MIG Welder problems

[gromit]

My MIG welder was playing up last time I used it, intermittent wire speed.

I purchased it in the UK (I've been out here for 21 years now) so it must be about 30 years old. Cost about 350GBP at the time.
Never got used that much until the beginning of this year when I was working on modifying a car trailer.

I stripped the feed unit down today and found the grease in a couple of bearings was congealed. Then found that there is a lot of friction between the plastic spool and the mounting, added some lube as a temporary measure. Seems better, the wire feed has always been noisy. I've never changed the liner for the wire so maybe that should be next on the list.
Can you buy the wire feed module for an antique like this ?

[p38arover]

It's unlikely BOC ever brought that model into Oz. Were they in Oz back then? I doubt it.

Ask Toxic Avenger, he's got a lot more expertise on this sort of stuff.

[weeds]

It’s in bloody good condition for 30years...

[Homestar]

Not sure if the liner on that is replaceable, but you should be able to get a suitable whole torch and cable kit that could be fitted.

As mentioned, Toxic would have a lot better idea.

[FisherX]

As you said, if you have never changed the liner I'd be looking at that. I would at the least pull it out and check its condition. Its probably rusty inside if it is the wire wound type after all these years.

[gromit]

Not sure if the liner on that is replaceable, but you should be able to get a suitable whole torch and cable kit that could be fitted.

As mentioned, Toxic would have a lot better idea.

Might be an option.



As you said, if you have never changed the liner I'd be looking at that. I would at the least pull it out and check its condition. Its probably rusty inside if it is the wire wound type after all these years.

Looked like it was nylon, I'll take the torch apart and see how easy it is to remove. The wire feed end was simple.....


It's always been noisy when feeding the wire, no matter how much tension you put on the wire feeder it slips sometimes. I did wonder if the groove in the wire feeder has worn.
Running better since greasing the bearings, I'll check the liner next.

Thanks,

Colin

[Homestar]

If you’ve taken a peak and think the liner will come out, should be a simple fix. 👍

[Bigbjorn]

It's unlikely BOC ever brought that model into Oz. Were they in Oz back then? I doubt it.

Ask Toxic Avenger, he's got a lot more expertise on this sort of stuff.

Ron, BOC were here under the name CIG, Commonwealth Industrial Gases. They may have sold welding supplies to Captains Cook and Phillip.

[p38arover]

Ron, BOC were here under the name CIG, Commonwealth Industrial Gases. They may have sold welding supplies to Captains Cook and Phillip.

Yes, I used to buy from CIG. I thought BOC bought them out. Is that not the case?

EDIT: BOC formed CIG in 1935. One learns something every day.

[loanrangie]

Looks almost identical to my 130amp CIG mig right down to the plastic tensioner.

[ian4002000]

Have you cleaned the liner ?
Pour metho down the liner and then blow out with an air gun. Makes a big difference. it should be done often but most of us including me rarely do it.

Ian
Bittern

[p38arover]

Hmm, maybe I should do that with mine.

[gromit]

Have you cleaned the liner ?
Pour metho down the liner and then blow out with an air gun. Makes a big difference. it should be done often but most of us including me rarely do it.

Ian
Bittern

Should be interesting trying to get metho down a .6mm hole.......

Colin

[p38arover]

Old syringes are very useful. I use them for placing oil in difficult spots.

[Toxic_Avenger]

That machine is before my vintage.
I wouldn't bank on any parts availability unless you get a machine for spares and do the old switcheroo.


Firstly, can define how the machine was 'playing up'?

To test wire speed irregularities, get a stopwatch (on your phone), Disconnect your gas, ensure you are not part of the welding circuit, and dispense 15s of wire a few times. You should have a fairly consistent length of wire each time. If NG, wire feed is the problem. If good, look somewhere else.

Assuming it IS wire feed, then...

First thing I'd look at is for binding in the liner / tip both consumable items which need periodic maintenance. Steel liners can rust, and do pick up copper shavings off the MIG wire, which can clog it over time. If you are also using a crusty 21 year old spool of wire, you'll probably have some surface oxidation on the spool.
If shopping for a new liner, look for a suitable ID diameter liner for your setup (probably 0.6-0.9mm), then check that the OD is going to fit in the wire feed housing. Ensure liner is equal to, or greater than torch length (you can cut them down neatly with a knife or sharp side cutters if needed). Put a new tip on while you are at it. This just all screws apart on the torch end, and you'll have a fastener of some description on the machine end. Pull it out of the conduit, a man of your skills will have no concerns here.


