Official Luthiers Forum!

I'm just curious. They'll be musical instrument finish arguments as long as there's instruments. I think it would be interesting which finish, or finishes everyone uses, and why they use them.


My "normal" finish is nitrocellulose lacquer. I use it for a few reasons. The most important one is I know how to use it, and how to make it look great. I pore fill with CA and seal with shellac, reguardless of finish.
I tried KTM-9 and it didn't think it had the clarity I like.
I've done a couple guitars with EM6000 (I think 6000 is the number). I liked the look, but want to see them in a year or so before further consideration.
I'm doing a few varnish finished guitars with Epifanes gloss varnish. I experimented on scrap with several varnishes, including tru-oil and rockhard, but like the look, feel and application of the Epifanes best. ( I can spray it)

I have (and still am) considered Polyester. I spray my guitars in a automotive paint booth so I could safely spray it. I hate the wait between spraying and buffing with Nitro but I resist new knowledge. I'm not sure I want to learn another finish. I would also have to use a different sealer.

What do you use, and why?

_________________
I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

I may go against the grain & general consensus here but I prefer to use two pot Urethane unless a customer asks for Nitro. I have used Nitro and it does give a lovely deep gloss but there is the hardening period before polishing & I've found it is quite brittle and chips easily which I don't like. I use the Urethane and whilst the gloss isn't maybe quite up to the depth of Nitro, it takes a good polish & certainly hardens quicker after application plus is much much tougher to accidental corner knocks and general bangs during the guitar's life. Having said that the nitro is easier to repair as new paint melts in to previous coats that Urethane doesn't. And as long as the finish isn't applied too thick, I defy anybody to hear a sonic difference in the guitar without the use of some clever analysis gear.
The Urethane does use isocyanates in the hardener so requires good ventilation and masks although if you have access to a proper spray booth, it may have positive ventilation helmets? But then Nitro can bite you too!

_________________
Nick Oliver

http://www.oliver-guitars.com

Woody,

Is the Epifanes Gloss Varnish a spar varnish? I'm not very familiar with it but have read some folks really like it.

Thanks!

_________________
Formerly known as Adaboy.......

Stewmac's waterbased acrylic

My workshop is in a highschool so I have to be ultra careful about allergies, fire risk etc

_________________
My soundclick xx luthier blog xx luthier soundclick

It's a spar varnish but it dries quicker than most. I've been told it's what Collings uses on their "Varnish" guitars.
http://www.jamestowndistributors.com/userportal/show_product.do?pid=92&familyName=Epifanes+Gloss+Clear+Varnish

_________________
I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

I use violin oil varnish. I brush it on REAL thin and scuff sand with 400 grit between coats. It can take six weeks just to varnish. Then let the instrument dry in my drying booth for another month. One nice thing about violin varnish is that you can rub it out to whatever gloss you prefer. You can go from a matte to a mirror gloss. It is very time consuming, but the effort, in my opinion, is well worth it. I have never tried any other method.

The Epifanes varnish is getting some very favourable reviews on Mandolin Cafe, check out the current thread “Spirit vs. oil varnish”. I have some ready for testing… Woody B, I’d be interested in hearing more about how you are applying it and how you like your results!

So far I have mainly used nitro over various fillers, and its main asset is how easy it is to get a good looking result with. One drawback is long term stability, it is known to get brittle and break down over time. I also hate the toxic fumes and waste, and really feel like I should be moving to something “better”. So far I’ve had OK results with spraying spirit varnish (shellac, mostly) and varnish sure can look nice, but they both have their own problems. It is also harder to make them gleam like the hood of a new car, which seems to be the ideal for many modern makers… My finishing equipment is not sophisticated enough for the most modern finishes and I don’t know of anyone who specializes in instrument finishing for individual makers up here, so I’m pretty much stuck with what I can accomplish with my basic set up. In my situation, nitro makes sense, sort of...

_________________
Rian Gitar og Mandolin

I personally have tried the following:

1) Nitro...Great finish with good results from home application, BUT, the explosive and toxic nature forced me to abandon doing this in my home shop
2) Two Waterbourne finishes...USL and KTM-9 were easy to apply and finish but they turned out to be too soft as well as still having that pesky blue tint.
3) French Polish...Beautiful finish and renders the appearance of the wood like no other can but it is such a fragile finish and requires routine maintenance. Nevertheless, FP is my favorite for personal guitars.
5) Catalyzed Polyester...For over a year, I have been using Cat Polyester. The finish that Joe White applies is by far the best I have ever seen and I would be hard pressed to ever use anything different now.

