I have been told it can be done

[W]

A while back on the old forum I asked about using shrink tubing to improve fit on a spring guide. Got several replies that would lead one to believe this is a easy thing to do. Well I have cornered the market on shrink tubing both in sizes and types and have had no luck installing it. There appears to be several types and sizes and they all claim to shrink by about half after heating. I also picked up a heat gun and it does a excellent job of activating the wrap. the stuff also is adhering to the spring guide. The problem is after appling the tubing I can't get it inserted in the spring with out destroying it. Any hints or specific brands, type or tricks would be greatly appreciated. I can't afford a lathe to make new spring guides so I am still looking for a usable substitute to get rid of spring twang.
W

[daved]

If it's actually sticking to the guide, it sounds like you may be getting shrink wrap that has an adhesive inside, the kind usually used for underground repairs.  If so, it's much too thick for your application.  I know, you already figured that out :-).  I've used shrink tube on several Gamo's and even an R9 for a short time, the cheap 1/2" diameter stuff seems to work most of the time.  I think GB is the brand I've used, I get it at my local hardware store.  If that's still too tight, then maybe you don't need it in the first place.  You didn't say what kind of gun you're working on, but some do have a decent guide to spring fit from the factory.  Good luck.

Dave   

[W]

Dave
 Thanks for the reply. I am working on two guns a Gamo 890 and a Crosman 800. Both have a nasty twang. I have not tried a diameter as close to the diameter of the guide it's self as half inch. I also see GB brand should be available at Ace hardware. I'll see if they have some half inch. thinner the better?
W

[daved]

That sounds like the right stuff, Walt.  And Ace should be a good source.  One of the guns I did it to was a Gamo 440, basically the same as your 890.  I did a soft tune on that one, used a JM Merlin spring.  Only shot in the high 700's, but talk about SMOOOOTH!  Sweet little rifle, I may have to get another one someday and do that again :-).  Later.

Dave

[larspawn]

Walt,

I've done the Bubba tune a few times.  I picked up a shrink tube "party pack" of different sizes from Harbor Freight.  I've also used 3M mat adhesive with great success.  You want the tubing to be tight.  I usually have to "screw" the spring onto the guide.  If it isn't a tight fit you won't get the benefit.  As the spring compresses it will get looser.  So if you have a fit that allowes the spring to slip off the guide when not under compression it will be too loose under compression.  

Andy

[Pete]

try diffrent DIAs.....as it shrinks it be comes thicker

[Phil_B]

I have tyred the shrink tubing with little success. In my attempts it only lasted a short wile, then came off the guide and bunched up inside the spring. But along the same idea I have had great success with cutting strips of soda bottle about 1/8 inch wide and as long as the guide . I use 4 of these strips and crazy glue them to the guide length wise at 12,3,6and 9 o'clock. Wrap with black tape real tight and let sit over night. The next day I unwrap the tape ,which some times is a pain, then use a cleaner to remove the adhesive from the tape on the guide. I then check for fit with the spring ,most times It is too tight so then I chuck up the guide in the drill press and sand it down to a tight fit. This has worked well for me and has lasted for a long time. On a side note, I also use soda bottle plastic for buttoning my pistons, a paper hole punch works great .

[W]

Phil
Thanks for the idea. I think I am going to bite on this one. I have a Gamo spring guide I can use for a trial. I am guessing thinner the better on the plastic and I might try epoxy I have some of that in the shop. What grit paper did you use to size the guide after the strips were adhered in place?
W

[Phil_B]

400-600 I think, Just go slow and check for fit often If you take to much off you got to start over,  I learned that the hard way

[uncle paulie]

W......Try the plastic/epoxy route as a test before trying it on the spring guide, many epoxies won't stick to some plastics, I know most will not adhere well to polyethylene and most nylon blends. You'll end up with an epoxy coated spring guide and no plastic! Same goes for the CA.( Crazy Glue)

pv

[W]

What can I say. I probably wouldn't have tried this if I didn't have a extra guide from a Gamo gone bad project but I did and so I did. I roughed up the guide and the plastic strips with 80 grit, cleaned both with isopropal and applied the strips from a one liter Sam's Cola bottle with Crazy Glue, sanded to fit and put it in my twangy 890. The gun goes thump! The twang is gone. It's held up through twenty rounds so far. I will continue shooting.

[MichaelM]

What can I say. I probably wouldn't have tried this if I didn't have a extra guide from a Gamo gone bad project but I did and so I did. I roughed up the guide and the plastic strips with 80 grit, cleaned both with isopropal and applied the strips from a one liter Sam's Cola bottle with Crazy Glue, sanded to fit and put it in my twangy 890. The gun goes thump! The twang is gone. It's held up through twenty rounds so far. I will continue shooting.

as long as the ends are glued down good and the spring doesnt catch them and they have a bit of taper I bet it would last a good LONG time.... soda plastic is what I use on a couple guns now to button up the piston and have yet to have one come off...

[Davee1]

Right On W!!!  Dont ya just love that thump?  I can still remember my first "thump" which means that your work was all for good.  Good Job man!!!
Hope your soda strips hold up.  Time will tell.