Stronger rubber cement?

On Tuesday, January 3, 2017 at 5:04:38 PM UTC-8, Joerg wrote:
Gentlemen,

Is there something stronger than the usual rubber cement in the patch
kits? Ideally something that won't dry out so fast or where multiple
cheap small tubes are available.

The reason is that I sometimes have larger holes from side wall
blow-outs. Not inch-long gashes but one or two tenths of an inch long.
The tubes I use are super thick and, therefore, expensive. $15-20 each
and that's not something to be thrown out lightly. Instead of the li'l
REMA patches I need to use thicker rubber from an older sacrified tube
but this has to be vulcanized/cemented really well.

--
Regards, Joerg

http://www.analogconsultants.com/

Use E6000 or UV8600 glue.

On 1/3/2017 11:23 PM, Jeff Liebermann wrote:


Contact cement. It's a neoprene rubber based goo that remains fairly
flexible if applied in a very thin layer. Smear some on both the tire
and the patch, let air dry for at least 10 minutes (longer is better),
and stick together with a little compression pressure. I've used a
roller, two blocks of wood and a C-clamp, and beating on the sandwich
with a hammer. They all work.

I generally change tubes on the road, then patch the leaking tube at home.

At home, the first step is to clamp a 1" dowel in my bench vise and
drape the tube over it with the leak facing upwards. That's the support
while I scuff the tube using ordinary sandpaper. I find the cylindrical
surface makes it easier to scuff thoroughly.

With the inner tube still hanging from the dowel, I then apply cement,
let it dry a bit and apply the patch. Next I take another dowel held
perpendicular to the one in the vise, and roll back and forth over the
patch to apply pressure. The contact area is thus smaller and the
pressure on the patch greater. I don't believe I've ever had a patch
fail after being applied this way.

--
- Frank Krygowski

On Wednesday, January 4, 2017 at 9:15:06 AM UTC-8, Frank Krygowski wrote:
On 1/4/2017 10:17 AM, Joerg wrote:

Ever since I began using REMA patches and the cement that comes with
them my result were less stellar than in Europe with the classic kits.
Those contain much thicker patches that looked like round chunks of
tube, sometimes slightly beveled. Can't find those here in the US.

Currently I have two tubes of the thick expensive kinds where REMA
patches partially came off after test-inflating outside the tire.
Despite being very diligent with sanding and applying.

I don't see any value to test inflating a freshly patched tube outside
the tire. You're imparting stresses that the patch-to-tube bond will
never see in its normal working life, and it will be difficult for that
immature bond to resist them.

Patches that have completely cured stand up to being inflate outside the
tire, in my experience. I've never had one fail.

--
- Frank Krygowski

And inflating the tube inside of the tires places compression on the still vulcanizing patch to aid.

On 2017-01-04 08:39, David Scheidt wrote:
Joerg wrote:

:I'll look into contact cement. Gene also suggested that. Cost is not so
:much an issue but shelf life after opening is. The usual rubber cement
:is toast only a few months after opening.

Go to your local auto parts store. Buy a can of vulcanizing fluid.
It'll come with a brush in the lid. The can in my desk at work has
been open and used for five years. Still good.


Excellent idea!

--
Regards, Joerg

http://www.analogconsultants.com/

On 2017-01-04 09:14, Frank Krygowski wrote:
On 1/4/2017 10:17 AM, Joerg wrote:

Ever since I began using REMA patches and the cement that comes with
them my result were less stellar than in Europe with the classic kits.
Those contain much thicker patches that looked like round chunks of
tube, sometimes slightly beveled. Can't find those here in the US.

Currently I have two tubes of the thick expensive kinds where REMA
patches partially came off after test-inflating outside the tire.
Despite being very diligent with sanding and applying.

I don't see any value to test inflating a freshly patched tube outside
the tire. You're imparting stresses that the patch-to-tube bond will
never see in its normal working life, and it will be difficult for that
immature bond to resist them.


With Gatorskin tires and shallow rims it is a must. I only did this once
and never again: Fixed a hole on the side of a tube, mounted a new
Gatorskin. Those can take over an hour of wrestling to get the bead
over. Pumped it up. Next morning on the day where I wanted to ride ...
flat :-(


Patches that have completely cured stand up to being inflate outside the
tire, in my experience. I've never had one fail.


I did.

--
Regards, Joerg

http://www.analogconsultants.com/

On Tuesday, January 3, 2017 at 5:04:38 PM UTC-8, Joerg wrote:
Gentlemen,

Is there something stronger than the usual rubber cement in the patch
kits? Ideally something that won't dry out so fast or where multiple
cheap small tubes are available.

The reason is that I sometimes have larger holes from side wall
blow-outs. Not inch-long gashes but one or two tenths of an inch long.
The tubes I use are super thick and, therefore, expensive. $15-20 each
and that's not something to be thrown out lightly. Instead of the li'l
REMA patches I need to use thicker rubber from an older sacrified tube
but this has to be vulcanized/cemented really well.

--
Regards, Joerg

http://www.analogconsultants.com/

Permatex #2 Non-hardening

On 2017-01-04 08:37, wrote:
On Wednesday, January 4, 2017 at 7:41:16 AM UTC-8, Joerg wrote:
On 2017-01-04 06:26, wrote:
On Tuesday, January 3, 2017 at 5:04:38 PM UTC-8, Joerg wrote:
Gentlemen,

Is there something stronger than the usual rubber cement in
the patch kits? Ideally something that won't dry out so fast or
where multiple cheap small tubes are available.

