Koa Bath Cabinet (Part 3 of 3) – Door and Completion

Remember what I said about koa being expensive and my being careful to ensure I don’t mess things up.  Well, in hindsight, I should have better tested my technique for the metallic portion of my pineapple inlay, as the details below will explain.

In order to produce my pineapple inlay, I had to cut 60 small pieces from the burled maple and walnut pieces.  So I printed out my number graphic of my pineapple onto clear label paper so I could apply them individually to the wood to get the best portions for my assembly.

With the labels applied, I spent some quality time with my scroll-saw and cut out the pieces.  After all the pieces were cut, I realized I need to cut some extra for a test.

My initial idea was to use a gold colored resin to fill the gaps in the inlay.  When mixed up and applied to the test sample, it looked great and definitely gave me the look I was going for.  Lesson #1: When the resin is surfaced down level with the wood, it loses the luster of the exposed cured resin and turns into a murky brownish-green. Unfortunately, I did not capture photos of the result.  Definitely not the look I wanted!  So I then decided that the route of using brass powder may be the way to go.

After the test assembly, I took a very deep breath and applied my pattern to the actual door panel for cutting the inlay recess.  After making sure nothing would move on me, I held my breath and cut the recess.  Thankfully, it was successful!

I then printed out my pattern on clear label paper again in order to assemble the inlay pieces for gluing to the door.  I ended up being happy with the results for a first time inlay attempt.

After the disappointment of the resin, I then cut some recesses into the sample panel and tried two versions of the brass powder after research online.  The two techniques I came across was to flood the dry powder with CA glue after filling the recesses and the second was to mix with clear resin.  Once again, I did not photo-document this part of the process.

The results of the test was that the CA glue method gave me the look I desired.  Once sanded, the brass essentially looked like a solid, bright piece of metal.  The resin technique, however, resulted in a muddy mess with no brilliance.  Therefore, the winning way forward was to use the brass powder and CA glue…

…or so I thought.

As you can see form the photo above, it did not turn out at all like I expected.  After some more research I was able to determine that the brass powder was so fine that the CA glue would not absorb as needed and instead would have a tendency to float on top of the powder.  This resulted in the pockets of nothing but solid CA glue and no brass powder.  Attempts to reapply the brass powder and CA glue resulted in obvious patches.  

I had to accept defeat with this method.  However, due to continued planing of the various patch attempts took my door panel down too thin and the door panel was starting to warp.  Not to mention, the pineapple itself was beyond being salvaged.  I had to face the fact that I needed to redo the door.

So I bought some more koa, cut new inlays form the maple and walnut and set them aside.  This time I did several experiments and finally came up with an idea to use resin and cast the metallic portion separately, apply gold leaf, and then inset into the door.  

Some astute readers may be asking why cast it outside of the door and then inset it.  Why not just set the resin in the door, and then apply the gold leaf.  Well, for one, I had a brilliant idea that involved mold-making (something else new for me) and it would just be too tedious to apply gold leaf to the door!  Boy was I wrong…. 

So I ventured down my foolhardy path, bought my mold-making supplies and set out to make my positive mold of the door, which in turn would be used to make a duplicate mold of the door for casting the resin.

The first step was to seal the wood to ensure the silicone did not damage or stick to the door.  Of course, the sealer would need to ultimately be removed in order to apply the actual final finish.  What could go wrong???

So far, so good.  Got really good molds on first attempts!  So I could move on to the actual casting of the resin.  Even though I knew it would not end up curing to the look I wanted, I still added the gold color to the resin.  I figured it would at least give me a good base color for the gold leaf.

In order to keep the face of the cast flat, I poured the resin in the mold, and then applied a smooth flat surface on top of it and then inverted the mold for the resin to cure.  After a day to setup, I pulled it from the mold and then applied the gold leaf to it.  Man, this is going great….

