Sleeving FX .25 STX Supreme liner

[rkr]

Humm, FX guns expert is using silicone to attach a CF tube over FX liner. Silicone does not cure inside as air is not getting through to let the silicone cure? I have done some seals from silicone and when there's a thick layer it takes days or even weeks to solidify and in this situation it's most likely staying in liquid form. For vibration dampening uncured silicone might actually do the trick but I believe most of us try to stiffen the barrel as much as possible? I'm rather confused about this thread, epoxy works - why not use it?

[mtnGhost]

It's been gone over before, but which would be best for our needs- Unidirectional?  High Modulus?  Filamet wound?  I think Unidirectional, but I'm not an engineer though.

High modulus is probably fine. I'm layering tubes using the uni to sleeve closer to the liner, using the HM around it for sturdiness. I'd imagine these thin uni's would hold up on their own and provide adequate structural stiffness, but I'm a go all out kinda guy lol

[cosmic]

loc-tite 638

[YEMX]

loc-tite 638

This is what I've used in the past

High modulus is probably fine. I'm layering tubes using the uni to sleeve closer to the liner, using the HM around it for sturdiness. I'd imagine these thin uni's would hold up on their own and provide adequate structural stiffness, but I'm a go all out kinda guy lol

Why not a single type for the entire sleeve?  Just curious.  So, if I'm reading that right, you'd use unidirectional as an inner sleeve to shore up the FX barrel, then sleeve that in High Modulus? 

[mackeral5]

I typically use  Loctite 680.....it is what I am familiar with and so far it has worked very well for me.  But I could see using a variety of different epoxies. 

the thread started out questioning  what tubing others had used to sleeve .25 FX liners. 

Initially there was a lot of theoretical talk, even a good bit of real world experience shared around sleeving FX liners, but in .22 vs .25....

It quickly became apparent this was not going to be a simple answer to get.   

At some point the discussion around Ernest replacing the Orings in an OEM FX application w/silicon caulk came up.  I am convinced this was a perfectly executed troll because Matt couldn't resist the opportunity to pump himself up and bash Ernest. 

Somewhere around post 50 we started homing in on the answer.....

It only took 55 posts to get to the answer, lol...  Courtesy of mtnGhost...

Rockwest Composites sells a very nice variety of CF in English units of measure, including .375 which will be almost perfect for the .25 FX STX Superior .25 liner.

Great discussion though. 

[YEMX]

Rockwest Composites sells a very nice variety of CF in English units of measure, including .375 which will be almost perfect for the .25 FX STX Superior .25 liner.

Sorry to get the discussion off track again- anyone know off hand what the O.D. of a .30 liner is? 

[mtnGhost]

Rockwest Composites sells a very nice variety of CF in English units of measure, including .375 which will be almost perfect for the .25 FX STX Superior .25 liner.

Sorry to get the discussion off track again- anyone know off hand what the O.D. of a .30 liner is?

Budget for 0.396"

[mtnGhost]

loc-tite 638

This is what I've used in the past

High modulus is probably fine. I'm layering tubes using the uni to sleeve closer to the liner, using the HM around it for sturdiness. I'd imagine these thin uni's would hold up on their own and provide adequate structural stiffness, but I'm a go all out kinda guy lol

Why not a single type for the entire sleeve?  Just curious.  So, if I'm reading that right, you'd use unidirectional as an inner sleeve to shore up the FX barrel, then sleeve that in High Modulus?

Nothing wrong with a single sleeve! This 64" tube is going around a 500mm .25 on its own, and a 600mm .22 with the help of a uni sleeve (they don't stock what I needed for a one-piece tune compatible with the .22 liners, but they can custom make them for a (substantial) fee.

[YEMX]

...Budget for 0.396"

When my barrel comes in, I'll measure it best I can.  My tools aren't the best. 

Ah- gotcha about the lack of available size tube.  Makes sense. 

[mtnGhost]

...Budget for 0.396"

When my barrel comes in, I'll measure it best I can.  My tools aren't the best. 

Ah- gotcha about the lack of available size tube.  Makes sense.

Yeah, 0.396" is the common largest diameter on both this .30 pellet and .30 slug liner in front of me now. (Using good calipers for the measurements)

[Rallyshark]

In my experience, the uni-directional is great stiffness length wise, but it will split if pushed too hard.  Putting some 3k roll wrapped weave over it will take care of any splitting concerns.  High mod or other type will work great.  Basically, you'll want a "weave type" of some sort on the outer tube to give it better all around strength with no worry of failure

[Sbak]

Coulda skipped all the BS at post #11 I said to use 3/8 I'd tube at the beginning

[mackeral5]

Coulda skipped all the BS at post #11 I said to use 3/8 I'd tube at the beginning

Knowing to use 3/8 and finding it were 2 different things....I couldnt find anything but metric sizes until post 55..

[darkcharisma]

Coulda skipped all the BS at post #11 I said to use 3/8 I'd tube at the beginning

Knowing to use 3/8 and finding it were 2 different things....I couldnt find anything but metric sizes until post 55..

you havent utilized Google to its fullest. dont tell me you used yahoo search? oh man yahoo is so 1990s. 