Also check your wire pretension. This should be enough to draw the wire thru, but not crush it between the feed roller and idler roller. The spool should have little resistance, but not so much as to maintain momentum when the WF motor stops and on-spool under its own inertia.

I'd also pull off the gear housing for the wire feed drive. Might have some bad teeth in there, or a slipping shaft. Not much you could do if this is the case.
I'd also have a look at the potentiometer on the back of the wire speed feed control. If you get the chance to spray some deoxit or contact cleaner on it, you might have some luck, if it's an electrical speed reference problem.
Cast your eyes over the board for any obvious issues.

[gromit]

That machine is before my vintage.
I wouldn't bank on any parts availability unless you get a machine for spares and do the old switcheroo.


Firstly, can define how the machine was 'playing up'?

To test wire speed irregularities, get a stopwatch (on your phone), Disconnect your gas, ensure you are not part of the welding circuit, and dispense 15s of wire a few times. You should have a fairly consistent length of wire each time. If NG, wire feed is the problem. If good, look somewhere else.
You could actually hear it speeding up & slowing down and sometimes it stopped feeding the wire.

Assuming it IS wire feed, then...

First thing I'd look at is for binding in the liner / tip both consumable items which need periodic maintenance. Steel liners can rust, and do pick up copper shavings off the MIG wire, which can clog it over time. If you are also using a crusty 21 year old spool of wire, you'll probably have some surface oxidation on the spool.
New spool of wire, nylon (?) liner.

If shopping for a new liner, look for a suitable ID diameter liner for your setup (probably 0.6-0.9mm), then check that the OD is going to fit in the wire feed housing. Ensure liner is equal to, or greater than torch length (you can cut them down neatly with a knife or sharp side cutters if needed). Put a new tip on while you are at it. This just all screws apart on the torch end, and you'll have a fastener of some description on the machine end. Pull it out of the conduit, a man of your skills will have no concerns here.


Also check your wire pretension. This should be enough to draw the wire thru, but not crush it between the feed roller and idler roller.
I could tighten this down till the spring was almost fully compressed and the issue continued.
The spool should have little resistance, but not so much as to maintain momentum when the WF motor stops and on-spool under its own inertia.

I'd also pull off the gear housing for the wire feed drive. Might have some bad teeth in there, or a slipping shaft. Not much you could do if this is the case.
Did that and greased the bearings.
I'd also have a look at the potentiometer on the back of the wire speed feed control.
If you get the chance to spray some deoxit or contact cleaner on it, you might have some luck, if it's an electrical speed reference problem.
Cast your eyes over the board for any obvious issues.

The plastic wire spool runs on a plastic spigot, there was a lot of friction here. Lubricating helped overcome the issue but nut sure why this happens. Never had this before over several spools so maybe a cheap plastic spool ?

Checking out a couple of UK forums and the welder turns up under several different names (back in the day.....)

Need to get my Argoshield bottle re-filled and try some welding.....


Colin

[bee utey]

On my antique mig welder (1970's) I ground down the grooved feed roller to allow the pinch roller to get more grip. From memory the plastic liners were for aluminium, steel wires ran in spiral wire liners. Shouldn't be hard to extract the liner and get a new one for it from a welding supply shop. I also make sure the welding gun has the easiest possible curve to the welder, makes it run smoother. Friction on the spool mount is important so that it doesn't over run and tangle the wire around the post.

[Toxic_Avenger]

I've seen intermittant feed issues as a result of a dicky switch in the handpiece. Might be a valid course of investigation. The
Fault find by wiggling the torch cable while actuating switch. Youn might find a cause/effect pattern.
I even had one issue where the old torch had a continuous feed... which stopped when the operator held the torch above his head. Turned out the trigger spring retaining washer was flopping around inside the trigger switch and shorting out the contacts, but breaking contact when inverted.

The above might resolve the 'stop feeding' condition.
You could also look into the integrity of the high/low switch to see if this is a cause of the speed fluctuations.

