Danny D. wrote, on Thu, 10 Dec 2015 00:30:03 +0000:

Does anyone on this newsgroup know of any commonly available substitute
for this black goopy inner liner sealer?

This seems to be the inner liner sealer goopy tar.
But I don't know if there is a box store equivalent.

$1 per ounce:
http://safetytireseal.com/sc16.html

$2 per ounce:
http://www.ebay.com/itm/Tire-Patch-R...-/121309678038

http://www.lawsonproducts.com/lawson...ler/1417734.lp
http://yourtireshopsupply.com/produc...ant-16oz-re76f

I still haven't been able to figure out what this stuff is
made up of, and where I can get it at reasonable prices in
small quantities at the box stores.