REMA patch shelf life

Quoted message said:

Bruce Ball said:

Stretch effect? If a repair patch is applied to a tube which has been inflated to an operating
diameter or larger (usually the case), then the stretch effect is between the ears rather than on
the tube after installation and inflation.

Patching over a blowing leak is not a reasonable method for applying a patch. Besides, when
deflating the tube for installation, the patch will buckle into a dome, under which the tube pulls
away. I suspect this is one of those specious offerings from a disgruntled reader.

Jobst Brandt [email hidden]

Blowing leak? Over several years of patching tubes I find most punctures to be small, as are those
produced by goathead thorns. Quite often the thin film of vulcanizing fluid seals the small puncture
to withstand the low pressure of a tube inflated to that close to operating cross-section. At the
maximum, the small amount of pressure is not blowing great streams of air thru the puncture. Patches
adhere well under these conditions; mine do not leak during the remaining life of the tube. This
even so with larger punctures when there is indeed a fair amount of air escaping thru the puncture.

Agreed that a deflated tube will produce a slight dome of the patch, I disagree that the tube pulls
away, by experience. The pull-away syndrome I suspect is a matter of conjecture that occurs between
the ears and not by the tube. After all, a properly sized tube for tire, minimally inflated to
casing size, differs not that much from a flatted tube. And again, a patch applied to a tube
inflated to operating cross-section carries no induced stretch/stress when inflated into the tire
casing, i.e. no constricture effect. An argument to the contrary is, I suspect, anal retentive by a
symptomological commentator.

Isn't it more reasonable for the operating tube and patch to match without strain?

Patching over a "blowing leak" is indeed reasonable; the pressure is slight, the seal is quick,
there is no constricture. Most important is a clean, sanded tube suface, a dried, thin vulcanizing
film, a burled patch.

In further contention, patches properly applied to tubes inflated to operating cross-section can be
installed to the tire, inflated to normal pressure, e.g. 110psi, and ridden with no further
problem.. Whatever further vulcanization that takes place does well in situ.

Specious offerings of disgruntlement? Naw, we're dispelling [censored].

Bruce Ball

David Reuteler said:

[email hidden] wrote:
: I suspect this is one of those specious offerings from a disgruntled reader.

have you ever considered just omitting the last sentence of every one of your posts?

Cheers!

Bruce Ball

Bruce Ball said:

Quoted message said:

It's been forever since I've bought a patch kit. I use old inner tubes for making patches because
they are a dime a dozen and I can cut a patch to any size that I need from them. I use some
common rubber cement to make it stick. A few times in a pinch I've used RTV Silicon sealant and
even Goop as glue. Never had one fail. The best patches I've used are some old Camel hot patches
I have left over from my father when he worked for a service station. Patches are at least as old
as me but still work like a charm. The rubber is still good and they flare up like new. If you
can find new ones available I'd recommend them.

Quoted message said:

I tried that but I didn't have any luck using pieces of inner tube. Additionally I like the
feathered edges of patches.

The reason this works so poorly is that butyl tubes in contrast to latex tubes, do not pass the
volatile solvents of the patch glue and must be carefully dried before placing the patch. Latex
tubes and Rema patches absorb and transmit the volatile solvents and assure curing, given time,
after the patch has been put in place. In addition, sanding off the surface of a patch cut from a
butyl tube is difficult and if not done sufficiently, will cause delamination even if everything
else was done right.

The feathered edges are also missing as you note. This isn't so important except that a conventional
tube is thick enough to make a lumpy spot tin the tire that can be felt. I haven't seen the success
mentioned above among the people who have tried this including myself. I tried this because all my
tubulars latex tubes were patched with latex patches from discarded tubulars.

Jobst Brandt [email hidden]

Bruce Ball said:

Quoted message said:

Quoted message said:

Stretch effect? If a repair patch is applied to a tube which has been inflated to an operating
diameter or larger (usually the case), then the stretch effect is between the ears rather than
on the tube after installation and inflation.

Quoted message said:

Quoted message said:

Patching over a blowing leak is not a reasonable method for applying a patch. Besides, when
deflating the tube for installation, the patch will buckle into a dome, under which the tube
pulls away. I suspect this is one of those specious offerings from a disgruntled reader.

Quoted message said:

Blowing leak? Over several years of patching tubes I find most punctures to be small, as are those
produced by goathead thorns. Quite often the thin film of vulcanizing fluid seals the small
puncture to withstand the low pressure of a tube inflated to that close to operating
cross-section. At the maximum, the small amount of pressure is not blowing great streams of air
thru the puncture. Patches adhere well under these conditions; mine do not leak during the
remaining life of the tube. This even so with larger punctures when there is indeed a fair amount
of air escaping thru the puncture.

How do you know whether the patch did not lift over its inner circumference? I have done "autopsies"
on tossed out tubes, especially ones that were ridden right after patching and found most to have
lifted close to their periphery and some of these were the explanation for slow leaks. The test is
to cut through the middle of the patch with shears to see how much of the interface is full of talc
from inside the tube. Please try that and report back.

Quoted message said:

Agreed that a deflated tube will produce a slight dome of the patch, I disagree that the tube
pulls away, by experience. The pull-away syndrome I suspect is a matter of conjecture that occurs
between the ears and not by the tube. After all, a properly sized tube for tire, minimally
inflated to casing size, differs not that much from a flatted tube.

All tubes that are intended not to wrinkle are smaller than the tire casing into which they are to
fit. Therefore, all correctly sized tubes will be a bit undersize. Just note the labeling on the
tube and package that always list a range of tire sizes for which they are intended. Even the
smallest of these tires is larger than the tube.

