Hi all

I've be using MIG on and off for a few years, but would like to TIG my terrapin chassis, wishbones, ali parts etc As this is a long term project I have plenty of time and patience to learn and perhaps do a course. I am fully aware of the difference between the 2 and the costs timescale etc involved.

I have around £700 to get a welding and would like to get an AC/DC welder for rather that have to buy one for ali futher down the line.

RTECH have quoted me 700 isn for a 160 amp tig with ac/dc function and foot pedal. The guy gave a good impression on the phone and they don't mind spending time on the phone and give good back up as far as I can see. Does anyone have experience with these welders?

Also is 160 amps on a TIG comparable to 160 amps on a mig penetration wise?

Thanks

Shaun

I've a r-tech 161 ac/dc with a years warranty, only done 5hours work for £600- with filler rods and other extras/digital pedal

Try and find out what semiconductors the machine is using, cheaper ones have MOSFET where if you want reliability in the long run then IBGT but as always comes at a price and gets fitted in the high end devices, millers, Lincoln etc.

Since my welder was stolen last month I have been looking at the Thermal Arc Range, although a bit over your budget look promising and IBGT in the manual.

I will wait until after Christmas and see what I can get rolled into any deal, auto helmet, regulators etc all mount up but with a bit of hard bargaining you should get wrapped in the deal.

After getting a TIG welder maybe 10 years ago now I have only picked up the mig once for a hard to get at weld. TIG is lovely to use

Ref your question on power, TIG is a slower process so watch the % load values, you will easily weld the chassis @ 100 amps if not less, Ali is a lot more power hungry as it conducts the heat away. Mine was a 200 amp machine, it never got cranked above 100amps and never cut out.


Regards Mark


[Edited on 6/12/12 by mark chandler]

[Edited on 6/12/12 by mark chandler]

thought they were IGBT? (insulated gate bipolar transistor)

Anywhoo have a look on the mig-welding forum, you will find that R-Teck have a very good reputation for customer support and usually do "shop soiled" units alot cheaper. The company dont manufacture them , they are chinese made but are reworked by Rteck to make em reliable. I may have read somewhere that they fit them with IGBT's. I nearly bought one myself but instead opted for a good old wire wound Marshall Dynabolt that weighs a ton (bought off Mark^). Its a seperb machine about 30 years old the same as a Miller Dialarc HF250.

Also as Mark says Thermodyne machines are very good, I have a Thermal Dynamics plasma cutter with will cut well above the rated thickness.

[Edited on 6/12/12 by fazerruss]

Thanks for the replies!

This is the unit in question

http://www.r-techwelding.co.uk/welding_equipment/Tig_Welder/Tig_Welder_R-Tech_Tig161

You are right they are selling ones with scratches for around £700 on ebay with pedals too. The also state siemens IGBT's are used.

Looks like this is the one for me!

Cheers

160amp AC/DC will be plenty for anything you will need to be doing at home. Looking at the spec of that R-Tec machine, the 160Amp is only 35% duty, so you cant run it flat out for long, but if you are only welding 3mm steel, then you will be running at about 70ish amps(Depending on the joint type you are welding. i.e butt, or fillet), Or 3mm Alu, you will be running 100ish amps(again depending on what type of joint you are welding)

I have an SWP Invert-R 200amp AC/DC with foot pedal, but im not really keen on using foot pedals, i prefer to either use pulse mode ( if your welder has that function) or just set the welder with a nice slope in/out, and then release the trigger if you need to drop the amps briefly, then press it again to raise the amps up again.

If you are going to be welding small fiddly bits, then i find the type of torch you use makes a big difference. for smaller fiddly work a WP17fx ( flexy head) is much nicer to use than the bigger bulkier WP26FX. again you have to watch for the duty cycle, as i think the wp17 heads are rated 110amps @60% where the wp26 heads are rated 150amps @60%. For what you are doing though i would have theought that the wp17 will be man enough.

quote:

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Originally posted by fazerruss
thought they were IGBT? (insulated gate bipolar transistor)

Anywhoo have a look on the mig-welding forum, you will find that R-Teck have a very good reputation for customer support and usually do "shop soiled" units alot cheaper. The company dont manufacture them , they are chinese made but are reworked by Rteck to make em reliable. I may have read somewhere that they fit them with IGBT's. I nearly bought one myself but instead opted for a good old wire wound Marshall Dynabolt that weighs a ton (bought off Mark^). Its a seperb machine about 30 years old the same as a Miller Dialarc HF250.

Also as Mark says Thermodyne machines are very good, I have a Thermal Dynamics plasma cutter with will cut well above the rated thickness.

[Edited on 6/12/12 by fazerruss]

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I've recently purchased the 250A AC/DC unit and am highly impressed so far with both the welder and customer service. I also bought one of their imig 160's at the same time but have yet to use it.

As has been said, the 160A will be plenty for the applications you listed.

Several years ago I had a Sureweld 160 amp DC Tig.
It did everything I asked of it (including my chassis & bones). Don't think I ever went above 130 amps.

I upgraded to a Miller AC/DC 200 Dynasty when I made my nose cone.


With AC the polarity changes many times a second (adjustable frequency) and when the electrode is positive
it cleans the oxide and only when negative inputs heat into the metal.
Since we run negative about 65% of the time it's only heating the metal 65% of the time, so we need to up
the amps to compensate.

Aluminium is also a great heat sink so for bigger thicker jobs we also need higher amps. An ally casting for example.

I have frequently run my Dynasty at 180 amps.


So to sum up (IMHO) a 160 is fine for DC, but a 200 is better for AC, and a water cooled torch is also a benefit.
Remember that for 35% of the time the heat is in the electrode.

HTH
Paul G

quote:

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Originally posted by fazerruss
thought they were IGBT? (insulated gate bipolar transistor)

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I bought an inverter-fusion solid-state job from weldequip. He's a great guy and offers great support. It's a tiny welder and can chuck out 200A no problem, but it is only DC.

I would check to see if the solid-state ones can weld AC - the action is so smooth and incredibly controllable - start time, crater time, pre and post gas, pulse and many others that I don't use.

TIG is so civilised after mig.

I would also recommend getting a 45A supply fitted straight from your main-board and be sure you have the right breaker on it. This is no issue at all for a competent electrician.

Purchased the shop soiled r-tech 200amp ac/dc welder over Christmas, well worth the money.

I had a WSE200 that was stolen, before that a large coil based system by Marshall Dynabolt.

You can see and feel the quality when unpacking compared to the WSE200

Welding it beats both machines with ease, big thumbs up from me.

If the machine was sold as new I would not have noticed the difference, it is immaculate.

i recently upgraded from a giant wse200 to an rtech 161 ac/dc and its a belter . the giant is good value but struggles on thin ally where the r trch can put a stack of dimes on the edge of a 1.6 ally plate without melting the edge away .