Frank Lloyd Wright Desk Lamp - #10 Dye Testing, Sanding, Completing the Base & Central Column plus Fixture Preparation

Now it is time to start nailing the finish down.  I took some scraps, sanded them to the final 320 grit then mixed up a set of 5 samples using alcohol as a carrier for the dye, applied it and after they had dried put on three coats of wipe-on satin poly.  The good news is that I am mixing up the samples using only a tablespoon of alcohol and a few drops of dye so there is not much waste.

While the finish test pieces dried I started doing the final sanding on the baffles.  I began by working on the end grain.  The blade I use to make cross cuts is a high quality one specifically designed for this type of work and it does a really good job.  However, in this case I wanted the end grain to look every bit as good as the faces.  That means sanding it through the grits to 400.  This is one grit finer than the faces and that’s because when applying dye to end grain it takes darker than face gain.  Sanding to a finer grit will lessen the difference.  Here is a photo of the left and right sides of the notched baffle end.   On the left is the saw cut edge.  It’s good, no blade marks or burning but it is not up the smoothness needed.  The right shows the quality of finish I want.

Now that the glue has cured holding the plywood top to the base I can take the clamps off and start to bring the base flush with the plywood.  In post 5 I cut the rabbit a little deeper than the thickness of the plywood.  That was so I could use a scraper to bring the top of base piece down to match the plywood exactly.   Since plywood varies in thickness that gives me a little buffer to work with.  I can always shave a little off the top of the perimeter pieces but because the veneer on the plywood is only about .025” thick there little to no margin of error there. 

A scraper is simply a hardened piece of steel.  The one shown is about 2¼” X 6” and only about 1/32” thick.  It cuts with a razor-sharp burr on the edge so small you can barely see it.  With a good burr, it will take off shavings so thin you can see through them which gives great control in shaping a surface.

The photo below shows the three stages of bringing the solid wood base perimeter pieces flush. 

1. At the start make a squiggly pencil line across the plywood and the solid wood perimeter piece.
2. Using the scraper start cutting away the outer piece which removes the pencil line from the solid wood piece.
3. When the pencil line on the plywood is just removed the joint is flush.

Last bit of work on the base is to finish sand to 320 and “break” the sharp corners.  This is done by making a few passes of 220 grit sandpaper held at a 45-degree angle to put a tiny chamfer on the edge.

Now I had the initial dye samples finished and in evaluating them two were pretty good and the rest were OK except for one, it just did not work.  Looking at the couple I liked I mixed up one more sample and stained a scrap piece.  I will go ahead and start giving it the three coats of finish then take it in the room I will use to see how it looks.

While I was going through the finishing process I went back and worked on the actual light fixtures.  They are simple candelabra bases that get screwed onto a 1” long section of threaded pipe.  The pipe will get glued in place with an epoxy glue.  Below is a cutaway section showing the components.

The pipe comes in longer sections that get cut to length with a hack saw.  The ends are filed smooth and a bevel is added with a grinder on the outside ends to get rid of sharp edges.  Last, I mount the pipe on my lathe, wrap some sand paper around a small round file and smooth the inside edges.  I don’t want any sharp edges that could abrade the wire and cause a short.

I also glued the top onto the central column.  It is pretty straightforward glue the tenon into the central column making sure it’s aligned right then glue and clamp the cap on.  There are a few process notes though.  First is to apply the glue to the hole the tenon goes in.  That way when you put the tenon in the excess glue is forced further in the joint.  If I put the glue on the tenon the excess glue would end up squeezing out the joint where the cap and the column meet making a mess to clean up.  Second, is to use a pair of clamps to make sure the cap is on square and not cocked due to uneven pressure applied by a single clamp. 

Last, I added a backer board clamped to both the column and cap.  This made sure the faces of the cap and the column were in the same plane. 

I have been giving the assembly sequence quite a bit of thought and as of now this is my plan:

1. Dye the central column.
2. Dye all the exposed surfaces of the spacers.
3. Dye all the surfaces of the boxes except for the outside face plus the top and bottom edges.
4. Finish just the inside face of the boxes.
5. Assemble the three sides of the boxes.
6. Sand the outside faces and edges of the boxes.
7. Dye the remaining box face and edges.
8. Mask off the areas of the central column, spacers and boxes that will get glued.
9. Finish the central column, spacers and boxes with 3 coats of satin wipe-on poly.
10. Epoxy in the threaded pipe for the light fixtures.
11. Wire fixtures.
12. Glue spacers to boxes.
13. Glue the spacer/box assembly to the central column.
14. Glue the baffles in place.
15. Screw the column assembly to the base.
16. Complete wiring.

I think this will work.  By finishing the central column and the spacer/box assembly when I glue them together any excess glue will be on an already finished surface.  Clean-up will be easy as the water-soluble glue should just wipe off.   Also, because the pieces are already finished the water will not raise the grain nor will the excess glue leave a film that would inhibit the absorption of the dye.

At least that’s the plan, for now.  Time will tell if it works.

Next Up – Dye Testing, Pre-Finishing, Box Sub-assembly, Finishing