[mtnGhost]

This 600mm should be cured by the morning. I homed out 0.035-0.040" in that glossy high modulus tube. The fit was snug, but I wound up adding some anaerobic RTV between that tube and the thinner standard modulus unidirectional tube that sleeves over the liner. I didn't think I was going to be able to get the darn thing together, but I muscled it by hand and got it in there. Talk about scary, forcing a thin
CF tube inside another tube with ~200lbs of downward force .. what could go wrong?!

Anyway, it seemed to work out well so I went ahead with the job using a generous layer of the Loctite  E-120HP. Before I move forward with adding a gap-sealing layer between the outer CF tube and the steel FX barrel shroud, I decided to wrap it with one snug layer of PTFE tape. Still working on sketching out something to stretch the barrel on both ends with ER-16 collets, so I'd like to have access to the lier outside of the FX tube for now. Beat case scenario - I notice a positive change in harmonics and I won't have to do anything else with it (wishful thinking LOL)

[mackeral5]

Coulda skipped all the BS at post #11 I said to use 3/8 I'd tube at the beginning

Knowing to use 3/8 and finding it were 2 different things....I couldnt find anything but metric sizes until post 55..

you havent utilized Google to its fullest. dont tell me you used yahoo search? oh man yahoo is so 1990s. 

I didn't use either search engine.  We have a specialized forum, the sharing of specialized information is the primary intent behind its creation. . 

Some times it's about the journey, not the destination.

[Corny]

It’s not very difficult to slot a 1/4 steel rod with. Hack saw....chuck it up in a power drill and use the abrasive clothe to remove .02-.03” from the inside of a cf tube.

If I recall correctly, think it took 15-20 min. And that with trial and error on wrapping the abrasive cloth around the rod properly.

I used epoxy from a cf repair kit. And JB weld on the steel to steel components.

[mackeral5]

It’s not very difficult to slot a 1/4 steel rod with. Hack saw....chuck it up in a power drill and use the abrasive clothe to remove .02-.03” from the inside of a cf tube.

If I recall correctly, think it took 15-20 min. And that with trial and error on wrapping the abrasive cloth around the rod properly.

I used epoxy from a cf repair kit. And JB weld on the steel to steel components.

I am familiar with this method, but previous attempts at using similar methods resulted in either moving the bore off center or varying ID somewhere along its length.  It's not one of my go to methods due to my lack of ability to use it precisely.  I'm not challenging the effectiveness of this method when used by others, but it hasn't worked well for me. 

It looks like Rockwest Composites combined with the various ebay sellers should provide great selection for future projects.   

In a couple of weeks I plan to pick up a stick of their .375/.503.  I am getting closer to being comfortable with using this liner in my B51 project. 

[Rallyshark]

It’s not very difficult to slot a 1/4 steel rod with. Hack saw....chuck it up in a power drill and use the abrasive clothe to remove .02-.03” from the inside of a cf tube.

If I recall correctly, think it took 15-20 min. And that with trial and error on wrapping the abrasive cloth around the rod properly.

I used epoxy from a cf repair kit. And JB weld on the steel to steel components.

I am familiar with this method, but previous attempts at using similar methods resulted in either moving the bore off center or varying ID somewhere along its length.  It's not one of my go to methods due to my lack of ability to use it precisely.  I'm not challenging the effectiveness of this method when used by others, but it hasn't worked well for me. 

It looks like Rockwest Composites combined with the various ebay sellers should provide great selection for future projects.   

In a couple of weeks I plan to pick up a stick of their .375/.503.  I am getting closer to being comfortable with using this liner in my B51 project.

I understand your concern Mike D, and we all have to use the methods we are comfortable using for our particular projects for sure.  The biggest trick with this method is only opening it up the minimum amount required, and much like using a lathe, it is hard to get it off center to a certain extent.  The key is in keeping the drill spinning and the sand paper moving, while not opening up one part of the CF more than another part.  That is especially true for the end sections, since that is where keeping things centered is the most important.  Think of it like spray painting, you have to keep a steady movement and never let it sit in one spot more than another.  I use more epoxy than I know I need, and the extra is pushed out at the end when installing the liner in the CF.  What spaces may have a slight variation are filled with the epoxy.  I've found harder part being the thimble end of things and the leade in.  That is the part that has caused me the most trouble when I've done it.  All that being said, I've been pretty happy with the last one I did.  Repeated long range accuracy has been the reward when I did get it right. 

I used a drill mounted to be stationary and at a constant speed, while moving the CF up and down on the rod with a dremel sanding drum that was cut and placed on the rod.  I found the  inherent roundness of that sanding drum gives me a more consistent result.  Not that I'm saying you should do what I do.  I'm just saying what did work for me at least.  It is pretty awesome to be able to make 300+ yard shots on 12oz cans regularly, and 200 yards and under are very high percentage shots at this point. 

Like many others have stated, there is more than one way to skin the cat for sure.  I look forward to seeing some good results from the gun when you do undertake the barrel build, regardless of the methods

[mtnGhost]

If you're honing a CF tube out to fit a liner or another tube, it's a good idea to add an extra couple of inches to the side that you're inserting the honing rod into. That side will end up larger, so I just cut that extra length off (using a sharp cutoff blade on my lathe, which I was comfortable doing seeing how clean my test cuts were).

Make sure you clean out the (nasty) material often - otherwise you're wasting time! I went a little heavy on my bonding agent like Donny.

I rolled the tube over the bead on the liner in a constant direction, moving it forward a couple inches at a time, and then backing up an inch or so, creating a vacuum of sorts that sucked in the extra epoxy.