On Thursday, November 29, 2018 at 12:50:52 PM UTC-5, Joerg wrote:
I've got a bunch of patch kits that contain yellow "Propatch" cement
tubes. On Sunday I had to use a kit, as usual for another rider. We
found the hole, sanded the tube, opened the li'l cement tube ... phuffff
... only air was left inside. It was inside an extra plastic wrap and
all, didn't help. So we had to use my spare tube.

Do you guys know a brand that is better and where a bunch of these
little tubes could be bought sans patches? Not so much for me but for
other riders because many reported similar problems.

--
Regards, Joerg

http://www.analogconsultants.com/

The cement and patch are designed to work with one another. There are chemicals on the patch that are activated by chemicals in the cement. Different manufacturers use different activators. You will get best results, if you don't mix manufacturers.

I've found the Rema Tip-Top patches with their tubes of cold vulcanizing fluid to work extremely well.