Morris Minor Owners Club

I know this has been mentioned before on this forum but I just wanted to say that I carried out the modification today as shown at http://www.mig-welding.co.uk/forum/show ... php?t=4061 and am extremely pleased with the result. Until now I thought that my welding ability was never up to much, but after modifying my SIP 105 Turbo MIG I feel like I'm welding like a pro (almost!) Instead of a bead of varying thickness and splatteryness (is that a word?) I am now laying down smooth and neat welds. If you have a SIP or Cosmo MIG go for this mod and you'll never look back I used a transformer (part No. 504-016) from RS Components ( http://uk.rs-online.com/web/ ) instead of the one suggested because it was £10 cheaper and I didn't have to cut a hole in the casing of my MIG. Perfect.

I struggled for 18 years with my SIP, and wish I'd known about that forum much earlier. I changed welders as mine was not going to last much longer (main transformer gradually lost power on bigger welding jobs) - otherwise I'd have been trying that mod also.

Glad to hear you've managed to cure yours! That forum is really good IMHO.

I have done the 'tie-plate' mod (using two strips of Meccano!) and that helped. I have read about the tranny mod - but didn't feel it was necessary in my case. I feel my problem is the stupid big coil of wire I bought - it has too much inertia and the drive rollers struggle to get it rolling. I never had any bother with the normal small wire reel. Unfortunately - I threw away the empty bobbin!

That was one of the contributory factors with my welder. Too big a wire roll

I used 0.8mm wire on my sip - the 0.8 rollers were knurled so it handled the big reel without problems (although still gave 'typical' SIP weldability).
I was having a lifetime of problems when using 0.6mm wire (on any reel!)

That's interesting Ray - may just try that. Can the same liner be used - just need larger diameter nozzle tips ?

I use .8 on my SIP-105 with the original liner, just different tips.

Ok - thanks - think I will invest in some parts! Does it need much more current to get the weld going ?

I've never got 0.6 wire to work with mine, (except stainless, for some reason) it just spends it's time birds-nesting round the pinch rollers whenever it sticks to the weld - never had any problem with 0.8 and big reels, though I 'assisted' the grip on the pinch roller very early on with a small G-clamp.....

If you were buying a welder today would you buy a SIP and modify or buy something else? Is there concensus on the best hobbyist welder?

If I was buying a new or good second hand one, I would probably go for something a bit more up-market than the SIP (mostly because I know how much use it will get!) I think SIPs are really aimed at the DIY market (bit like the difference between Black and Decker and Bosch) If you're getting it to renovate one car and then the odd little repair afterwards it will be fine, if you're going to do loads, spend a fair bit more and you won't regret it!

Tip: whatever you buy, don't let the wire go rusty between use - you can't weld well with rusty wire and it ruins the liners, if you're putting the welder away for a while, it's worth winding the wire back onto the spool, removing it, sticking it in a polybag and keeping it in the airing cupboard.

I wouldn't wish a modern SIP welder on a beginner, you would probably give up and spend the rest of your life as a non-welder!

To anyone who is interested in getting their SIP to work-here is what I did to mine!

First- the "birds nesting" around the pinch rollers. On mine this was mainly due to the tubular nozzle shield screwing down too far, so it ended nearly level with the nozzle, so the wire used to weld across the nozzle! Made a spacer ring from a couple of suitable sized spring washers tweaaked in a vice to make them into continuous circles.
Also a big problem was the exit from the feed rollers not being in line with the entry to the feed tube to the handset! Using a 4mm drill bit in the liner end fitment showed how far the point was from the correct line! Also the fact that if you wiggled the handset "cable" where it exits the machine, the alignment fluctuates wildly. I made a more secure steel mounting, (insulated from the case) which overcame that one.

I ended up re-making the pinch roller support arm from steel, as the original plastic one was permanently deformed due to having been left under tension for long periods of inactivity!

Regarding the transformer mod, I had an old 12 volt transformer knocking around, and used that. Although the original was a higher voltage, 12 volts is plenty for my work, and makes the speed adjustment finer!

Top tip for any Scots out there is to throw the plastic wire liner away and use the twangy thing from one of your wifes net curtains instead! Replace the net curtain with a bit of string and she won't notice(yet)! Makes for a much smoother wire feed!

As you can see- you really have to want to stick with an SIP if you do all the above work on it. Wouldn't want to pay someone to do the mods!
BMC- I would love to watch you re-reelig your 0.6 wire onto a smaller reel!!

If you really want to drive yourself MAD load up a roll of aluminium wire...... the amount of time I spent swearing and pulling our liners full of wire because it had birdsnested AGAIN (every single time the weld even slightly stuck, or slowed down a bit) makes using 0.6 steel wire seem like a doddle!

Wow, I must be really lucky .. I use a large reel and I very rarely get a bird's nest going ... I'm starting to think I must be doing something wrong if I'm not experiencing all these problems that everyone seems to have with SIP welders.

But is that 0.6 or 0.8 wire? Reel size doesn't make much difference but if it's 0.6 I'm impressed!

I use 0.8 as I mentioned earlier in the thread ... I guess I have to face the fact that I'm so terrible at welding that I dont realise I'm having problems

Its probably down to having taught myself to weld using the same SIP welder, if I'd been properly taught with a proper welding set then I would probably be having lots of problems with my SIP just like everyone else.

" Top tip for any Scots out there " - thanks LA! Seriously - does the inside of a net curtain thing really work ? We don't have any (thankfully) - but they must surely still be available somewhere. As for the re-reeling - I have an 8mm film editing device somehwere which winds from reel to reel - so I guess I would use that! But I do plan to invest in a small reel of 0.8mm wire to try that first.

Yes, the net curtain twangy bit does work, it was a bit of lateral thinking on the part of a lady (gasp) on the aforementioned welding forum. She noticed the similarity between the super expensive steel liners and the twangy stuff while she was doing some girly stuff with the nets!
Available from any hardware/curtain shop at around £2 for a 2m length (that is how much my SIP needed). Far, far less drag than the plastic liner on that horrid little feed motor.