Replies

1. 
   Dave45 | May 30, 2006 04:24pm | #1

   If it's thoroughly dry, go over it with a 150 or 220 grit paper, tack it off, and put on another coat of finish.  That should smooth it out pretty well.  You can repeat this as often as you like using finer sandpaper each time until you get a surface smooth enough to suit you.  Personally, I wouldn't try for a furniture quality finish.  It's a picnic table, y'know - lol.

1. 
   [email protected] | May 30, 2006 04:30pm | #2

   what do you mean when you say tack it off? I was brushing it off with a wisk brush-is that not enough?

1. 
   Dave45 | May 30, 2006 04:45pm | #3

   Probably not.  Sanding can leave a lot of dust and some of it gets trapped in those "whiskers" where the grain raised.  I often use an air hose to blow the dust away then follow up with a tack cloth or a wipedown with paint thinner.  Even that isn't 100% effective, but it gets most of it. 

   Some years ago, I made some blackpowder guns and "whiskered" the stocks before I finished them.  "Whiskering" involved spraying them with water and heating them over a propane torch with a fan flame spreader.  That raised the "whiskers" which I sanded with 220 and 320 grit sandpaper.  It took a couple of passes, but the stocks came out as smooth as glass.

1. 
   [email protected] | May 30, 2006 05:00pm | #4

   thanks...a wipedown with paint thinner...a cloth dampened with mineral spirits ok?

2. 
   HowardAcheson | May 30, 2006 06:36pm | #5

   First, you only pre-raise the grain if you are using a waterborne finish.  The the grain does not really rise. Grain raising is a misnomer. What happens when you wet a wood surface is that small wood fibers swell causing them to stand up and stay standing when they dry. When you sand them down, you are just cutting them off more cleanly.

   Almost any finish will cause the fibers to swell. That's the reason that surface feels rough after you apply the first coat of finish. The wood fibers have swollen with the finish and it's like your beard stubble. Letting the first coat dry and then sanding with 320 paper will again give you a smooth surface. The first coat also "seals" the surface preventing fiber swelling when you apply subsequent coats.

   So, a first coat of finish will always feel rough.  Apply the first coat thinned about 25-30% with mineral spirits.  Let it dry and then sand it using the 320 paper.  Do this by hand, not machine.  Now you apply the following coats.  For exterior applications, apply 5-6 coats of finish for a durable finish.  But, anything left outdoors exposed to the elements and the UV from sunlight will require periodic refinishing.

   Howie.........