Tube Soake In Oil Results

writes:

A client open on Sunday had an electronic postal scale that
read only in ounces, but that was more than good enough.

The dry tube weighed 3.8 ounces.

The same model tube from the same batch that sat in oil for
a month or so weighed 7.0 ounces.

After I cut both tubes and measured, the oil tube turned out
to have expanded permanently to 21 inches longer than the
dry tube, just from being blown up outside a tire.

Hmm, i wonder if oiling some old rotted "campagnolo world logo" hoods
will bring back some of their lost elasticity? It certainly cannot
hurt since they are unusable and i've tried just about everything else
.... What kind of oil did you use?

- Don Gillies
San Diego, CA

On 26 Jun 2005 15:37:53 -0700, (Donald
Gillies) wrote:

writes:

A client open on Sunday had an electronic postal scale that
read only in ounces, but that was more than good enough.

The dry tube weighed 3.8 ounces.

The same model tube from the same batch that sat in oil for
a month or so weighed 7.0 ounces.

After I cut both tubes and measured, the oil tube turned out
to have expanded permanently to 21 inches longer than the
dry tube, just from being blown up outside a tire.

Hmm, i wonder if oiling some old rotted "campagnolo world logo" hoods
will bring back some of their lost elasticity? It certainly cannot
hurt since they are unusable and i've tried just about everything else
... What kind of oil did you use?

- Don Gillies
San Diego, CA

Dear Don,

I used ordinary 10w-40.

The feel of the oiled rubber hard to describe, sort of
softer and smoother.

Because a 3.8 ounce tube ended up weighing 7 ounces, I
assume that the rubber soaked up almost its own weight in
oil, even though it doesn't seem terribly oily on the
surface after being wiped off.

I just tore a small piece of the confetti-test rubber in
half. It's still just as weak as when I took it out of the
oil over a month ago, but the typing paper that it's been
sitting on shows no oil stain.

But I think that oiling your hoods would produce an effect
exactly the opposite of what you want. The oiled rubber may
feel better, but it's lost a great deal of its tensile
strength.

When I pumped the tube up outside a tire to about the same
size as a dry tube (an oval sagging 4 feet to the ground),
it didn't contract back to its original size.

The oiled tube ended up 21 inches longer than the dry tube
after both were deflated.

Worse, the oiled rubber section pulled apart with my bare
fingers, just as the oiled rubber tube burst under pressure
too low for my pump gauge to register.

So I expect that an oiled rubber hood would either stretch
permanently out of shape or simply tear as soon as you tried
to mount it.

Like a scrambled egg, deteriorated rubber is hard to repair.

Carl Fogel

On 26 Jun 2005 15:34:44 -0700, (Donald
Gillies) wrote:

jim beam writes:

bottom line, if you do oil spoke nipples, you run the risk of having
that oil seep through to the tube and the tube can rupture.

Why would someone oil spoke nipples rather than grease spoke nipples
?? It seems to me that you don't want the lubrication to be gone in a
few days or after a few rides, so that you can retrue a wheel a few
weeks or months later, and that grease ( which is oil plus soap ) is
the only way to achieve this happy state.

I think that with a suitable rim strip - such as velox - grease would
have a hard time getting to the inner tube area.

- Don Gillies
San Diego, CA

Dear Don,

It's hard to say how much oil on rubber might contribute to
the occasional odd tube failures posted here.

My kindergarten tests only demonstrate that oil does indeed
reduce the tensile strength of butyl rubber far more than I
expected before Joe Riel dug up his information.

Still, it seems like a good idea to keep oil off tubes--the
bang when the tube exploded while I was carrying it was
quite startling.

As for oiling the spokes, it's recommended in "The Bicycle
Wheel"--and I hasten to add that it struck me as a perfectly
sensible idea before I began forgetting that I had tubes
soaking in oil in my garage.

Furthermore, plenty of people oil their spokes and have no
trouble at all with mysterious tube failures, which could
well be factory tube defects, weird rim/tube fitting
problems, or unrelated stuff running down the valve stem and
getting onto the tube.

