Dining/Game Table - #23 Resolving Stain Problem & Starting the Finishing

After thinking about how to fix the unstained pores I had an idea and decided to do some testing.  For my test material, I decided to use the Alignment Guides.  They are wide enough to give me a good sample and if things don’t work out quite right they are under the table and hidden from view behind the Outer Rail.  Here I am ready to start staining.  I will pour out some of the stain from the glass jar into the smaller plastic container.  That way when, not if, I eventually knock things over I will lose only a small amount of stain not the whole mixed lot.

Staining Setup & Materials

First, I stained the Alignment Guide assembly and when I examined it sure enough just like my large sample there were unstained pores here too.  

Unstained Pores

Before I go further I want to touch on the stain itself.  I have been using stain to indicate the finished mix of dyes and alcohol but that’s not really right.  A stain is an opaque pigment that for the most part remains on the surface of the wood and in it’s pores.  A dye on the other hand is a translucent material that penetrates deep into the wood and provides color from within.  I like to use dye because it is translucent and does not mask the character, figure or chatoyance of the grain.  Also, in this case I had several colors of concentrated dye and could easily custom mix the color I needed.

For the test, I am going to take advantage of a gel stain’s property of packing into the wood’s pores.  Here’s the sequence I used and observations:

1. On the left half I rubbed a dark walnut gel stain that has the consistency of pudding into the pores and wiped as much off it as I can.  It filled the pores but also slightly darkened the entire treated half.
2. I then gave the whole piece it’s first coat of lacquer, let it cure then lightly wet sanded with a 1,500-grit pad to remove any dust nibs.   The left half looked quite good while the right half still had the unstained pores.
3. On the right half that had just the dye mix and lacquer I rubbed the dark walnut gel stain into the pores and wiped off the rest.  Because the one coat of lacquer had sealed the non-porous surface but not filled the pores the only area impacted by gel stain was the pores.
4. A second coat of lacquer was sprayed on the whole piece.

The next day I gave the second coat of lacquer a light wet sanding using a 4,000 grit pad.  Going in I thought the stain (dye), lacquer, gel stain and lacquer would give the best results.  To my surprise, it did not.  The best was the left test; stain (dye), gel stain and lacquer.  The result is a richer slightly deeper color even better than what we had decided on using.  A silver lining to a problem.

Left, Dye/Gel Stain/Lacquer - Right, Dye/lacquer/Gel Stain/Lacquer

With the stain mix and finish application for the body of the piece settled (color of applique pieces are still under discussion) I could start the finishing process for real. 

The lacquer spray mix is a combination of satin lacquer, lacquer thinner and a small amount of retarder.  I mix it in a quart plastic container then pour into the 8 ounce cup used on the spray gun. 

Lacquer Materials

I decided to start the finishing by spraying 2 coats of lacquer on the MDF.  It will be hidden under the pad but because if MDF gets wet is swells up and loses structural integrity I wanted to provide some protection in case of a major spill.   It will also give me a chance to refresh my spraying skills before I start on the oak itself.  No stain is needed and I use the HVLP spray system for the application.  Setup is simple, the HVLP turbine goes in the shop plugged into the radio controlled on-off switch for the dust collector.  The 1” air supply hose gets run outside to the spray stand that consists of two sawhorses and a set of pyramid risers.  That’s it, once pieces are sprayed they are brought into the shop and set on blocks to dry.

Spraying Lacquer

Once sprayed and cured overnight the MDF is lightly sanded with 220 grit sandpaper to knock down any roughness due to dust.  I don’t want a really smooth surface but one with a little tooth to help hold the pad in place.  The oak will follow a bit different process because I want a really, really smooth surface. 

MDF Sealed with Lacquer

I started the actual finishing by completing the stain work on the alignment pieces then dyed and stained the oak sub-structure for the MDF.  Most of the individual components are not very wide which does not lend them to the HVLP sprayer.  Also, the weather has not cooperated much forcing me to spray in the shop.  Those two considerations have meant a number of the pieces have been sprayed using the air-brush.  It is quite a bit slower but gives the same quality and is more in tune with the constraints noted above.  I gave them two coats of lacquer wet sanding between coats with a 2,100-grit pad and with an 8,000 grit pad at the end.  This completes the hidden pieces so from now on I will be working on the visible pieces.  I know if you are on your back on the floor under the table you can see the sub-structure parts but most of the time they will be out of sight.

The legs went fine as did three of the four Outer Rails.  When I applied the dye to the last piece I noticed a series of vertical lines (scallops).  They are caused by tiny hills and valleys on the face.  My guess is they were a result of sympathetic vibrations when I ran that piece through the thickness sander.  Because they are so small I did not see them when doing the final sanding and preparation for staining.  Unfortunately, the only way to fix the problem is by sanding the piece flat then re-staining.  Leaving them is not a good option because when I spray the piece with lacquer they will just get more pronounced.  After sanding and re-dying it looked just fine.

Sanding Scallops

Here is an in progress shot with a bunch of different pieces dyed and stained.

Dying & Gel Stain Pieces in Progress

Next Up – More Finishing plus Applique Size Problem, Masking, Stain Color & Installation