What different types of finishes are there?

[White_Wolf]

Hello, this is my first time posting. I was once registered with the old forum, but never got around to posting. I love the new forum; SMF is the best free web forum software available :icon_thumright: I visit Warmoth practically every day and fantasize about building my dream guitar. In doing so, I've become very curious about the different D.I.Y. finishing options.

So far I have heard of Shellac, Nitrocellulose, Polyurethane, and Tru-Oil/Tung Oil.

I was wondering what other kinds of finishes exist for guitars, and what the pros and cons are for each of these different chemicals. Such things regarding their pros and cons that I want to know is:
1. Which ones form the most scratch resistant barrier?
2. Goes on the thinnest?
3. Creates the highest level of glossy shine?
4. Protects the wood?

And just any other kind of peculiarity, pro/con, you can think of.

 

[JK]

Welcome. I too would like to see a brief pros and cons for the various types of finishes. You can find it by reading a lot of pages and posts, but a quick summary would allow you to zero in on one or two ideas and then persue them first. There are a lot of experience brothers in the forum that could give us this info, please do.

 

[Alfang]

I'm reminded of Bubba telling Forrest how many ways there are to prepare shrimp :toothy10:

John

 

[Tonar8352]

Alfang is correct but I'll give it a shot at being short and as complete as possible.

Oil finish-: Tru-Oil, Tung-Oil and various others will probably be the easiest for the DIY'er since it does not require spraying.  You could build a nice sheen but it won't be that glassy deep look of lacquers or polys.  It will be able to put on really thin and will take additional coats as a maintence thing over time. Easy to repair.

Poly:  This would be a 2 component finish,  which means that it has a activator that causes it to dry.  If you put the activator in the paint and do not use it, eventually it will dry hard in the can.  We call that the "pot life", you have to spray it once it is mixed in a short period of time.  The advantage is it is extreamly hard, has great gloss and gloss retention, and can be put on smooth in a few coats.  In the vintage Fender world this is know as thick skin finish, the owner of the company I work for developed the product that Fender switched to in 1968.   Warmoth uses this type of finish very effectively. Not easy to repair.

Nitrocellulos Laquer: This is my preferance because of my love for vintage guitars.  The advantage is it remelts each coat so it becomes one film as it is put down.  It can be tinted, shaded, come in fully pigmented colors, mixed with powders for gold/pearls/blues/etc.  To me it is sonically better that Poly because it does not wrap the wood as tightly as the poly. It is not bullet proof as you can tell by looking a many old guitars, it cracks, checks, and wares through.  This is how the whole relic business started.  People wanted guitars to look like they were from 1954.  Lacquer is perfect for this.  It is easy to repair.

Shellac-  I use this as a sealer or barrier coat.  As a finish coat it is generally used as a French Polish.  French Polish is a technique that uses shellac with pumice and rottenstone to produce a high graded hand rubbed gloss finish.  This is considered by many to be the best finish for acoustic instruments such as classical guitars or F5 Mandolins.  It produces a very thin high gloss finish that is beautiful to look at and sonically the best.  It is very fragil and will not withstand alcohol.  It is fairly easy to repair.

Within each of these catagories there are several different terms you will hear.  Acrylic, Water Borne, Alaphetic Urthane , Pre-Caytlized, Conversiton Varnish, UV Cure Urethanes, etc. on and on..........  you know like fixing shrimp.  But the bottom line, what will you be able to work with and make work for you is the best.  One word of caution if it says brushing lacquer or brushing poly it will not produce the same results as the spray grade lacquers or 2 part poly's.  I know some have used them to their satisfaction but they are not the same.

I hope that helps

 

[rahimiiii]

Brushing is generally used for undercoats like polyester sealer or sanding sealer where spraying is difficult (very thick therefore requires a LOT of CFM or PSI). Since these are going to be sanded anyways its okay to brush it on. I think I am going to brush on some polyester resin on ash to fill the pore once and for all. Fender has used fullerplast which is basically polyester sealer in the vintage time by the way... they do this to seal wood so that it takes less paint to achieve a glass finish. I will brush it on kinda thin and sand it til there's not much left... the goal is to fill wood pore, not make a bulletproof barrier.

You can brush lacquer if you sand and buff it later and still get a glass shine, but it takes many coats and careful brushing technique, since lacquer melts into each other as more coats are built you are just pushing the coat below away like a bulldozer.

 

[Greg P]

Tonar's post should probably become a sticky or something.  It is everything summed nicely up in one post. 

 

[White_Wolf]

Within each of these catagories there are several different terms you will hear.  Acrylic, Water Borne, Alaphetic Urthane , Pre-Caytlized, Conversiton Varnish, UV Cure Urethanes, etc. on and on..........  you know like fixing shrimp.

mmmm, shrimp! :blob7:
Well now that I know the categories, and now subcategory names, I can look up terms like "Alaphetic Urthane" on Wikipedia.
I've read a few different pages on French polishing using Shellac. It's described as a very labor intensive and time consuming way to finish musical instruments.

Polyurethane sounds like what I'd most likely want to try. I plan on getting a Mockingbird style guitar in either Cobalt Blue or Prussian Blue, with chrome hardware. I want the finish to be really glossy, almost mirror-like.

Oh yeah, one more thing: About Nitrocellulose finishes, I hear a lot of warnings in regards to guitar stands that the foam padding will negatively affect Nitrocellulose finishes. I seem to read in several different places that Nitro tends to have a negative chemical reaction to many things. I was wondering if you found this to be true or whether its chemical delicacy is mainly just in regards to a specific type of foam?

 

[jackthehack]

Never seen any reaction with the foam padded stands they sell at Guitar Center/Musician's Friend.

 

[RLW]

Michael Dresdner is one guy who is worth checking out. He used to be the luthier at Guitar Trader in Red Bank NJ back in the 70's and 80's, and also wrote a column in their monthly newsletter/stocklist.

http://michaeldresdner.com/

He definitely knows a thing or two about finishing wood.

 

[rahimiiii]

Never seen any reaction with the foam padded stands they sell at Guitar Center/Musician's Friend.

I wrap old T shirt around all guitar stands, it is a cheap insurance against such damage...

 

[-CB-]

Even in those categories, man, I can think of things....

Starters... Tung Oil you buy, is often not Tung Oil at all, but polyurethane with "some" Tung added.  You can also get REAL tung oil that is pure (look up pure tung oil in google).  Problem there is it takes a long time to really dry hard, but once it does... gosh a great finish.  Dont expect major grain filling from it, but its very durable once dry.

Nitrocellulose lacquer.  Every brand is different.  You can get it in a more raw form, and with many sorts of additives... most of them are semi compatible with each other.  Additives include flatteners, flowout (retarders), UV inhibitors (most all of them have that now), fisheye preventers (another retarder chemical), anti blush (yet another retarder) and hardeners.  Seems that each company has its own idea of what a good finish should be.

I'm tending to prefer Deft lacquer these days, as the base coats ( with color ) can actually be brushed on, made even in color, and then clear coated with the same stuff in aerosol.  Its really tough when finished and dried.  All lacquer takes a few weeks to "really" set up (or a drying booth).