mcarterbrown.com - Redux pierce-pin assembly: cut threads & LIQUID seal

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Redux pierce-pin assembly: cut threads & LIQUID seal

EDIT - See the post below; looking for more info on the liquid seals.

I had the Redux completely apart yesterday and had some spare pierce pin assemblies on hand which I think were standard CCI's.

The CCI's had about twice as much threading as needed for the Redux so I cut them down.
More accurately, PMI 3 cut them down with his razor saw!

If they were left long, they would interfere with the cup-seal or valve spring. Cut cown, they fit perfectly.

Shown below is the DD68 Redux valve and the cut pierce-pin assembly that came installed as well as an uncut CCI assembly. NOT shown: the o-ring that seals the assembly and acts as a spacer. (don't omit that o-ring or you'll likely have a massive leak on your hands!)

From the valve insert thread, the second photo shows the total length of the pierce pin assembly, subsequent to cutting it down.

http://www.mcarterbrown.com/forums/a...1&d=1266804796
http://www.mcarterbrown.com/forums/a...e_insert-8.jpg

I blew out my first pierce-pin seal today, dumping a near-full 12-gram. It was a CCI seal on a backup assembly identical to the Redux assembly except the seal.

The Redux pierce-pin seals are silicone rubber installed as a liquid. I've never blown that seal yet.

Mongo posts about this here:
http://www.mcarterbrown.com/forums/c...tml#post747843

Quote:

Originally Posted by mOngo (Post 747843)

The silicone bead seals I'm talking about were done using a small cooking injector (looks like a hypo) and gently squirting the warm clear silicone ( aquarium silicone) into the piercing pin cup- shaping it a little if need be and then drying while level and vertical... it was a hassle at first, but after a few tries it worked like a champ!!!! you need to fill the entire bottom being careful to leave the piercer clean, and level it, then dry it! wow...... problem solved! AND, they last a long, long, time if done right. Mongo

See also: http://www.mcarterbrown.com/forums/c...tml#post744939

Here's a photo of the DD68 seal, clearly showing a meniscus formed when the silicone was poured:
http://www.mcarterbrown.com/forums/a...1&d=1272850650

I'm compelled to get a few more assemblies and make my own using silicone.

Interesting, mine is just a stock CCI pierce pin/seal. I have heard from Steve that he can use silicone as well though.

a buna o ring will work just fine. that what i used to use in m sheridan valves.

Quote:

Originally Posted by Rednecksniper (Post 1290862)

a buna o ring will work just fine. that what i used to use in m sheridan valves.

You use a buna-N o-ring on the pierce pin side of that assembly? I can see using one on the base as a seal...

yes the pierce pin side.

rather than buying a new seal from palmers which would cost oooodels, i threw a buna o ring in there and it has never leaked. nitrile stands up just fine to Co2.

Liquid Silicone PiercePin seal

One more thing- this arrangement is MANDATORY on a slamchange grip for a Redux or a dd68- you'll not have to worry about "blowing your seal out" when short changing 12 gram- and, again, it lasts a long, long time!

Quote:

Originally Posted by mOngo (Post 1295568)

My 'dux has seen over a year of heavy use and I have yet to blow out the seal. Outstanding.

I picked up some aquarium seal the other night and tried it but the one I got seemed very thick. Even heated to about 212°F/100°C, it stayed somewhat solid and difficult to work.

Necessity is the mother of invention and I had an unopened tube of McNett "SeamGrip", a clear, liquid urethane sealant I decided to try. Without much heat, it pours like corn syrup and it's resistant to extremes of heat and cold, helpful when dumping a 12-gram into the seal.

http://www.mcarterbrown.com/forums/a...1&d=1273272355

I'll let you know how it works out. Failing that, McNett makes "SilNet", a similar but silicone based sealant.

UPDATE: SeamGrip FAIL!

Fail fail FAIL!

All aboard the failboat...let's go FAILing!

Dumping a 12-gram blew that stuff right out of the assembly, cutting a nice slice in it.

Back to the drawing board... have to pick up some SilNet silicone sealant and give that a shot.

I tried a new approach: a bit of JB-Weld behind a standard CCI pierce-pin seal.

Acid test: I dumped a FULL 12-gram into the pierce pin assembly while installed in the Redux.

No blown out seal!

I'll report after testing this during some games.