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Could do with some help/advice regarding my MIG welder [hopefully SOLVED]
David Jenkins - 12/7/21 at 12:18 PM

Some of you may recall that I was having some difficulty with my Sealy 150/5 MIG welder recently. I've now had some time to take a good look at it, and to do some test welds. Note that this welder did work a few years ago, but has been sitting idle lately.

weld test
weld test


Looking at various YouTube videos, it looks like my wire speed is way too low - but I turned it up to maximum and got the same result. These horrible blobs represent tests will all sorts of wire speed and voltage settings - always the same result. IMHO, I have a wire feed problem, however I may have got my analysis totally wrong!

I did find one error - I had an 0.8 nozzle tip instead of an 0.6 one, but that's been replaced with the correct item.

Anyway - here's what I've found so far...


I plan to get some Argon/5% CO2 gas very shortly, as I always found that much easier and forgiving to use. I will also get a new spool of wire (probably a much smaller spool, like 1Kg), However, I would appreciate any input from anyone while I'm waiting!

[Edited on 12/7/21 by David Jenkins]


nick205 - 12/7/21 at 12:58 PM

I'm sure you know this and have it in order, but...

Earth clamp good?

Metal as clean as you can get it?


David Jenkins - 12/7/21 at 01:03 PM

quote:
Originally posted by nick205
I'm sure you know this and have it in order, but...

Earth clamp good?

Metal as clean as you can get it?


Both good! (but I will check again)

The metal was cleaned with one of those scotchbright wheels, then wiped with meths.

It's the feeble wire feed that concerns me mostly.


nick205 - 12/7/21 at 01:25 PM

Understood.

In which case have you investigated getting replacement feed rollers for your welder?

Most welder makers do repalceent sets. It may be that the groove is worn and not gripping correctly.

You may find a welding supplier local to you who can supply the parts and evenn advise on the issue.


djtom - 12/7/21 at 03:00 PM

You certainly have a feed problem - if I try to hold the wire at the nozzle on my welder and pull the trigger there's a strong push and it's pretty hard for me to hold it tight enough that the feed roller slips. As suggested, adjust roller preload or replace roller if it is knackered.

However, looking at the test piece, I don't know what settings you are using (you say all sorts), but none of those welds show any heat or penetration.

Hard to say without knowing what size/thickness that lump of scrap is, but if you turn a 150A welder up anywhere near max I'd be expecting to see welds looking a lot flatter and hotter than that - in fact 150A will happily blow holes in 1.5mm wall RHS. If you are certain that the earth clamp is well connected, take the cover off (unplug beforehand, safety first!) and make sure that all the power feeds from the transformer to the front panel are tight. It looks like you are not getting much current at the workpiece.


jps - 12/7/21 at 03:04 PM

I'm no expert - at best I am of the view that I can stick 3mm plate bits together, and they pass the hammer test for strength - but....

quote:
Originally posted by David Jenkins
  • The wire comes out when I pull the trigger, and the feed roller spins energetically according to the feed setting, but I can hold the wire at the tip and the roller just spins - there's no noticeable 'push' on the wire.

  • Do you meant you can pinch the wire with your finger and it stops coming out? If so - i understood this to be a big no-no. I setup the wire tensioner on my MIG so that I can't do this - if I pinch the wire as it's coming out of the torch with the trigger pulled it just pushes through my fingers.


    quote:
    Originally posted by David Jenkins
  • When I weld, there's lots of banging and popping going on, with spatter going everywhere.


  • This sounds like insufficient gas flow to me, especially the spatter.

    I get banging and popping when the wire speed is wrong, too fast and you can feel it pushing the gun away from the workpiece, too slow is usually banging and popping. Have you actually checked the wire speed is changing as you turn the dial - e.g. by timing how much comes out over a set period of time? Even if the speed is right, i wonder if you're getting in consistent wire feed?


    Partofthechaos - 12/7/21 at 03:11 PM

    What I know about welding and welders could probably be written on a postit note, but I watched this video recently which seemed to have some really good ideas in it: https://www.youtube.com/watch?v=c3B1mB07P4k . A good chunk of the video seems to be related to wire feed, could be worth a watch?

    Apologies if I have completely misunderstood!


    JeffHs - 12/7/21 at 03:28 PM

    I started with a second-hand Clarke HohbyMig 90 amp machine. I upgraded it with a much better torch but The wire feed was always a problem.
    I replaced it with a SIP 150. It had exactly the same wire feed mechanism as the Clarke and consequently it too was intermittent. I changed the liner to a wound steel one from Machine Mart and it transformed the machine. I can longer blame the machine for my crap welding!


    theconrodkid - 12/7/21 at 03:36 PM

    to me looks like you have not enough amps, check conexions on trans and earth lead, if it,s been sitting somewhere damp that will cause problemos
    150 amps should be able to melt 3mm no probs
    on my 130 amp, i changed the earth lead from the tranny and put a dinze on the casing, some mega copper for the earth cable and it really made a difference.


