Chemistry Experiments

I remember Mr. Hanson didn’t think much of my skills in Chem class and I’ve not improved much probably.

I can’t use a traditional stain, pigment (i.e. Minwax) or dye stain on this project due to all the inlay.  It would color the lighter woods and they would no longer contrast like they do now.  So the options are to do no coloring or use a chemical reaction stain.  I’ve run tests with just a protective coating of shellac and also with a wash of Potassium Dichromate.  Here’s a few notes on what I learned.

Potassium Dichromate in solution with water will darken Mahogany and other tannin containing woods.  It’s poisonous so some caution (i.e. gloves and ventilation) are required.  In theory it will not color woods like holly that contain little or no tannin – the reason they are white.  Well this is all well and good except that one of the bandings I made has a fair amount of maple or similar light wood that does react to K2Cr2O7 and turns sort of green brown.  Look at the pictures below and you can see most of the bandings turned muddy and just plain ugly.  Even diluting the solution further didn’t work.

DSC_0186So that was a failure.  So my first reaction was to just try a shellac finish and I did some tests.  I purchased two types of buttonlac: Kusmi #1 and Bysakhi from www.shellacfinishes.com (they also have the recipe for the solution above).  Sadly I’m not seeing a lot of difference between them, though the Bysakhi is supposed to be darker.  I like the color but I thought it would be a little darker.  The Kusmi #1 looks close to blonde to me in solution and pretty clear in use.  I mixed these initially to 2lb cut with 190 Proof grain alcohol, filtered and then reduced down to 1lb cut.  I followed directions from Don Williams and found pretty good success.  Three sessions brushing on the 1lb cut shellac with an artist’s Taklon brush, with a light sanding after the first, and then a high quality 0000 steel wool (I used Liberon) before the final coat of shellac.  Each coat of shellac really becomes three layer or until it becomes tacky while working it (so 3 x 3) .  I applied a coat of Johnson’s Paste Wax with a 0000 pad but the pores were not very full of finish and a little more open than I wanted.  So next I applied some beeswax with the now popular “polissior” and rubbed it out.  It looks good and feels fantastic.  I did learn that I need to make sure none of the hide glue remains on the clock case before I start; I wasn’t as careful with the samples.  See the two columns of samples on the right:

DSC_0187

Back to the K2Cr2O7 though.  I have some slightly different tones in the mahogany wood used for the project: just a fact of life.  So I really wanted to see if I couldn’t do something to sort of even out the brown tone.  I realized I just needed to protect the banding with some shellac before applying the K2Cr2O7: it stops the solution from reaching the wood and thus the lighter colors are preserved.  See the columns on the left.  One more example below, from left to right, no shellac before coloring and then two kinds of light shellac – I think it makes no difference.

DSC_0188Finally a shout out to Greg Gayle who supplied me with several pounds of real-deal beeswax.  It works well as a final step, slightly filling in the pores and making a fantastic surface that feels just wonderful.  It makes you want to touch the wood.

DSC_0185On the right is the unrefined stuff he gave me, complete with all kinds of foreign objects, the little piece on the lower left is a small fairly clean piece I had been experimenting with and then the tub is my first try at refining (filtering) beeswax.  Not too hard to do: use a double boiler because liquid beeswax is apparently flammable.

I’m glad I did these tests.  I feel much more confident.  I still don’t love finishing and I know I have a lot to do, but I don’t worry it will be a disaster.  Now I should “knock wood”.

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One Response to Chemistry Experiments

  1. Lynn Collins says:

    Mr. Hanson did not think much of my chem skills either. After 15 minutes in his class I had a hard time keeping myself “on track.” Not his fault: I just couldn’t stand the subject.

    FYI From what I’ve red about old items (rifles from about 1700 on) it is the oxidation of the vinishes that darkens them. So, what will your stuff be like in 100 years? Also, there are some video on youtube about Holland & Holland. The Old (1725) high class Englash firearms making company. They mentioned useing a chammy to reduce their finishes between coates to fill the pours. They finish with what the man called “slickem,” he did not state the formula, but indicated it contained wax: I think beeswax. I would imagine they use something like old fashioned turpintine as weel as alcohol.

    FYI The package store at the O Club at SJAFB used to carry Everclear PGA. It made wicked punch….

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