waterborne varnish

[Tim Keenan & Rebecca Counts]

Kevin R. Aldrich wrote:
> 
> Dear List,
> 
> How do people feel about finishing soundboards with water-based
> polyurethane?  Is it advisable to apply *water* to a bare soundboard?  Does
> anyone out there have experience in this area?
> 

Kevin and List:

The only water-soluble polyurethane product I have used on a soundboard 
is Flecto's Diamond Coat.  It gave very good results.  I don't think that 
there is actually very much water in it.  It is just formulated in such a 
way that it is miscible in water, so that water can be used in cleanup.  
I have used it in many other applications, and have no complaints at all 
about it.  I find it a delight to work with. It is much, much easier to 
work with than Varathane, and dries much faster, and is crystal clear 
when cured (although it looks like skim milk in the can)--it imparts no 
colour of its own, unlike varnishes and Varathane. In a shop with the 
humidity controlled around 45%, it is very easy to work with a brush 
without leaving brush marks, and dries to the touch in about ten minutes, 
and can be recoated in about 30 minutes.  It does not raise grain, which 
is one reason I think there can't be a whole lot of water in it.  The 
manufacturer does warn about using steel wool on surfaces to be treated 
with it, though, so there is probably enough water to cause steel dust to 
discolour the finish. Make sure to use a high-quality synthetic brush (I 
like nylon with flagged bristles).  Natural bristles will swell.  I can't 
comment on any other manufacturer's formulations.  I read a piece in (I 
think) Consumer Reports comparing various products, and Flecto's was the 
one that scored the best.  Some of the others had complaints about 
foaming and brushability.

That's my take, anyway--I love the stuff.  And it doesn't make me sick.

Tim Keenan
Noteworthy Piano Service
Terrace, BC