Stains and Dyes

  • As a cabinet maker, I have always found finishing difficult. It has been said that if cabinet makers were any good at finishing, the trade of French polisher would not exist.

    Over the years, I have stumbled across a handful of simple methods which work for me, and I stick to them. Up until now, I have only been concerned with tinting and polishing hardwoods, such as oak, walnut and mahogany.

    The Sextus kit which I have just acquired is the first time I have been faced with the challenge of transforming the appearance of the plywood frame and pendula into what is conventionally accepted as “show” wood. There are good technical reasons for the interacting parts being made of plywood, so leaving these unfinished does not worry me.

    Plywood is notoriously difficult to colour well, because the density of the grain varies enormously over its surface. And then there are the end grain “stripes” to contend with. Most of the proprietary wood colours are “stains”, which are just ground up pigments suspended in a liquid. The grain characteristics of plywood mean that the particles of pigment lodge in the rough grain and give a blotchy appearance.

    Unlike stains, dyes are “liquid colour”, and tend to colour the wood fibres more evenly.
    George is an expert in the dyeing of textiles, and, from the help he has given me, I am confident that he has the knowledge to overcome this problem of uneven staining of plywood.

    I am still on a steep learning curve, and maybe the final solution will involve combinations of dyes and stains. I will be very interested to see how this discussion develops.
  • Hi all

    Not an expert in dying wood here but know a few things about textiles that may be applicable and with Pauls help may overcome some problems.
    The obvious one is uneven staining but due to the nature of the beast wood grain is always hungry for dye or stain, Want to try and put this in layman term and i sometimes use an analogy myself in my head to suss out a problem.
    Imagine you cut a short piece of dowel and that represents an arena where the rolling stones are playing. We have several large doors (grain) that the fans (dyes) are trying to get in, several small ones and a stone wall around. To get even displacement we put bouncers on the big doors (levelling agent) this chucks them out only to run around and find another door. Eventually we get even distribution but this only works with heat in the dyebath .
    My next thought was to use a gel such as gelatin with dyes encased.
    That would be like tying all the fans together so only the front people would get access and stick to bouncers doors and wall at a one person depth.
    Will do some research over Christmas and let you know findings.


    Hope that helps



  • As a very amateur woodworker, I would offer some possibilities:

    One is to use shellac; it is very easy, if tedious to apply, and its other shortcomings (poor water and alcohol resistance), do not seem to apply to clocks. The color of shellac varies from nearly a nearly transparent blond, to a deep garnet; combinations of those two extremes would do well to contrast different parts of the clock. The application process is tedious in that for best results, you need to apply many coats, and sand in between (the extreme of this method is actually the French Polish). A final coat of buffed wax would deepen the finish. Plywood can actually show nettoyance (a shiny, shimmering effect under varying lights) with this finish.

    Another possibility is to seal the wood. A a thin 'cut' (mixture) of it can be used as a pore sealer, which will help the plywood absorb stain more uniformly. A mixture of carpenter's glue and water (called 'sizing', I seem to recall) serves the same purpose.

    Lastly, one interesting option is the process called ebonizing. Tannins can be found to varying degrees in different woods. This is the same substance that makes red wine red, and brackish ponds black. Tannic acid reacts with rust to form a black compound, so the application of, say, steel wool diluted in vinegar, to a high-tannin wood (like oak) results in a blackening effect of the fibers. You can cheat, of course, and actually apply tannic acid onto the wood before hand. Similar chemistry applies to the process of fuming, made popular during the heyday of the Arts and Crafts design period.

    A small tangent, while on the topic: the opposite effect (removing tannins to bleach the wood) can be achieved with muriatic acid (in particular with poplar, which has a nasty green tint to it.

    One final comment on finishing. The key to a great finish is (and I apologize for the stock phrase) to finish the finish. For shellac, it is a final sanding and wax application. For varnishes, lacquers and oils, it is the application of pumice, rotten stone... even a rub with #0000 steel wool is the difference between 'Hey, you know how to use a paintbrush', to 'Wow!'.
  • I've used Aniline dyes before on other wood projects with success. Always good to experiment on a piece of scrap to check desired colour etc

    i.e. http://www.leevalley.com/en/wood/page.aspx?p=20081&cat=1,190,42942

    I plan to use it (an ebony colour) on the face ring of my Sextus & Nonus. They are water based so if you plan to use a water based finish over it you have to seal it first or the finish when applied will tend to "reactivate" the dye. Oil based finish can be applied over it as is.
  • Worried about the finish in the gear teeth, just finish the wood before you cut the gears. I'm 78 have tremors real bad but was able to cut everything out and the
    Clock runs and keeps time.

    Al
  • Hi,
    I built a clock kit from another vendor . I wanted to color some of the wheels and parts black.While looking around the local big box lumber dealer I noticed some contractor size black magic markers. I used those to color the wood and it worked really well .The markers produced a good black color. Some of the parts I shellacked before I colored , some afterwards and some during the process. For a final finish I spray varnished the parts.