R15757 snipe further from cover of anonymity:
Quoted message said:Quoted message said:I can let the glue dry over night and it is still a tacky sheen in
the morning.
Quoted message said:Oh man, this is getting comical. In a previous post some months
ago--when we happened to be discussing this exact issue although you
seem to have forgotten--I mentioned that the glue should dry until
your so-called tacky sheen is all gone.
I guess you have a different definition of tackiness. A clean glossy
surface of dried patch glue remains tacky until it oxidizes and
becomes useless as an adhesive surface for a tire patch. If that
were not so, patches would not adhere at all. Or, conversely, there
would be no need for patch glue.
Quoted message said:"Tackiness" I equated with stickiness. I said the glue should dry
until all hints of stickiness have left it, which is easily tested
by pressing a finger or fingernail onto the glued area and pulling
it off.
I think you are redefining tackiness. Smooth surfaces, such as glass,
or a clean fingernail, stick to completely dry Seran Wrap (PVDC) that
has for its useful life a tacky surface. This is the goal of applying
patch glue to a sand papered inner tube. The red gummy surface of the
Rema patch is designed to bond to that surface and combine with it to
a point that it cannot be practically removed... except by heating.
That is a chemical process that takes time.
Quoted message said:And you made your ignorance unambiguous when you replied, and please
permit me a paraphrase as I do not wish to look up the exact quote,
that if the glue had dried that much then a patch would not stick to
it "any more than it would stick to a dry window pane."
Can you say this without impugning my intelligence or are you trying
to be rude? As I said, if it did not display tackiness, a
characteristic of smoothness, it would not work as a primer on surfaces
to attract a patch. It all depends on what you visualize under your
definition of "dry enough" and what works.
Quoted message said:It was then that it hit me: Jobst Brandt has never actually patched
a tube correctly, so he doesn't know what it's like. Fascinating!
What do you believe is incorrect about tubes that I have patched,
considering that you have never seen patches that I have applied to
tubes. What makes you so adamant in denouncing my ability and
understanding of applying patches? I get the impression that I
somehow caused you injury or embarrassment and that you are trying to
get even.
Quoted message said:Quoted message said:As I said, have you tried pulling a patch off immediately after
application?
Quoted message said:Yes a few times when I was attempting to patch two nearby punctures
with a single patch, and missed. Then I tried to pull the patch off
and reposition...
Quoted message said:Quoted message said:If so, you will notice that the patch can be pulled off easily even
by pulling the cellophane from one corner.
Quoted message said:Eh?? Now you're freakin me out. No--the correctly installed patch
is extremely difficult to remove from the first second after
installation. If you proceed as directed, the patch locks on to the
tube immediately and it ain't comin' off. You better get it right
the first time. If you ever get around to trying it, you'll have
one of those eureka! moments.
I see you avoid explaining why Rema patches are made so that the
cellophane can be peeled from inside to outside after applying the
patch, something that Rema designed so the patch will not peel off
while pulling off the cellophane.
If you don't believe that, how about sticking a patch on half way
while holding onto the raised portion and note how easily it pulls off
without separating the red part from the black, something that is not
the case with a cured patch.
Quoted message said:Quoted message said:Maybe you can explain in non-Rube Goldberg terms how dry the glue
must be ...
Quoted message said:The glue must be dry enough that it loses any hint of stickiness,
easily determined by touch. Dry. Rema directs a five-minute wait,
I have found that 3 minutes is usually enough.
OK, So ten minutes is enough but how long is the minimum? We are not
out on the road to sit around gratuitously waiting more than enough to
apply a patch. I proposed a realistic measure that sees when all the
volatile parts of the glue have evaporated. What do you believe
occurs beyond the point where the glue thickness is essentially zero
and only a tacky sheen that replicates the surface of the tube
remains? Just repeating that this is all wrong and that your patches
are perfect does not resolve anything.
Quoted message said:Quoted message said:...and what the mechanism is that causes patches to separation from
the center outward.
Quoted message said:Hmmm lesseee... If you don't let the glue dry before applying the
patch, the patch don't stick?
Quoted message said:Quoted message said:I think you have not tested what I explain...
Quoted message said:[censored]! I cut through all the patches in a perfectly good tube
and you'd better recognize. None of the patches showed any sign of
pulling away. (As I already pointed out in a previous post.)
Leave the feces out of this. I also explained that I have examined
many patched tubes with partially delaminated patches and explained
that these have two causes. The first is from not removing mold
release (the natural surface of the tube) with sand paper and the
second that the patched tube is immediately put into service. Of
course glue that is not dry is the third cause but that was already
covered in the instruction on waiting before applying the patch.
I have seen the results of properly patched tubes that later had
bulged patches from immediate use after patching. Although the patch
was flat on the tube before inflation, on removal afterwards it was
bulged and had its center delaminated although without leaking then or
later. Subsequent autopsies revealed this condition.
Quoted message said:Quoted message said:Hold it! Let me know what it should say, and be specific.
Quoted message said:Well you could just say, "simply follow the directions in the patch
kit, they work great." I mean, if someone is patching a tube, they
probably have the directions folded up right there.
That won't work because drying time is not a constant and the
instructions do not mention patch curing time in place, something that
you insist does not occur although I can demonstrate it (as you can).
Quoted message said:Or you could simply direct people to: allow several minutes for the
glue to dry (until a fingertip pressed lightly onto the glued area
can be pulled away without any hint of stickiness) before firmly
pressing the patch on. While there is a minimum drying time for
glue to be effective, there is no maximum if the glued area can be
kept reasonably clean. The glued area must exceed the area of the
patch so that all the patch's edges are in contact with dry glue.
Here's the best part: Once the patch has been firmly pressed over
the puncture, the tube can be stuffed back into the tire and ridden
immediately without worry, provided the rider has thoroughly checked
the inside of the tire for any protuberances.
Well as I said that works and it must be done at times but you should
not be surprised if it develops a slow leak later and I explain how
this can occur. That the patch should land on a fully prepared area
goes without saying, but the hazard of riding a fresh patch remains,
especially for a tube that is substantially smaller than the tire
cross section, a common practice these days of weight saving. In fact
some of the tubes I find along the road are abut as large in cross
section as the tip of my little finger. This size is smaller than a
common Rema patch when the tube is laid flat for patching.
Quoted message said:If you say that, then you can just cut out all that other irrelevant
gobbledygook.
You may call it that but I believe the dynamics of a tire and tube
should be understood for an appreciation of what a patch or boot must
endure. I suppose you haven't tried the business card test of tire
casing distortion or you would be aware of the distortion a tire an
tube experiences with every rotation.
Quoted message said:Quoted message said:I hope you are aware that in cold weather and high humidity, glue
curing takes longer.
Quoted message said:Jobst, "curing" is an irrelevant concept here and you need to get
over it. Just spread the glue on, LET IT DRY, press the patch on,
and ride. That's it, you're done.
OK, so you like to use the term "dry". Well drying takes longer in
cold weather and high humidity. Are you aware of that?
Quoted message said:Extreme cold can make patching impossible because the glue crumbles
off the tube. High humidity might mean a few extra minutes of
drying time.
Oh. That's a new concept. I think you'll find that patching glue
does not freeze and does not get brittle with cold temperature. It
just loses volatility and takes longer to dry. Try it, you'll like
it. I only brought that up to underscore that drying time is a
variable for which a different control than a stop watch can be found
and that measure is the appearance of the glue surface and how it
looks when ready to use. I take it that this is what you are arguing
about, nothing else.
Jobst Brandt
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