Official Luthiers Forum!

First build completed! Followed Cumpiano’s classical plans:

Sitka spruce top
Honduran mahogany back, sides, and neck
Amazon rosewood fretboard and bridge
Ziricote bindings and headplate
Truoil finish on back and sides, (attempted) French polish on top

Just a generalized thank you for all the expertise shared on the forum—it has been a great resource and I am very grateful! Excited to start working on #s 2 and 3!

And now some questions/requests for feedback if folks would oblige:

—There is so much involved in guitar building that I figure focusing on improving one aspect/challenging myself with one focus each build is a productive approach— what did you focus on in your early guitars that helped you grow as an instrument builder the most?

—finishing seems to be where I faced the most challenges. Given I am just a hobbyist, any recommendations on finishing resources to shorten the learning curve, especially for hand applied finishes?

--upon final sanding to prep for finish, the mahogany started showing this color variation. The variation seemed to reveal itself more as I progressed through the grits, and intensified when I raised the grain with distilled water. Any suggestions on methods for evening this out?

—below is a photo of the top after I played just a few hours, right where my arm lays—seems like I have the dreaded alkaline chemistry that eats French polish. I’m considering trying Royal Lac next; any cases of similar issues? Does the picture suggest something besides my alkaline hypothesis?

Congratulations on finishing your first!
Finishing is one of the more difficult parts of guitar building. If shellac reacts to your body chemistry you might want to try a waterborne finish. Most finishes have a learning curve, so doing some test panels during the time you are building your next guitar may allow you to work things out before needing to apply the finish to it.

Bravo!

The arm contact area looks quite nice for the moment I've never tried royal lac, but it does sound like a good option.

Regarding the back color, if passage of time was involved then it could just be oxidation and will even out over time. Did you use a colored pore filler? I used LMI micro-bead paste on my first guitar and had trouble with blotchy color. By the time I got it evened out, there were open pores and I had to start all over... I've used shellac/pumice since then, but I'm still not very good at it.

My "quick and easy" finish when I can't get proper FP to work (i.e. most of the time):
1. Scrape the surface smooth
2. Wipe on a couple fairly heavy coats of shellac
3. Lightly scrape the raised grain
4. Wipe on another coat
5. Sand with the 3 coarsest micromesh grits (rust/green/black)
6. Wipe on a final coat of dilute shellac in line with the grain.

It produces a high gloss, but slightly streaky. Aside from waiting an hour or two to fully dry before the micromesh, the whole process is maybe 10-20 minutes of work. And if it ever wears through, it takes seconds to wipe some more shellac over the bare spot and it's good as new.

For open pored woods, pumice filling takes the place of step 3, and that usually takes me several hours.

Nice one!

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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.

Nice work! I French polish with Royal Lac and I’m happy with it. Might be an alternative for you.

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Steve Smith
"Music is what feelings sound like"

Great work! How’s the sound?

As for the next one(s) will it also be a classical?


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Kyle, that came out really nice!

Blotchiness is a bigger problem with tinted varnishes; especially on spruce. I think that the tru-oil soaked in more in some spots than others. I haven't used it, but my feeling is that tru-oil is very thin. It will soak in. The belly needs sealing before varnish, but even hardwood needs some sealing. Shellac will work, and you already have it. It will raise up the grain too, and you can smooth it up if you like. But you have to keep sealing until it just barely still feels like wood.

That said, I think that products like tru-oil, and Osmo polyoil work good and are easy to use. Maybe they don't give the protection of other things, but they can be recoated after using a pad; like a real wood floor that is just waxed. Some of the scratches will go away too.

They are probably best if you don't really need the shiny bowling ball look.

As far as the crazed shellac? I have seen people playing guitars; maybe expensive ones, maybe not; with knitted "sleeves" on their right arm, so they don't touch the belly with their skin. Maybe the Royal Lac that Steve suggests is more resistant. I don't know.

The one thing to do is to find out what works for you. I do everything different because I don't know any better. But it works for me.

It is addictive, because you know that you can do better on the next one. I always do something very different, so there are always new things to learn.

Good luck.

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Why be normal?

Nice job and congrats on your first! What a great feeling it is to play your first.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

I have actually used Tru-Oil and it can make a great finish. If you build up sufficient coats it can create a deep finish with enough build to make a high gloss surface, if that is what you want. It is a lot more user friendly than french polish, and you could use it on the top of the guitar as well.

She looks great Kyle good going and congratulations my friend.

A finish that we don't talk about much, but that can make a nice looking durable finish, is wipe on polyurethane. Probably not a good choice for rosewoods and other oily woods, but suitable for most other woods when applied thinly. It's fairly inexpensive and readily available.

https://www.youtube.com/watch?v=PXbwCr9CNxE (Braxton lives on in internet immortality.)
https://www.youtube.com/watch?v=yTXfOsEadxI&t=0s

That's a great outcome for a first. How long after the last FP session did you notice the marking?

Royal Lac is a possible alternative to shellac if you want to keep doing FP. But it does cross link after a few months, so you lose some of the touchup capability of traditional FP, but it's more protective against water, alcohol and body chemistry.

Another vote for Tru-oil. Very easy, easy to touch up.

If you stick with shellac (pun not intended), you could up your game and end up with a first class finish on some later builds.

