Finishing Wood

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Linseed/Varnish/Dryer

I have experimented with several different methods of wood finishing.  I believe the easiest method that produces the finest results obtained when using rubbed oil finishes.  These finishes do NOT provide a good layer of protection from abrasion or vapor penetration, but they do look quite decent.  I will first offer a preamble, then address my methodology. 

Watco Danish Oil is a linseed, varnish, and Japan dryer mix. It is possible to make the same thing yourself that's  cheaper in large quantity. Otherwise, I normally use Watco with a little added varnish and Japan Drier. The added varnish will help the Watco build quicker. I add a tsp of Japan Dryer, but only as a safety precaution. I had a gallon of defunct Watco that didn't set up/harden. Five days later the Watco on the speaker cabinet remained pungent and the wiping rag was still damp and pliable. It wasn't dry, and neither was the speaker cabinet.  The wiping rag should be stiff in 1-2 days, and this is a good indicator that the Watco is working correctly.

The difference between a Linseed based finish and a Bartley's finish is how much the finish soaks into the wood and how the finish creates color. The Bartley's is essentially a surface finish that doesn't soak into the wood to create color/contrast. The Linseed based Watco will soak-in and accentuate the wavy look of Cherry wood. I like this uneven appearance, but some folks don't.  The preference is a trade-off.

The steps for my Watco/Brew are as follows.

1. Sand to 150 - 220 grit sandpaper. Some folks sand to 220, but there is little difference since the grain will stand up during the 1st coat.

2. Goop the Watco on the project and re-apply every 15 minutes (or so) to ensure a good soak on the 1st coat. Wipe excess after about 1 hour.   Wipe occasionally as weeping occurs.  Some of the Watco will weep from the open grain of the lumber, and should be wiped clean.

3. Let dry for several days.

4. Sand with 400 grit paper.

5. Repeat steps 2-4 for 2nd coat.

6. Apply subsequent coats of Watco/Brew with 0000 steel wool. Wipe excess after about 15 minutes. Apply some "elbow grease" if the grain is standing up.

7. Repeat step 6 until you are happy. Normally 5-6 coats of Watco brew will be fine.  This number will vary depending on how much varnish is added to the Watco.  I generally add 1 qt of varnish to a gallon of Watco. 

8. Apply MinWax finishing wax if a light gloss is desired. I like this look, but my wife doesn't. She claims it shows more dust.  I have tried several different waxes, but always return to the standard MinWax finishing wax.

Additionally, I recently discovered an exceptionally good article from John Paqay.  I highly recommend reading this article.  His commentary is very substantive! 

John Paquay Article

 

Lacquer

After reading Bob Flexner's book Understanding Wood Finishing I decided to try a high build finish.  I learned that spraying a perfect finish was truly impossible, but some experimentation with rubbing yields astounding results.  Bob claimed that the clearest finish is obtained with Lacquer, so this is what I use.  I have learned that musical instrument makers also use lacquer.  With these methods it is possible to obtain a mirror flat finish equal to the highest quality dining room tables. 

* Warning! - Always use a respirator and prodigious ventilation when spraying lacquer.  It can go "boom".  It will kill brain cells.  It will provide a splitting headache.

* Tip - Use full spectrum flourescent lights when spraying and rubbing lacquer. These are the ones that simulate sunlight.  This makes the hue of the finish much easier to see.

This is my approach:

1.  Spray 1-2 coats of lacquer.

2.  Sand flat with 220 grit sandpaper.  The purpose is to flatten any grain standing upright after exposure to the finish.  I use my random orbital sander with a vacuum attached for this. 

3.  Spray 8-10 more coats of lacquer.  Subsequent coats will dissolve into the previous coats so there is no need to sand between coats.  Lacquer typically dries in 30 minutes, so this operation can be performed in 1/2 day with ease.

4.  Block sand with 220-320 grit sandpaper until the finish is flat.

5.  Spray 2-3 more coats of lacquer.

6.  Allow lacquer to dry completely.  I don't have this one scientifically explained yet, but it seems that when the lacquer stops smelling bad then it is completely dry.   The advantage to allowing the lacquer to dry completely is that it won't clog as much sandpaper when rubbing.  It seems like 1 week+ will allow the lacquer to dry completely.

7.  Wet sand with 800 grit paper.  The purpose is to flatten the orange peel and dry spray.  It helps slightly to sand with the grain, but this is not completely necessary.  Spray a little water on the surface.  Sand a little.  Wipe dry to check your work.  Spray a little.  Sand a little.  Wipe dry and check your work.  It will be obvious in reflected light when the finish is rubbed flat.  There won't be any shiny spots from the glossy finish remaining..

8.  Wet sand with a 3M 1500 grit pad.  I use a Porter Cable 7336 for this operation.  I also use a household sprayer.  An old window cleaning container works well.  Spray a little.  Sand a little.  Wipe dry to check your work.  Spray a little.  Sand a little.  Wipe dry and check your work.  It will be obvious in reflected light when the finish is rubbed good.  The other possibility is to dry sand with 1500 grit automotive paper.  If sanding by hand, I recommend 1200 grit then 1500 grit automotive 3M sandpaper.

9.  Rub with 3M Perfect-It III Machine Glaze and a glazing pad.  I use a Porter Cable 7336 for this operation too.

The result is a deep clear mirror-like finish.

I haven't tried many lacquers, but will summarized my preferences herein.  The Rudd high solid content lacquer (@$25) to equal the Sherwin Williams lacquer (@$35).  My previous preference is a Rudd pre-catalyzed lacquer in a "90" gloss.  It dries slightly quicker than the afore mentioned lacquers and the finish is harder too.  There is no change in clarity.  My current preference is Sherwin Williams post-catalyzed lacquer.  It requires a sealer, but the final finish dries slightly harder than the Rudd pre-catalyzed lacquer.  I tried Deft (Deft is Lacquer), and it is quite soft by comparison.  It has an acceptable reputation for a commercial product and the small spray cans of Deft work nicely to fix mistakes.  Additionally, Deft has some retarders that make it viable for brushing.  It is theoretically possible to obtain a decent finish with a brush.

If the Lacquer is labeled "water white" it will likely look much better with a tint.  I use a honey amber tint in my water white lacquer.  It works fabulous and provides a slight warmth to the finish.

Please let me know if you have any questions regarding the information presented above.  There is probably room for clarification on some items.