On Sun, 27 Jun 2010 06:22:05 -0700 (PDT), Bob Villa
wrote:

On Jun 22, 10:03*pm, Judy Zappacosta zappajNOS...@Use-Author-Supplied-
Address.invalid wrote:
My kid wants to use my dad's vintage US Divers circa 1970's black scuba
fins in the pool but I won't let him until we solve the problem of the oily
rubber coming off in our hands.

We bought new straps and soaked the fins themselves for days in a bucket of
pool water, but still the oily black inky rubber comes off as you rub the
fins in your hands.

Is there a "coating" or some way to stop old scuba fins from smearing oily
black rubber on everything it touches?

There are many naysayers here...I think this is only oxidation.
Someone mentioned a toilet flapper (which I have encountered) with a
similar problem.
Although I have not seen anything I would call oily? It appears to be
the black pigment separating from the encasing material, neoprene
rubber.
I would try a non-chlorine abrasive cleanser and then silicone.
Good Luck,
bob

Neoprene, (polychloroprene) is produced from "divinyl acetylene, a
jelly which firms into an elastic compound similar to rubber when
passed over sulfur dichloride."

Neoprene itself is inert, doesn't oxidize readily and has unique
elastic properties that make it useful in a wide variety of
applications.

The problem Judy is experiencing is from decay and separation of the
Neoprene from the compounding agents used to fabricate the fins. Those
compounding agents can be hazardous. To quote Wikipedia on the
subject:

"Although neoprene itself is not a skin contact sensitizer, certain
neoprene adhesives contain 4% rosin (CAS No. 8050-09-7, previously
known as "colophony"), which is a skin contact sensitizer under the
European Union Dangerous Preparations Directive 1999/45/EC.[1]

Lead-containing compounds, such as litharge (lead(II) oxide), are used
as compounding agents to prepare finished products made of neoprene,
and these can have a toxic effect on human blood, kidneys, and
reproductive systems."

If the smell of the degraded fins exhibits a turpentine odor, the
compounding agent was resin and it is a skin and inhalation hazard.

If the smell is "metallic" or nearly odorless then the compounding
agent is lead-based and it is a direct hazard to your children's
health.

In any case, you are FAR better off for the sake of your children to
buy them new fins and toss these old ones in the trash.