Shellac Or Not To Shellac

[crash6882]

I am limited on time to get enough coats of finish on my current build. Polly has to dry for at least 24hrs and this will only allow me to put two coats on. My question is if I can use SHALLAC. I know that it will be a softer finish, but the way that I am looking at it is all the old guitars had it ( polyurethane wasn't invented then). Has anyone ever used Shallac, and if so how did it look?????????

[godzilla]

Hi crash6882, I don't really have an answer to your question but would like to tell you that on my first build I used six cans of Minwax spray poly and ended up with 18 coats in one day waiting 30 minutes between coats. These were light coats, and the end result turned out pretty nice I think.

The finish is prolly the very last place I would want to rush things IMHO.

Steve

[erikbojerik]

+1 on patience

The quality of the finish is directly related to the amount of time you spend on it.

Sooooo many guys finish the woodworking and think "It's almost done!"....when in reality, it's about half-done in terms of the amount of time you'll spend on the proj.

[avengers63]

To answer the question, yes shellac will put an acceptable finish on wood. It won't be as durable as others, but it would be servicable. Also, it's likely to have a slight yellowing effect on the wood. This will really only be noticable on the lighter woods, though. If you go with shellac, get flakes & denatured alcohol & mis your own because shellac has a relatively short shelf life, which the pre-made cans are likely to have past.

God bless Bob Flexner. If you don't know who he is, then you're probably in DIRE need of his book. Seek it out before you do anything to the wood. You'll thank yourself later.

[fryovanni]

I use Shellac often (French polish). It is not a fast way to finish a guitar, but it is a wonderful finish in my opinion. It is not as durable os some of the more modern finishes, but as mentioned it is servicable and has a very long history of success. If applied properly it offeres great protection, and is a nice thin finish.

Speed in finishing vs quality. With the proper equipment, finish(type), and application schedule a finish can be applied pretty quickly. There are people who offer these services and have their system dialed in to be able to achieve good results. You can't achieve that kind of speed without having your system dialed though. If you want that speed outsource it.

If you finish the guitar yourself. The first thing you NEED to do is focus on flawless prep and fill. A major mistake many people make is thinking that they will fix or fill a finish during clear coat stages. That will take MUCH longer, and often will lead to complications and a poor final product.

When I prep for shellac. I usually will use Z-poxy (this is an epoxy finish, not glue) to grain fill and give me my base surface to apply shellac. When I surface the fill I am looking for 100% even surface(all pores are filled and a very thin level coat of Zpoxy covers the instrument. This type of epoxy fill is slow setting 12-24 hour (not as some glues that set in very short periods), which is required for a thin self leveling coat (by thin I mean less than a teaspoon of Zpoxy will fill an entire acoustic body). I will usually level and remove scratches up to 400-600 grit (carefully going through each grit to clear scratches). Then I start the french polishing process. A light wash coat, then a weeks worth of building sessions(building sessions add micro thin layers of shellac applied with very high pressure). If leveling is required, I use 600 grit, then apply more body sessions if needed(all depends on how poorly I apply the body coats). When it is looking good I move to glazing(very thin smoothing layer with a light cut of shellac). At that point I move to final level and polish/ buffing. At that point 1200 grit is agressive, and I try to start at 2000+ and work up to 12000. I wouldn't count on less than two weeks to apply this type of finish, if your grain fill and prep is poor you will spend much longer (shellac itself makes a poor filler, if you are going to use it as a fill instead of using Zpoxy, you will need to use a process called pumicing which involves little shellac and a lot of polishing/sanding to develop an even fill).

Look over Milburns tutorial on French Polishing- Tutorial . This is a great explanation of the process.

There are many features that are nice about FP (Low cost to set up, forgiving, repairable, you can use all food grade materials *using Everclear, Shellac, and Olive oil), but it is not a "fast" finish.

Peace,Rich

[Woodenspoke]

Straight shellac for the most part is not a durable finish. Dries quickly due to the Alcohol base. You can buy it dark and or clear or in colors in between, dry or premixed. I have even seen water based versions. I have had good results with most of these shellacs. French polish is not a straight shellac finish so I don't think it answers your question.

It's not always how fast you can build up a finish but how durable a finish is. Yes its easily repaired easy damaged and for most instruments unsuited for the task. As a between coat seperating different finishes it has no equal. I don't hate shellac and have used it on period furniture in which my family made quick work of destroying as well as base coats on guitars.

Maybe a wipe on poly with some added japan drier would be a better alternative to the quick finish you seek.

Edited April 13, 2008 by Woodenspoke

[fryovanni]

Straight shellac for the most part is not a durable finish. Dries quickly due to the Alcohol base. You can buy it dark and or clear or in colors in between, dry or premixed. I have even seen water based versions. I have had good results with most of these shellacs. French polish is not a straight shellac finish so I don't think it answers your question.

It's not always how fast you can build up a finish but how durable a finish is. Yes its easily repaired easy damaged and for most instruments unsuited for the task. As a between coat seperating different finishes it has no equal. I don't hate shellac and have used it on period furniture in which my family made quick work of destroying as well as base coats on guitars.

Maybe a wipe on poly with some added japan drier would be a better alternative to the quick finish you seek.

To be sure I am understanding, French Polish is a process that uses a tiny bit of oil to help in the application(although this does not remain as part of the finish). French Polishing requires shellac flakes disolved in alcohol. It is a hand applied finish, and not a sprayed finish so it may not be the direction he wanted to go(I assume that is why you say it is not answering your question).

As an instrument finish, Shellac has proven itself for centuries. Modern two part finishes are pretty amazing though. You can't beat them for clarity, speed, UV protection, and durability, and applied well are a very thin/light finish (I wouldn't hesitate to have one of my projects shot, but I am not set up to shoot it myself).

[Woodenspoke]

I am just going by the original post. I have no issues with French polish or the finished result. If you treat your instrument with respect it is certainly a winner. I made no comments to your French polish post nor did my description of what form shellac can be bought in make any reference to your post?

Given the question using straight Shellac and the unknown application of the finish to some unknown instrument, I still recommend a wipe on poly and Japan drier to speed up the process.

In either case it takes time to put on any finish in a home shop environment.