Official Luthiers Forum!

Hi Folks,

I have not been on the OLF a lot of the past couple of years (But have never stopped building, just cutting down on social media). I have been searching for the best finish for a small shop, one where I do not need a spray booth, and can work in my small shop. I build both Acoustic guitars and electric guitars. Looking for safe, but - if possible - durable finishes. Following is what I have tried:

- French Polish: I enjoy French polish for acoustic guitars, and completely did my first few guitars that way, and since do all the tops via French Polish
- Royal Lac: I tried Royal lac on my last acoustic guitar that I am finishing up now, and found it easy to apply, and like the results. Will try more, but not on electric guitars... or should I?
- Tru Oil: I have used Tru oil for both acoustic and electric, and have my process down to where I get a really nice finish, and can buff glossy as well. Issue is durability (although, as a player, tru oil is by far my fav finish for necks - its just very comfortable)
- Rattle Can Lacquer: I have gotten some good results from rattle cans, but I have to do this outside, and living in Florida, the chances of getting 4 or 5 days in a row with acceptable humidity are slim. I have several electric guitars that came out nice, but it just isn't a good option for me where I live

For pore fills, I have used Z-poxy with good results, and Acqua coat with good results. My last guitar I tried LMI water based mahogany fill with good results too. For electric guitars where I am hand dying maple etc, I am dying, pore fill, vinyl sealer to seal colors, shellac then finish. I should mention I am a fan of shellac for sealing everything (I always have fresh 1 and 2 lb cuts made).

Curious about Crystal Lac? Any other products? I like to pad finish on if possible, I don't spray. But open to try something new (as long as it doesn't require a spray booth).

Thanks folks!

Glenn

GF Endurovar is durable (I have about 12 done in EV) , can be brushed, and may work padding (they say you can use a pad applicator) but I've no experience, dries very quickly before re-coat, easily sanded dry.
GF advises against shellac under it, but I've had no problems at all with fresh mixed shellac flakes (they used Zinsser shellac for trials).
I've normally use epoxy pore fill, but I've heard it does well over Acqua coat too.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I have done a few in Royal Lac now and I do believe I am beginning to like it. I'm interested in what others here have to say about small shop finishes too. I have not tried water base in probably ten years now but I never could get it right. My understanding is that they are better now. Regular old button shellac has been my go to for years now. But it is a delicate finish.

I have used oil based polyurethane thinned with mineral spirits and wiped it on.
Wipe it on with long strokes and let it self level.
Results are similar to tru oil but with a hard finish.
I do not like the feel of it on the back of the neck, but sanding with 1000 grit paper worked well.
The wipe-on finish in a can is too thick and hard to work with.
I did not fill the grain on this guitar.
I use poly on all light colored fretboards and it holds up well.

_________________
wah
Wah-wah-wah-wah
Wah

A fellow searcher here, Glenn. I actually went to the trouble of building a decent spray booth for my home shop, but I can't really use it in the dead of winter (the make-up air is too cold), so having a way to hand apply finishes is pretty important to me, too. There are two things not on your list that I think would be worth your while to investigate:

1. As Colin mentions, Enduro Var from General Finishes. It is a really good waterborne finish, and you can just brush it on with a foam brush. There's a lot of level sanding that way. Maybe padding is a better application process to avoid all the sanding, but I have not tried that yet. Enduro Var over System Three Silver Tip epoxy as a pore filler/first coat of finish gave one of my recent guitars a great looking finish, and it is very durable.

2. Although you mention Royal Lac, you didn't mention Royal Lac Post Catalyzed. Vijay (the maker) has formulated it so that it can be both sprayed and padded. There are some videos on YouTube from Prana Custom Guitars, who finish electric guitars, where they sing the praises of RL Post Cat. If the durability of a finish impresses somebody who finishes electric guitars, I'm impressed. I'm about to apply my first RL Post Cat finish in a week or so (I'm applying seal coats right now), and I will be padding it on.

Good luck with the search!

Ken Parker demonstrates TruOil over epoxy, all wiped on. I like a glossier shine than I could get with his technique, but it was definitely the least effort for the most pro result. I assume since it’s an epoxy finish at heart that it will be durable as well.


