Replies

1. 
   Paul_Snyder | Oct 20, 2002 09:38pm | #1

   It depends on which "tung oil" finish you plan to use. Some "tung oil" finishes are actually varnish and offer very good protection when you apply enough coats to build a decent film finish. Other "tung oil" finishes are an oil/varnish blend and should not be applied too thickly because they do not cure as hard as varnish.

   I'd use one of the "tung oil" finishes that is actually varnish - you get the ease of wipe-on application but the full protection of varnish. Waterlox original (waterlox.com) is a favorite in this category.

   For more information on varnish and oil blend finishes, and a list of brands and what they actually are, go to this link - http://www.popularwoodworking.com/features/finish2.html

   Paul

   F'burg, VA

1. 
   AllenS51 | Oct 20, 2002 10:21pm | #2

   I am trying to use a tung oil that is a varnish.  Can you top coat this with polyurethane without any negative effects?  Would the urethane finish make the piece more "glossy" and hold up better?

   Allen

1. 
   Paul_Snyder | Oct 20, 2002 10:50pm | #3

   You can use a urethane over varnish if you want to. But varnish is pretty durable itself and you can get it in a gloss sheen. If you're using a wip-on application, apply 6-8 coats to build a good film.

   Unless you're finishing a high-wear surface like a tabletop, you don't really need the added durability of poly.

   Sand lightly bewteen dry coats of your finish(es) to smooth the surface and promote good adhesion. 320 grit sandpaper is a good grit to use.

   Paul

   F'burg, VA

1. 
   AllenS51 | Oct 21, 2002 12:21am | #4

   I am currently testing some walnut samples using Minwax Special Walnut stain with a polyurethane coating.  I am comparing them to a tung oil finish without the urethane.  I like the looks of the oil finish better than the stain and urethane.  The stain and urethane combination tends to show the small checks of the walnut grain more than the tung oil.  The tung oil appears to give a more dark uniform smooth appearance.  Do you know of another method I should try?  I have not tried the oil urethane combination as of yet but I am planning to do so.  I am also going to follow your advice and try the 6 to 8 coats of just tung oil.   Is is better to sand between coats with 320 sandpaper or use 0000 steel wool or both?

   Thanks

   Allen

1. 
   Paul_Snyder | Oct 21, 2002 02:14am | #5

   The 6-8 coat recommendation was based on your saying the "tung oil" was really a varnish. 6-8 coats of wiping varnish builds a protective film. If you use an oil/varnish "tung oil" mixture, then 3-4 coats is about as much as you want to apply - just enough coats to get an even, dull sheen - don't try to build a significant film with these combination products; they're intended to provide a "close to the wood" look.

   If you can get a smooth, level finish with 0000 steel wool then it's a good choice. Varnish is pretty durable and I've found even 320 can be a little slow going for my taste. Sandpaper on a sanding block helps to level out the high spots/nibs in the surface. Once the finish is leveled, the steel wool will probably be enough for the coats that follow.

   On the poly showing the defects in the surface of the wood, you can apply a couple coats, sand the finish back some and apply a couple more coats and sand back again (220/320). Repeat until the surface of the varnish/poly film is smooth and level (the defects are no longer showing) being careful not to sand too much and cut through the stain. Then apply the last coat. Another option is to start with a paste wood filler to fill the pores and defects on the surface of the wood so that it is smooth and level before you begin the rest of your finish steps. Here's a link to an article on paste wood filler - http://www.wwforum.com/faqs_articles/fillers.html

   Paul

   F'burg, VA

2. 
   PlaneWood | Oct 21, 2002 06:35am | #6

   I have top coated over both Tung oils.  The kind with the dull sheen is non-polymerized and takes a little longer to dry.  After drying thoroughly (couple days), I've had no trouble brushing, spraying, or wiping on poly.  With the higher gloss stuff (polymerized - which means its been cooked at a high temp for a considerable period) it will dry in a day.  I'm assuming here the use of thinned tung oil (at least 50%).  The 100 % pure can take a week to dry, depending on temp and humidity. 

   PlaneWood by Mike_in_Katy
   PlaneWood

1. 
   AllenS51 | Oct 21, 2002 01:41pm | #7

   Thanks for the info.  Would you recommend any other type finish for a Walnut dresser?  What would you do use the tung oil  plane or topcoat it?

1. 
   PlaneWood | Oct 22, 2002 12:16am | #8

   For a dresser, I would let it set a few days then top coat it with 2 or 3 coats of hand rubbed poly.  I always use high gloss poly then buff last coat with steel wool to a semi gloss.  Thin the poly a little then flood it on and rub it in with the palm of your hand.  Then get a cotton rag slightly wet with paint thinner and rub it in till no residue is visible.  Let that cure, smooth with steel wool, then do it again.  Don't wait more than 3 or 4 days between each top coat. 

   PlaneWood by Mike_in_KatyPlaneWood