Installing long PVC sleeves onto tubing

[Joel]

I have to install a bunch of 24†long, 1.2†ID, 1.55†OD PVC rubber grips, on to some 1.25†OD electroless nickel plated tube handles. The end of the tubing where the grip will be started has an inch of threads and there will be adhesive spread over the tube. The grips fit the OD of the tube quite snugly.

I am unsure of the best way to hold the starting end of the grip out from the tube so the glue won’t be pushed into a bead at end of the grip. As there is an obstruction just past this stop point, this device must be removable with the grip in place. I am considering something like a split ring (flat, like a main bearing) with round end pins to space it away from the glued tube.

I am also unsure how to install the grips efficiently. Plugging off the tube and using air pressure sounds like my best bet so far. This will be a regular job so I need to work out something as simple and reliable as possible.

Also, can anyone recommend a good adhesive to bond the PVC rubber to the electroless nickel plating? It needs good thermal resistance (about 250آ°) and the ability to expand with the sleeve. I have ordered some different glues for testing, but if anyone has any experience, I would like to hear about it.

Thanks.

[winchman]

Could you make a vacuum fixture to hold the rubber grip so it is larger than the tube it goes on?

The fixture I imagine would be made in two pieces. The outer piece would be a plain tube. The inner piece would have lots of holes, and the holes would be connected by shallow interconnecting grooves on the OD. The vacuum port on the outer piece would line up with one of the grooves. The inner and outer pieces of the fixture would be sealed together at the ends.

The rubber grip would be inserted into the fixture. A plug would be put into each end of the grip to expand it so it seals to ends of the fixture. Vacuum would be drawn to expand the grip tight against the inside of the fixture, and the two plugs would be removed. The grip would then be larger than the tube it goes on so there is no interference fit to deal with

The ID of the grip (or the tube OD) could be coated with adhesive before the grip was moved into position. Releasing the vacuum would let the grip shrink onto the tube, and the fixture cold be removed.

I don't know if it would work, but it would sure make things easy if it did.

Roger

[winchman]

A second possibility is to use a mandrel to expand the grip before putting it in a freezer. After it was frozen, the mandrel could be removed, and the grip could be slipped over the adhesive-coated handle. It would shrink tightly in position as it thawed.

Roger

[rockrat]

I like winchman's vacuum idea.

Can you put the glue in the grip first? Then when it was pushed on, the glue would want to migrate to the closed end. Downside would be that the glue might not get good coverage toward the front of the grip.

We used hairspray on bike grips when I worked at the bike shop. That stuff was slick to start and dried like glue when finished. Can't imagine putting that stuff in my hair.

[Boucher]

PVC is a thermosetting plastic I don't know what temperature it melts but it is going to be very soft at 250*

[Ian B]

Joel,

Can you take something like 0.100 steel wire with a smooth finish (whatever you can find, piano wire maybe?). Cut 6 lengths, lay it along the length of the plated tube where you want the sleeve to end up, spaced evenly around the tube.

Paint the adhesive onto the tube and over the wires.

Slide the rubber sleeve into position.

Pull the wires out. There should be enough glue left in there from the spaces between the tube, the grip and the wires to do the job, and it'll be evenly distributed. Maybe give the sleeve a quick twist before the glue sets.

hth,

Ian

[Joel]

Roger, your idea sounded so good that I built a vacuum fixture this evening. Unfortunately, I can’t seem to make it work very well. It looks like the PVC is too stiff to expand despite the fact that I made the ID of the fixture only a little bit bigger than the grip. It does make the grip slide over the tube more easily so maybe it will still end up working better than anything else.

rockrat, applying a viscous glue evenly to such a small ID might be a challenge, but I will test and see how it works out.

Boucher, this is more of a rubber product and is supposed to tolerate in excess of 200آ°. Testing has shown that this is a very conservative figure and I want as much margin as I can get with the adhesive.

Ian, I was hoping for a faster and cleaner method, but your idea does solve some problems quite nicely. I will give it a try also.

Thanks guys.

Any other ideas???

[Ian B]

Different approach altogether; mould / cast the handles on. Make a split annular sleeve that fits over the tube, inject a suitable thermoplastic into the annulus.

Ian

[dsergison]

winchman, LOL

Swedish made penis enlarger..... that's not my bag, baby! Austin Powers

[shawnspeed]

Used to install handlebar grips on motorcycles with hair spray, when wet it has a lubricating effect, when dry it stuck the grips on hard enough that cuttin' was the best method of removal to install the new color of the week...Shawn

[Evan]

Temporary plug (bolt through a rubber plug) the far end of the metal handle securely. Install temporary plug in the end of the grip with an air fitting, maybe a schrader style from an inner tube. Spray adhesive inside the grip (hair spray?) and start the grip over the handle. Then apply air pressure while sliding the grip on the handle.

[bspooh]

Joel,

Do you really need that much adhesive to secure? Can you just slide the rubber grip on, and then just pry up both ends and dab some adhesive on the ends?

brent

[bspooh]

I have a rubber grip that I apply to a handle, but instead of any glue, I machine 3 knurls in the handle and then beat the rubber grip on..very difficult to come off..

brent