[gromit]

I've seen intermittant feed issues as a result of a dicky switch in the handpiece. Might be a valid course of investigation. The
Fault find by wiggling the torch cable while actuating switch. Youn might find a cause/effect pattern.
I even had one issue where the old torch had a continuous feed... which stopped when the operator held the torch above his head. Turned out the trigger spring retaining washer was flopping around inside the trigger switch and shorting out the contacts, but breaking contact when inverted.

The above might resolve the 'stop feeding' condition.
You could also look into the integrity of the high/low switch to see if this is a cause of the speed fluctuations.

I have a feeling it was mostly the friction between spool and plastic spigot it runs on. When it stopped feeding the wire feed was still running just not able to pull the wire from the spool. The congealed grease in the bearings didn't help.

Bottle filled today so I'll try using the welder at the weekend.

I did find that BOC are 'sort of' competing with the 'buy your own bottle' offers.
They are now doing annual rental on D size including one refill. Ideal for infrequent users.
Oxy & acetylene annual rental & one fill would be $188 inc GST. Small bottles....yes, but easier to justify to SWMBO.


Colin

[Toxic_Avenger]

Most machines will have some kind of idle tension system on the spool, too little friction and it will over-run, 'birds nest' the wire or jam.

The gas thing is not news to me. The point of differentiation is the absence of any deposit up-front, and an included fill each year, which is unique.
Info here (https://www.boc.com.au/shop/en/au/fill-for-less?utm_campaign=li-fill-for-less&utm_source=banner&utm_medium=referral&utm_content=Find%20Out%20More%20-%20Xmas)

[mick88]

Colin make sure you have the right roller in it for steel wire.
You should have got a few with the unit when you purchased it new.
If the serrated roller is used on steel wire after a while you get a build up of fine dust/filings in the feed tube and it causes feed issues.


Cheers, Mick.

[gromit]

Colin make sure you have the right roller in it for steel wire.
You should have got a few with the unit when you purchased it new.
If the serrated roller is used on steel wire after a while you get a build up of fine dust/filings in the feed tube and it causes feed issues.


Cheers, Mick.

Mick,
Only one came with it (from what I can remember from 30 odd years ago), not serrated but always worked OK.

Problem seems to be resolved. There is no friction adjustment on the spool (it's controlled by a spring). The plastic spool was 'picking up' on the plastic spigot, lots of dust and scuff marks on the inside of the spool so creating way too much friction.
Will confirm it's OK at the weekend.

Colin

[gromit]

Since starting this post I've been gifted a Unimig but still want to fix this old MIG welder.
I decided to look at the liner, problem is I can't find a source for a replacement.
Its black PTFE 4mm OD, it actually terminates in a pneumatic fitting at the torch end. There is a coiled wire liner for the torch.
I'm using 0.6mm wire.

It's a BOC Migmaster Turbo 130 but was sold under Cebora and Snap-On brands from my limited research.
I could replace the torch but as it's a backup welder I really don't want to spend much fixing it.

Anyone know where to get PTFE tubing 4mm OD 1mm ID ?

Colin

[roverrescue]

Gromit
For a number of years I’ve used bobthewelder.com.au for supplies

I reckon if you contacted them they would be able to get you out of trouble?

S

[workingonit]

...still want to fix this old MIG welder...Colin

I have a BOC MIG about 23 years old, can swap the polarity around for gas or flux core, still going.

A welding supplier should be able to provide a liner of some sort. You may have to trim it.

I had trouble with the pinch roller. The top and bottom rollers on my machine sit on separate plastic plates. Despite being held by two screws the bottom plate moved away from the top plate, thus widening the pinch gap, to the point that no amount of tension adjustment would pinch the wire sufficiently. Remedy was to undo the bottom platte securing screws and move the bottom plate back to its original point - the holes in the bottom plate are slotted giving opportunity for this creeping, and the screws can't bear down enough on the plastic to ensure no movement at all.

Interesting to see if yours had a made in Finland sticker.

[gromit]

I have a BOC MIG about 23 years old, can swap the polarity around for gas or flux core, still going.

A welding supplier should be able to provide a liner of some sort. You may have to trim it.

