Air Gun Home :: View topic - phantom compression tube assembly has hole in it

Amigo · Veteran Member

Hey Smash, I think Kanyon's idea of using a flapper type hone is probably your best bet to remove that tap break-thru burr.

For added air leak insurance a drop of an epoxy like JB Weld applied with something like a toothpick to an absolutely oil free surface might do the trick.
I know working at the bottom of a tapped hole is tough, but if a guy took his time and applied due diligence, he could "git'er done".

I'd want to apply the epoxy and give it time to thoroughly set first. After the flap wheel, then a guy could follow up with a 400 grit break hone in a fore & aft lapping pattern. The 400 grit surface seems to be about right for holding the ideal amount of lube with synthetic seals.

Is this what they call turning lemons into lemonade??

Good luck,

Amigo

smashingembryos · Member

thanks for the replies

you guys have some very good ideas for me and i thank you for that.
i thought i heard a few people say its a good idea not to hone that end of the compression tube, is that right? (i realize this is would be the exception)
never thought of jb weld (mostly cause i dont like it, but im not against it)
im thinking i cant just leave the hole there even if (when) i get the burr out of there cause its probably almost as bad for the seal as having the burr there, thinking that having a slightly compressed seal running over a hole is still going to eat away at it. but i did ponder dropping some solder down the hole as its easy to fill and easy to sand also relativly easy to clean out of my threads if/when i get some on them.
no matter what happens i really doubt that i was/will lose any air pressure from that little hole between the locktight and screw in place, but i am concerned about my seal.

any thoughts about the solder idea?
and under normal circumstances is it best NOT to hone that end of the compression tube?

AirGunEric · Site Admin

A burr in the path of the piston seal would be the primary concern- eventually it will chew a hole in the seal and reduce power significantly.

That being said, the idea of honing is not just to remove the burrs and such, but the "cross hatch" pattern if the honing is done properly will actually aid in piston sealing. Much like an internal combustion engine, the piston seal (or rings and cylinder walls in the case of an engine) wear with use- although in an airgun with a "soft" piston seal the majority of the wear is on the seal, not the cylinder wall. A proper cross-hatch as opposed to a mirror-polish type finish keeps enough "texture" on the walls to help insure the seal will, in fact, seal by not being able to slide too easily and allow air to pass around it.