The insulator is a clear polyurethane that is designed to penetrate the wood
and lock down the oils. The sealer is a UV clear polyester that fills the
grain and the aerospace grade polyurethane clear leaves a hard durable UV
resistant finish that will last for years. I have it on the teak on my boat
and it is untouched after a year in Florida. I expect to get 5 years plus
out of the system...maybe more if I am diligent in the upkeep.

--
Shield Finishes and Nauticoat Marine Finish Systems
www.shieldfinishes.com
"Mike G" wrote in message
ews.com...
In article ,
says...
Most people opt for varnish over polyurethane because of price. All the
high dollar boats have a insulator/sealer/polyurethane topcoat system.
Stuff is beautiful and last forever.



I'm not familiar with the insulator/sealer/polyurethane system but it
sounds interesting.

However, if you walk into your local finish supplier or chandler's and
you pick up a quart of polyurethane off the shelf it is still a varnish.

Over the years, heck centuries, varnish has had many definitions. It's
mostly defined by it's make up during that time period.

Today it's usually accepted that a varnish is a combination of

Curing oils, be it linseed, tung, or these days, a modified soy oil,

Resins, in the old days these would have been natural resins, amber,
rosin, etc. Today they are synthetic. In other words plastic.

A Carrier/thinner. Usually mineral spirits.

Polyurethane shares the basic ingredients as the lower octane stuff but
it's resins form a stronger mechanical bond then the lesser varnishes so
it is kind of set off on it's own.

From a woodworking perspective, oddly enough, this is not necessary a
good thing.



--
Mike G.
Heirloom Woods

www.heirloom-woods.net