From: pmeyer@.intel.com (Paul Meyer)
Subject: Polyurethane advice for hot dry climate?
Originator: pmeyer@sedona
Organization: Intel Corp., Chandler, Arizona
Distribution: na
Date: Thu, 3 Sep 1992 21:14:34 GMT


	Another question, this time on finishing a table top.

I just built a computer table.  Solid pine, 6'x30", trestle table.  The
top is built up out of 2x6's squared with a jack plane.  I was amazed
how tight the joints were.  I 'stained' the whole thing with a
white-wash finish (Deft's Desert White Oak, or something like that).
Looked good.  I had decided on a polyurethane finish (Behlen's water
based poly, satin finish), and the trestles and cross piece and pegs
turned out fine.  But...

	The table top was smooth and clean and I put on a coat of poly.
I used a foam brush (as the label recommended) trying very hard to keep
bubbles from happening.  I was mostly successful on the bubbles, but the
brush marks and some bubbles showed up VERY clearly when dry.  So I
sanded with 320 and tried again.  Same results.  I tried a regular
brush.  A little better on bubbles, but now the brush strokes were
worse.  Up until than, I had been putting it on with long slow brush
strokes the full length of the table (or half if I needed to refill the
brush).  I tried switching to putting it on like paint, brushing it back
and forth with the grain.  This was the worst yet, brush strokes
everywhere.

	I need to use the table, and I had wasted a week on finishing
it, so I sanded with 400 to smooth the worst of the brush strokes, got
out my paste wax, gave it two coats of paste wax with hand buffing in
between, and I'm now using the table.  I'm still not satisfied with the
top, but it's functional and it doesn't look bad except to me.

	So, two questions:  What did I do wrong, and how can I fix it?  

My suspicions:  It's Arizona and it's dry.  It was probably 85F or so
and very low humidity when I was finishing.  Is this water based poly
drying too quickly to flow out the bubbles and brush marks?  Or do I
need to work on my technique?  Or is Behlen's a difficult poly?  Will a
solvent based poly dry more slowly or flow better?

	Is there any finish that will do better in these conditions that
can go over water based poly, or do I need to sand down to bare wood?  

	What should I have used in the first place?  This is a
computer/writing desk.  I'm starting to think that it would be nicer to
have more of a wood feel than the glossy plastic feel the poly gave.  
If I sand down to bare wood, I'm going to seriously look at some
of the 'simple' finishes.  Tung oil, etc.  Are they going to be
satisfactory for a desk top?  What do people recommend?

	
BTW, I really like the way the table turned out, and it was simple to
make:
 _______________	__________________________________
 --------------		   -			      -
   \    /		   |			      |
    \  /		 --|--------------------------|--
     \/			 --|--------------------------|--
     /\			   |			      |
    /  \		   |			      |
   /    \		   |			      |
 --------------		   -			      -

	Very rough sketch.  The top was built up out of normal 2x6's,
the cross piece was a 2x6 with neat reddish stripe all down the middle.
The trestles were 2x4's for top, bottom, and 2x6's for both parts of the
X.  At crossing point of the X, both 2x6's (1.25 x 5.25 after planing)
had 3/4" dadoes so they fit together to make a 1.25" thick X.  I put a
mortise through the middle of each X to accept the tenon on the end of
the cross piece.  There are wedge pegs horizontally through the cross
piece tenon where it sticks through the X.  
	The top is simply sitting on 4 dowels on the top of the
trestles.  It's heavy enough it doesn't move at all.  The whole thing
comes apart in about 15 seconds, but it's sturdy enough to stand on!
I'm already planning additions (a keyboard slide, shelves, etc.)  

	So, let me know how I should finish it next time I try.  
-- 
Paul Meyer
pmeyer@sedona.intel.com

Newsgroups: rec.woodworking