    David Jenkins - 12/7/21 at 04:17 PM

    jps - correct, I can stop the wire with my fingers, even though the drive wheel is still spinning. Consistent wire speed is the problem. Plenty of CO2 flowing.

    djtom - the steel is about 3mm. I would also expect to be able to blow right through it at max wire speed, but all the symptoms are as if I had it on minimum speed.

    JeffHs - I'm not sure that the liner is the problem (although I accept that it could be). I can pull the wire through the whole system easily when the pinch roller is loose.

    theconrodkid - plenty of amps available - it's just the wire is blowing back to the nozzle as soon as it touches down, as the feed rate is too low. Normally the wire should be attacking the weld pool fast enough that the only part of the wire that melts is the bit a fraction above the weld pool.

    One problem with trying to change parts is that the welder's quite old, and trying to identify what I need is just about impossible on the Sealey website!

    I've just been out to get some argon/CO2 gas, and I'll get a small spool of fresh wire tomorrow, and see how I get on with that.

    [Edited on 12/7/21 by David Jenkins]


    rusty nuts - 12/7/21 at 05:22 PM

    David, have a look on the Mig welding forum , there is likely to be a load of info on your particular welder faults . It might be worth changing the liner , they can and do cause problems but it might be a cheap fix


    jacko - 12/7/21 at 05:57 PM

    Is the liner in the torch a tight fit if not it will move up and down making the weld spit and splutter as the wire goes though it
    Graham


    motorcycle_mayhem - 12/7/21 at 06:48 PM

    First thing is to look at the obvious wire feed problem, worn rollers, feed motor (and/or control gear and/or relay). Poorly wound Chinese wire won't help either. Wire should give you quite a hard time trying to stop it coming out of the nozzle, in fact if there's any slack post roller it'll bunch up quite nicely at the liner junction if try and stop 0.6mm wire.

    Assuming that's now fixed, look at the earth attachment, any corrosion/looseness/fraying/whatever will limit your current. Then the torch feed (both ends). Gas solenoid and plumbing.

    All OK? Look at the power selection gear (I assume a switched transformer unit, not invertor), then check out the diode pack. If you've got low voltage AC and not a good DC output you'll have exactly what you see at the moment....


    David Jenkins - 12/7/21 at 06:53 PM

    Looks like I've found a solution!

    Connected up my new cylinder of argon/CO2 mix, set the controls to mid-range - and got a bead. It's not correct yet, but now I've got a bead I can work up to the correct settings. Obviously there was something amiss with the CO2 cylinder - it is approaching empty, but gas seemed to be flowing OK... but maybe it wasn't. Looks like jps wasn't far wrong with his guess about gas flow.

    I've still got a few things I'd like to sort on my welder, mostly the idle roller tension, but at least I have a starting point.

    Thanks for all the help and advice!


    David Jenkins - 12/7/21 at 07:07 PM

    quote:
    Originally posted by Partofthechaos
    What I know about welding and welders could probably be written on a postit note, but I watched this video recently which seemed to have some really good ideas in it: https://www.youtube.com/watch?v=c3B1mB07P4k . A good chunk of the video seems to be related to wire feed, could be worth a watch?

    Apologies if I have completely misunderstood!


    No need to apologise! That's actually a useful video - now bookmarked.


    rf900rush - 12/7/21 at 10:09 PM

    I have a SIP 130
    Well known wire feed issue
    I believe this is common on alot of cheap MIG's

    There is a mod for this MIG.
    MOD LINK

    There is also a feed drive motor power supply mod as well.

    MOD LINK

    My Mig was a different machine once I had made both of these mods.

    These changed mine from a pile of crap into a useable machine, Have a look at these upgrades, as they may help on your


    ianhurley20 - 13/7/21 at 01:42 PM

    quote:
    Originally posted by JeffHs
    I started with a second-hand Clarke HohbyMig 90 amp machine. I upgraded it with a much better torch but The wire feed was always a problem.
    I replaced it with a SIP 150. It had exactly the same wire feed mechanism as the Clarke and consequently it too was intermittent. I changed the liner to a wound steel one from Machine Mart and it transformed the machine. I can longer blame the machine for my crap welding!


    I second this. My 20 year old MIG was an absolute pain until I replaced the liner with a wire wound one from ebay. Had to open out the holes it passed through as the dia was larger than the old plastic liner. Result - my MIG became easy to set up and use, I could make minor changes and no wire feed stutter of any sort


    David Jenkins - 13/7/21 at 02:02 PM

    I bought a replacement liner from Machine Mart this morning!

    Today I finally managed to weld the part I was planning to do several days ago. The new gas mix is so sweet to use, with a nice steady arc, a nice crisp "fizz" while welding, and very little spatter.

    I'll try the new liner soon and see how much difference it makes.