I consistently varnish boats that have only been curing for 7 days in a warm room without any problems. Like Jay, I wash and sand the boats with water and a little dish soap in the bucket. This helps to wash away any amine and also to prevent the white paste caused by wet sanding from dryng too fast on a sunny day outside. Simple dish soap should rinse clear away and leave no more residue than the contaminates in simple water. I eat off dishes I wash with dish soap so unless you use distilled water, water from your tap or hose is not pure and has contaminates in it like hard water minerals or maybe flouride if that is added to your drinking water. I start out with a varnish that does not require any sanding to build up quick protective layers, wait a day or so for those coats to dry, then wet sand again and add several more coats of high gloss.