I had trouble with the pinch roller. The top and bottom rollers on my machine sit on separate plastic plates. Despite being held by two screws the bottom plate moved away from the top plate, thus widening the pinch gap, to the point that no amount of tension adjustment would pinch the wire sufficiently. Remedy was to undo the bottom platte securing screws and move the bottom plate back to its original point - the holes in the bottom plate are slotted giving opportunity for this creeping, and the screws can't bear down enough on the plastic to ensure no movement at all.

Interesting to see if yours had a made in Finland sticker.

I've tried a couple of welding suppliers including BOC & also Ebay for a liner with no success.
This one is made in Italy I think.
Several articles on the internet and in many cases people (in the UK) are changing the torch to get round the problem.

Colin

[Homestar]

Since starting this post I've been gifted a Unimig but still want to fix this old MIG welder.
I decided to look at the liner, problem is I can't find a source for a replacement.
Its black PTFE 4mm OD, it actually terminates in a pneumatic fitting at the torch end. There is a coiled wire liner for the torch.
I'm using 0.6mm wire.

It's a BOC Migmaster Turbo 130 but was sold under Cebora and Snap-On brands from my limited research.
I could replace the torch but as it's a backup welder I really don't want to spend much fixing it.

Anyone know where to get PTFE tubing 4mm OD 1mm ID ?

Colin

Looks like 4mm OD with 2mm ID is a common size but not 1mm ID.

[Toxic_Avenger]

Some liners (PTFE Binzel for example) have a collet style end on the liner.
Tweco is more of a crimped on fitting. There are not too many different end fitting styles.

The liner is only there to guide the wire thru the torch lead. It doesn't hold gas, it doesn't carry power. So within reason, as long as the liner is loosely sized to your wire diameter, and it fits in the torch cable, you should be right. Then you just need to work out how it is secured on the drive roll end - looks like a grub screw of some description in this case? The burny-end of the torch liner usually just rests against the back of the contact tip

[gromit]

Some liners (PTFE Binzel for example) have a collet style end on the liner.
Tweco is more of a crimped on fitting. There are not too many different end fitting styles.

The liner is only there to guide the wire thru the torch lead. It doesn't hold gas, it doesn't carry power. So within reason, as long as the liner is loosely sized to your wire diameter, and it fits in the torch cable, you should be right. Then you just need to work out how it is secured on the drive roll end - looks like a grub screw of some description in this case? The burny-end of the torch liner usually just rests against the back of the contact tip

2mm bore is available in 4mm OD but seems a bit big for 0.6mm wire.
Torch end terminates at the gas valve in a pneumatic fitting then spiral wire from there. Other end clamped in place.

Unusual design and hence parts difficult to source from my limited research.

Colin

[BathurstTom]

I recently reco'ed my little unimig mini 120. It's well over twenty years (or more) old and the wire had seized up in the liner. Cost me about $16 delivered for a new one off of ebay. Australian seller. Very good to deal with. Really knows his stuff.

https://www.ebay.com.au/str/weldersonline

Tom.

[roverrescue]

Gromit
What is the connection at the unit end?
I have an old (taking up space) torch with 3 or 4m whip (can’t remember) Euro fitting from a Lincoln PowerMIG
It’s a 250A torch
Has a bit of burn through on the neck which you’d need to fix to prevent entraining air into the gas mix.

I was in middle of a build and needed to be up and running so bought a new 300 or 350A torch

Anyways if you want it
It’s yours happy to post

S

[gromit]

Gromit
What is the connection at the unit end?
I have an old (taking up space) torch with 3 or 4m whip (can’t remember) Euro fitting from a Lincoln PowerMIG
It’s a 250A torch
Has a bit of burn through on the neck which you’d need to fix to prevent entraining air into the gas mix.

I was in middle of a build and needed to be up and running so bought a new 300 or 350A torch

Anyways if you want it
It’s yours happy to post

S

Thanks for the offer.
The gas valve is in the handle so I'd have to add a separate valve.
I'll probably just move to the Unimig and try a few more suppliers for a suitable liner for this old welder.

Colin

[AK83]

Just a thought:
You can get 2x1mm tubing, and you can get 4x2mm tubing .. could you get lengths of each and try to insert the 2mm OD tube into the 4mmOD tube to make it double tubed?
Can imagine it'll be hard to do over the length of the torch hose, but maybe some slippery stuff(water/soap, or WD or whatever to help it reduce friction)

Had a quick search and there is a mob that seems to offer various sizes of tubing in the UK.
4x1mm was one of the options.

