The preparation of polyurethane varnish must be strictly controlled according to the ratio specified by the manufacturer. The following are the ratios of several brands of polyurethane varnish:
(1) Proportion (weight ratio) of "685" polyurethane varnish:
685 A component (containing isocyanate group) 100
Curling, so the appropriate amount to add is not curling. Diethyl ethyl alcohol is a drier, and it can be omitted when the temperature is high in summer. The role of oil is defoaming, generally do not add too much, it will cause the paint film to sag. Polyurethane "former" will absorb moisture and absorb moisture in the air , so it should be tightly closed immediately after use.
(4) Formula (weight ratio) of "7511" polyurethane varnish:
7511”polyester 50
7511"polyurethane curing agent 50
Butyl acetate appropriate amount