Quoted message said:

And again, a patch applied to a tube inflated to operating cross-section carries no induced
stretch/stress when inflated into the tire casing, i.e. no constricture effect. An argument to the
contrary is, I suspect, anal retentive by a symptomological commentator.

Can you be a bit more direct in your technical explanation of this phenomenon?

Quoted message said:

Isn't it more reasonable for the operating tube and patch to match without strain?

Only in theory. In practice, undersized tubes are used.

Quoted message said:

Patching over a "blowing leak" is indeed reasonable; the pressure is slight, the seal is quick,
there is no constricture. Most important is a clean, sanded tube suface, a dried, thin vulcanizing
film, a burled patch.

If you consider the massage given by a flexing bias ply tire to the patch, which is securely
attached to the tire casing by near 100psi, you'll see why patch separation of newly patched tubes
occurs. That is why patching the tube, rotating it to the spare position and using the spare is the
reliable way of proceeding. To test the massage of a tire casing, lay a plain business card between
tube and casing facing the tread and ride for 100 miles. The card will turn to mm sized confetti.

Quoted message said:

In further contention, patches properly applied to tubes inflated to operating cross-section can
be installed to the tire, inflated to normal pressure, e.g. 110psi, and ridden with no further
problem. Whatever further vulcanization that takes place does well in situ.

There is no further vulcanization. Rema patches, although not easily removed by hand, can be peeled
off effortlessly by heating the patch on a smooth hot surface, just enough so the back side of the
tube begins to feel hot to the thumb pushing the patch against the heater.

Quoted message said:

Specious offerings of disgruntlement? Naw, we're dispelling [censored].

Thanks. Those are the words that come to mind when I read extensive conjecture, such as yours, in
rebuttal to tried and tested procedures that any rider can verify for himself.

draco.acs.uci.edu8b.1.htmlOpen ↗

Jobst Brandt [email hidden]

Quoted message said:

Quoted message said:

what i noticed is that w/ the film the patch is less likely to stick to the tire. (yes, i use
talc. and yes, i'm confident that it's the patch and not the surrounding glue that's sticking
to the tire.)

Why do you use talc?

mainly, the talc acts as a lubricant & makes it easier to mount & remove the tire on the rim,
thumbs no levers. it also prevents the tube from sticking to the tire and it also *may* allow the
tube to seat itself better within the tire. use baby talc to dust the tube & tire -give it a try.

[email hidden] (B.C. Cletta) wrote in :"]news:[email hidden]:

Quoted message said:

mainly, the talc acts as a lubricant & makes it easier to mount & remove the tire on the rim,
thumbs no levers. it also prevents the tube from sticking to the tire and it also *may* allow
the tube to seat itself better within the tire. use baby talc to dust the tube & tire -give it
a try.

There seems to be some disagreement on the subject of talc. Take a look at these related pages:
faqs.orgsection 9.htmlOpen ↗ yarchive.nettire talc.htmlOpen ↗

--
Wayne Menzie

[email hidden] wrote in message news:<[email hidden]>...

[snip and search for talcum powder]

Dear Jobst and Bruce,

I'm reading your posts on patching tubes, lightly inflated and otherwise, with all the interest of a
basset hound at the greyhound track.

I know that real bicyclists patch tubes, and I haven't got the ghost of an argument against it, but
I just have an embarrassing and unreasonable prejudice against patching.

Despite your disagreement, both of you patch with gusto and at least enough success to find it
worth doing.

So what would you two suggest to a nutcase who carries spare Slime tubes? Can I patch them, or must
I first embrace dry tubes? I'm not implying that either of you approves of slime, much less accusing
you of performing such depraved experiments, but you do know one end of a tube of glue from the
other and I don't.

Do I need to make the switch to dry tubes and patches cold-turkey, or can I waffle and try the
methadone of having it both ways, slime and patches?

I'd hate to lose my chance to lead a normal life just because my first timid efforts at patching
were doomed not by my clumy technique, but by an inherently unpatchable tube.

Carl Fogel

Carl Fogel said:

So what would you two suggest to a nut case who carries spare Slime tubes? Can I patch them, or
must I first embrace dry tubes? I'm not implying that either of you approves of slime, much less
accusing you of performing such depraved experiments, but you do know one end of a tube of glue
from the other and I don't.

Quoted message said:

Do I need to make the switch to dry tubes and patches cold-turkey, or can I waffle and try the
methadone of having it both ways, slime and patches?

Quoted message said:

I'd hate to lose my chance to lead a normal life just because my first timid efforts at patching
were doomed not by my clumsy technique, but by an inherently unpatchable tube.

I haven't tried it but you must be sure that no slime contaminates the surface to which the patch is
to adhere. How you do that may or may not present a problem.

There is another problem though, that I have experienced with "slime" inside a tube that presents a
major safety hazard. In the last days of tubulars, when quality control was lost, I had Clement
Campionato del Mundo tires whose seam protector strip was misplaced so that the casing selvage was
exposed to the thin latex tube on which id caused a multitude of tiny leaks. Being on the last day
of my tour in the Alps, I was not willing to change the tire so I stopped at a dairy shed and got
some (Swiss) whole milk of which I pumped a shot into my tire, knowing that the ingredients would
stop pin-hole leaks.

A couple of weeks later, still riding the same rear tire that was now air tight, I ruptured the tire
on a rough trail and after returning to pavement got a blowout as I was leading a pace line of
riders. They were sprayed with rotten milk as I began fishtailing across the road on butterfat in
the tube. Although the road was straight, I slid all over the road trying not to crash into oncoming
traffic or off the road.

Slime inside a tire that goes flat from a major puncture will make the rider lose control as the
tire goes flat. On a front tire, it will definitely cause a crash.

Jobst Brandt [email hidden]