Garden Railway Forum

GTB wrote: ↑Sun Jun 02, 2019 12:48 pm Forgot to mention.....

O-rings can vary a little in dimensions, so if the piston is too tight and hard to move when the o-ring is fitted, even when oiled, you may also have to shave a little off the depth of the groove in the piston.

It's one of those goldilocks things, the o-ring fitting has to be just right.

Graeme

The PTFE tape worked well for all the piston rods and valve rods so thats cool. Not so cool I managed to break a 10ba bolt in the rear cylinder end where the slides are bolted, so it means I need to remake that again as well as the screw that goes on it Not sure about piston rings as yet, but I am sure I will sort out something as we go along, lol

-steves- wrote: ↑Mon Jun 03, 2019 3:02 pm Not so cool I managed to break a 10ba bolt in the rear cylinder end where the slides are bolted, so it means I need to remake that again as well as the screw that goes on it.

Been there, done that, got the t-shirt. It doesn't take much force to shear the head off a 10BA screw......

They usually shear just below the head, so if there is enough thread left to grip, it may be easy to unscrew the stub of thread, as it isn't usually under any tension once the head is off.

Graeme

GTB wrote: ↑Mon Jun 03, 2019 4:26 pm

-steves- wrote: ↑Mon Jun 03, 2019 3:02 pm Not so cool I managed to break a 10ba bolt in the rear cylinder end where the slides are bolted, so it means I need to remake that again as well as the screw that goes on it.

Been there, done that, got the t-shirt. It doesn't take much force to shear the head off a 10BA screw......

They usually shear just below the head, so if there is enough thread left to grip, it may be easy to unscrew the stub of thread, as it isn't usually under any tension once the head is off.

Graeme

Unfortunately not, the bolt bottomed out on the glange thread below it, the bolt was about .3mm too long and snapped off seemingly just below the top of the hole and is under full tension From what I can see no way to get it out at all Ah well, put it down for a few days and go back to it next week, again, lol

I am pretty sure you can desolve the bolt with aluminium phosphate (i think) and it does not affect the brass, i have done this before in a dish on the stove. be warned, it smells.....

Maple wrote: ↑Wed Jun 05, 2019 12:22 pm I am pretty sure you can desolve the bolt with aluminium phosphate (i think)

Aluminium Sulphate, otherwise known as Alum, is the chemical you are thinking of......

It forms a weak acid solution when dissolved in water.

Graeme