I really lusted after the H17/H20, but being poor had to have a C13 instead...
While I was cleaning it up preparing to refurb, I discovered an asset tag from the ARDE (Armaments Research and Development Establishment) - Fort Halstead, where my grandad worked as senior toolmaker in the early...
The 7x12 I have came with one from the factory, eleiminates a lot of the fears of snappage! They'e not complicated to make from first principles, put a one-way ball/spring-valve in piston with a couple of O-rings, plumb a bypass with a needle vlave and aball valve to shut the motion off - but...
I had that South Wales factory on my patch as a new network engineer (bloody hell, that was last century...), got called (all the way from Hampshire) to a tools-down network outage, changed the fuse in the plug and...
inside the tailstock quill should be pretty soft (unhardened) so it can get a grip on hardened tooling, so a bearing scraper should take off any burrs, the hard bit is seeing where they are - bit of blue on a fresh, clean morse taper something?
it's not that difficult, especilly if your possibly-future-son-in-law is a detective constable who doesn't think you're a loonie, £40 for a 3-year licence. The hard bit is getting anyone to sell small quantities...
that looks like contamination, and appears to go right round, the full length of the bead - assuming you've throughly cleaned the filler rods maybe the purity's not what it should be?
I've seen a video of Ron Covell TIG welding copper, so it is done - if i unforget diserroneously he was making a radiator grille for a tiny retro racecar to be sent off for plating?
Not that I'm much of a welder, but... I think it's wise to have more than one machine to cover that many different needs, a cheap plasma cutter (the ones from Lidl are very good value, I bought one a couple of years ago and it's excellent, I already had a compressor but there are now ones with...
A similar problem, similar solution - bitumen for felt roofs, to get it off your hands squirt a load of baby oil in disposable gloves, put them on for 20 minutes and it'll wash off!
If it's the breaker tripping, changing the connectors won't help - your sparky can look and see whether you could have a higher-classed breaker of the same current rating, a "type C" instead of a "type B" - the C will allow a larger inrush current briefly but cut at the same continuous current...
It's more about spring/damper rates, a picture (in your head) to explain: stick a bloody great lead disc, nicely balanced, to the wheelrim, take it over an uneven surface - to ensure it tracks the surface you need a much higher spring rate to push it back into contact, and that means much...
Silicon bronze mig wire? it doesn't harden with the quench from the surrounding metal, depends whether he can a)get away with the appearance and b)get away with the slightly lower tensile strength in the threads.
Drying out can be speeded up a fair bit by applying a low voltage to the motor's windings - did the Holbrook's by attaching an *old school transformer* battery charger to gently warm it up, did the same with the crusty Oxford welder when turning it into a 240-415 step-up for the phase converter...