MIG or TIG

[Rob Morley]

I'll have a go some time and let you know how I get on :-)

[Tony Bryer]

If you start from nowhere, how easy would you say it is: is it like plastering where it takes ages to master the technique and you make a mess of it while learning, or is it like electrics where if you know the theory you should be able to do an adequately competent job, albeit at a slower pace than a pro?

[usenet]

It's certainly something that needs some practice. Some experience of arc welding, soldering or brazing may help as many of the requirements (clean surfaces, holding steady, etc.) are similar.

I found the most difficult part was to hold the torch close enough to the work and steady enough.

[usenet]

I don't quite follow this, you seem to be saying:-

Practical Classics say the SIP 130 was best buy.

You agree (saying "Which I did").

Then you give various things wrong with it, maybe they're just minus points on an otherwise good welder.

Finally you say you can't do butt welds on thin material.

I suppose (if I *have* followed you correctly) that what you have said makes sense but it would be much easier to follow if there wes a 'but' or a 'however' somewhere.

[Dave Plowman (News)]

Which it did. Others (including on here) have said it's rubbish.

Yup.

Yup.

Yup.

Basically I'm saying that I'm not an experienced welder. So really can't say if the machine is at fault, or if it is just my technique.

The wire feed business is strange. It changes speed automatically if you change the current. However, on the minium current setting - needed, I'd guess, for thin sheet, it stalls until the control is advanced above about half way, and then changes speed dramatically with a tiny movement. This is with fresh undamaged wire and 'inner' etc. On the higher current settings it operates over its full range and appears to give linear control according to the knob position.

It could be mine has a fault, of course. But others have mentioned this problem.

[Rob Morley]

Practical Classics also said my old Clarke was a best buy, and I found it to be pretty crap.

Mine does nothing until around 9 o'clock, but it adjusts fairly smoothly after that.

I just had a go at butt welding some fairly thin sheet with mine - it's set up for gasless so not ideal for thin stuff, argon mix would make it run cooler. Anyway, I got acceptable results just by sticking it on minimum power with the wire speed at 12 o'clock - it was a bit splodgy because I had to pulse to avoid burning through, I tried reducing wire speed but it wouldn't maintain a stable arc, I tried increasing power and it burned. ISTM the main thing about butt welding thin sheet is to get the pieces lined up so there's a constant gap between them and they're totally flush - careful fitting and lots of tack welds make it easier to get a satisfactory result.

[Dave Plowman (News)]

Yup. So I'm asking the impossible?

I bought some clamps from IIRC Frost which set a gap of around 1mm - perfect they say for butt welding. Couldn't get that to work either.

[Rob Morley]

As I said, that was gasless - using Ar/CO2 mix with a 0.6mm wire should produce a neater result with less chance of burning, you could probably make a continuous weld with that setup that wouldn't need much linishing. You could try tacking a strip of scrap steel down the back of the butt, then grinding it off afterwards.

[Dave Plowman (News)]

Well, most of the stuff I need to do on cars would make grinding something off the 'back' impossible because of access. If rear access was easy then I'd be happy with a joddled join with seam sealer applied afterwards. And I can make a fair job of those. Indeed heavy grinding on the face because of a 'thick' weld is likely to end up with holes in the panel. Unless it's because I'm equally as useless with a grinder as the welder... ;-) And I mean this most sincerely, folks.

[Andy Dingley]

Anything. SIP don't make big welders. Their mid-range welders are poor, compared to what else you can get for the same money, and their low-end are just rubbish.

Other opinions vary. Some people claim that their's work. However the people who complain all complain about the same fault (unreliable wire feed) and those who reckon it's OK have rarely used a real welder.

I use a Murex Tradesmig 185, which is the biggest you can hang off a domestic supply. I was offered a new one recently (bargain offer at the welding shop) for £550. As a comparison, it barfed its wire feed (wire jumped off the reel and jammed) _again_ recently - for the second time in two whole years. With the 130 Migmate I had years ago, this happened on every foot of run.

Oh, and I make stuff like this:

I ordered an ex-demo (but unused) SIP

There are two sorts of "special supply". One is a 16A fused spur to a round blue socket, and is within the DIY grasp of uk.d-i-y posters. This is worth doing, if you weld at a bench in the same place all the time.