I used a water based size to apply the gold leaf.  I noticed some areas did not adhere as well to the resin, so reapplied these areas and moved on to seal it with acrylic.  During the application of the acrylic, more leaf detached from the resin.  So I again reapplied.  However, at this point, I did not have a nice smooth application of my gold leaf.  But It was giving me the sparkle I wanted so I accepted the result.

In the meantime, I thinly planed the door surface to get rid of the seal coat for application of the finish.  I then applied the finish as I did with the cabinet body.

Anybody pick up on my error?  Well, I cast the mold at one thickness and then planed the door down.  This resulted in my cats being deeper than desired.  Uggghh.  Well, I could correct that.  After all resin is easily machinable right?  I get the bright idea to shave a bit off the back of the resin cast using my planer. BAD IDEA!  The planer picked up the cats and destroyed it.  Oh well, I wasn’t really happy with the gold leaf anyway.

So, I recast the resin in the mold.  This time not filling it completely to allow for the less depth now in the door.  Applied the gold leaf and moved on to set it in the door.  Despite these best efforts, the cast would still not sit flush with the face of the door.  Also, while tapping in the resin into the recess, I marred the gold leaf in several locations.  Again… UGGGGHHHH!

Since I was so smart in my thinner casting and was sure it would work, I had one shot at this and glued in the cast as I was inserting it.  Did I just ruin another door?!?!  I eventually came back to the realization of what I should have done in the first place.  sand it smooth and apply the gold leaf directly to the door!

So I had to take off the finish applied to the face of the door and get the resin level with the wood.  In some locations, the casted resin was so thin due to my brilliant plan of thinning the casting, that it left holes in the surface.  I then had to keep applying resin to these areas and more would appear after I sanded each patch.  Ultimately, I realized I needed to just pry out the cast as best I could and just apply new resin into the door.

Finally I had a smooth surface for the gold leaf.  It was ugly at this point, but smooth.  I then applied frisket film to the door and carefully cut out the portions needed at the resin so that I could mask off the portions of the door not intended to receive the gold leaf.

After my lessons with the water-ased size not working well with the resin, I turned to an oil-based size for this application in hopes that it would better adhere to the resin.  I ended up going with One Shot Fast Dry Gold Size.  

Now for what seems like lesson #324.  I decided that I would apply the gold leaf prior to removing the frisket.  My thinking was it would make it easier to apply the acrylic seal coat, since my test of applying the tung oil finish to the raw gold leaf would dissolve it.  So, I applied the leaf and then the seal coat.

However, when I started to remove the frisket, it also took up large portions of the gold leaf with it leaving a very patchy end result.  I should have just bit the bullet and removed the mask after applying the size adhesive.

So at this point, I had to get out my magnifying goggles (since I can no longer see!) and meticulously paint on size to the areas needing leaf while being careful not to apply it to the wood I want to leave exposed.  After several passes of size and leaf to get all voids filled, I then used the same process to paint o the acrylic seal coat only on the leaf, since i wanted the tung oil finish for the wood.

I noticed at this point that I was starting to develop some roughness to the gold leaf, which is not what I originally wanted.  I wanted it smooth.  However, at this point, it was very close to the look I desired, so I am content with the appearance.  Finally, I applied 4 coats of Murdoch’s Hard Sealer to the door.

After letting the door cure for a day, I then attached it to the cabinet and stepped back to admire the koa wood and, by far, the best transparent finish I have been able to achieve for a wood project to date.  After the finish has cured for 30 days or so, I will rub-out the finish with steel wool and wax for that final, smooth, matte finish (note, the cabinet body has already had this step done).

Took some missteps along the way, and while not perfect, I am very happy with the final pineapple inlay.  

I also learned through this build that despite my love for its looks, I am apparently allergic to koa.  If I did not take precautions and where a full-on respirator instead of simple dust mask when doing even the lightest sanding of the koa, I would not be able to breath that following night.  But it was so worth it! Come on now, has a toilet paper holder ever looked so good…. 😉