Below are some comments as to the possable reason some rollers turn to gooey tar and others don't.  These comments were taken from Yahoo reeltoreel forum.  

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"stops142" <stops142@y...>

Date: Sat Mar 27, 2004 4:32 pm

Subject: Re: Melted Rubber Idlers & Belts

How many of you have purchased a used Ampex, Norelco, Philips or

> > other Tape deck only to find it did not work when you got it

> > because the Rubber components have melted down to a Tar like

> > substance? I have restored many consumer Ampex machines because of

> > this problem. A bulletin I got from Ampex stated this was caused by

> > improper "Curing" of the rubber product. It seems many Rubber Belts

> > & Idler wheels were made overseas and were not made to spec.

>

> Aha! That would explain the apparent random experiences I have

> encountered with 'gooification' of rubber. I spent a bit of time

> discussing this matter with a guy who refurbed by X-10R recently. WE

> renewed all rubber just in case although it looked and felt OK. He

> showed me a couple of identical decks of his own where one deck's

> rubber was original and just fine, while the other's had gone to goo.

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: "retiredradiodj" <NiteOwlDJ1@a...>

Date: Sat Mar 27, 2004 11:46 am

Subject: More on Melting Rubber.

Some of the Decks I have worked on had their rubber components

melt down, others were fine. The Curing of the rubber (baking, Heat

treatment) sometimes was cut short by the manufacturer acording to an

Australian bulletin I once received with an old Magnecord that was

manufactured in Australia. (some Maggies were made in that country)

They had a re-call on some of them that had their idler wheels turn

to soft spongy like rubber. The Rubber would peel off the metal hubs

like bubble gum. The Pinch rollers were OK as they used the ones made

here in the states. Acording to the writer, the "Curing" process

involves placing the finished rubber parts in some kind of liquid for

several days, then Baking them at a certain temperatures, and if this

was not done properly, the chemical break down over a period of years

would begin, thus the meltdown of the rubber. I have heard of other

instances of the rubber components having additives causing this

problem also. I had one of those Ampex consumer decks that I managed

to get to just before the meltdown began. I removed the drive belt,

which normally is about 18 or 20 inches long, and stretched it out to

almost 12 feet before it broke. I then rolled it into a ball and set

it on a shelf in my workshop and forgot about it for about a year.

I noticed a black drip of what looked like black paint on top of a

Seeburg Jukebox Mechanism cover I had on the bench that I was

cleaning, and noticed the string of black goo coming from the shelf

where I placed that rolled up Ampex belt. It had completly melted

down and dripped off the shelf. Luckily it cleaned off the plastic

cover ok. I even heard stories about Aircraft tires in storrage for a

long time go bad. They blow up like baloons and burst through the

plys like hundreds of small bubbles. I'll even bet the blowout of

good car tires was caused by this problem. I had an english bicycle

in my garage for the last 20 years that eventually gave out to this

problem. Scraping the goo off the rims was an all day job.

I had two Gates CB-200 Broadcast turntables where one had the Goo

problem, and the other did'nt. Don't figure..?

Chuck.

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"retiredradiodj" <NiteOwlDJ1@a...>

Date: Fri Mar 26, 2004 2:38 pm

Subject: Melted Rubber Idlers & Belts

I  have restored many consumer Ampex machines because of this problem. A

bulletin I got from Ampex stated this was caused by improper "Curing"

of the rubber product. It seems many Rubber Belts & Idler wheels were

made overseas and were not made to spec. I even had this happen to

the Pinch Rollers on my Scully 280-B decks. Removing the Goo is a

Pain in the *?*, but I found that Paint Thinner removes the black goo

quite easily. Lighter fluid works also, but purchasing the Paint

thinner is a lot cheaper then the Ronsonol. I still and will continue

to use Ronsonol for cleaning the Heads on my Tape Decks. I clean the

Idler drives with Vita-Drive, the Capstan Rubber pinch roller with

Alcohol, and give the Heads a final wipe with Alcohol, then a Dry Q-

tip. I have a mayonaise jar filled with Black goo that once was

several Drive Belts & rubber Tires from old Tape recorders. Anyone

interested in some Roofing cement? Chuck.

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"stops142" <stops142@y...>

Date: Sat Mar 27, 2004 4:32 pm

Subject: Re: Melted Rubber Idlers & Belts

Yep, if you need rollers rebuilt, head on over to Terry's place. He'll

fix'em up for you real good. It's worth to cost of the rebuild to keep

our "dinosaurs" alive and tickin'. Between Terry and his rubber

factory and Joe's Head stockroom store, we can keep our "dinosaurs"

from being extinct.

thx Monte

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