clare wrote, on Thu, 10 Dec 2015 16:26:28 -0500:

And that is what the "scraping" is for - to expose raw clean surface
for gluing..

The old trick of applying glue, lighting it with a match, then
scraping off the remains before applying more glue and the patch did
the same thing.

This is an interesting trick.

Seems to me, the goal of the pre-buff solvent is to dissolve a thin
skin of the inner liner, so that we're down to a different layer of
rubber for the patch to adhere to.

What I like about this trick is that it negates the need for the
pre-buff solution, although if the pre-buff solution is Naptha or MEK,
it's easy to come by in the home box stores.

So, the real trick will be to find a substitute for the final inner
liner sealer.