Rubber idler wheel rubber restoration

Take out the wheels, put new rubber on them, freeze them with liquid nitrogen,or CO2 liquid spray, then machine the cold, hard rubber to the proper dimensions. You might have to re-cool occasionally. I dont think you can apply some magic to the old,almost crumbling stuff.

A better description ,dimensions etc would help. If they are the thin metal discs with rubber at the periphery of the rim and returning over the disc, both sides, a few mm, then I have a fudge for those. Otherwise O rings are useful, don't usaually need to be flat , to work

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

I'm not sure if anything here would help - but I believe - MCM Electronics sells a kit of some sort. Check with them. They do have a web site - maybe you can go there to look up the "keyword".

Google "rubber rejuvenator". There are a lot of products.

I've used Fedron (from Federal Mining and Manufacturing) successfully.

From the description, it doesn't sound like a rejuvenator will help.

Some photos would help to determine if an off-the-shelf rubber tire, belt, or O-ring could be pressed into service here.

Also, isn't/wasn't there a place that would rebuild your rubber parts on a custom basis?

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Fedron will restore "hard as a rock" (the OP's description) rubber. Whether it's the appropriate product for this particular purpose is not clear.

Try news:rec.antiques.radio+phono Old rubber is a common problem, and several people there rebuild rubber drives.

for google group users.

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Michael A. Terrell
Central Florida

Are you thinking of PRB? They are long gone. What little is left is now part of Russell Industries.

They have a downloadable cross reference for availaible parts at:

I haven't installed it, but I will compare it to the old printed version I have on hand.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Been there and done that too, Michael A. Terrell.Vietnam 1964.

(Page tree, tain)

I have my DD 14 to prove it too. cuhulin

Try xyol (xylene) the paint thinner. I was told by a Xerox repairman they used it on copier rollers when they got hard.

I have used it and works for me.

Dave

Zippo lighter fluid apparently works too, my friend soaks hardened rubber parts in it. When they get really bad there's not much you can do other than replace them though.

Are they "slippery" hard or "brittle" hard? Can you see any cracks on the drive surfaces? If they are brittle hard w/ major cracking (i.e. cracks that run into the rubber below the drive surfaces) I would be surprised if you could find any chemical that will help.

If they're not that bad, I've had good luck with GC Electronics Rubber Rejuvenator.

For really, really hardened rubber I've had success with Teac Rubber Cleaner (Part No. RC-2). This a potent, oily liquid that smells like liquid moth balls. I found a discussion thread that indicates it is no longer made, but it looks like Rawn makes a close replacement:

"... I've used the old TEAC rubber conditioner since about 1979 and I still have about 1/2 oz left of an old 2 oz glass bottle. That's how far it goes when used in moderation. That was my favorite for pinch rollers. The bad news is TEAC doesn't sell it anymore. The good news is it was made for TEAC by Rawn and they still sell the latest incarnation as "Re-Grip" They changed the formula a couple times because someone in California found some chemical in it to be carcinogenic. But none of my tape decks have gotten cancer, so I guess the joke's on California.

..."

I still have a mostly-full 7 oz can of the Teac cleaner from 20 yrs. ago. Guess I'll keep the cap on it...

"Mr. Land" hath wroth:

Slippery hard. I spun both idlers while burnishing with fine emery cloth to roughen the surface. That's helped, but without the compression provided by the normally springy rubber, the turntable and tape recorder both still slipped. Also, no flat spots.

The idler in the Gerrard turntable looks like the top row, 2nd from right:

No cracks. It's not like they're ready to crumble or fall apart. The rubber is intact, but hard as a rock. I didn't photograph the idlers but can do so when I return to the scene of the crime, er... customer, because there's no obvious damage. Just a hardening of the rubber.

Others have suggested machining it down and adding a layer of new rubber from a belt or rubber sheet. I've done that in the past and it works. It might work with the Sony idler, which is quite wide. However, the Gerrard turntable idler is only about 2mm wide at the point of contact, and will therefore be difficult to resurface.

Well, I may be lucky here as there is no obvious cracking. However, I suspect if I bend the rubber sufficiently, it will crack instead of stretch.

I've tried the stuff in the past. Like the other rubber cleaners, rejuvenators, restorers, and recovery compounds, it softens only surface of the rubber. My guess(tm) is about 0.3mm deep at most. The rubber is not porous so the solvent only affects the surface. What I'm looking for is something that has a sufficiently small molecular diameter to penetrate deeper than just the surface.

Sounds interesting. I'll see if I can find some. Moth ball stench would be a naphthalene. That can probably be found at the hardware store.

I'll probably order some tomorrow.

I just found a box of ancient idlers and belts to practice on. I've got about a week to tinker before attacking the antiques.

--
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When you've failed with the gooey stuff. This is what I've done for a Beogram idler. I assume from the pics you directed to , that it is based on a thin metal disc. I cut a strip of moped inner tube, left the original ribber moulding in place just in case my fudge did not work, seriously stretched the moped rubber over the pulley rim and glued in place. There was axial room to allow for the greater thickness and adjusted for the change in "gear ratio" at the adjuster cone mechanism

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

Yeah, that was probably it. I think someone else suggested another place that has a similar service.

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Yep.

TEAC used to sell a rubber rejuvenator for cassette decks that was essentially xylene. A suitable substitute can be bought in the US as a paint/gunk remover called "goof off" in the yellow metal can.

The "PRB Line" section at Russell Industries still does rebuilds. Check out this:

I have had some success by boiling idlers and belts in water for a few minuets Costs nothing to drop an idler in a pan of water, give it a try. Cheers John.

That looks like a page out of their mid '70s paper catalog. How did you find it? Most of the links of the Russell website are dead, and most good pages are dated 2002.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida