Model Engine Maker

General Category => Chatterbox => Topic started by: Jo on May 08, 2019, 08:38:40 AM

Title: Inverter Welders
Post by: Jo on May 08, 2019, 08:38:40 AM
After many years of owning a monster transformer based Stick welder (and a not as big but still heavy mig welder ) I was introduced to a rather nice (= very expensive  :-X ) French Inverter welder the other day. It did an excellent job welding cast Iron so I feel a need to buy one  ::) , I have never used Tig so not sure if I need that  :headscratch: I guess it could be used to weld up faults in Aluminium castings???

These are all new to me so guys any suggestions as to what I should be looking for? I see they start rather cheap :noidea:

Title: Re: Inverter Welders
Post by: Bluechip on May 08, 2019, 08:53:55 AM
John Mills (Doubleboost ) did a series on t'tube ... MIG though ...  Dunno if it's relevant  :headscratch:


Title: Re: Inverter Welders
Post by: Jo on May 08, 2019, 09:23:58 AM
Thanks Dave,

I was thinking an Inverter for Arc/Tig rather than Mig welding. I see Double Boost did a long series on one of those a few years back as well  :)

Title: Re: Inverter Welders
Post by: Jasonb on May 08, 2019, 09:26:52 AM
I have a Machinemart inverter which works OK for me using stick. It does have the facility for tig but it is very basic with no control of anything and scratch start. If you want to be able to do reasonable tig  and aluminium then R-tech also do AC/DC ones that start around 700 with a lot more adjustment and easy starting etc. Doubleboost also shows them on a few of his videos probable 3-4 years ago.
Title: Re: Inverter Welders
Post by: Vixen on May 08, 2019, 12:12:32 PM

Inverter welders have come of age and are now very good, lightweight and not that expensive.

But for TIG welding, it's a bit like any other specialist or precision tool, you should be asking the question

"Where can I get the required quality, not where can I buy the cheapest "

Title: Re: Inverter Welders
Post by: Jo on May 08, 2019, 12:27:52 PM
I wasn't looking to mortgage the house for one  :hellno:

I get the idea that the inverters with two knobs (current and penetration) are better for Tig welding and the ones with one are only really suitable for stick welding.

Title: Re: Inverter Welders
Post by: Jasonb on May 08, 2019, 01:06:59 PM
The more knobs the better ;) have you got a link to a two knob one?

You are unlikely to get a 1 or 2 knob jobbie that will do aluminium as that needs AC and as I said they start around 700.

For Stick you really only need the current adjustment but for tTIG it is better to have more knobs to adjust things like the HF start which is far better than trying to strike the arc like you do with stick as that is allyou get on the basic MMA/TIG units, you can adjust how long the gas flows for before and after the electric stops so you won't go wasting gas (costs money), pulse of the power and so on.

Like with everything you get what you pay for. If you really only want a light portable stick welder that will run off a 13amp plugtop then the small ones from machinemart or r-tech are fine. If you feel you need tig then spend the money and get something better spec'd. You would need to add the cost of the Tig torch etc to the basic ones if you want to use them for Tig so that's another 100. Also allow for an auto darkening helmet if you don't already have one.
Title: Re: Inverter Welders
Post by: Jo on May 08, 2019, 09:25:27 PM
I've got a pic of the front panel of a second hand one I am tempted to buy and that has 4 knobs   :noidea:

Title: Re: Inverter Welders
Post by: gjn on May 09, 2019, 10:48:49 PM

Most of these combined ARC/TIG inverters are DC only, you will not be able to weld aluminium with one of them. For that you need an AC/DC TIG which entails a fair jump in the asking price. On the plus side, the one you show at least has HF start, most are scratch start only.

Rgds - Gavin
Title: Re: Inverter Welders
Post by: Jo on May 10, 2019, 08:33:25 AM
Thanks Gavin,

I've never tried Tig welding so don't know what is needed  :noidea: other than Argon gas... it could be rather expensive buying a gas bottle  only to find the welder won't do Aluminium welding  :Doh:

My dinosaur of a Stick welder is just a huge transformer with no adjustment - welds with 1mm rods ok but I can't see it working well with anything larger. Never had any problem scratch starting with it  :)

Title: Re: Inverter Welders
Post by: Roger B on May 10, 2019, 09:38:09 AM
Farm and Workshop Welding has a pretty good guide to TIG in all its forms:

You can pop over and borrow my copy if you like  :)
Title: Re: Inverter Welders
Post by: Jasonb on May 10, 2019, 10:21:30 AM
Jo, does not look like that one does ali as I can't see a knob to switch between DC and AC.

It will make a better Tig welder than the basic Machine Mart ones as it looks to have the features I mentioned earlier, size of stick really depends on what Amps it can deliver but I should think it OK for 2.5 rods.

My "145" Machine Mart is best classed as a stick welder with the facility for very basic tig but will work fine with 2.5mm rods and has anti stick so you can strike an arc easily

Suppose it really comes down to deciding what you want, lighter stick machine with basic TIG option, TIG for steel with stick facility or TIG for steel and ali with stick facility. Any tig will also involve refundable bottle cost and gas costs and depending on what you get you may also need to add TIg kit, regulators etc.
Title: Re: Inverter Welders
Post by: Jo on May 10, 2019, 11:18:14 AM
Thanks Guys,

 :thinking: I think I might have to go and give that second hand one a try and see if my supplier can explain all this stuff.

