Replies

1. 
   tom77 | Mar 04, 2011 10:30am | #1

   Table top finish

   A good quality varnish is my choice for table tops.  I apply two coats and then wet sand with 400 g to level.  Then two more coats and wet sand again to level.  I am usually close to level at this point. One or two more coats, wet sand level with 600 g, and then rub out or polish to desired sheen.  I currently favor using wet abralon pads on a ROS to get a satin sheen.

   Min Wax WOP will work, but you will have difficulty sanding it level without going through the top layer.  You will need at least six coats, which can be applied in two or three days.  You could apply six coats, sanding lightly with 320 g in between every other coat.  Sand it level after six+ coats.  Wipe clean.  Then apply one coat, striving to maximize smoothness. I use untextured Viva paper towels, folded into a smooth pad.   If your table top is big, this will also be difficult.  WOP dries quickly, so you will have to be both smooth and quick.  You can buff the final finish to the sheen you want, but be careful not to rub through the top coat.  Remember to wipe the edges with your wet pad after each coat to clean up any runs.

   I suspect that you may not save a lot of time using WOP on a large table.  If your table is small, it is a good choice.  Try practicing on a sample.

   Good luck, Tom.

1. 
   derosa | Mar 04, 2011 11:03am | #2

   The top is over nine feet long. You are right, it is probably too big to wipe on, without drying before I can cover the top. What brand of varnish would you recomend?

1. 
   tom77 | Mar 04, 2011 02:30pm | #3

   This thread will probably start some fireworks, but so be it.  I have used Varathane gloss varnish with good success.  Many of the experienced members of this forum recommend that polyurethane varnishes be avoided because of aesthetics.  (They look like plastic)  Varnishes with other resins like alkyds or phenolic are recommended.  Brands include Pratt & Lambert 38 or Behlen's Rock Hard varnish.  I have tried Behlen's and saw no significant difference in appearance when compared with Varathane.  The color does indeed vary between the various brands.  Some are quite a bit darker.  And finally, all of the resins are plastics.  They do have different characteristics such as color, hardness, toughness, cure rate, etc. 

   I am interested in the experiences of other members of this forum who have significant finishing experience.  What parameters of the various varnishes should we understand?

   Best regards, Tom.

1. 
   SteveSchoene | Mar 04, 2011 09:11pm | #4

   I'm one who recommends avoiding polyrethane varnish for furniture.  Appearance is a small part of the reason.  I have done side by side tests on the same wood and can see an adverse impact, at least from some angles and under some lighting.  But, it is subtle.  But, there are more important reasons why i avoid it.  The first is that it is hard to rub out to an even sheen.  The abrasion resistance that is the main positive attribute of polyurethne varnish, also makes the abrasive rubbing out process more challenging.  Polyurethane varnishes also tend to have more adhesion issues than non-poly varnishes.  They won't stick well to shellac with it's natural wax.  It's more problematic with oily woods, and it really needs a very thorough scuff sanding between coats.  That is recommended with all varnishes but it's not nearly so critical as with poly.  Poly, at least the single part poly that is commonly available, is also not very UV resistant so it can be a problem for exterior use. 

1. 
   tom77 | Mar 05, 2011 09:30am | #6

   poly varnish discussion

   Steve,

   Thanks for providing the additional information on poly varnishes.  That helps me to better understand some of the past Knots discussions.  I have tried Behlen's varnish and experienced problems with slow curing. (multiplle days)  I had to add some Japan drier to get it to harden in a reasonable time.  I suspect there must have been a quality control problem, because so many people have recommended this brand.  I have not been able to find Pratt and Lambert varnish locally. 

   Best regards, Tom.

2. 
   AutumnWoods | Mar 04, 2011 10:09pm | #5

   My thoughts

   I'm partial to waterlox for wipe on applications, but for large tabletops I prefer more protection.  Behlen's Rockhard table top varnish works well, but I usually have to block sand it level and rub it back out.  Or you can sand it level and use a wipe on over that maybe.

1. 
   HowardAcheson | Mar 06, 2011 03:23pm | #9

   From a protection and appearance point of view, there is little technical difference between Behlen Rockhard and Waterlox Original.  Both are made with phenolic resin which produces a harder, more durable finish than alkyd resins used in other varnishes.  The primary difference is that Behlen's uses linseed oil as its oil component while Waterlox Original uses tung oil.  This gives Waterlox a very slight edge in water and  watervapor resistance.

   Phenolic resin makes both products quite dark and amber so they work particularly well on dark colored woods.

