Tig Welder

[John OlsenParticipant @johnolsen79199]

Hi Alex, Maybe I should clarify, when I said HF I meant High Frequency start, not Harbour freight.

With HF start there is a high frequency source in the welder which will start the arc before the electrode touches the job. With simpler welders, you have to scratch the electrode on the job to get started, which risks contamination and sticking. It is a very worthwhile feature, especially for learners, who will spend enough time resharpening electrodes without having to touch them to the job deliberately.

When you do touch the electrode to the job while welding, there will often be a bright flash and the arc will change colour, with steel to a pretty shade of blue, with copper to green. The only thing to do is to stop immediately, clean the job and put a new point on the electrode. There is a tendency to hope that it might come right, but it will only get worse.

My first major task for the welder when I got it was making up some stainless steel tanks for my steam launch. The material is about 1mm thick. The first tank I did had flanges and I found that trying to do a lap joint was very hard. It is better to avoid flanges and just do a butt joint. I wouldn't put myself in the same class as the welds in the pictures shown above, but I can get pretty acceptable results. Aluminium is harder, I can sometimes get that nice "stack of dimes" look, but not consistently. I think that you have to realise when the job is starting to get hot, and stop for a bit before proceeding.

John

[Martin King 2Participant @martinking2]

Hi All, Just bit the bullet and ordered the RTECH unit same as Ian above. Very helpful people and they threw in some goodies to sweeten the deal.

Hopefully I will soon no longer have to keep hunting for people to do odds and sods of small scale welding for me. It is getting really hard to get these jobs done.

I spent ages looking at the SHERMAN units from Poland but they were out of stock of the compatible foot pedals and told me that others would not fit. Quite a bit cheaper but went for a UK based company in the end.

Fingers crossed for another steep learning curve!

Cheers, Martin

[SteviegtrParticipant @steviegtr]

Great news. I hope you get on well with it. For gas i use the rent free bottle. Was expensive to start with , but just pay for gas now. Just a note. Make sure you use tig rods & not gas welding ones. They are stamped on the end & i believe have silicon in them.

Steve.

[Martin King 2Participant @martinking2]

Thanks Steve,

Got to get out and get some gas, there is a HobbyWeld outlet not far away but also I have a pal up the road who does lots of food grade welding in stainless and alloy, his standard is as good as the guy shown above in this thread. He uses HUGE argon bottles in his workshop and has a system for decanting to his smaller bottles for use on site. He says he will try and find me a bottle for my use which will be great if it works out. He also uses an argon /helium mix on some work.

Looking forward to having a go, he has already given me a great big box of small stainless, alluminium and steel off cuts to play with!

Cheers, Martin

[SteviegtrParticipant @steviegtr]

. Brilliant. Good luck.

Steve.

[Martin King 2Participant @martinking2]

Got The Hobbyweld argon bottle and RTECH just came back to say that they will throw in a consumables kit for the 2 torches that I ordered; pretty good service so far and the kit gets here tomorrow.

Cheers, Martin

[SteviegtrParticipant @steviegtr]

My blooming bottle has dropped from 3000psi to 2000. I have not used it that much. Always had this trouble with oxygen bottles. With the hand wheel as opossed to the bottle key. I tighten it off the best i can & knock the gauges back to zero. Best i can do.

Years ago we had a blank which we screwed into the Oxygen bottle when not using it. Maybe something to ponder.

Martin what size bottle is it. Mine is 3 feet high & 8" dia. not sure of how many litres.

Steve.

[Ian ParkinParticipant @ianparkin39383]

Martin

or anyone else who buys a digital machine by rtech

theres a slight glitch where if you are using the memory locations set up for your different materials/jobs

when you save a set of parameters that’s then the default on start up

so if location 2 is thin alloy on ac

and the last location you saved ( no 6 say) is dc thick steel

when you turn on it will go to is no 6

so if you doing a job on your thin alloy and switch off for a tea break when you switch back on all your settings are wrong.

