On Jun 9, 7:50*pm, Evan wrote:
On Jun 9, 9:13*pm, "The Henchman" wrote:

Concrete sub-floor, no backer board. *40 year old 4 x 3 tiles with yellow
"mastic" as the adhesive. * It's caked on good underneath and it's old. * *I
wanna prevent renting a Hilti/Kango with a scrapper cause it'll cost $100
around these parts for a day. *That'll be a last resort I guess

Solvents?

And type of manual scrapers?

grinders or some other abrasive?

I can't damage the sub-floor (concrete) underneath.

Spend the $100 on the proper tool, or borrow one from someone you
know that owns one...

~~ Evan

Any alternative to the scraper is going to be much more labor
intensive and time consuming.

Harry K