Classic cars forum & vehicle restoration.

[47Jag]

I'm getting my MIG welder out of it's 20 year slumber. It's Migmate 120 and I had bought and fitted a new torch before work put an end to progress on the bodywork. I was under the impression that the torches were to a standard spec. (I now know better). I've probably forgotten what I learned at night school. We will find out in due course. My question is this, the 'new' torch is a Trafimet 14 and it came with a .8 mm tip. Will it be OK to use this size wire on my Migmate. Will I need to step up the current or is it just a case of trial and error. I had a look on the 'net for .6 mm tips and they are available for 40p each but the supplier has a standard delivery of £6.50 All advice welcomed.

Art

[colwyn500]

Art, I expect that your welder would be up to the job, especially with the fact you probably wouldn't be racking up the amps with car work. Even so, I would stick with 0.6 tips simply because bodywork generally needs the lowest output possible and the smaller wire makes this possible.
I don't know that torch but I would pop into BOC and see if the tips are standard.

[47Jag]

It was made in Italy and the tips are 6mm diameter and 25mm long. The original Migmate tips are only about 4mm diameter. I need someone in Melton Mowbray to buy and send them to me Of course I should have realized that thicker wire means more current and therefore bigger holes.

Art

[MikeEdwards]

I had a quick search around and while I can find a part number (MD0008-06) they don't seem easy to get over here. One site - http://www.trafimet.cn/en/goods.php?id=1013 - lists a load of spare tips but doesn't really tell you much, another site - http://www.everlastgenerators.com/product/ev-md0008-06-6mm023-contact-tip-kit-10-pc - from searching on that PN seems to suggest $9 for ten but who knows what postage on top? Might be possible for a decent engineering firm to make some given the dimensions.

I'd perhaps recommend you get on the forum at mig-welding.co.uk and get in touch with a member called 'weldequip', as he specialises in selling MIGs and parts, and might be able to help.

[47Jag]

I phoned DIY Welding and the guy said he would supply me with tips and only charge postage. The £6.50 quoted on their website was for next day delivery. I can wait 'til Monday

I have a BOC regulator (the proper one). What pressures and current should I be using when welding sheet metal. The pressure regulator has lines that indicate the pressure but they seem quite thick. Is it something that doesn't have to be exact (I'm guessing)?

Art

[Penguin45]

10-12psi for gas. Use test pieces to assess current requirement. Start at minimum settings - bear in mind that most body panels are 0.8 - 1mm, so find some scrap off-cuts to play with before going anywhere near the vehicle.

If you're out of practice do "join the dots" rather than try for continuous beads until you're feeling more confident. A few spots to secure the panels, then fill in the gaps. Dots or very short bursts will reduce heat build-up and reduce distortion.

Practice, practice, practice - that's all it is once you've got the basics back.

P45.
_________________
'67 Wolseley MkI 18/85, '70 Austin MkII 1800 The Landcrab Forum.

[colwyn500]

With the gas, flow rate is important, and to get best economy you also want to start with a fairly low flow and increase it if the weld is spluttery or it's hard to keep a smooth arc. I find that wire speed is the most influential thing over the neatness of weld and have to micro adjust until I get it just right.
Most people know that the steel needs to be really bright and shiny but when i want a perfect weld I even go as far as degreasing the joining edges. Obviously safety issues there with flammable liquids and welding so care is needed to work in an organised way.