Is it a good idea to use high build after this?

[Steves69LS3]

Hey guys.
Im in the absolute final stages of my prep work.
Here are my layers.
Epoxy
Slick sand blocked to 400
Epoxy blocked to 400
Some break throughs
Can i do a coat of epoxy and then a few coats of spi 2k high build to finish everything off to 600??
Also i have some high build leftover from last summer. Will the medium hardener still be good even if i kept it sealed and in the basement not seeing extreme temps?
Thank you

 

[Barry]

Your plan will work but if activator can is less then 50% full I would test first, if over 50% i would test also but should be good.

 

[Steves69LS3]

Thanks Barry. But when in doubt just get new.
I will order new activator

 

[John Long]

Your plan will work but if activator can is less then 50% full I would test first, if over 50% i would test also but should be good.

How is best way to test and what should we look for Barry?