Canadian Airgun Forum

Just a quick overview.........I have used plastic port tubes of various types and never been completely happy with the results. Consequently I switched to aluminium tubing. This tubing is abailable at any hobby shop (think model airplanes). It is very thin walled but more rigid than plastic. The tubing measures .282 and fits very nicely in a drilled 9/32 hole and can be cut using a small tube cutter and a fine tooth hobby saw (cheap - also at the hobby store).





the tubing cutter creates a bevel on one end of the tube that fits nicely in the drilled portion of the receiver/barrel..........and the sawed end is straight and fits into the tube/valve precisely.






Note here that I've drilled COMPLETELY into the valve body. this is done just so the aluminium port tube does not need to be cut exact to length. Close is good enough as the depth of the new tube in the valve can be pre-set simply by inserting the new tube in the valve hole and pressing down on it with the barrel/breech hole..........it sets it at the exact depth needed.

Here's where the problem starts. I've used a number of bonding/sealing materials so far with intermittent results. Blue Loctite has been the best so far but everything must be done 'just right'.........and the bond is very good.......meaning that it's a bit of a chore to dissassemble the gun again and get everything clean Also tried a variety of 'Crazy glues'........this stuff just doesn't do it for some reason. I've thought of Accraglass and a few of the metal mix (JB WELD) but this stuff tends to want to be permanent and that I DON'T need.



I'm going to try a couple of others I picked up and will report on the success (or lack of) in a future post.

Please note - anyone trying this should really use a drill press for the process. Cheap ones are available for about 60 bucks that will really do the job........see photo



If anyone has any questions or suggestions please feel free to contact me - I will be very gratefull. When everything works just right with this system then the results are very pleasing..........eventually I hope to get the process perfected and will advise when (IF) that happens.

Cheers - Gus

I've done that in the past, Aluminum is excellent if you know what you're doing, increase fps by about 35 fps over the poly tubing. I didn't need to use any sealant what so ever. The trick of using aluminum is that you got to make sure all surfaces that you drill must be 100% flat perpendicular in the valve and on the barrel, which take most of the time doing it before the exact, I mean exact measurement of the tube to be cut.
I still have the gun untill now and works great.

Hi SNIPER..........I've also gone that route and the results, as you say, can be impressive. the reason that I changed out to this method is to see if I could get the same results in a much shorter time by allowing the new port tube to 'seat itself' so to speak.................but, because the new hole in the valve is drilled completely through, a sealant of some sort must be used.........as there is no shoulder in the valve for the bottom of the new port tube to seal against. So far this process is, by far, faster than the former and gives the same results...........IF, and this is where I'm experimenting, I can find a product that will provide a quick and accurate seal around the new port tube. It's also easier on the breech side as the port hole is also enlarged (9/32) and the chamfer from the drill bit closely matches the tube cutter chamfer on the new port tube.





The hole looks too deep..........it's not.......it's crappy light and my camera playing tricks.

In order to hold the barrel steady in the breech I use blue Loctite between the barrel and the breech.........and allow it to cure. This serves to steady everything for the drilling process. NOTE TO ALL - use great care that you don't go too deep here and force burrs into the bore.......they will screw up the pellets when you load them.

Cheers - Gus

Take a look at the 680. Loctite sleeve retainer. I use this all the time to secure bearings, races sleeves etc Works like a hot damn when I over bore a hole. Will; also work with aluminum as I just tried it. I use brake clean of carb cleaner to clean before applying as I buy the stuff by the case.,but any solvent will work http://68.72.74.116/PRODUCTS/680.htm. I use heat if I have to take anything apart. Small like that a soldering gun would work
Q: How can I remove a fastener that is "permanently" locked in?

A: The application of heat is needed to remove a fastener that can't be removed with a hand tool. Temperatures of 325F and above is needed to break down a standard anaerobic, 500F for high temperature Anaerobics. A heat gun or propane torch is commonly used to do this process, and careful disassembly should occur while parts are still hot. Once apart, and cooled, use methylene chloride (Chisel #79040) to remove cured excess material. Always wipe down the fasteners with clean up solvent to remove the wax film that Chisel leaves on the surface.

Don't no if this will work for you but an added benifit is it sets up real quick

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Thanks Scruffie...........I'll add it to my list of 'going to get' and give it a try.

Appreciate it - Gus

Good work and info Nice clear photos that are just the right size.

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Should have said that the 680 is high strength. the 609 is a general purpose sleeve retainer . might be easier to take apart

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If you think education is expensive, try ignorance.

Hi Gus,

I did your way to start off with but it was taking too much time and try out all kinds of sealants sometime would work for so many shots and then it starts leaking, tried blue loctite, red, marine spec., metal to metal bond ... etc.
this way with nice straight cut, no sealing, no leaks and no problem.
But perhaps it's good experimenting ....... gain more knowledge ....

Sealent? Whay not just use hot glue? Seems to me that it'l do all you want, and if you need to clean it off just heat 'er up with the heat gun.

Ryan

to bad companies don't build guns that are fited tight . there would be no need for the sleeve .

renn ? if you drill all the way in the valve what creates the preasure to seal it in the barrel . the sleeve will never be squeezed tight ,like it should onless there is a shoulder for it in the valve to push on the barrel .
do you guys plug the barrel and see if anything comes out around the sleeve? thats what i do with everthing .

JezX - a bonding agent is used to seal/attach the port to the inside of the valve as well as the barrel/breech port. This seems to be where the problems occur. If it works it seems to work great..........it just doesn't do it all the time which means a lot of work duplication to tear it down and re-seal. But I'm working on it.........there's got to be an answer out there - couple good ones on this thread already

Cheers - Gus

I'm tweaking and tuning far too often to be (semi-) permanently sealing the transfer port. Poly tube for me until I'm convinced its ready for it. Its already a pain to change anything but the mainspring.

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