my baidarka is read for the finish. It is covered with 10 oz nylon. Will Varathanes spar urethene or indoor polyurethene work on the nylon. canthese products be tinted with artist colors. how much varnish is required on the first coat. Does the varnish need to be fully cured before applying addional coats or can it be dry to touch. how many coats are needed? thanks Mark