I'm going to resist the urge to smear grease on cloth rim
tape and do a Dr. Nick test:

"And remember, if you're not sure about something, rub it
against a piece of paper. If the paper turns clear, it's
your window to weight gain."

http://www.snpp.com/episodes/3F05.html

Carl Fogel

writes:

It's hard to say how much oil on rubber might contribute to
the occasional odd tube failures posted here.

Another concern, probably insignificant concerning the quantity,
is oil contaminating the innards of a tube from lubrication in a pump.

What pump washer lubricants do not affect butyl rubber? And what,
precisely, is "mineral oil?" I've gotten various answers seaching on
the web.

Joe

Joe Riel wrote:
writes:


It's hard to say how much oil on rubber might contribute to
the occasional odd tube failures posted here.


Another concern, probably insignificant concerning the quantity,
is oil contaminating the innards of a tube from lubrication in a pump.

What pump washer lubricants do not affect butyl rubber? And what,
precisely, is "mineral oil?" I've gotten various answers seaching on
the web.

Joe

mineral is commonly referred to as "dino" in the car world - the stuff
you get out of the ground and refine. other oils include p.a.o.
synthetics & silicones. there's many of them.

pump washers should be greased, not oiled - lower volatility.

this problem would not arise if tubes were made of a synthetic rubber
like buna-n, but that has much higher air permeability than butyl. as
buytl is the best in this regard, it's easier to address the oil problem
rather than the rubber.

Donald Gillies wrote:
writes:


A client open on Sunday had an electronic postal scale that
read only in ounces, but that was more than good enough.


The dry tube weighed 3.8 ounces.


The same model tube from the same batch that sat in oil for
a month or so weighed 7.0 ounces.


After I cut both tubes and measured, the oil tube turned out
to have expanded permanently to 21 inches longer than the
dry tube, just from being blown up outside a tire.


Hmm, i wonder if oiling some old rotted "campagnolo world logo" hoods
will bring back some of their lost elasticity? It certainly cannot
hurt since they are unusable and i've tried just about everything else
... What kind of oil did you use?

- Don Gillies
San Diego, CA

oil disrupts what's left of the bonding - won't work. closest you'll
get is brake fluid, but it's really a lost cause.

you may be interested to know that not only do natural rubbers [hood
gums] deteriorate over time, but the oil from your skin deteriorates
them too. modern hood rubbers are [oil resistant] synthetics for this
reason.

writes:
A client open on Sunday had an electronic postal scale that
read only in ounces, but that was more than good enough.
The dry tube weighed 3.8 ounces.
The same model tube from the same batch that sat in oil for
a month or so weighed 7.0 ounces.
After I cut both tubes and measured, the oil tube turned out
to have expanded permanently to 21 inches longer than the
dry tube, just from being blown up outside a tire.

Donald Gillies wrote:
Hmm, i wonder if oiling some old rotted "campagnolo world logo" hoods
will bring back some of their lost elasticity? It certainly cannot
hurt since they are unusable and i've tried just about everything else
... What kind of oil did you use?


Armorall is the usual choice for latex hoods.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

On Sat, 25 Jun 2005 17:55:41 -0600 wrote:

Last month, I took a piece of inner tube that had been
soaking in oil (forgotten for a few months) and found that
Joe Riel was quite right about oil reducing the tensile
strength of butyl rubber

Your results were quite predictable, but it's a rather extreme test to
submit an inner tube to. It's just a whole lot more oil than any tube
would ever be exposed to in real life.

Butyl absorbs a certain amount of oil and swells up when it does so.
You might want to try just putting a small drop somewhere on the tube
and mark the place (a circle with the drop in the middle) with a ball
point pen so you can find it later. You'll find that the exposed tube
expands and "blisters" up.

With the amount that might soak thru spoke nipple, I doubt if it would
ever be noticable.

-
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Jim Adney
Madison, WI 53711 USA
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