What I want is something that will provide a bit of welding when I get round to working on my BB1  ::)

Title: Re: Inverter Welders
Post by: jadge on May 10, 2019, 12:25:18 PM
Like everything else you get what you pay for. I bought a TIG welder some years ago for work, specifically for use on stainless steel. I also did a stainless steel TIG welding course at the local college; and I won the best overall learner prize. The prize was a very nice leather apron and a pair of thin welding gloves, specifically for TIG, donated by a local welding supplier. When I was buying from the said supplier somehow the matter came up and they said I was the only person who'd ever written and thanked them for the prize. I'd make the following observations:

DC is for mild steel and stainless

For aluminium you will definitely need AC

The minimum stable weld current (for thin material)  is as important as the high currents

I bought a foot pedal with my welder, but a pulse capability on DC is easier, ie, the welding current alternates between two values, so you can move and dab the welding rod in the melt pool but then the current decreases so you don't blow a hole, move on at low current and repeat as the current switches back to high.

Pre and post gas flows are pretty standard

For AC TIG welding balance may be useful, ie, how the AC current is biased between plus and minus for better oxide cleaning or better penetration

For AC TIG welding frequency control is nice but not essential, it controls weld width and to some extent penetration

Stick welding essentially comes free with an inverter based welder, the arc is definitely more stable than with a buzz box

I've never used scratch start but I would think it's a complete PITA, go for HF start

Auto darkening helmets are great, you can see what you're doing right up to striking the arc

I went a bit OTT and bought an ESAB Tig2200i DC/AC welder with all the bells and whistles complete with water cooled torch. While looking I also looked seriously at the RTech range and talked to them. I chose EASB because of a local rep for service and any other issues. We can safely say that my welder is far more capable than the operator. I use plain argon as the gas. Other gases are available, but argon is relatively cheap and a good all rounder. Other consumables are tungsten electrodes and gas lenses.

A final point to consider is duty cycle at higher currents; industrial welders will be much better in this respect than many of the hobbyist machines.

Title: Re: Inverter Welders
Post by: Jo on May 10, 2019, 12:36:05 PM
Thanks Andrew,

I went a bit OTT and bought .... welder with all the bells and whistles complete with water cooled torch.

The bells and whistles can be very attractive  ;)

Title: Re: Inverter Welders
Post by: bent on May 10, 2019, 05:56:07 PM
Never really had the opportunity to be a good welder with my dad's old Lincoln tombstone, but I could lay some serviceable beads with it after a few minute's practice.  Years later as an engineer, I tried to get handy with a cheap Sears Mig buzzbox we had in the R+D shop at that company, and again after some practice could lay serviceable beads.  But I never felt like either tool had any precision, you got what the gun/rod could deliver and that's that.  Seeing what a good tig welder with a  good machine could do (e.g. rocket engine parts), and tig's general versatility with various metals, I wanted to learn to do it.   I had a few projects in mind, so when I bought a welder of my own, I got a DC inverter Tig machine from a higher-end Chinese manufacturer (it also has a plasma cutting setting, using a different torch of course, and a different (air/N2) gas feed system, and came with a stick holder as well).  The plasma cutter capability comes in handy.  Tig was actually easier to learn, and to me felt more natural after doing a fair bit of torch and iron soldering over the years - the torch is a heat source like a pencil flame, and you dab in filler metal as you go.  Have never even used the stick feature, as tig is just too handy for anything I'm doing, which is mostly small stuff (1/8" thick or less).  Even played around with welding up some cupro-nickel. (the wife had a lot of old european coins made from various Cu/Ni alloys, so I made a little candy dish, sticking a bunch of 2 schilling and 30 kroner and suchlike coins together with some copper filler from old Romex wiring.  FWIW, cupro-nickel is pain to weld, not nearly as easy as steel or even stainless).  But still, Tig is fun.  The only thing I don't like about my machine is that the footpedal cannot be set to a current limit, you get full machine current (80 or 90 amps on 110v feed?) with full pedal, so it is a little trickier to learn to use with light gauge metal.  I may trade up one of these days for a more controllable machine, and also get an AC capable box for aluminum...
Title: Re: Inverter Welders
Post by: Jo on May 15, 2019, 04:24:42 PM
A quick visit to my supplier and it was found that his need for my money was greater than his need for his Inverter Welder  :mischief:

It comes with a few bells and whistles, nozzles, rods...  I just have to get time to find out what they are for   :noidea:


P.S. it also came with over 10 years of Live Steam Mags   :)
Title: Re: Inverter Welders
Post by: Roger B on May 15, 2019, 05:24:58 PM
That looks to be a comprehensive kit  :)  :) Plenty of learning/practice there  ::) Thoriated electrodes are mildly radioactive but for hobby use shouldn't cause any problems.
Title: Re: Inverter Welders
Post by: Jasonb on May 15, 2019, 06:06:49 PM
Just need those rolled up rims and you will have something to practice on ;)


PS Should be plenty of locos in the mags to interest you :LittleDevil:
Title: Re: Inverter Welders
Post by: Jo on May 15, 2019, 06:19:11 PM
Just need those rolled up rims and you will have something to practice on ;)

Indeed but you know the rules: you can only request/complain about the delivery timescales if you are paying for them, so I will be thankful when they arrive  ;)

The only failure for the day was I didn't pick up any more welding rods in the bundle :Doh:

Title: Re: Inverter Welders
Post by: bent on May 15, 2019, 06:26:24 PM
Anybody wanting to learn to Tig (or Mig, or stick) weld, or get better at it, should definitely watch some of Jody's videos at Welding Tips and Tricks:

or follow his youtube channel,
Title: Re: Inverter Welders
Post by: Jo on May 15, 2019, 06:51:55 PM
Thanks Bent, I'll plan to watch those  :)

Title: Re: Inverter Welders
Post by: b.lindsey on May 15, 2019, 09:51:03 PM
Looks like some nice kit there Jo. Keep us posted on your experiences please.