Ok, here is the recipe I use for making a casein/oil emulsion (You will have to increase the amount for a cello.):

Water phase:

Oil phase:

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxx

Using the casein/oil emulsion recipe on a viola:


On the bare wood, I applied dilute Venice Turpentine (horse linament, which is probably pine rosin with some mineral oil). This VT was very dilute in pure gum turpentine. UV for some hours. (Sorry to be so vague.) I doubled the above casein/oil recipe for the viola.  Maple of the viola had been exposed to intermittant sun over the course of more than two years. The sides colored much more than the back.

First coat of the emulsion/oil, using ACE Spar varnish, -- apply mineral spirits, then casein/oil emulsion. I use a sponge. Expose to UV for more than 12 hours. Then high rubble was scraped off. Second coat of emulsion applied, no mineral spirit this time. Another 12 hours of UV. Sanded with #600 paper. Now Conservation Support Systems Orasol Yellow 3R, which I believe is the same as Kremer's 94402 Yellow 2GLN sun gold,  in denatured alcohol applied using a small section of paper towel or small sponge. Allow to dry. Next, thickened ACE Spar Varnish applied with finger. Result is very nice look, though obviously it is yellow slightly brown, and needs some combination of red/brown over it.


Notes on making casein only ground:


January 5, 2014

William Johnston rosin + sugar sealer color. Plus casein ground.

As per William's website, place 1 tablespoon rosin and 1 tablespoon sugar in a can. Heat slowly on hotplate (outside). At some point the mix bubbles, foams up and turns black. Remove from heat and cool. Add denatured alcohol, or alcohol. This solution, applied to maple, gives a bit of color and enhances the figure. Apply the above solution to maple. Perhaps 2 coats. (This is the sealer)

Next, take 1 teaspoon JO-3 casein, add enough water to cover the casein. Wait 1 hour. Add a little more water. Stir for 1 minute. Add 1/4 tsp. Mrs. Wages pickling lime. Stir for 3 minutes. Perhaps add another 1/4 tsp lime. Stir. Add 1 tsp slaked plaster. Stir. Apply, by rubbing, to the maple which has been primed (sealed) with the rosin_sugar sealer. Add dry slaked plaster directly to the wet casein/plaster. Rub more. Burnish into the wood with some sort of burnisher. (your call).

Remove excess. Allow to dry.

Rub with 400 grit paper. Apply some gold alcohol based dye stain, Transtint honey amber, available at fine woodworking stores. Or the yellow stain of your choice. At this point, the maple is very smooth and filled. Almost could be used as a final finish. Joe Robson's amber varnish, which, to me, is yellow brown, rubbed on, looks great. But I would want to add some red over this brown. My taste only.

So far, my result looks good.