The other is 3-phase, which is what you need for big welders - now that _is_ a little serious to have installed.

Just for the basics though, just fit a good quality plug and socket like MK. Using a junk socket, or a plug with a badly fitting fuseholder, and you will get problems with overheating or contact welding. Be sensible with extension leads too - but for car bodywork, you're just nowhere near having real problems here.

If I'd said I would buy it, then I'd buy it - but next time ask _before_ shopping !

A "gas only" machine (rare these days) is useful. A "no-gas" is not something I'd buy. You can certainly learn on it, you can even do useful work with it, but you're paying over the odds for the wire. Get your use out of it, then sell it for a £300 upgrade machine in a year or two, if you're serious and you like welding,

They're all arcs really, but yes.

[Dave Plowman (News)]

I'm not wanting to argue with you Andy, but PC used a pretty experienced welder for their tests - IIRC someone from the Colchester college that teaches car restoration. Perhaps the one they tested was a 'special' ;-)

Trouble is 550 quid plus is a bit different from the 150 that you can get the SIP for.

I've not had any problems with the wire coming off the feed - merely the speed control. Think I might investigate fitting a better motor and control - this ain't going to cost 400 quid.

What machine in your opinion has the best wire feed? I could perhaps enquire about replacement motor costs.

[Rob Morley]

I'd forgotten that bit.

That's a potential problem, especially if the two sides weren't perfectly aligned or there are ripples, both of which are pretty likely. I usually take the worst off with the grinder then skim it with filler

Even if you manage not to go through, linishing will weaken a weld - just try to leave it stronger than the rust you're replacing :-)

[Andy Dingley]

I used to read computer magazines avidly. Then I started writing for them. Since then, I no longer read them. It's like Bismarck's comment on politics and sausages - best not to see either of them being made.

Agreed. I can almost justify the 150 quid SIPs, on the grounds that the equivalent Clarkes et. al. aren' much better. However my Dad has a 185 SIP Turbo something that was a waste of 300 and would have been much better spent on a Cebora.

Wire actually coming off has one main cause - a new reel, where the wire tension in the outer layer is a bit low. Once you've used that top layer it settles down. Although on big reels this obviously happens a tenth as often as on little reels.

My SIP problems seemed to be related to poor friction drive between the roller and the wire itself. I was forever fooling around with mad ideas like ferric chloride washes to strip the copper clean from the roller, and I never did stop it slipping.

Haven't looked. Since abandoning rubbish welders I realised that there aren't any "good" wire feeds, just "OK" or "Bad". There is either day-in, day-out reliable perfection, or else they're unacceptable. You just can't do good work on a bigger weld, or get any sort of production throughput, if the feed is anything less than trustworthy.

[usenet]

So none of them are worth buying then?

[Andy Dingley]

No, not at all. But once you get to "OK" performance, they don't improve it any further. From the mid-range welders upwards, wire feed is just something that _works_.

[callmepaul]

Well, it arrived (SIP 130 DP), and I must say that I found the accompanying owners manual very poor - hardly any diagrams at all!

The wire feed seems awfully tight on this machine (it came fitted with gasless wire but as I want to initially use it with gas I installed some 0.8mm steel wire). A little book I have for novices states that if the rollers are correctly adjusted, it should be possible to stop the wire feed at the torch tip with light finger and thumb pressure. This machine seems to grip the wire much tighter than that (knurled knob is backed right off), and there doesn't seem to be any way of making it grip less tightly.

Having said that, the wire feeds through OK (albeit a little erratically as others have reported), and I hope that when I strike the arc for the first time this won't be too problematic. Thanks.

Reagrds,

Paul.

[Dave Plowman (News)]

Yup. Very poor for a DIY device.

[Paul]

I'm finding the problem is seeing the work! All I can see is a brilliant arc, and the rest is in darkness - this is whether I turn the mask dial up to fully light or fully dark. The only way I have found around it is to shine a 500W halogen lamp at the work :-( Regards,

Paul.

[Rob Morley]

My favourite sort of welding mask has a peak and a clear window above the normal lens - you use the clear window to line everything up, then tip your head to use the dark lens when welding. Unfortunately the health & safety types decided they are hazardous and banned them :-(