizontal flat due to the higher fluidity of the weld pool.
Changing up to drop into dip allows you to work out of position...

 

[arther dailey]

Aha, this is a good bit of advice, great thanks.

 

[Omniata]

It was discussed some time ago in this thread:

http://www.mig-welding.co.uk/forum/threads/metal-transfer-modes.3785/

Bearing in mind gas will also have an effect, you'd probably be better on Argoshield Universal than Light as a lower CO2 level is needed to encourage spray transfer...

 

[HughF]

This was .8 wire, 5mm plate, around 27v iirc. Argoshield heavy iirc.

 

[Omniata]

Here's a 3 page cut from BOC's manual, look on the second page, 310, the chart shows a simplified view of the transition ranges...

The vertical gap between wire lines in the green shaded area is where globular occurs...
Unfortunately they don't show the spray range for 0.8mm wire , providing you can get a high enough voltage and maintain it with either 80/20 gas or equivalent you should be able to find a happy medium where you can run spray for thick, and dip for thin...

 

[HughF]

Universal is 80/20, light is 95/5, the light has less co2

 

[Omniata]

...
Bearing in mind gas will also have an effect, you'd probably be better on Argoshield Universal than Light as a lower CO2 level is needed to encourage spray transfer...

Universal is 80/20, light is 95/5, the light has less co2

Whoops! My bad... BOC Universal it targeted more for thicker work and spray through...
Light is really 93/5/2, and Universal 86/12/2, Argon/CO2/O2, the added O2 has a wetting action and IIRC is similar to ~6% CO2 per 1% relatively.
Not sure if @shenion can help here as they have different mixes in the US and he did a lot of work with his own gas mixer designed for the purpose.