[singleminded]

The boss is between 1/16 and 1/8 thick as far as i can tell..John

[iansoady]

I think I would be tempted to drill & tap the boss you mention. Even if you go through into the tank interior you could use JB weld or similar to seal it.

[singleminded]

I managed to get some extra light inside the tank and the round'button' that the stud should be part of does not go through the tank wall.
The stud , which is part of a larger base, fits into an indentation in the tank. it was just about possible to see the indentation from inside.
As soft solder would melt on the base and the base did not release from the tank I have to assume it is spot welded or brazed on.I am not going to get the base off. I may get the threaded part either tig or mig welded on to avoid any unnecessary distortion of the tank..John

[singleminded]

I'm sure the 'stub' part should be part of the button you see in the second photo.
I've looked inside the tank with a bore scope and cannot se if the fitting goes through the tank, so I'm not absolutely sure if the 'stud' is in a threaded boss through the tank as I've seen on other tanks.
Still thinking this through though..John

[wessex_man]

I think its a stud used on the later tanks. You could try and confirm this by feeling around the inside of the tank for evidence of the insert. Once confirmed and if you are feeling brave you could attempt to remove the broken stud by drilling a small hole in the stud (not too deep as to brake through the tank) and use one of those easyout tools
https://www.youtube.com/watch?v=SMrDYJvY0Ts

[singleminded]

I knew the earlier tanks were all soldered and i'm sure as you say that my tank is welded.
My tank looks like the second picture you posted and I can't make out if the studs have been cut off or broken in some way as both are missing but the base is intact.
i tried heating the tank till I could melt solder on the 'button' and it is still on the tank.
I agree that the 'kindest' way to fit new studs will be to solder them on, which is what I'm going to do..John

[wessex_man]

Up1929 were certainly soldered. (The whole tank was)


In the early 30's welded non panel tank it has an insert in the tank which accepts a stud. I think this carries on with the instrument in the tank types. Shame I don't have a picture of one without tank rubbers fitted.


Are you sure that the stud has not been sheared off? If I had to fit one I'd solder it on.

PS knowing Sunbeams they probably had variations on a theme to use up old stock and either may be possible.

[singleminded]

I've managed to get a spare tank for my '32 9A but the tank rubber studs have been cut back to the mounting 'button' on the tank side.
Does anyone have a suggestion as to whether these may have been soft soldered on or brazed.
It doesn't look like they are fitted through the side wall of the tank..John