How do I maintain the natural color - Mahogany

Most clear finishes will eventually get a little darker as they age. The only thing I can think of is the water based finishes like Emtech or Crystalac. They go on clear and wont darken over time.

https://thecrystalacstore.com/collections/all?page=2&sca_ref=47054.Mb3CZXZ6Od

https://www.targetcoatings.com/shop/water-based-lacquers/

 

The wood darkens because the finish soaks into the pores quite a distance; mahogany--especially softer varieties--is like a sponge.

One way would be to sand it smooth to 300, vacuum it well, and then spray very light coats of shellac from about 14" to 16" away.

This gives the alcohol a chance to gas off a little before it lands on the wood; the shellac will be thicker when it lands and won't penetrate it as far as it usually does. Use light mist coats, with at least 30 minutes dry time between. You don't want a flood coat with the finish shiny on the wood; it should be very light, with a matte appearance. Once you get 15 or 20 coats on, then you can apply your clear of choice, level sand, etc.

 

You could always ...



...leave it bare.

 

The waterborne poly finishes go on clear and stay clear but I still think the wood will darken under the finish, I know that cherry certainly does.

 

*it's going to darken with any finish that gets the wood wet. Dampen it with some mineral spirits, what you see is the lightest it will be with finish.

*water white vinyl sealer will give you the least tinting. As mfguitar mentions waterborne poly does not yellow with age like nitro. Mahogany is going to darken with age if exposed to the light, but we're talking years.

*mahogany has a very open pore structure, I'd consider zpoxy to fill the pores before finishing.

 

You are correct that almost any wood will darken as you apply finish, I don't know of any clear finish that won't do this. You can get a pretty good idea of how much the color is going to change by wiping the bare wood with naphtha - that's the color you can expect. You can, of course, darken or change the color by using either dyes in the finish or stains on the wood - I frequently stain mahogany to match rosewood. Remember that mahogany is a porous wood and needs to be pore filled - that can affect the color also.

Here are three examples of mahogany guitars. I'll try to show a picture of the bare wood, pore filled and then one finished. This was pore filled with paste (from StewMac, they no longer sell it) and finished in lacquer. In the first picture the spruce top is laying on the mahogany back, second is the pore fill and third is the back. The final finish on this guitar is a waterborn lacquer called KTM-9. It is no longer available, I would expect Target waterborn to be similar







I have stopped using the paste pore filler and switched to a finishing resin called Zpoxy. It adds a very slight amber tint, does a great job of filling pores and enhances grain better than anything else I've tried

This is mahogany with zpoxy pore fill and nitrocellulose lacquer







And my latest creation, mahogany with zpoxy and nitro








That's pretty much what you can expect out of mahogany. The cardinal rule, of course, is to practice on scraps of YOUR wood with YOUR products.