Dunno where to get or how to order, but I'll post the link to what I'd found.

Valpar Industrial.

I did a search for pneumatics.

I guess the other option is to find a pneumatics supplier and see if they have anything.

Actually, scratch that.
Did a search on the bay and found a 2x1mm tube supplier(in NSW), went back to find them again and got lost in the mire, but found this shop(in WA) instead .. with an option for 4x1mm tube .. among many incrementally small alternative options to boot.

Ebay link (https://www.ebay.com.au/itm/Silicone-Rubber-Tubing-Silicon-Tube-Hose-Medical-Food-Grade-ID-from-0-5mm-to11mm/121841722645?hash=item1c5e552515:m:mWz_9mCJuyGyKmu ev7v65-Q)

Not cheap tho!

EDIT: go to their shop, they also have other options for material types as well. eg. viton and PTFE too. Not quite the 4mm OD you wanted, and those options come in 3x1mm, but I'd reckon the other two material types would be stronger and less prone to heat damage(mainly at the tip end).
Didn't see nylon as an option too.

[gromit]

Just a thought:
You can get 2x1mm tubing, and you can get 4x2mm tubing .. could you get lengths of each and try to insert the 2mm OD tube into the 4mmOD tube to make it double tubed?
Can imagine it'll be hard to do over the length of the torch hose, but maybe some slippery stuff(water/soap, or WD or whatever to help it reduce friction)

Had a quick search and there is a mob that seems to offer various sizes of tubing in the UK.
4x1mm was one of the options.

Dunno where to get or how to order, but I'll post the link to what I'd found.

Valpar Industrial.

I did a search for pneumatics.

I guess the other option is to find a pneumatics supplier and see if they have anything.

Actually, scratch that.
Did a search on the bay and found a 2x1mm tube supplier(in NSW), went back to find them again and got lost in the mire, but found this shop(in WA) instead .. with an option for 4x1mm tube .. among many incrementally small alternative options to boot.

Ebay link (https://www.ebay.com.au/itm/Silicone-Rubber-Tubing-Silicon-Tube-Hose-Medical-Food-Grade-ID-from-0-5mm-to11mm/121841722645?hash=item1c5e552515:m:mWz_9mCJuyGyKmu ev7v65-Q)

Not cheap tho!

EDIT: go to their shop, they also have other options for material types as well. eg. viton and PTFE too. Not quite the 4mm OD you wanted, and those options come in 3x1mm, but I'd reckon the other two material types would be stronger and less prone to heat damage(mainly at the tip end).
Didn't see nylon as an option too.

Hi Arthur,
I really need PTFE for the heat resistance and slipperyness, the torch end (beyond the gas valve) is spiral wire so I need it from the wire feed to torch (2 metres).
Most welders use spiral wire for steel and PTFE for aluminium but this DIY welder uses PTFE for steel.

I'm in the Pneumatics business and can source most sizes of tube but it's not often you need PTFE and such a thick wall thickness is unusual anyway.

Maybe 2mm OD with a short section of 4mm pushed over the end where it goes into the push fit pneumatic fitting. Wonder if it might be a bit floppy and move inside the umbilical cord as the wire pushes through ?


Colin

[AK83]

Yeah, thought PTFE was the go, have a look at the ebay link, that seller(in the store, not the listing I posted) has PTFE in a similar size(3x1mm).

Looks like $18/m

Note sure how the 3mm OD would work at the end for 'ya.

[gromit]

Yeah, thought PTFE was the go, have a look at the ebay link, that seller(in the store, not the listing I posted) has PTFE in a similar size(3x1mm).

Looks like $18/m

Note sure how the 3mm OD would work at the end for 'ya.

Arthur,

I found a steel wound liner listed for the 'Snap-On 130' which is another name this welder was sold under.
I've ordered one of them and I'll see whether it fits OK.

Also found what might be the correct PTFE liner from the UK listed as Snap-On 130 & Cebora 130. Might be an option if the steel wound one doesn't work out.


Colin

[gromit]

Ebay to the rescue.
Steel wound liner arrived today, OD was under 4mm so it wouldn't grip in the pneumatic fitting at the torch end so I fitted some heat shrink over the end.
Installed, cut to length, clamped.....works much better than the old PTFE liner.

Another job off the list.


Colin