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formerly known around here as burbank
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http://www.patfosterguitars.com

Did you give the top finish enough time to harden properly? Being your first go it may be quite thick and this can take long time to harden.

Cheers Dave

why not?



Pat

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Pat

Hi Pat,
Polyurethanes often don't dry on oily woods. If you used a barrier coat of shellac you may get away with using them on stuff like cocobolo and BRW, but I would do "2 or 3 barrier coats" just to make sure the wood and poly don't touch.

Congratulations, Kyle! Every guitar feels exciting to finish, but the first is extra special.

Regarding your question about prioritizing or improving, I do an after action report after each instrument. I think about what went well, what didn’t, where I’d like to improve, be more efficient, etc. It’s really worked well for me.


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Wow thanks for the replies everyone!

I’m planning on making 2 steel strings next. I have sets of walnut and cherry, with some spruce from Alaskan specialty woods. I’m curious to see any tonal differences I can hear with 2 guitars made with 2 soundboards with different qualities. I figured it might be a fun and valuable thing to start recording what, if anything, I notice in evaluating component qualities. Any suggestions on what you measure and record as you build?

I’m very happy with the sound so far. The bass notes are much more powerful than my guitars and the B and E strings are much clearer. The one exception is the G, which sounds “rounder” than the other 2 trebles (if that makes sense). I know it can take a bit for a guitar to settle into its sound; how long do you normally give it before starting to evaluate the sound?

Thanks for the suggestions re: the arm. I think I’ll refinish and let cure. It would make sense that I applied too thick and didn’t let cure enough; I did let it rest 2 weeks from last polish before stringing up, but I’ll try to let it rest longer this time

Beyond a general improvement in craftsmanship, my specific goals/focus for #s 2 and 3 are better execution of the rosette (I’m building a router circle jig vs the popsicle stick method I used on #1) and improving the finish, so I really appreciate the suggested alternatives!

Clay (or others) any waterborne finish that you’ve found manageable for finishing novices?
Steve and Pat: I’ve watched a few videos from Royal Lac and Robbie O’Brien; do you have any thoughts on your process different from the manufacturers recommendations that have led to success?

Try Aquila Ambra. Best sounding G I've tried. I hate the usual fat nylon ones. I used to use Savarez 520F with a wound G, but it breaks all the time.

2 weeks should be more than enough for shellac to dry. Granted I'm used to using a very thin film, but it's dry enough to handle in minutes, and hard enough to sand after an hour or two.

Does it feel at all sticky after you've been playing for a while? The photo looks like you had some fairly coarse sanding scratches, but your arm rubbing against it softened the shellac and smushed it into them, creating a smooth surface. If it doesn't feel sticky, then give it more time before refinishing. Otherwise you'll never know if it really needed it...

As for what data to record, I mostly do weight and thickness of various parts. And a whole lot of photos, especially of the bracing from many different angles. And audio recordings of tap tones so I can compare spectral analysis in the future. One recording with the back spool clamped on, and one after gluing it. The mass of the clamps changes it dramatically, but by having the before-and-after of past guitars to compare to, you can make a better guess how it will turn out while you can still take the back off and do more brace carving.

Kyle thats a really nice looking first instrument. Check out Robbie Obriens French polishing class online. he also offers a virtual French polish class. Robbies French polish technique is really easy to learn.

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Hi Kyle,
Other people can probably give you better advice on waterborne finishes. The one I liked they quit making and I usually spray solvent based finishes.
Waterborne finishes usually dry slower and are less smelly, so being able to brush them in a home setting is an advantage they have over many solvent based finishes.

The two waterborne finishes I've used are EM6000 and Endurovar, both as brush-on finishes. I used EM6000 for about 8 years and then switched to Endurovar. You can get very good results with both of them as brush-on finishes. They can also be sprayed of course, but the only piece of equipment you need for brushing it on is a good brush. Both finishes are manageable for finish novices.

- You can get a high gloss finish with both.
- EM6000 repairs beautifully. I don't know about Endurovar yet.
- EM6000 requires adding a retarder so that the finish doesn't set up too fast while brushing it on. Endurovar doesn't need retarder for brushing.
- EM6000 sometimes can have a faint bluish cast on dark woods like Indian rosewood that's visible in reflections under just the right lighting conditions. Endurovar doesn't.
- EM6000 builds very slowly when brushing so it requires a lot of coats to get enough build to not sand through when leveling. Endurovar builds much faster so the total number of coats needed is much smaller.
- Endurovar seems to cure harder than EM6000.

A caveat to the above comments about Endurovar is that General Finishes reformulated Endurovar about two years ago. It's now called Endurovar II. I've been using up the original formulation that I have, so I haven't tried the new version yet.

I've used Z-poxy and System Three SilverTip epoxy as pore filler under these finishes.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

Plus one for photos. One forgets all too quickly just what happened on a build. And with digital photography there is no cost apart from time.

The other thing is to label your raw material. Starting out you just have a couple of sets of back and sides and tops, but as you move on it is surprising how much guitar wood you acquire. So write on it what it is (you really can’t tell which type of spruce it is) and where you bought it. You can imagine why I suggest this!

Good luck with the next builds.

Dave M

Hey well done:)


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