Since I'm a constant tinkerer, I'm hoping to try a combination of a FP top along with the remaining guitar with Cat Polyester. Stay tuned!

_________________
JJ
Napa, CA
http://www.DonohueGuitars.com

I use Behlen's Rockhard Table Varnish because it produces a nice finish and is easy to apply. Environmentally friendly.

_________________
Ron

So how does the Epifanes compare to the KTM-SV? Both are spar varnish......

_________________
Formerly known as Adaboy.......

I can't get a "perfect" finish with Epifanes. It looks great 4 feet away but I've got some small pin holes and pores, mainly on the sides. A better job of pore filling would probably help. I drop fill these places when using nitro but the Epifanes didn't like drop filling. I'll take and post some pictures tonight. I want 2 options for my customers, and so far Epifanes is my "varnish" oprion. I didn't have much luck trying to spray Rockhard. Me and brushes don't get along for some reason. I spray 3 coats of Epifanes, level sanding between coats with 600 grit. 24 hours between coats. (I thinned it until it looked right) I've buffed (micromesh, by hand) 6 days after the last coat. I haven't tried KTM-SV. Epifanes was recommend to me by a friend who repairs and restores boats, and is getting one of the Epifanes finished guitars I'm working on. He said Collings uses it. The painter in the body shop where I spray my guitars stripped and re-finished a Les Paul with automotive urethane clear coat. I may try some of it. I agree with Nick, I don't think any finish the proper thickness is going to have an impact on tone that I can hear. I've got the "recipe" for the varnish my Great Grandfather used on Violins. It's main ingredient is motor oil, and motor oil has a BUNCH of stuff in it that wasn't there 70 years ago.

_________________
I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

Woody, I'd love to see Granddad's formula - I'm wondering what would force motor oil to dry.

You CAN buy non-detergent oil in most auto parts stores. A 10-weight is also a useful lubricant in the shop - don't use multi-grade or high-detergent oils for a general lubricant, the detergents attract and hold moisture in suspension.

Dan

_________________
Dan
http://www.acme-archtops.com

I used catalyzed polyester on my most recent guitar and buffed it out just this past weekend. It's easy to use, but because of practicality, I'm going to try something a bit more simple on the next one. It's also very difficult to buff.

Good tread!!!

I use KTM9 mostly because I don't like the hot/cold checks that nitro gets over time. Nitro also chips easily. So far (9 years now) KTM has held up pretty well. The biggest complaint is that it needs to be rubbed out a with a plastic polish every 3 or 4 years. (or rebuffed)

I'd love to use cat poly but with the shelf-life issues and equipmet needed to spray it, it is out of reach.

The blue tint of KTM is easily managed with a little amber color mixed in before spraying, but it is only needed when spraying very light wood.

_________________
Joe Beaver
Maker of Sawdust

I have a HPLV spray setup and spray outdoors. I've tried:

Nitro - only because I was asked. It went fine, like the melting coats but I needed 6 weeks before I could buff it out. Also bugs like to fly into it.

Tru Oil (hand applied) - I highly recommend this for necks, smooth as a baby's bottom. I will not use anything else for necks unless someone is really committed to something else for a specific reason.

Precat Conversion Varnish - this is my go-to finish, sealed first with shellac underneath. Dry to the touch in 10 minutes, level sand after 90 minutes, I can lay down 5-6 coats a day if I'm efficient. Let sit 1 week to get rock hard, then buff. Buffs great. But the fumes will kill you faster than crack.

This summer I am going to try System 3 Mirror Coat as a clear coat for solidbodies - with the body slowly spinning on a rotisserie to keep the thickness even. Hoping to maximize the ratio of (hardness) / (buff-out-time) but would never do it on a soundboard.

_________________
The member formerly known as erikbojerik....

I like Nitro or French polish the best.Nitro because of repairability and durability.French polish if i'm in a hurry because it's fast.And they both seem good for tone as well.So they both are my pick.

I like nitro best, because of ease of application, repairability, and looks. I've tried french polish, and
it comes out very nice, but it's a lot more work IMHO. Tried Tru-Oil on one guitar, but I didn't like it.
Messier to apply than either nitro or fp, and didn't give as nice a final appearance (again, IMO).
I tried a pre-cat nitro on a couple of guitars, and it applies just as easily as regular nitro, but doesn't
have the ease of repair. I guess I'm willing to put up with a little more fragile finish than the super
hard ones. I think a musical instrument gains appeal if it shows a few signs of use, shows it's appreciated.

