1 health care provider listed above who practices in a country other than the United States, who is authorized to practice in accordance with the law of that country, and who is performing within the scope of his or her practice as defined under such law.
Do the math 500 hydrants @ $50 per hydrant = $25000 - OPEX for job Gas, Hotel, Food, Paint, Misc Tools, Repairs Say 25% overhead or $6250.00. This leaves you $18,750.00 - your marketing cost to get the job $3000.00 = 15,750 / 60 days to complete = $262.50 per day for painting a few fire hydrants.
My point was that I would trust the packaging.... Since the drywall mud packaging is only talking about adding another layer of mud, it is of no practical value to the OPs question of How long does it take for joint compound to dry and cure before we can put a sealer on it? and then paint it.....