The reason is that I sometimes have larger holes from side
wall blow-outs. Not inch-long gashes but one or two tenths of
an inch long. The tubes I use are super thick and, therefore,
expensive. $15-20 each and that's not something to be thrown
out lightly. Instead of the li'l REMA patches I need to use
thicker rubber from an older sacrified tube but this has to be
vulcanized/cemented really well.

-- Regards, Joerg

http://www.analogconsultants.com/

Jeorg, considering the amount and extent of flats that you get
perhaps you should observe Tosspot's recommendations:

http://www.tyre-equipment.co.uk/acat...-PSF_Plus.html




:-)

I don't get many flats but if I do they are nasty tears on the
sides where tubes flex all the time. Caused by side wall failures
of tires.

So I need something that is super strong in the vulcanizing process
and where the tube or can contents won't dry out after just a few
months of storage. I always fix at home so cold storage and the
necessity to use pressure tools and such would be no problem.

-- Regards, Joerg

http://www.analogconsultants.com/

Considering that you get sidewall failures you should probably only
use tires that have bead to bead belts and also high thread-count
cords. Doing so would give you a dramatic drop in the failures.


That was the reason for the tire thread a while ago. Retroguybilly
suggested CST Correre but they don't come in 25mm. I will try their
Conquistare tires which supposedly are 3-ply in the sidewalls.
Unfortunately only for the foldable versions.

The Gatorskin Hardshells are claimed to have improved side walls as well
but I am concerned that they also run too small like regular Gatorskins.
I am tired of having to wrestle them on. They do have good life span
though and I get 2500mi out of a rear tire. Most other riders with other
tires out here get 2000mi or less.


If
you're getting failures of Gatorskins that must be some sort of
terrain you commute on.


It's unavoidable out here. There is often the occasional "Pavement ends
in 200ft" or plain old singletrack that has to be conquered by road bike
to get to another town. Like at least once a week he

https://goo.gl/maps/fyCyQs3MC6x

This is also why my road bike is almost as dirty as my MTB. Which causes
another problem for the side walls. A week ago I stopped because of a
weird phhhsssrrt... phhhsssrrt noise. Turns out mud had caked in the
crown of the fork, dried up and was rubbing against the tire.

--
Regards, Joerg

http://www.analogconsultants.com/

On Wed, 04 Jan 2017 07:27:48 -0800, Joerg
wrote:

I'll look into contact cement. Gene also suggested that. Cost is not so
much an issue but shelf life after opening is. The usual rubber cement
is toast only a few months after opening.

I've had the same experience. The problem with the leaking bottles
and tubes seems to be related to heat. My squeeze tube of contact
cement doesn't last very long after it's used once, so I'm not sure
that looking for a better glue is the right answer. A better way to
prevent outgassing seems to be a better approach. As David Scheidt
suggests, buying the rubber cement or whatever in a can lasts much
longer. I keep my can inside a plastic Ziploc bag, which seems to
help. I've considered putting it inside a glass jar, and pressurizing
the jar to above the vapor pressure of the solvent to limit loss by
evaporation. I've done this with some chemicals and drugs, but never
tried it with glue.

Also, be sure to test the strength of your contact cement joint.
There's nothing stronger than a vulcanized bond, so I'm fairly sure
that contact cement will not be as strong as a proper vulcanizing
patch. Whether it's strong enough is the question.

It also has to become a pliable connection because those cuts are on the
side walls. Ever since moving to tire liners plus thich tubes plus thick
tire surfaces I don't get "regular" flats via running surface punctures
anymore.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Wed, 04 Jan 2017 10:00:45 -0800, Jeff Liebermann
wrote:

One more suggestion. Perhaps what you want is just a better container
instead of a better glue? I haven't looked into what's available, but
I would think that you might be able to find a better bottle which
does not allow outgassing.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 2017-01-04 10:00, Jeff Liebermann wrote:
On Wed, 04 Jan 2017 07:27:48 -0800, Joerg
wrote:

I'll look into contact cement. Gene also suggested that. Cost is not so
much an issue but shelf life after opening is. The usual rubber cement
is toast only a few months after opening.

I've had the same experience. The problem with the leaking bottles
and tubes seems to be related to heat. My squeeze tube of contact
cement doesn't last very long after it's used once, so I'm not sure
that looking for a better glue is the right answer. A better way to
prevent outgassing seems to be a better approach. As David Scheidt
suggests, buying the rubber cement or whatever in a can lasts much
longer. I keep my can inside a plastic Ziploc bag, which seems to
help. I've considered putting it inside a glass jar, and pressurizing
the jar to above the vapor pressure of the solvent to limit loss by
evaporation. I've done this with some chemicals and drugs, but never
tried it with glue.

Also, be sure to test the strength of your contact cement joint.
There's nothing stronger than a vulcanized bond, so I'm fairly sure
that contact cement will not be as strong as a proper vulcanizing
patch. Whether it's strong enough is the question.


I'll ask the automotive place for vulcanizing fluid as David suggested.

As for preventing oxygen to get at it I am wondering whether CO2 would
work. I started making beer to trapping some of the CO2 generated during
fermentation shoud be easy. It comes out of the air lock.

--
Regards, Joerg

http://www.analogconsultants.com/