Replies

1. 
   SantaFeTom | Aug 13, 2010 10:51am | #1

   Rub on or wipe on?

   I may be answering the question wrong because I am not really familiar with rub on poly. All I know is that I thin regular poly 50/50 with mineral spirits or naptha and wipe it on with a rag. I started doing this in the past year and am amazed how superior the finish is compared to what I had been doing with brushes and paint pads. The downside is that it takes twice as many coats but there absolutely no brush marks and I haven't had the need to rub out the final coat.

2. 
   SteveSchoene | Aug 13, 2010 03:28pm | #2

   Wiping varnishes are little more than regular varnishes thinned to wiping consistency.  To achieve the film thickness of a brushed on coat of varnish requires about 3 wiped on coats.   I assume you are referring to Minwax Wipe-On varnish--I don't see a product called Rub On on the Minwax web pages.   Polyurethane varnish isn't my usual choice for furniture, I'd prefer using a non-poly varnish since it is clearer, is easier to rub to an even sheen, and has fewer problems with adhesion.

   Though I do know at least one very capable finisher who uses foam brushes for varnish,  he is in a distinct minority.  Most find it much easier to spread varnish with a good quality natural bristle brush--I'm particularly fond of brushes which contain a mix of OX hair.  By the way, removing defects between coats is best done with 320 grit paper.  With 220 not all scratches might be fully filled with thre subsequent coat.  Runs and sags are best approached by using a scraper (the blade from a utility knife, or a razor blade, works well as a scraper. 

1. 
   WillGeorge | Aug 14, 2010 12:19am | #4

   For what it is worth...

   I agree that OX hair brushes are wonderful! I have several of this brush..

   http://www.woodcraft.com/Product/2005842/17811/Corona-2-ChinaOx-Hair-Brush.aspx?refcode=05INFROO

   I use mostly for applying wipe-on oils. Yes, I use a brush to apply the wipe on oils. No lint! I also use a gray/grey 3M pad between coats to rub out any 'nubs'.. Works for me. I have to work in a small garage shop and sometimes the wind blows and I get dust at unexpected times.

   As for.. "and general swearing when I later discover a run I missed".. I find that wipe on oils are VERY forgiving of almost any thing you do. Even when wax was applied. I use naptha or gum turpentine to remove any wax. Seems to work for me.

   (Windy here in Chicago.. But I think that the expression "Windy City".. is because most of our politicians, over many year,s are largely responsible for the nickname sticking... AS in.. they are full of 'Hot Air'....)

3. 
   HowardAcheson | Aug 13, 2010 04:21pm | #3

   Here is something that should help. A friend of mine who was an early advocate of wipe on varnishing, put it together years ago and it has worked well for many.

   QUOTE

   There are a number of suggested application regimens that are totally subjective. The number of coats in a given day, the % of cut on various coats, which coat to sand after, when to use the blade and a whole host of other practices are all minor differences between finishers. There are some things that I consider sacred when applying a wipe-on finish.

   First, you can use any full strength oil based clear finish.  Polyurethane varnish or non-poly varnish is fine.

   If you are making your own wipe-on the mix is scientific - thin. I suggest 50/50 with mineral spirits because it is easier to type than any other ratio and easy to remember.  Some finish formulators have jumped on the bandwagon and you can now get "wipe on" finish pre-mixed. If you use a pre-mixed, thinning is generally not necessary.  But making your own is cheaper and you know what's in it.

   The number of coats in a given day is not important. Important is to apply a wet coat with an applicator and merely get it on. Think of a 16 year old kid working as a busboy at Denny's you have sent over to wipe off a table. Sort of rub/swirl the the material on like you would if you were applying a paste wax.  Don't attempt any straight strokes.  The applicator should be wet but not soaked.  The applicator can be a non-embossed paper towel shop towel, half a T-shirt sleeve or that one sock left after a load of washing. Once applied,leave it alone. The surface should not be glossy or wet looking and, if applied correctly, there should be no "brush stroke" type marks.  If you have missed a spot, ignore it - you will get it on the next coat. If you try and fix a missed spot you will leave a mark in the finish.

   Timing for a second coat involves the pinkie test. Touch the surface with your pinkie. If nothing comes off you are ready for another coat. If was tacky 5 minutes ago but not now, apply your next coat just as you applied the previous coat. Remember, you are wet wiping, not flooding. After applying the second coat, let it fully dry for 48 hours.  Using 320 paper and a sanding block lightly sand the surface flat.  Now, begin applying more coats. Do not sand between coats unless you have allowed more than 24 hours to elapse since the prior coat.  The number of coats is not critical - there is no critical or right number to apply.  For those who need a rule, four more coats on non-critical surfaces or six more coats on surfaces that will get abraded seems to work.

   After your last coat has dried at least over night you will have boogers in the surface. You should not have marks in the surface because you ignored application flaws. You may have dust, lint and, if you live in Texas, bug legs. Use a utility knife blade at this point. Hold it between your thumb and forefinger, near the vertical, and gently scrape the surface. Gentle is the important word - no harder than you would scrape your face. If you start scraping aggressively you will leave small cut marks in the surface. After you have scraped to the baby butt stage gently abrade the surface with 320 dry paper or a gray ScotchBrite. Clean off the surface. Now, leave the area for two hours and change your clothes.  Apply your last coat with a bit more care than the previous coats and walk away.

   An anal person is going to have a tough time with this process. Missed spots have to be ignored. Wet wipe, don't flood. Scraping to babies butt smooth means scraping no harder than scraping a babies butt. Ignoring any of these will leave marks that are tough to get out. Getting these marks out requires some aggressive sanding to flatten out the surface and starting over.

   Jim Kull

   END QUOTE

   Finally, It works better to use a gloss varnish for all coats except the last.  The flatteners in semi-gloss and satin tend to rapidly fall out of suspension when the finish is highly thinned.  If you want a non-gloss finish, use it only on the final coat or two and be sure to stir the material frequently or you will end up with cloudy streaks.

    

4. 
   SteveSchoene | Aug 14, 2010 06:56am | #5

   If you have use poly, then

   If you have used poly, then you have used varnish.  They are just somewhat different kinds of varnish.  They apply exactly the same way,   Poly  uses alkyd resin with the addition (modification by) some polyurethane resin.  The polyurethane resin softens (toughens) the varnish, making it more abrasion resistant, but at the same time, it  makes the film a little less clear, especially if applied thickly.  It doesn't adhere as easily to substrates, or itself, so more care in preparation is necessary  Because of it's abrasion resistence it doesn't rub out as easily (rubbing out is after all an abrasive process.) 

5. 
   HowardAcheson | Aug 14, 2010 11:20am | #6

   Let me add to Steve's excellent response.  There are a number of non-poly varnishes available.  Pratt & Lambert #38 and Sherwin Williams Varnish are generally available at Sherwin Willians Paint stores--or, they can order it.  Cabot Varnish #8000 (gloss), 8002 (satin) are available in some areas.  Finally, Waterlox Original Gloss or Satin and Behlen Rockhard are some other choices.  All can be thinned to produce a wiping varnish.

   Finally, don't make your project your learning curve.  Test out and learn your finishing process by making up some sample boards and go through the whole finishing process.  It takes a couple of trys to be able to produce good results.  You may also want to buy either Jeff Jewitt's Taunton Complete Guide to Finishing or Bob Flexner's Understanding Finishing.  Both are excellent and will get you quickly down the road to being a good finisher.