Piston Head Without Nut

[Ron Z]

Cork can be rather brittle when it gets older. It really isn't strong. It works as a seal because it is somewhat elastic, but in most cases it is enclosed so supported- piston on the inside, barrel on the outside, flange at both ends. Otherwise it is likely to tear or break.

 

...which is one reason why I am surprised that there is nothing at the inside end. Any friction (and there will be some) with the barrel as the piston moves up and down is going to try to pull the seal off of the piston, and will eventually succeed, unless there is a physical barrier in front to keep it from moving.

[siamackz]

Cork can be rather brittle when it gets older. It really isn't strong. It works as a seal because it is somewhat elastic, but in most cases it is enclosed so supported- piston on the inside, barrel on the outside, flange at both ends. Otherwise it is likely to tear or break.

 

...which is one reason why I am surprised that there is nothing at the inside end. Any friction (and there will be some) with the barrel as the piston moves up and down is going to try to pull the seal off of the piston, and will eventually succeed, unless there is a physical barrier in front to keep it from moving.

I agree, I think the only way to really resolve this issue is to use a die and place some kind of a tiny screw on top of the head.

[Ron Z]

Use a nylon nut or screw if you can. Metal, even brass, will corrode when in contact with ink. Black nylon is even better.

[siamackz]

Use a nylon nut or screw if you can. Metal, even brass, will corrode when in contact with ink. Black nylon is even better.

Thanks Ron, much appreciated!

[siamackz]

Thanks to the excellent advice received here, I learned a new skill

I made threads in the piston head. Then I sanded down a nylon nut. And voila!

The nut is important because not only does it ensure that the cork doesn't pop out, but by tightening and loosening it helps expand and contract the cork, respectively, which allows you to adjust for a perfect seal in the barrel.

Edited July 28, 2018 by siamackz

[fountainbel]

That's the way to go, well done Sia !

Francis

[siamackz]

That's the way to go, well done Sia !

Francis

Thanks for always being so encouraging Francis!

[CS388]

Great job. Well done!