Sent from my iPhone using Tapatalk Pro

Don,

Do you have any specific links to Prana's use of RoyalLac?

Some good suggestions! Thanks!. rirhett, actually, I get a pretty darn good finish with Tru oil, but looking for something more durable. Attached is my current OM guitar I am building - used tru oil on B&S, and Royal Lac on top.



Glenn

If I could get a finish that looked like that with Tru-Oil I don't think I would bother using anything else!

Don what does the post cat do to the regular Royal Lac? Does it make it harder or something?

JF--

Here are links to the Prana videos that talk about Royal Lac Post Cat:

https://www.youtube.com/watch?v=R98JsXK6rMo

https://www.youtube.com/watch?v=OhdLVEH4CD8&t=601s

https://www.youtube.com/watch?v=QeTLOy2A4CA&t=963s

https://www.youtube.com/watch?v=AN-145JJ2b8

https://www.youtube.com/watch?v=WQIKTO0khAU&t=1494s

I think there are more, but those should give you an idea of how much they like the finish.

There is a durability difference between the original formula and the post catalyzed version. I asked Vijay Velji (the maker) about this. Here is his response:

"By the nature of Chemistry, Post Cat finishes are always more durable in terms of solvents and scratch resistivity. The added advantage is that it cures faster due to the catalyst that forces film forming as a faster rate."

So, it cures faster than the original formula, and it is more durable. You can spray it or pad it. I'm going to pad it and see how it goes on. Here is a link to some instructions that James Orr put together for both spraying and padding, using information that came either directly or indirectly from Vijay:

http://www.luthiersforum.com/forum/view ... +Royal+Lac

I hope this is helpful.

Thanks! To be honest, Tru oil on my guitars that have been played for a number of years now has held up pretty well. However, I am finding not so much on electric guitars. I was originally planning on using Royal Lac on my next acoustic guitar as well - maybe I'll try the post cat. But For electric guitars, I am really looking form something much more durable - again, maybe post cat royal lac will work? I'll likely stick to tru oil for the necks, as it feels really good and no sticking no matter how hot/humid it gets.

This is current Electric guitar with Tru Oil (Blue guitar) I am finishing up, and current with Rattle can lacquer (Flag).


I am happy with the end result of the rattle can, but it takes WAY too long for me to get the right days, etc. I won't be doing it again (this was my 4th rattle can experiment)

Glenn

That's Royal Lac with Tru-Oil on top, if I read it right. I'd be concerned about breaking the 'fat over lean' rule with that. Oil painters use 'lean' undercoats, with more solids and less oil, and increase the oil in successive coats. The idea is to avoid having a hard and brittle coating over a softer one. The hard coat can't move with the soft stuff under it, and ends up cracking.

Have you tried any oil-resin varnishes? There are a lot of them, and they vary, of course, but some can work very well as guitar finishes. They tend to be chemically much more stable than nitrocellulose lacquer, which breaks down over time. They are also much more solvent resistant then shellac, which, aside from dissolving in alcohol, also goes into alkaline water solutions, and seems to be attacked by some folks' sweat. They do present some challenges, of course; not least acquiring the skill of applying them evenly, and they can take some time to rub out to a good shine. On the plus side, some of the modern varnishes are almost as hard as nitro, and much tougher, being very difficult to scratch. Varnishes also tend to have a 'right' refractive index on wood, so that the light penetrates well and gives saturated color and depth.

I'm using one called 'Murdoch's Ure-alkyd 500' which is sold as a floor varnish. It's made in Vermont, using the waste from the Cabot cheese factory for the resin. I don't know what oil they use, but they use a citrus solvent for the thinner, so it's more pleasant to use. I can get a film .0025"-.0035" thick that polishes up to a nice shine, and it's very durable. Another good one, I'm told, is Pratt & Lambert $38, which is now sold by Sherwin-Williams, I believe.

A friend says that whenever there are a lot of ways of doing something, it's a sign that either everything works pretty well, or nothing does. There is no 'perfect' finish, that is reliable, easy to use, environmentally friendly, looks great, protects the wood from damage, light, and chemicals, doesn't hurt the sound, and is durable. All you can do is try to find one that has features you need, and drawbacks you can live with.

Here's one in BRW that I made a few years ago with the Murdoch varnish, just before it's final polish.