   I have tested both on walnut and mahogany and can't see much difference in either.  Waterlox is slighly more viscous but adding about 10-15% more thinner to Behlen and it is almost identical.  Used full strength, it is somewhat more touchy to get good flow out

1. 
   AutumnWoods | Mar 05, 2011 11:49am | #7

   Interesting Observation

   I appreciate your observation, perhaps that's why I've always had good results with both products.  The main difference I see between the two is that with Rockhard I can apply it thicker and build quickly on finishes I'm planning on level sanding and rubbing out.  I've never had the patience to apply that kind of thickness with waterlox, but other people may have had a different experience with it.  Honestly, when a client stresses the need for surface protection, even at the expense of the feel of a piece, I use two coats of ML Campbell's level seal to build thickness followed by two coats of conversion varnish.  It's not my preferred finish because of it's plasticized feel, but sometimes I buff on a thin coat of wax to help mitigate that.  Of course, you have to be set up to spray that kind of finish so it's not for everyone.  I've never had anyone complain about the durability of waterlox or behlen's rockhard and I've used both for years.

2. 
   JerryW | Mar 06, 2011 02:21pm | #8

   General Finishes Arm-r-seal semi-gloss would be my recommendation.  It is absolutely idiot proof.  On a large surface, apply with a 4" foam brush (only dip brush about 1/4" and preplace finish ahead of brush stroke by daubing every 8" - "float i t on" with the brush).   Each coat dries in 5-6 hours, can be rubbed down in between with 0000 steel wool.  4-5 coats and it is really nice an protects the surface very well.  It is a "urethane varnish".   It is carried by Woodcraft, Rockler, et. al as well as lots of unfinished furniture shops.   They also make a full range of water based finishes, but I have not tried them.   GF also has a superior, responsive tech service group.

   Jerry

3. 
   cahudson42 | Mar 24, 2011 04:52pm | #10

   Wiping Varnish

   I recently used a wiping varnish described by Gerrett Hack back 1997 or so on a small cherry table top, and liked the results. I finished a previous similar table using Watco Danish Oil. Compared to that, the new table has more of a satin finish, seems harder, and water beads better on it - though I don't have any durability info at this point.

   Garrett's wiping varnish is one part Turpentine (use Turpentine - NOT mineral spirits, naptha or anything else), one part Tung Oil (real - from Woodcraft), and one part Spar Varnish. While Garrett used several different varnishes depending on availability, I used ACE Hardware Spar Varnish 'house brand'. It is phenolic resin based, inexpensive, and seems to work great.

   If you are an FWW 'member' you can review his original article here:

   https://www.finewoodworking.com/Materials/MaterialsPDF.aspx?id=2447

   There was a follow up article a few years later by Mark S. FWW Editor: 

   https://www.finewoodworking.com/Materials/MaterialsPDF.aspx?id=2724

   Why not let us know whatever you did - and how it worked out?

   Chris

1. 
   HowardAcheson | Mar 25, 2011 10:58am | #11

   Just a comment about this finish.  It's a pretty standard oil/varnish mixture.  You can use either pure tung oil or boiled linseed oil.  The oil makes little difference other than the tung oil is a little less amber but is much slower to cure compared to boiled linseed oil.

   As to the turpentine, the thinner used has as it's only function making the mixture more readily absorbed into the wood.  The absorbability of an oil/varnish is not affected by the thinner used.  The thinner--whether turpentine, mineral spirits, naphtha, etc.--does not remain a component of the mixture.  It fully evaporates within a few hours and no part of it remains in or on the wood.  The only components of the mixture that remain are the varnish and the oil.

   So, we're right back to the standard oil/varnish mixture.

1. 
   cahudson42 | Mar 27, 2011 11:26am | #12

   Wipe on Thinner etc.

   Hi Howie,

   While I agree that your comments on which thinner used should not make a big difference, it is possible that the rate of evaporation of each can have an effect. Until reading Garrett's article, I always used either Naptha or Mineral Spirits. But it seems to me the Turpentine has a far lower rate of evaporation, which may have a positive effect on absorption, flow out, and adhesion.

   Even though the turpentine stinks to high heaven, using it definitely gives me more time until 'tack up' for soaking in and subsequently wiping off - with a great look after I do.

   I also am now a complete convert to Tung Oil - when I used to always use Boiled Linseed oil. The Tung Oil based wiping varnish definitely beads water better than the same number of coats using linseed. And while the Tung Oil is expensive, the ACE phenolic spar varnish - last time I looked - was about $10/qt - $30/gl. Overall, cost is certainly no more than Waterlox.

   The viscosity of the mixture - with turpentine and Tung Oil - is much higher than Watco but easily brushed on as well.. It will lay great on a flat surface, and run less on vertical/tilted.

   Finally, I support earlier comments on using a phenolic resin varnish. I also think its superior to common soya/alkyd and urethane.