Which £300 welder, Mig or Tig considered.

[greenhorn]

Afternoon all,

Having recently completed an introductory course in welding at my local college, I'm now on the look out for a suitable first welder.

I'm after something that I can use for modifying motorcycles, although I'm sure other uses will come up. Mainly welding in new parts of frame, brackets, maybe a bit of bodywork. That sort of thing. So I'll be doing 1-3mm mild steel and I'm not too concerned about having a pretty line of beads as I'm planning on grinding everything flush anyway.

I was thinking of a Clarke Pro 90, but having spoken to a very helpful chap at my local welding suppliers, he seems to think that a Tig would be better for my needs, regarding weld strength amongst other things.

Any advise from you chaps would be extremely useful as there seems to be a lot of choice out there.

cheers in advance

Rich.

 

[cumbriasteve]

If his comment referred to the weld strength I would not seek any more advice from him, a weld is a weld regardless and is only strong if done correctly.

A MIG would be the what I suggest and something a bit more than a 90 amp machine, 135 minimum and 150 would probably be better.

 

[BrokenBiker]

weld strength is nothing to do with process really, i can get much stronger welds with my stick welder than with my mig on same settings, but my mate can get much better welds with his mig than i can with either of mine. All depends in your skill

 

[waddycall]

For bike work I'd go for tig myself. My reasons would include neater welds, no spatter etc. I'd also have more faith in a tig weld I'd done than mig. Also if your workshop is a similar size to mine it's nice to not have sparks/molten metal flying around especially when petrol tanks, oily rags etc can be in the same space.
Also if you went for an arc/tig inverter you'd likely have more capabilities due to the fact you could stick weld thicker materials. A new mig in the price range would probably be pretty limited on output and material thickness.

 

[waddycall]

These seem to get good reviews....
http://www.r-techwelding.co.uk/welding_equipment/Special_Offers/Tig_Welders_R-Tech_Tig160PDC-SALE

 

[greenhorn]

Cheers for the advice guys.

That tig does look good, but would be stretching my budget a bit. I'm only going to be doing a pretty small amount of welding (probably no more than 1 linear metre on this particular project) so I don't really want to be spending more than about £300. On the other hand, I don't want to end up with some piece of crap.

 

[octo0072000]

a clarke 150 gas mig should suit you then

 

[Jim Davey]

Some very, very worrying comments above, like it or not weld strength does vary from process to process, low amp mig tends to promote lack of fusion and cold lap and per kilo of weld has some of the lowest strength ratios compared to MMA and TIG. This is of extra concern if "the welds are to be ground flush after". Think about it, a poorly penetrated mig weld, is then mostly ground off then very little strength will remain. One of the major benefits of tig is the ability to add heat and gain penetration before adding the filler which effectively cools the puddle while still achieving relatively small welds that will require little or no cosmetic finishing afterwards.

Mig welds despite looking good can often break surprisingly easily (trust me on this) do some research and you'll find out for yourself. It can be fine, but the prep is very important. I'd feel far more comfortable tackling safety critical brackets and frame alterations on motorcycles using tig. That's why most of the custom bike fabrication firms use the tig process for frame alteration (ok, they use mig for knocking up fuel tanks etc and for sheetmetal, but for anything important they tend to revert to tig.

 

[greenhorn]

I've found this, but I'm a bit wary of buying such a cheap Tig setup.

http://www.unitedwelding.co.uk/thermal-arc-175se-240volt-176-p.asp

With the optional tig torch it comes in at £260.

obviously there's the used option, which would allow me to get a lot more for my money, but you always run the risk of it being a bit of a lemon.

agh, too many choices.

 

[daleyd]

One thing to consider is the ease of use. Tig can be difficult to master, and is much slower. a decent standard of mig weld would probably be easier for a novice to achieve. (Depending on your ability to pick things up you may pick tig up quickly but I think the above is a good generalisation)

A good mig weld would be stronger than a bad tig weld.

 

[cumbriasteve]

Some very, very worrying comments above, like it or not weld strength does vary from process to process, low amp mig tends to promote lack of fusion and cold lap and per kilo of weld has some of the lowest strength ratios compared to MMA and TIG. This is of extra concern if "the welds are to be ground flush after". Think about it, a poorly penetrated mig weld, is then mostly ground off then very little strength will remain. One of the major benefits of tig is the ability to add heat and gain penetration before adding the filler which effectively cools the puddle while still achieving relatively small welds that will require little or no cosmetic finishing afterwards.

Mig welds despite looking good can often break surprisingly easily (trust me on this) do some research and you'll find out for yourself. It can be fine, but the prep is very important. I'd feel far more comfortable tackling safety critical brackets and frame alterations on motorcycles using tig. That's why most of the custom bike fabrication firms use the tig process for frame alteration (ok, they use mig for knocking up fuel tanks etc and for sheetmetal, but for anything important they tend to revert to tig.

I stand by my advice given and don't find any of the other comments 'very very worrying'.