Spoke to rtech and they confirmed that this is how they work defaulting to the last saved location.
So i set up no 9 with a really long pre flow and saved that
So as long as i remember to always save no 9 again after setting up another number and saving it
When the welder is turned on it goes to no 9 which hopefully will alert me when the arc doesn’t start.

hope this helps

[Martin King 2Participant @martinking2]

Hi All,

First off Ian P, many thanks for that info, will keep an eye on it.

Here are some first thoughts with my new machine and first ever foray into Tig welding;

It is certainly NOT as easy as the YouTube videos make it out and practice is the only answer I think.

The RTech machine I have is this one:

https://www.r-techwelding.co.uk/tig-welder-ac-dc-170a-digital-tig-170ext/

Delivery and service has been exemplary with most helpful operatives.

The first argon bottle from HobbyWeld turned out to be only 1/3rd full so always check before leaving their depot.

I had a couple of hours tuition at my friends workshop which at least removed the fear element from this bit of kit.

First go on some stainless scrap was this:

just ran some beads then tried a corner joint.

starting and stopping are the messy bits but as long as you get REALLY comfortable BEFORE you start it makes life much easier; any tension in your posture or position seems to translate directly to the work.

I had a small 4mm steel table 500 x 400 made with a grid of M12 holes, then welded 3" upstands on angle to the corners for my first go with mild steel. This went very well and the table has proved very usefull as it is easily portable. When used outside I use large cardboard cartons as a wind and arc flash shield, works OK.

One of the main reasons I got this was to allow me to do small Silicon Bronze brazed repairs in smallish cast iron items.

I was STAGGERED by how expensive the rods are, 1 kg was over £60 and does not go very far at all! I save the small ends and tack them together to avoid waste.

Started with a small bench vice that had small missing areas, cleaned with angle grinder back to good metal then heated with gas torch until very hot, placed on the table and started at about 75 Amps.

I found it hard to avoid melting the cast and so turned the amps down. This led to the rods just balling and not flowing evenly. Turned the amps up and it was a bit better but odd bits of melted cast in the work which later proved VERY HARD to machine.

The finish of the brazing was quite black with small blow holes and inclusions although the build up was strong and fit for purpose. It got MUCH easier after the initial layer next to the cast iron was laid down and the material could be reworked with just the torch to smooth things out.

The job machined OK and any small holes were filled with JB Weld prior to painting.

I think that as I am using the torch in 2T mode I am not varying the current as the job heats up but have not yet tried the foot pedal as it is another thing to think about at this early stage.

So far so fairly good!

Regards, Martin

[Martin King 2Participant @martinking2]

BTW,

Edges and corners are hard to do and can waste a lot of material, not got round that one yet, any thoughts welcome!

Martin

[egaParticipant @ega]

Posted by alex murphy on 20/11/2020 18:21:39:

[…]

esab welders I have had used their helmets they are wonderful but not sure about their welders too

I have had two ESAB auto-darkening helmets, both costing over £100, both failed over time.

I now use a cheap and cheerful but equally effective item from SIP.

[SteviegtrParticipant @steviegtr]

Martin i liken the foot pedal to playing the guitar. You spend ages learning to play & then you have to learn to sing while playing. Takes some doing.

Glad you got going though. Amazing what you can make/ repair with a tig. It is slow going but so satisfying.

Steve.

[Martin King 2Participant @martinking2]

Steve, Hmmmm, I am tone deaf and normally deaf also, is this going to be a problem with the foot pedal?

Martin

[Oily RagParticipant @oilyrag]

A question for the TIG aluminium welders – when OA welding ally I was taught to use a soap solution painted onto the aluminium to gauge the point at which the parent metal was at the correct temperature to weld. The soap turned to a black 'cloud' on the surface and this was the right point to introduce the weld rod. Is this still the case with TIG?

[Ian ParkinParticipant @ianparkin39383]

Oily rag

you just apply the torch to the work and you see a puddle of molten metal…then apply your filler rod and move along.

if its thick alloy it’s quite easy

if its thin < 1.5mm its easy to melt an edge

again lots of practice on thin stock and much wasting of argon

[Ian ParkinParticipant @ianparkin39383]

Martin

I use the foot pedal just as a switch on/off

set the amps on the welder and its easyier than using the trigger either in 2t or 4t mode

its very important with Tig to observe ABC…..always be comfortable.

[Author]

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