I have used gas for 40+ years and it would do all of those, but my gear has probably passed it's sell-by date. I have no pressing "need", but from discussions elsewhere, TIG would seem to be the best option.

Difficult with the range of material thickness's. If you were good in the past then 2mm with MMA (stick) welding should be fine. I used to be ok down to 1.6mm. A 140A inverter will cover all that. If you need to go to MIG (wire welder) for the thin stuff then 6mm will require a reasonable sized set.

The other option is to pop rivet the patch on the mower and buy a cheap 180A transformer for the rest.

Self dimming helmets/visors are wonderful.

This engine frame was welded with a 140A  inverter and 2mm rods

There is a free download of the Air Products book here theweldingacademy.com/.../

Thanks for the suggestions. I'll probably go for a cheap arc welder and pop rivets!

I never properly mastered gas welding, the results of my efforts resembling colanders!

Many years ago I did an oxyacetylene welding course as evening classes along with a mate, the two of us thought we would be doing all sorts of repairs, but I never actually got around to buying an oxyacetylene Porta Pak, though occasionally I did borrow a small arc welder.

I was actually taught soldering and brazing in the workshop at school whilst doing the O-Level Metalwork course prior to that and have a selection of five propane gas torches.

For mobile repairs a oxyacetylene Porta Pak is probably still the simplest option for use in the middle of a field, but these days there options that are far easy to use, but that usually mean getting the workpiece to the workshop.

Last night after reading the original post I had a look to see what introduction to welding courses are being run locally, the pickings are at bit thin, back when I was a lad every college ran part time evening courses for hobbyists as well as starting people off in a career. There’s nothing in my immediate area, the closest being in the next county as a part time day course and it is only open to those aged nineteen and over, which isn’t an issue for me, but doesn’t help a young budding engineer to start gaining additional skills.

I could actually quite fancy doing a term of evening classes over the Winter doing basic welding or some other skills training, but nothing like that really seems to exist anymore.

I pretty much taught myself 45 years ago. In those days, an affordable car needed annual welding.

The Introduction to TIG welding courses I found is at the Holme Lacey campus of Herefordshire and Ludlow College.

https://www.hlcollege.ac.uk/course/580f774745408/Introduction-to-TIG-Welding

The college is immediately adjacent to the Warners Holme Lacey Hotel, I think the college which is an agricultural college was actually originally the estate farm of the big house that is the hotel.

If you like living dangerously you could book a midweek break at Warners with your wife, then slip away for a days welding tuition leaving her to partake in the activities at the hotel.

I should perhaps add, I met my wife in an agricultural contractors workshop on a farm whilst I was helping to build a road going rowing machine built from the chassis of one of the Invacar “invalid” cars like the ones that used to be seen along the touch lines of football matches, Which Worcestershire Young Farmers then rowed to the AGM at Blackpool and I have been quietly getting away with things for years since then. Eyebrows have been raised about some of the training courses I have been on during the last year and qualifications gained.

www.help-my-mobility.org/.../Whatever-happened-to-the-ice-blue-Invacar.aspx

That article about the Invacar is worth reading “Each car was painted in ice blue and powered by a 500cc or 600cc Steyr-Puch engine With a top speed of between 40mph and a terrifying 80mph - giving it the power-to-weight ration of a BMW M5”

and there’s a classic quote from Sir Bert Massie towards the end of it.