Heat-shrink teflon tubing for a 13xx brass piston -where to get it?

[markasaurus]

I have seen pictures of brass pistons that people have used Teflon tubing on (great grammer I know) and i think this is a worth while modification.  Does anybody know where to find this kind of tubing?

I contacted airgunsmith (it's their piston) and asked them about lubricating the piston with Molly paste.  Their reply was that you should NOT use Molly paste, they had done tests with it and it gums up the valve.  So I want to use the heat shrink Teflon tubing on the piston to make pumping easier and avoid scoring the pump tube.

Does anybody know where to get this tubing?  And has anybody actually tried something like this?

[1377x]

I have seen pictures of brass pistons that people have used Teflon tubing on (great grammer I know) and i think this is a worth while modification.  Does anybody know where to find this kind of tubing?

I contacted airgunsmith (it's their piston) and asked them about lubricating the piston with Molly paste.  Their reply was that you should NOT use Molly paste, they had done tests with it and it gums up the valve.  So I want to use the heat shrink Teflon tubing on the piston to make pumping easier and avoid scoring the pump tube.

Does anybody know where to get this tubing?  And has anybody actually tried something like this?

can you post these pics you saw or a link to them?

your piston shouldnt be scoring the tube .bluing wear down thats normal if you heatshrink the piston that might make things a little tight in the tube making pumping harder

[arkmaker †]

I'm not understanding exactly what you want to do........Shrink wrap over the oring? Or in place of the oring?? Please enlighten the old fool that I am 

[sandpiper]

Home depot or lowes carries it but not sure how big. I'd like to see a pic of what you're referring to.

[markasaurus]

I got the idea from this fellow chevelle who made a super-crosman.  He used a very long piston with teflon - the link for the whole article is here, the pictures of what he did after

http://www.bing.com/images/search?q=crosman+1322+wood+grips&view=detail&id=B5B73B0EA454FC17E4702302F0B9E9F2FC12D192&first=1



Text
"Here is the new piston I made for my 1322 carbine. To make the piston more precise I bought a tapping jig that mounts in my drill press which helps to tap the threaded holes in the piston perfectly straight. I also bought a new pump tube because the old one had some scratches from when the original pump link pin walked out into the pump tube. It help power a little having the newer pump tube. I have since added a set screw to the piston pin to keep it in place on both of my new pistons. This piston uses the same 90UR urethane O-ring as the dual O-ring set up on my 1322 rifle piston. I have a bag of 100 and I'm glad I bought them because they should last me forever....

"The grooves for the O-rings and the Teflon were cut on my drill press using a technique I invented. It's amazingly precise but you do have to check your work often with a micrometer to stay within tolerance. Here are some pictures of that set up. I just change the number of dremel disks using different thickness ones to get the right groove width correct when I cut the O-ring groove. For the longer groove for the Teflon shrink tubing I have to adjust the height often by using either the drill chuck or the dremel chuck. I cut it close to the correct OD being careful to keep the dremel square to the work piece, then do the last few thousandths with a piece balsa wood with some 400 sand paper wrapped around the edge. I finish with 600 then buff with a dremel buffing wheel to get  the groove perfectly smooth for a good seal. I bought one of the Jacobs heavy duty chucks for my cheap drill press which really helped. The new Jacobs chuck cost more than the entire drill press, but it was worth it."

[1377x]

ahhh!
chevell the father of the roller trigger that dc and gs improvised a version of .chevell was my hero most the parts he made were done with basic tools and some ingenuity
imo,sounds like too much work with very little pay off
reading the link he tells you how he did it
source some shrink wrap and follow his lead.
seeing he did it with basic tools.once you find the correct shrink wrap measure its wall thickness,measure the od of the ring.turn down the piston the until the shrink wraps od is less than the o-rings od
i think i wrote that right

[cmj21973]

I have seen pictures of brass pistons that people have used Teflon tubing on (great grammer I know) and i think this is a worth while modification.  Does anybody know where to find this kind of tubing?

I contacted airgunsmith (it's their piston) and asked them about lubricating the piston with Molly paste.  Their reply was that you should NOT use Molly paste, they had done tests with it and it gums up the valve.  So I want to use the heat shrink Teflon tubing on the piston to make pumping easier and avoid scoring the pump tube.

Does anybody know where to get this tubing?  And has anybody actually tried something like this?

Try this: http://www.bing.com/shopping/search?q=teflon+heat+shrink&qpvt=teflon+heat+shrink&FORM=HURE

[markasaurus]

thanks a lot for the info fellow air gun enthusiasts...if i have to turn down the piston i.e. take metal off - I have to rethink the whole thing. 

[breakfastchef]

Use 75-90 duro o-rings and you will be fine. The teflon mod is really unnecessary. Sometimes the early modding pioneers tore apart their guns so much that they created conditions in which other problems would arise. These new problems required solutions like his teflon rings.

[1377x]

Use 75-90 duro o-rings and you will be fine. The teflon mod is really unnecessary. Sometimes the early modding pioneers tore apart their guns so much that they created conditions in which other problems would arise. These new problems required solutions like his teflon rings.

chevell was using 90 duro o-rings
he didnt want the metal on metal scratching the inside of the tube.my steel pistons wears the bluing of the inside of the tube which is only hurting the cosmetics.the shrink wrap kept the piston from scratching the inside of the tube
i think airgunsmith uses a piece of delrin on his pistons to prevent this