Varnish schedules and tips

[Andrew McSpadden]

I want to move away from spraying my acoustics and using Varnish. I see that Pratt & Lambert #38 gets high praise and seems to be an accepted standard. Can it be put on with an applicator like Shellac or is brushing the way to go? Does anyone wish to share their varnish schedule? I want to start experiments soon.

Thanks!

[Michael Lewis]

Since you are starting from the ground floor with varnish I suggest you contact the manufacturer for directions and suggestions for their specific product. There will be helpful technical folks to answer any questions you may have and they will give you specific information of tell you where to find it. They want their products to work well and will go to some lengths to see that you get good results.

[Brad Heinzen]

I haven't used the P&L, but with other varnishes, I've found that brushes work well. There's a store near me that sells inexpensive white bristle brushes that I like. They're a big step up from the cheapie chip brushes, but they cost a lot less than the usual Purdys or Coronas. I can get away with storing and using the same brush for the first few coats, and then switch to a new one for the final coat.

When I use varnish, I seal and fill with shellac, and it's worked out just fine. I have noticed that some varnishes are more prone to showing witness lines than others, and that all of them can be susceptible to developing deep scratches during leveling and buffing. I usually make sure to apply full wet coats, wait until the finish is well cured for buffing, go with finer grits than I'd normally use, and take care that all abrasives are well-graded. Other than that, it's like anything else - there is a learning curve to it.

[Pat Foster]

I started using Behlen's Rockhard Tabletop Varnish about 5 years ago, mostly following Alan Carruth's schedule with good results. Behlen's varnish is now synthetic, so I'm also looking towards moving to P& L. I expect I'll start with the old schedule on scrap and see how that works.

I did get witness lines sometimes when sanding, but found they disappear with buffing after curing. I was able to greatly reduce their occurrence by using hard sanding blocks key areas for finish prep and finish leveling, then going to the hard foam block that's included in the MIcro-Mesh kit for final level sanding.

I was in the good-varnish-brush camp, using only Purdy or Corona until this year. On a lark, I tried foam brushes, not expecting a good outcome, but was pleasantly surprised. Foam from now on for me. As in all things lutherie, YMMV!

[Dale Gulick]

What color is the P&L? I use Behlen's Rockhard and get fine results (with Al's schedule), but for some guitars it is too amber even when the buildup is kept super thin.