If a MIG weld looks good yet breaks easily it has been a poor weld and of course a poorly penetrated weld will affect the strength of the weld, that's exactly why I stated 'if a weld is done correctly'

I would expect anyone to learn the technique fully before tackling such an important task as a motorbike frame, failure to do so could lead to a disaster regardless if it is MIG or TIG.

Many strength critical components in industry are MIG welded, just the same as many are TIG welded, there can be many reasons for preference.

 

[Jim Davey]

Yes, but they don't grind the surface of the weld off afterwards do they? Tig is the better process for this application, admittedly, it's a little harder to master than mig but the suitability of the process is whats in question and I stand by my answer. I don't like to generalise but you tend to find with a tig weld, if it looks good, it is good, whereas mig can be deceptive in its appearance.

 

[hunter27]

As a very occasional diy welder many years ago I bought an Clark 100e mig from new and really struggled with it! my brother,a mechanic who sometimes used welders at work thought it was hard to use compared with what he was using at work.
I eventually bought a used Cebora boxer 175 mig, a much better machine and a lot easier to use. I also recently purchased a R-tech 160DC tig and I am delighted with it, sure it is a lot slower than the mig but it does give you more time to add filler rod and play with the weld. I also go over the weld afterwards to blend it in better if required without adding more filler(this is probably frowned upon by the experts but it seems to work for me)
I wished I had save up a bit more and gone straight for the Cebora instead of the Clark as it is much easier to use especially with me not being an expert.
PS don't forget to budget for the gas required
Pete

 

[greenhorn]

woah there fellas.

If it puts anybody's mind at rest, this bike frame will only be getting a new subframe and a few non-structural brackets, so the worst that could happen is my exhaust falls off.

rather than a straight up fight between mig and tig in principle (much as i do appreciate the advice), I was more looking for specific model recommendations or suggestions.

 

[daleyd]

woah there fellas.

If it puts anybody's mind at rest, this bike frame will only be getting a new subframe and a few non-structural brackets, so the worst that could happen is my exhaust falls off.

rather than a straight up fight between mig and tig in principle (much as i do appreciate the advice), I was more looking for specific model recommendations or suggestions.

When it falls off and locks your back wheel up or bounces onto a car behind you may reconsider!

In all seriousness though, you need to nail down what process you are going to do it with first, and from there you can narrow your choice down. As has been said above, for your budget all machines for a given type of welding will be pretty similar in terms of features etc.

The Clarke migs are generally well thought of on here, in terms of a mig machine I don't think you'll get much better for the money you are prepared to spend, barring a second hand buy.

In terms of tig machines, rtech or parweld inverters generally have decent reviews by owners. For that money you would probably be looking at scratch start, which is not the easiest to master but is useable, or possibly lift start which is a tad easier to get on with.

 

[RonMig]

the worst that could happen is my exhaust falls off.

4 years ago the silencer (brand new but with duff manufacturer welds) on my son's moped fell off at 30mph and smashed the windscreen of the Lexus behind him. Could have been much worse but even so, caused £1500 damage & loads of hassle. Take care to be certain of your weld quality...!

 

[greenhorn]

I think I'm set on a Clarke if I go for a mig. I'll check out those inverters and let you know.

thanks chaps.

I was joking about my exhaust falling off btw....

 

[cumbriasteve]

rather than a straight up fight between mig and tig in principle (much as i do appreciate the advice), I was more looking for specific model recommendations or suggestions.

Not a fight as such but you will always get personal opinions which you are bound to on any forum as well supported as this one is.... nothing wrong with that but it can make it harder for you to get a clear answer I suppose.

TIG is a very nice process and if I had the work for it I would love a nice outfit, I would still have a MIG though and if I could only have the one it would be a MIG but that is only because the work I do is ideal for MIG welding.

I suggested a 150 amp MIG because that's what I would hope to have if I was doing the work you mentioned, the difference being that I would not be grinding the welds down on the bike work because they would look nice enough to leave as they are.

So if I had to buy the machine today, unless I could get a used upmarket 2nd hand machine for a decent price then I would choose a Clarke 150, one of the original designs and not one of the newer budget Clarkes which don't go as low in power for car work.

The Ceboras are very nice machines too and plenty for sale if you look around, plenty of rough one's too I should imagine but a bit of care taken and you could find a good bargain.

Why the Clarke?, simply because after downsizing and selling my Portamig I bought a Clarke 135, accepting my belief it would not match the Portamig but would do and was delighted to find it is an excellent machine that after the initial setting up correctly produces first class welds no different to the Portamig albeit obviously more limited in capability of material thickness.

So..... I have the perfect solution for you, win Saturdays lottery and buy a nice big shiny MIG and top of the range TIG and of course some spare exhausts for when yours fall off!

 

[octo0072000]

try looking on here lots of good info you will have to register though to see the forums
britchopper.co.uk

 

[greenhorn]

At the risk of being gazumped, this chap is open to offers. What would people recommend?

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=131236667320&ssPageName=ADME:X:RTQ:GB:1123