Hardener for Laquer?

Having used a good amount of Lacquer, purchased from Sherwin Williams in NY, i have never had a batch which did not readily dry.
However, the last batch purchased still has a tachy feeling after 2 days. Went back to the store to ask for a hardener and was given a good amount of verbage on humidity, room temperature etc. All improtant of course. Explained that I am using heaters to dry the air, have between 80 - 90 degrees temp and have no problem with the previous gallon.
Still did not get a hardener.

Could one of you kindly tell me if all hardeners would act the same (maybe one part) and if I may have to consider another reason for this new batch to not harden?
Thank you in advance,
Rainer

You did use lacquer thinners, didn't you? Are you sure? Are you 100% sure it was the correct thinner?

If so. What did you put onto the timber before the lacquer??

Has it dried yet?

:U

'Hardeners for lacquer...' I have not heard of any.
Lacquers dry through evaporation of the solvents (lacquer thinners), and the process is reversible. (i.e. spill lacq. thinners on dried lacquer, and it'll come off.

Urethanes (2-pack paints) have hardeners. They cure via a non-reversible chemical reaction.
You used to be able to get a hardener for enamels, which was also isocyanate-based, like the urethane system, though enamels dry by oxidation - also a non-reversible process.