On 2017-01-05 07:59, wrote:
On Tuesday, January 3, 2017 at 8:04:38 PM UTC-5, 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/

You can use place a second offset patch over an existing Rema patch.
This way you can patch long slits using the F1 (25mm) Rema round
patch. Patch one at a time, then sand the top of the patch in the
direction of the patch center to the end, apply the vulcanizing fluid
and apply the next. Repeat the process until the entire slit is
patched.

Make sure you start and end about 15 mm beyond the slit. You may also
want to cut a small circle around the ends of the slit to stop the
slit from expanding when the tube is inflated.

You have not stated the tube size. This is important because the
patch must fit within the width of the tube when the tube is flat.
I've found I have to use the F0 (16 mm) patch for tube widths less
than 25 mm. I've found the wider F1 (25 mm) patch will work with
tubes with a nominal width of 28 mm and above.


Up to 2.4" for the MTB and up to 25mm for the road bike.


It's important that the patch edges are "glued." I've found the best
way to insure this is to lie the tube on a flat surface and burnish
the patch onto the tube after it's applied. I use a center to outside
burnishing motion. I use the rounded edge of a Rema patch kit as my
burnishing tool.

There are some rubber compounds that won't work with the Rema
vulcanizing fluid.


Oh. That would be a concern. I didn't know things were this finicky.


It also won't work in cold temperatures or when
the tube is wet. However, I've found that most of the time the reason
that patches don't adhere is due to improper application - pilot
error. Sand over a bigger area than you spread the vulcanizing fluid;
spread the vulcanizing fluid over a bigger area than the patch.
Spread a thin layer of the vulcanizing fluid and let it dry before
applying the patch. Don't blow on the vulcanizing fluid to hasten its
drying - the moisture in your breath will neutralize it.

If your tube has a rubber composition that will not work with the
Rema vulcanizing fluid, you may want to reconsider your tube choice.


There is no choice. I need very thick tubes and those are generally only
available from Sunlite. Soemtimes Kenda. One has to watch out for tubes
which are asymmetrical and only thicker towards the running surface.
Those are not as good as tubes that are thick all around.


I assume the reason you opt for a thick tube is to avoid flats.
However, you are paying 3 times what I pay for normal thickness
tubes. At about $0.75 per flat repair, I can make a lot of them to my
inexpensive tube before reaching your $15 threshold.


Doesn't matter to me. I simply do not wish to be delayed in my travels
by yet another flat and then arrive late and with dirty hands.

--
Regards, Joerg

http://www.analogconsultants.com/