Japan Drier?

[Delancey]

I am in the southeastern US, it's pretty humid outside and I am about to brush a coat of polyurethane spar varnish on my cabin sole and I have a feeling it is going to take a loooong time to dry.

Anybody have any experience using Japan Drier or similar with a polyurethane spar varnish?

I know they are mainly meant to be used with natural drying oils like linseed or walnut oil but don't know if it will work with polyurethane. Any feedback would be appreciated. Thanks!

https://en.m.wikipedia.org/wiki/Oil_drying_agent

[GordMay]

Per Klean-Strip® Japan Drier ➥ Klean Strip | Japan Drier
Do not use Japan Drier with latex paint, water-based finishes, lacquer, 2-component urethanes, epoxy paint or other synthetic finishes.

[Delancey]

Answered in one, thanks Gord! You are the king of researching. I always read instructions but forgot about the internets as a way to find them.

Their site says it can be used with polyurethane finishes. Anybody have experience using it?

Like for example if I add the suggested quantity to the half gallon of varnish I have on hand but don't use it all, how will it affect the remainder?

Or am I better off measuring out the small amount I need per coat and leaving the rest of the pot untainted?

[model 10]

If you are using an oil based synthetic paint you can add the catalyzer used in automotive acrylic enamel. This might sound fishy to some but it's a common practice.

[Bill Seal]

In a few months you might have a gallon of solid varnish. I think the stuff speeds up the polymerization.
A friend of mine uses automotive-paint type urethane hardener with Rustoleum on his hotrods. I'm thinking about using it on my masts. (But first I have to get up there)

[Cheechako]

I haven't used it , but suspect it will work. Maybe mix just a little and try it on a scrap of wood. Assuming you are talking just standard one part polyurethane.
However, the question needs to be asked why you are using spar varnish on the floor. Spar varnish tends to be softer and more flexible for the bending of the spar. It seems you want a hard polyurethane for the floor.

[Delancey]

Originally Posted by Cheechako

However, the question needs to be asked why you are using spar varnish on the floor. Spar varnish tends to be softer and more flexible for the bending of the spar. It seems you want a hard polyurethane for the floor.

The reason is practical necessity. It's what I have onboard. Been using it for a while. Seems to hold up fine on the sole. My wife doesn't wear high heels on the boat, just boat shoes.