[Public-List] Cape horn varnish

[Gordon Laco via Public-List]

Good day - 

Generally it's the sun that destroys varnish... Water gets involved once UV
has compromised the finish.  Moisture then can get in and lifts the finish,
completing the job of ending the life of the coating.

There are many 'short cut' products that keeping coming on the market, but
nothing yet is better than a good old fashioned varnish job with regard to
UV resistance and long life for the coating.

Speaking generally, urethanes and polyurethanes are harder than varnish, but
with the hardness comes brittleness and inability to cope with wood
expansion due to humidity.  And most of this family of finishes don't have
the UV resistance of solvent based varnish.  Normally they're only
recommended where there's no direct sunlight and or where high traffic
involving sandy shoes etc are expected. In the later case it's recommended
to cover the hard finish with regular varnish to protect it from the sun.

I know some companies claim remarkable results with regard to UV resistance
with only a very few coats... The company whose products I import and
distribute makes hard two part polyurethane clear finishes in addition to
our traditional varnish, but we don't claim they can stand on their own
without protection in high UV exposure.

The most durable clear finish for wood so far is still regular high quality
marine varnish laid on with the first coats thinned, then a build up of
eight coats.  Yes, its a lot of work the first year, but once that's behind
you, it only takes a maintenance coat of fresh varnish each spring (and a
touch up of dings as soon as they happen) to keep the finish looking like
new for up to ten years.

There are really no real shortcuts (yet) around that first season where you
layer up the finish from bare wood.

So with your vane's servo blade, it was most likely the time it spent out of
the water that compromised the finish...immersion with sun-rotted varnish
allowed water in to complete the job, but that came after...

I hope this is useful,

Gord #426 Surprise


On 2016-03-19, 7:58 PM, "Jeffrey Randall via Public-List"
<public-list at lists.alberg30.org> wrote:

> Last year I finally started to rely on my Cape Horn.  However as a novice I
> also left the Cape Horn paddle in the drink once too often.  I am
> refinishing the paddle and am interested to hear what others have used for
> a finish.   Is  3 to 5 coats of Cetol sufficient or would you use something
> different.
> 
> I am heading to the library tomorrow to see if I can rustle up some info on
> Practical Sailor but came here first.