_________________
Gene

Politicians and diapers must be changed often, and for the same reason- Mark Twain

I use Target USL but will switch to EM6000 on my next build (I had plenty left in the shop). I use it because I can safely spray it in my basement without any fancy ventilation equipment and from what I've seen, it's probably the best of these 'safe' finishes though I've not seen KTM9. However, I only put out one to two instruments a year.

If my volume went up and I actually sold things rather than give them away, I'd probably find a way to do polyester either myself or outsourced.

_________________
http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

Just got a guitar back via a guy I helped build this dred kit 3 yrs ago. HVLP sprayed KTM-9. Horrible failure of the finish, esp on the neck. It appears the guy has acidic sweat and he plays a lot. Looks like he rests his hand on the upper bout. One I did about the same time is began to fail on the neck after a year. I will never touch the stuff again. (Sorry guys, but a slam is in order here, we're talking about low end finish on a high end guitar, bad combo)

IMO, KTM-9 is not up to musical instrument grade. Others mileage may vary. I've sprayed hundreds on coats with nitro, so not a newbie there.

After sending out a recent guitar to Joe White for a finish, I'm going to send out another, as I don't have a spray booth anymore. Joe does great work.

JJ
Where do you get the Cat Poly and do you have mfgr and part number??

I did a guitar some time ago using automotive Urethane and it held up really well, good gloss - dont know about impact on sound but the automotive urethane clears are high build. Wonder if that is the difference to the poly?

You can get Cat Poly direct from Lawrence Mcfadden. They may only sell to a business though, I don't know. They don't sell it online you have to call them. I've got the #'s written down somewhere but they'll make sure you've got the right stuff. The catalysts are pretty nasty stuff. It's "cobalt" and MEK, neither of which you even want on your skin, much less in your lungs or eyes, so proper safety equipment and precautions are a must. The pot life is a short 20 minutes. I'm looking into UV cured polyester right now. The body shop I spray my guitars at uses UV cured primer sometimes. I'm in the process of finding out if they're light will cure the guitar stuff. UV cured, and catalyst cured polyester are identical after they're cured. Lawrence-Mcfadden also sells polyurethane for guitars. It has alot longer pot life( 10 to 12 hours?) similar to the automotive stuff. I was considering trying automotive urethane since it's readily available for me, but I was told (today) that it's got UV blockers in it. That's great for cars but a bright white sitka top would be bright white forever. Some people might like that, but not me.

_________________
I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

-

I use polyurethane. Minwax, more precisely.

It's the easiest thing to apply with a brush (I'm not equiped for spraying and won't be until I have a shop seperate from my home.). It doesn't need sealer (unless for rosewood), the smell is WAY less irritating than lacquer, it sands great within 8 to 10 hours and polishes great just 24 hours after the last coat (as long as it was sanded with 2000 grit). If I apply two coats a day, I'm done finishing a guitar in about 10 days.

The drawbacks is you have to seal rosewood with two coats of shellac otherwise it won't cure (which is not a big draw back...) and it yellows out a bit within the first few months (depending on light exposure). And this is not that big of a drawback in my opinion. It just look old a few years before lacquer finished guitars do.

A small note, stay away from the waterborn polyurethane. Way too soft as for most waterborn finish products.

_________________
Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

We might have another option in the near future. I work for an automotive paint company (PPG Refinish) and we have been spraying cars for several years with water based color coats. Due to environmental pressures, the water has now made it to North America. In fact it is mandatory in CA and thoroughout areas of Canada. Now here is the interesting thing. Speaking to some of our guys on the product side of the business, we are very close to releasing a water based clear. It is a high build made for automotive and if it works like the base coats all you need is air movement. In fact, on projects as small as a guitar you apply a coat and can air dry with a blow gun or fan and apply the second and third coats immediately after flash off. Its really awesome. I think I will do some homework and find out the film build specs. My understanding is that it is just a few months away. ANy thoughts?? Heck, if it holds up on a car, it should be plenty tough for guitars. Shops scuff and buff within hours following application of base coat and clear coat.

It's probably got UV blockers in it, which will keep bright white spruce top from tanning.

_________________
I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/