Hi Alan. For the OM Acoustic, it is Tru Oil on the back and sides, and Royal Lac on the spruce top - I do not put either on top of the other. I have never done a spruce top with tru oil, as I traditionally French polish the tops.

Glenn

Alan do you brush the varnish on?

Yes, would love to hear more bout how you apply, schedule, etc.

Thanks!

Glenn

Found this link on schedule for Murdoch's Ure-alkyd 500:

https://www.sutherlandwelles.com/how-to-finish-guitars-mandolins-and-ukuleles-with-murdochs-hard-sealer-hard-oil

^ Good stuff.

I french polished everything for years. I still love french polish as both a finish and a process--it's very pleasant in all regards. I did a couple of guitars french polishing pre cat Royal Lac. They came out very nice too--harder finish than regular shellac FP, but undoubtedly harder to repair whenever that becomes an issue. Of course, there's not a finish much easier to repair than FP.

Tru Oil is a great finish too--and I agree that there's not a better feeling neck than a Tru Oil finished neck. I can get a great gloss with it, and it's easy to repair. I haven't encountered the durability issues, but they would be easy to fix if/when they did come up. I have a friend who does all of his banjos with Tru Oil. Sprays it with cheap Harbor Freight jam guns, and throws them away when they finally get too gunked up to clean. His finishes are really nice, and the necks feel great.

My latest guitars have been HVLP sprayed Enduro Var, and I'm quite happy with the results. I'll probably stick with it. Again, the repair factor is a question in my mind, but I'm really happy with the results and it doesn't stink up the house.

Dave

Super helpful, particularly the video on buffing. They explain their process, which I'm going to re-watch and take notes on. Thank you!

We have mentioned this several times here in the past but TruOil over a Z-Poxy pore fill on a neck is bad news. They get fuzzy over time and at least in my experience nothing short of refinishing them will cure it.

Has anyone seen that with other brand epoxy pore fills?

_________________
It's not what you don't know that hurts you, it's what you do know that's wrong.

Terence, You might look at Ken Parker's finish, I believe he's using West System under True Oil. He states somewhere you need to wash the amine off the surface of the epoxy, which I believe, I haven't used epoxy for filler in longtime due to amine blush, bad stuff!. He has some really nice videos at his website under Archtoppery. There's something for everybody in those.

_________________
Jim Watts
http://jameswattsguitars.com

With Tru Oil on mahogany especially, but other porous woods too, I fill by putting on tru oil and sanding it with 400 grit while it's still wet. It forces a slurry of tru oil and sawdust down into the pores and after a couple of sessions like this, the pores are filled.

Dave

I have guitars that are 7 years old that have Tru Oil over z-Poxy with no issues. The one thing I do is Seal after z-poxy with Shellac. Then tru oil over the shellac - no issues whatsoever. And this is on a number of guitars. With that said, my my last number of guitars I used Aqua coat, shellac, then tru oil, and comes out pretty good as well.

Glenn

I'll second recommendations others have made for Aquacoat filler and General Finishes Endurovar. They are both easy to apply and hold up well. Of all the finishes that I am familiar with, these are the products I chose for inclusion in my book Building the Steel String Acoustic Guitar. A serious consideration for that though, had to do with the need to describe finish application in a book. The filler is applied with a rag, more or less in a manner described by Bob Gleason, rubbing it into the wood. The waterborne varnish is applied with a foam brush. Leveling the cured finish goes quickly.

_________________
R.M. Mottola
LiutaioMottola.com

Author of the books Building the Steel String Acoustic Guitar and Mottola's Cyclopedic Dictionary of Lutherie Terms.

When the weather is decent I use nitrocellulose, but during the winter months I am brushing Enduro Var. I will apply several coats during the day with a foam brush and reapply the finish when the previous coat is just dry to the touch. I think this helps avoid witness lines. I will let the finish dry overnight, scuff sand, and then apply the final coats, again only waiting until the previous coat is dry to the touch. Since I am doing this in the winter with low indoor humidity the finish dries quickly and all the coats can be applied in the space of a few hours.
Enduro Var does have what the company calls an amber cast, but I call it yellow as I find it less attractive. Their "High Performance" finish is supposed to be water white, so I may try that when I run out of Enduro Var.