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View Full Version : Varnish Tradeoff - Protection vs. Weight



Carl Schaefer
01-02-2005, 01:13 PM
I'm refinishing a 1955 Wright Penguin and I've nearly sanded all the varnish from the inside of the boat. I will refinish the insides bright.

Although she is an old boat, she will be a competitive Classic Penguin woody when she is done. Given my intent to race, how does one balance the number of coats of varnish for protection vs. weight. In other words, one would like to minimize the all-up weight of the boat after varnishing but still retain adequate wood protection and aesthetics. It appears that there was only about 2 - 3 coats of varnish on the inside bottom of the boat, the frames, the mast and boom, and the rails (surprisingly). Looks like there were more coats for the centerboard trunk, the thwart, and mast hounds. There was no varnish on the removable wood floor that sits atop the bottom frames!

Any insight would be greatly appreciated.

paul oman
01-02-2005, 01:32 PM
Seems a bit excessive to me. Don't forget that a lot of the varnish in the can is solvent and will evaporate away so a quart of varnish is the can is heavier than a quart of varnish dried on the boat. Probably easier to just not wear boat shoes (or underwear) to save weight in the boat!

Seriously, instead of varnish you might consider a two part linear urethane as a replacement for the varnish. Stronger and tougher so less coats needed and will probably last a lot longer too! I've experimented with a few drops of poly stain in the clear urethanes to give them that 'vanish' tint.

regards
paul oman
progressive epoxy polymers

Carl Schaefer
01-02-2005, 01:48 PM
Paul, I'll probably just stick with varnish as I have two quarts that I must use.

You said that it sounded excessive -- the number of coats? How many should be enough, then? 1, 2? Or more?

Someone earlier had mentioned to use thinned varnish for the first coat so that the varnish will penetrate the wood. I believe they mentioned to thin it 50% (I assume by volume).

[ 01-02-2005, 01:51 PM: Message edited by: Carl Schaefer ]

Dan McCosh
01-02-2005, 03:31 PM
It takes a minimum of five coats of varnish to provide reasonable durability. I would think the weight would be measured in ounces.

Scott Rosen
01-02-2005, 06:18 PM
Five to eight coats is enough for abrasion resistance and UV protection. Don't worry about the weight. It's insignificant on a boat the size of yours.

Wild Wassa
01-04-2005, 02:10 PM
Originally posted by Scott Rosen:
"It's insignificant on a boat the size of yours."

Scott, Sorry Mate, I disagree. Any weight is signifigant against other similar boats when competitively sailing against them, as just one of the weak links in the system. You are right up 'Poo Brook' if you are in wood anyway, against composite or newer glass boats just to start with. Every gram counts when racing ... I even take the pen out of my pocket and have weight restrictions on clothing.

Normal varnish practice is not considered as a competitive skin over here, far too heavy but a super light weight clear poly is excellent. Each of the two coat (or maybe 3 coats) is just like a sheet of gladwrap. If you have a racing boat you will end up polishing the paint off her by the end of the season.

If you are fair dink'um about attempting to be competitive or at least giving a good show, keep the boat as light as possible ... every gram counts.

I was able to reduce the weight of my little boat by 30+ lbs, when I took the oil based paint off her. I weighed the paint scrapings. If you put clear poly on your boat, you will even lighten your wallet greatly.

Warren.

[ 01-04-2005, 02:47 PM: Message edited by: Wild Wassa ]

Lulworth
01-04-2005, 02:48 PM
I agree with Warren. When it comes to dinghy racing, the effect of a few pounds on performance is measuremable and significant. Paint wieghs a lot but I suspect (but haven't troubled to prove it) that the lack of pigment in varnish makes it lighter than paint (TiO2 pigments are not that dense so its got to be a small effect). In my case, I could save a lot of wieght by skipping that second bagel in the morning. My Penguin is mostly painted but the thwarts, mast partners, gunnel and transom look great even with beaten up neglected varnish so they stay bright.

David (happy to be chatting about Penguins!)

Cullen T.M. McGough
01-04-2005, 08:03 PM
Yeah, you might win the race with less varnish...

BUT GOOD GOD MAN, THINK OF THE BOAT!

8-10 coats. Chicks dig shiny.

-Cullen

Carl Schaefer
01-04-2005, 08:15 PM
Thanks for the help, guys. Unfortunately, I don't think I'll go for the 8 - 10 coats. I don't think it's necessary. I'll probably stick with 5 or so. The boat is coming along nicely.

Warren, since these boats are dry sailed, no worries about wiping the paint off the hull as quickly as one removes the bottom paint on larger race boats from weekly bottom scrubbings.

Carl Schaefer
01-04-2005, 08:18 PM
8-10 coats. Chicks dig shiny. Alas, my friend, the only chick I gotta impress is the wife. Shiny is nice but she knows I like to win an occasional race.

Peter LeQuire
01-07-2005, 05:52 PM
Wouldn't it solve the problem by laying on as much varnish as it takes, and going on a diet?

Bruce Hooke
01-07-2005, 06:26 PM
In cases like this I usually start by looking at how many coats the instructions on the can say to apply. That at least provides a good starting point...

Wild Wassa
01-07-2005, 06:54 PM
Originally posted by Peter LeQuire:
"Wouldn't it solve the problem by laying on as much varnish as it takes, and going on a diet?"

I kind of doesn't work like that. Light boats with the crew at a competitive weight (a heavier crew) give a better performance than a heavier boat with a lighter crew if both boats and crew weights total the same. Even in the same boat a heavier crew will out perform a lighter crew (within limits). I've not ever fully understood this, kind of. When I sail with the heaviest crew (Mr Adam Feldman and I combined are 210kg), a Seafly dinghy is much faster than when I sail with my son, then our total weight is only 150kg ... even if we are keeping the boat flat on both occassions. Movable ballast and not the extra dead weight gives the performance difference.

Good fairing is more important than a 'little' bit of extra weight. Some times we even fair (sand and fill) between races on the same day ... it is worth it when we do it.

I should have said first up, that in an old racing dinghy you are looking for every single improvement that's realistic, just to keep up with newer boats. Saving weight on paint is one of the first options that can give a tangible improvement. Thin strings save weight, smaller blocks and cleats, trimming bolts saves weight, etc. When the savings are all subtracted, that's when it is most beneficial.

Warren.

[ 01-10-2005, 10:45 PM: Message edited by: Wild Wassa ]