kind of a 'catch 22' here. Although tung oil and to the same extent
linseed oil are good protectors of wood and at least linseed oil is a
preservative of wood and both are less susceptible to the protection
failures common to varnish, they both have the same common (for lack
of a better word) failing. They are both mildew food. So keep your
kayak dry and ventilated when not in use and you will keep it mildew
free.


"Brian Nystrom" wrote in message
news:VBqHe.7084$r12.4959@trndny04...
| wrote:
| I have a foldable kayak with a interior wood frame. Having left
water
| in the boat for too long, a number of pieces have what looks like
| mildew stain and some minor rotting. The integrity of the pieces
are
| fine and I am not concerned with the aesthetics. I would like to
| refinish the pieces with spar varnish but I am wondering if I need
to
| get the mildew stains out and how to do that. A light sanding
smooths
| out the pot marks but doesn't get the stains out. Any
suggestions??
|
| There are several ways to kill the mildew, but the most commonly
used on
| is to pour a bit of antifreeze into the assembled boat and slosh it
| around until all surfaces are covered. It will kill the mildew
| completely and help prevent it from coming back, but I don't believe
it
| remove the stains. Doing so probably isn't worth the effort, as the
| discoloration is probably too deep into the wood. Any rotted pieces
| should be replaced. If you want to coat the frame with something I
would
| suggest using 100% tung oil from a woodworking supplier (not one of
the
| "tung oil" finishes from the hardware store). Varnish may look good
and
| it protects well initially, but when it wears through or cracks,
water
| seeps in and becomes trapped under the finish, causing rot. A tung
oil
| finish isn't as waterproof as varnish, but it breathes and allows
any
| moisture that gets into the wood back out. If you allow the boat to
dry
| between uses, you won't have any rot problems.
|
| One thing that most people don't realize is that although fresh
water
| encourages rot, salt water is a good wood preservative. If you
paddle on
| salt water, slosh some around in the boat and make sure the frame
gets
| good and wet. Dump out any excess, but DO NOT rinse the boat out
with
| fresh water, as it defeats the purpose.

Mungo Bulge wrote:
kind of a 'catch 22' here. Although tung oil and to the same extent
linseed oil are good protectors of wood and at least linseed oil is a
preservative of wood and both are less susceptible to the protection
failures common to varnish, they both have the same common (for lack
of a better word) failing. They are both mildew food. So keep your
kayak dry and ventilated when not in use and you will keep it mildew
free.

That's incorrect. While linseed oil definitely suffers from that problem
(I know from personal experience), tung oil does not encourage mildew. I
was told this by the people in charge of preserving the boats at Mystic
Seaport and I've verified it through other sources. That's also why I
specified using 100% tung oil, as many "tung oil finish" products
actually contain little or no tung oil and may contain linseed oil.