: Have to use something. Clearcoat yellows too, just not as much nor
: as quickly. Hard to fix yellowing of clear materials, UV is
: powerful stuff.

: Bill H.

The problem with varnish compared to 2 part polyurethane is the amount of thickness you can build up, which directly relates to the UV protection. 5 coats of varnish will build up about 1 ml per coat. Automotive clear coat like PPG will build up at a rate of 2-3 ml per spray coat, and you can spray 1 coat about every 15-30 minutes. After 3 coats on my last boat I have close to 9 ml thickness, and it's 10 times harder than spar varnish. It may yellow in time, but I sincerely doubt it since the boats get stored indoors. However, you need to have a professional do this, which of course adds to the initial cost. it cost me $450 to have it done, but that included wet sanding after 3 coats and buffing it out. If you varnish every year and calculate your time at $20 per hour the cost for this is going to be in the $75 to $100 per year range, let alone the loss of paddling time. After 9 years of this the cost would be around $700, so body shop applied 2 part poly starts to look pretty cheap.

Bryan K