Finishing and Refinishing

[Bill on Bainbridge Island]

I'm in the process of finishing a toy chest made from beech and the finish is a glaze over tinted shellac.  The glaze is made up of 50% boiled linseed oil, 50% satin gel varnish and a dash of color using artists oil paste.  The glaze is taking forever to dry (4 days and counting).  It's gone from wet, to sticky, to dry to the touch over 4-5 days.  My question is for an additional coat(s) of glaze, can I use Japan drier in my glaze mix and how much should I use?  I have about 1 cup of glaze left over to use.  Your help is appreciated.

Bill

[Steve Mickley]

Bill;

...and one that will never properly cure.  My first suggestion is that you remove this finish as quickly as possible.  The most effective way may be to scrape off as much as possible, perhaps with the aid of plenty of mineral spirits.  Both BLO and gel varnish already contain sufficient metallic drier to fully cure when properly applied.  The problem is that BLO is not intended to be mixed with varnish and applied in this way.  The closest thing to your concoction is something called an oil/varnish blend in which more or less equal parts varnish, BLO, and thinner are combined.  The mixture is liberally applied, allowed to soak in for 15-minutes (more or less), and then wiped off and buffed "dry", leaving only a thin film on the surface of the wood.  But, an oil/varnish blend would only be applied to bare wood; it would not be applied over shellac or any other finish.  Applied as you apparently have the oil will overwhelm the ability of the drier to allow either the oil or the varnish to cure and you will be left with a soft, sticky mess.

A "glaze" is usually defined as a color coat applied between two coats of finish.  For example, a heavy bodied gel stain applied atop the shellac, manipulated to produce the desired color intensity, allowed to cure and then "sealed" with another coat of finish.  You may also have been successful by simply mixing a concentrated pigment such as Japan color with your varnish and applying it as a "toner"; but, the mixture you describe simply will not work.  Might you have misread an instruction..? 

Steve  

[Bill on Bainbridge Island]

Steve...Thanks for the response.  I got the recipe for the glaze from an article written by Jeff Jewitt in the March/April 2005 Fine Woodworking magazine.  He stated that making his own glaze was a good way to control your coloring instead of using store bought material.  His recommendation was to mix equal parts of BLO, an oil-based varnish, and artist's oil colors.  He used gel varnish because it makes the glaze thicker and less likely to run.  The glaze was applied over shellac as he prescribed.   As he did for his project, I applied a second coat of glaze over the first to get the correct color I wanted.  I am not sure following his instructions was the best procedure for my project based on your comments Steve.

[Steve Mickley · Accepted solution]

Bill;

...but, I strongly suspect that you have combined two "options" into a single homemade glaze.  Jewitt, in his book "Finishing" and in numerous articles talks about using BLO or varnish as the "binder" to hold the pigment in place in a glaze.  For example, "...oil-based (glazes) typically contain linseed oil or long-oil alkyd (varnish) as their binder..."  But there would, in my view, be no benefit (or improved result) by combining both.

Reading between the lines (perhaps inappropriately) I suspect there may be another factor involved in your problem.  You quote the FWW article as making the point that using gel varnish as the binder will make the glaze less likely to run.  That is true to a point; but, if the glaze is properly applied it is largely irrelevant.  First, glazes should not be applied (and left after manipulation) so heavily that they would run.  Second, as gel varnish is manipulated the gel properties will be lost and it will become more liquid.  While I have never tested the proposition it would be my guess that the simple act of thoroughly mixing the BLO with the gel varnish would significantly liquefy the end result, especially after the artist's color is fully incorporated.

I am all for "homebrew" when making your own will result in a better finish.  I also support the idea of using a neutral glaze base to which you add your own color.  But, the wide color range of commercially available gel stains provides the user with a host of properly formulate "glazes" that are easy to apply, and if manipulated into an appropriately thin coat will cure quickly. 

Finally, I overlooked the issue of Japan driers in my first reply.  Japan drier should be use infrequently and with great care, especially when added to products that already contain metallic drier.  Too much drier, and it takes very little to reach "too much", will result in a brittle finish that can quickly lead to cracking and crazing.

Steve