Glossy Finish for Purpleheart
A musical instrument maker gets advice on pore-filling glossy finishes that impede UV and oxidation color changes in exotic hardwoods. July 3, 2008
Question
What should I use to get a glass like finish on purple heart and other exotic woods? What should I use to fill in the grain? I need it to be clear, and I don't want to change the color of the wood.
Forum Responses
(Finishing Forum)
From contributor C:
What type of cabinets/furniture/other is it you’re looking to produce this finish on? What type of durability are you looking for? Are there any cost issues involved in the choices? Is ease of use/time issues/ or amount of steps an issue at all? Is it sprayable or hand applied? Is super clarity your main concern with the finished products?
From the original questioner:
I am finishing drums (the instrument). The finish needs to be durable and as clear as possible - high gloss. Time is not too much of an issue. I would like something sprayable, unless there is something better by hand application. Another problem is with purple heart you must use a uv protection or the wood turns brown.
From contributor C:
Are you familiar with using 2 component urethanes and polyester or not? Either one will work either by itself or in conjunction with the barrier coat being the urethane and the polyester the build coats. This is mainly used for high end high gloss finishing and usually a final coat(s) are done with urethane for easier polishing. You see this finish on guitars, yachts, pianos, and other.
As for the oxidation issues of the purple heart - you can apply HALS (hindered amine light stabilizers) to the bare wood which will greatly help the oxidation of the purple chromaphores naturally found in fresh worked purple heart or other exotics. You can also mix dyes with it to closely match the original color as we did at OSF and this will also greatly keep the color intact.
From the original questioner:
I have used a product called ICA Polyurethane, it has a base and topcoat both post catalyzed. I have never used polyester. What brands do you recommend? Where can I purchase HALS - is there a place online? I am in Kansas and it is really hard to find a finishing rep. here that knows what he is doing.
From contributor C:
ICA should be able to give you the info on the hals - if they use them at all. I believe they do. Their products may work but I’m not familiar with them.
From contributor W:
Gragg's Paint in Kansas City sells the ICA urethanes and also may be able to get you the Hals. I would go with a automotive Acrylic Urethane from PPG or Dupont as they have some UV protection built in and you can also buy a separate UV additive for more. It builds really well and can be easily touched up and buffed out later on if it gets damaged. Most high end personal aircraft companies have great success with this product on their wood interiors.
