'melted' gooey rubber drive bands

My first thought was that it was not the heat that got them, but incompatible plastics. I have seen this happen before - a plastic worm sitting in a plastic tackle box rather than in its bag, finding the plastic foot of a Woody doll dissolved from touching another plastic doll in the toy box, etc. Not all combinations do it, but I've seen it several times.

WT

This happened all the time to Philips drive bands in tape recorders of the sixties and seventies. I'd have thought they had changed the formulation of the rubber by now...

plastic

toy

that

If you store "rubber" grommets in hard plastic multi-drawers it is guaranteed to plasticise the hard drawer plastic into a mess. These bands were stored in open air on long cardboard cones for easy sizing . Neat Washing up liquid doesn't work but cotton wool and methylated spirits a couple of times after washing fingers does remove the goo.

Which reminds me, Philips actually did. In all of their videorecorders from 1986 up to 2002 I have had to replace maybe 1 drive belt that stretched a bit, never had one turn to liquid like they used to. On the other hand, in the same time period their pinch rollers were a disaster. Turning from soft rubber into a hard glass-like material, sometimes only after 1 or 2 years of usage.

Anyone know how square, flat or round drive belts are manufactured?

Years ago when I was a kid we had a phono turntable that had the problem of the rubber roller losing material onto the metal shaft it drove. Needless to say, the pitch didn't hold up well at all. :-)

What a riot...I very nearly sent this with "needles to say". :-)

Tom

The flat and square are molded as a long tube, then they are sliced off to the required width.

The round are molded to the proper diameter either to the finished size, or as a long bulk piece that is cut to size and glued.

Onieda used to sell a kit of bulk flat, square and round rubber along with a cutting jig and a tube of industrial crazy glue to make custom belts. The glue has to be VERY fresh or it didn't hold for very long.

Appreciated. Would the flat/square process be done hot and the slicing done hot or when cooled down ?

come to think of it , the round section bands I've sometimes seen trace of a seam line presumably from the edges of a 2-part mould where they join imprecisely.

I don't know. I posted what I was told by one of my suppliers years ago that manufacured replacement belts.

"Michael A. Terrell" wrote in news: snipped-for-privacy@earthlink.net:

In the early 70s, I used such a kit to make replacement bands.

The cutting and gluing was done 'cold'.

Surfaces to be glued must be clean very and oil free.

Freshly cut with a clean blade worked rather well, if I remember correctly.

yesterday i restored an old philips reel to reel from around 1963. strange thing was, the main belt was fine , but the rubber brake blocks, take up spool belt and take up spool clutch `s rubber insides had all turned to goop. Pinch roller was hardened on the outside but springy under that outer layer. my usual method is to scrape as much off the pulleys as possible with a screwdriver before trying to mop up the rest with tissues and q-tips dipped in alcohol.

Talking about vcr`s, As you mentioned,I`ve found the pinch rollers on the turbo and `charley` decks to die really quickly by turning hard. Also a few even newer (less than 4 years old) Aiwa models - turned bad way too soon in my opinion!

B.

The glue had to be fresh, too. The shop had the kit, but I never used it because I always had the right belts, or I would order one from PRB. We stocked about 200 different OEM or PRB belts and there was always a list of belts we were low on so the minimum order was no problem. Some of the other techs used it with a few problems.

"Wayne Tiffany" bravely wrote to "All" (11 Aug 05 07:35:39) --- on the heady topic of "Re: 'melted' gooey rubber drive bands"

It is the plasticizer used in the silicon rubber or plastic that catalyzes a reaction between the two surfaces. I recall leaving a vinyl guitar chord on the plastic case of some gear for about 1-1/2 month and when I got back to it the plastic surface had dissolved in a tiny puddle of the chord vinyl. Where it had touched it left a small pit on the surface of the gear. Also, the vapours from some types of caulking materials, such as polyurethane, also cause deterioration of plastics, rubber, and vinyl in immediate the vicinity to where they were applied. They don't warn, on the tubes, about this damaging aspect of the solvent to other bystanding organic materials!

A*s*i*m*o*v

WT> Reply-To: "Wayne Tiffany" WT> Xref: core-easynews sci.electronics.repair:339496

WT> My first thought was that it was not the heat that got them, but WT> incompatible plastics. I have seen this happen before - a plastic WT> worm sitting in a plastic tackle box rather than in its bag, finding WT> the plastic foot of a Woody doll dissolved from touching another WT> plastic doll in the toy box, etc. Not all combinations do it, but WT> I've seen it several times. WT> WT

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