Now if we can just find some Swedish guys, that were possibly around in the 70’s to tell us what the equivalent to AGA H52 is
It’s probably Swedish Stainless
I’ve repaired a few Pre 75 Maico frames over the years, mostly for knackered engine mounts. I don’t doubt it’s from loose engine mounts but it’s interesting that it’s mostly only Maico’s that suffer to the extent they do. I have often wondered about their balance factor.
The next common repair would be to fix up the badly modified rear ends. This is the result of the early frames being the same as 74 except for the rear ends and so many have been updated to 74 spec, I suspect a lot of them modified in the day, and poorly done, probably due to resources of the times.
I have had to repair a couple of front down tubes as well. These had many fractures throughout the tube. The swingarm knuckle joint has a hole that runs through them so any moisture from the rear pivot-shock tubes can drip into the lower section of the front down tube and rust them from the inside.
This probably occurs from cracks in the tubes from the modified shock mounts.
Any tube that has a crack in it will suck moisture in as it expands and contracts throughout the day but the vacuum inside the tube won’t let it back out.
I have seen this on frames of many brands.
Back in the 70’s stainless filler was common for welding mild steel.
Good TIG wire was scarce back then as it wasn’t all that common to TIG mild steel so no suppliers stocked good TIG wire.
Oxy wire of the time wasn’t copper coated, the rust layer wouldn’t bother an Oxy too much but would pop & fart when used with TIG
TIG was usually only found in the stainless steel game back then, and usually only in 3 phase. Accordingly stainless TIG wire was always around and it worked well for many applications
Nowadays cheap TIG machines can be bought quite easily just as triple deoxidized wire can too.
I have seen some samples from the cold welding machines.
I forget what letters they use for them (PMT or other) but I was looking at some demo pieces about a year ago. They’re wire feed like a MIG and it had welded a thin piece of Gal sheet to a thin piece of Aluminium sheet. I wouldn’t have believed it if I hadn’t seen it.
They were bloody expensive as I recall, I think $20,000 or thereabouts.
I worked with a firm many years back that was Laser welding stainless.
The flat sheets were clamped down in place and the Laser torch would run over top and fuse them together without filler. They were impressive welds except it couldn’t go around corners so they used to get me in to TIG the odd shape parts.
