I use one of these Erbauers:
https://www.screwfix.com/p/erbauer-ern643atl-hvlp-gravity-fed-spray-gun/6861h
Mine came with a 1.7 and 1.4 nozzle although they only describe it with a 1.4?
The B204 is one of the Saab engines, the turbos' were Garratt and Mitsubishi. The B2*4 series engines are the best for big tuning as the pistons and rods are stronger but the head not as good as the B2*5 engines so tuners mix them together to produce a hybrid. A Saab powered Astra would go like...
Google Adams gas and Hobby gas for rent free.
The ones you're using now give you about 7 minutes of gas. They are horrendously expensive on a car resto! The BOC Volkzone deal is about a fiver a month rental and 40 quid to fill. Well worth considering if you have a crusty Vauxhall!
Looks like you have a natural ability there mate, you obviously understand how the material acts, how to visualise the development and how to manipulate it.
.....sounds like it's a good weld, make a note of the settings and keep on practising :thumbup:
Use the magnets just for lining the weld up, put a few tacks in to hold it together firmly then take them off and put them out of the way so they don't pick up all the dust from the grinding!
Practice, absolutely no substitute.
Keep experimenting on the thickness and type of scrap you're going to do it on for real, once you get the right setting record it and practice some more, do this each time you start a new panel and for me at least weld very short runs, spots even rather than...
Because nowadays people pay thousands for their bikes and want to keep them worth that money, I'm not gonna criticise them, if that's what floats their boat then good luck to them.