On Tue, 28 Apr 2009 21:22:28 -0700 (PDT), Nick L Plate
wrote:

On 29 Apr, 05:08, wrote:
Trevor Jeffrey wrote:
Remove a well adhered patch. *You will see no indication of
chemical bond formation.
I find a well adhered patch not removable without
heating. *Heating affects the REMA patch orange rubber more than
the tube rubber so they separate with careful pulling. *I have not
cared what remains on the contact surface (it looks clean to me)
before applying a new patch and allowing it to cure.
I have also removed quite a few patches using a suitable solvent -
toluene and xylene are two that work.
The hard part seems to be getting a patch edge lifted to gain
access to the tube/patch interface. *Once that is accomplished the
rest is easy using a slow "peeling" technique in conjunction with
more solvent (think "cotton swab"). *Even well adhered patches will
come off clean leaving no sign that there was ever a patch
adhered/bonded there.
Everyone seems to agree on that last detail.
I cannot support this for I have had no desire to remove a well
adhered patch. *Why?

Assuming the rider followed good patching procedures, but chose to
ride his freshly patched tube whose patch can lift off radially from
the hole, forming the dome I described, without leaking. *Such patches
can become slow leaks but in time become "well adhered", requiring
special means for removal as described.

That is Why!

I'm getting splinters under my nails here.

I think it's time to buy a new tube.