Finish options on new work

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BR Ukuleles

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After reading through a very informative thread on repairability of finishes I thought it would be appropriate for a new thread that outlined some options for finishes on new work.

Being one of the lone Australian builders here my product choices are different to whats available to many of you. The one that I've settled on is a pre-catalyzed lacquer made by Mirotone over a pore fill of WEST Systems epoxy. It works well and I get a mirror gloss that I'm happy with.

There is the problem of toxicity and the smell from the lacquer that I'd like to reduce or eliminate. A mention by Rick Turner on his preferred method of hand finishing got my interest and hoped he would elaborate a bit on it here.

Others with finishing experience please jump in too. If you don't have any experience then please refrain from offering advice that you aren't qualified to make. Some grumpy old luthiers might jump all over you otherwise.:)
 
I, too share your concerns over the toxicity of nitro. I've been riding the nitro train too long and just doing what everybody used to. Other finishes I've tried (FP, Target 6000, Tru-oil) have been fussier to work with and the finished result lacking in one are or another. Perhaps a little to late, I am now taking the precautions I should always have but I'm afraid that years of exposure to this junk may have already taken it's toll. From the research I've done (Yes! I did some!) even the water borne finishes aren't 100% safe. Thanks for bringing up the topic Allen. It's time for a change and I will be following this thread closely.
 

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The good folks from Cardinal (a finish manufacturer making really good products) just turned me on to System 3 epoxies. They make one formula that is specifically used as a sealer/coating and has very, very low amine blush issues. I'm about to try it, and I'll report in.

The amine blush issue is a big deal with epoxies. It can prevent subsequent coats of finish from adhering well, and it also acts as an anti-catalyst for polyesters. You can deal with it by washing the amines off of cured epoxy with water...yes, water, not any kind of chemical solvent. I've been doing that with WEST epoxy used as a sealer...light sand, scuff with ScotchBrite, and then do a wash with a damp paper towel.

I have had really good results pre-sealing and pore filling with two coats of epoxy. It does a pretty good job of filling pores, and the great thing is that once cured, there's no further shrinkage. It' NOT the traditional dyed pore filler look as per Martin, but I'm not trying to do that.

Over the epoxy I'm using either Simtec's "Adhesion Promoter" or now the Cardinal equivalent urethane. These are "isolator" coats...sealers...particularly needed over rosewood or cedar, both of which have oils that are also "anti-catalysts" for the polyesters I like as build and top coats. They are also superior sealers under nitro, as Addam Stark is finding out.

The real key here is getting great adhesion, and sometimes you have to graduate from one material to another to another to get this. It's like the very best chrome plating over steel. It has to be copper, then nickel, then chrome to really get fantastic grip and the great look.

For those who want to try varnish, take a look at the Epifanes line. They have a formula that does not need to be sanded between coats as do normal spar varnishes. Behlen's Rock Hard is also favored by some American luthiers. I see no reason why these varnishes would not work really well over epoxy, and the finish could be brushed on in a simple clean room.

Another nice look is Waterlox tung oil (really a long oil varnish) directly over epoxy sealer/pore filler. It's not the music store finish glossy finish that so many expect, but it's a really superior take on an "oil" finish.

Yes, I'm a big fan of epoxy as the basic sealer. It adds a level of moisture resistance that no other coating can, it works nicely over a lot of stains (Behlen's SolarLux or US Cellulose MEK soluble dyes), and I do believe that it makes for the best adhesion of subsequent coats of anything that you can do. The thin epoxies also have fantastic wetting out properties and will really pop grain figure and natural wood colors. They'll also find any hidden flaws in the wood and help keep it together.

A number of American luthiers do a whole inside and outside treatment on Brazilian rosewood stump wood which can be problematic using epoxy on the joined but raw parts and then run the wood through a drum or wide belt sander. The epoxy penetrates well and helps to stabilize the wood. Look inside the guitar, and you cannot tell that this was done. The Smith CPES epoxy is practically water thin and is great for this.

I also know that a number of high end classical guitar makers are epoxy sealing guitars under French polish...and they aren't talking about it. It cuts down the FP time by at least 50% because all the basic wood prep and pore filling is done and stable in two days, and the FP can be less than half the number of coats.

Another more traditional technique comes from Romanillos who uses egg whites as a ground (sealer) particularly on tops underneath FP.
 
All the finishes that i've tried have been simple low tech. Tru-oil, Danish Oil, French Polish, Violin Oil Varnish, Violin Spirit Varnish and Behlens Rockhard - a modern type of Oil varnish.
The only one on the list that I would call tough and durable (in the modern Guitar sense) is the Rockhard. Doesn't really require much in the way of equipment although a simple light cabinet is useful. I wasn't a fan of the smell - has a Chemical odour that I didn't like. I doubt that brushing it on would cause much in the way of toxicity. It also gives a slight Green caste that is visible on very light coloured inlays.
There are other similar Varnishes that don't give the caste - or at least that's what I have heard.
These days I just stick to the Danish Oil and a brushed on Spirit Varnish. Not the toughest or hardest of finishes but old Martins supposedly had it. High end Mandolin makers use it but many Guitar makers think it too soft.
 
Thank you all for this thread. It's come at just the right time. When signing on I actually was going to find some previous threads to help me with some finish problems I am having with Tru-oil over a Macassar Ebony headplate.

I appreciate your detailed reply Rick. I will try some of the other varnishes you have recommended. I only have a small shop and no room for a spray booth so I am trying to do it by hand but i am having a heck of a time. I get so discouraged.

Thanks again for all your time in addressing this issue!
 
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I have worked with Waterlox Sealers for cabinet work. http://www.waterlox.com/products-item/waterlox-original-satin-tung-oil-wood-floor-finish.aspx Is that what you are referring to? It does a nice job but I didn't feel it has the ability to stand up to hard use like Nitro does.

(Hope I didn't piss off any cranky luthiers...) ;)


Rick Turner said:
The good folks from Cardinal (a finish manufacturer making really good products) just turned me on to System 3 epoxies. They make one formula that is specifically used as a sealer/coating and has very, very low amine blush issues. I'm about to try it, and I'll report in.

The amine blush issue is a big deal with epoxies. It can prevent subsequent coats of finish from adhering well, and it also acts as an anti-catalyst for polyesters. You can deal with it by washing the amines off of cured epoxy with water...yes, water, not any kind of chemical solvent. I've been doing that with WEST epoxy used as a sealer...light sand, scuff with ScotchBrite, and then do a wash with a damp paper towel.

I have had really good results pre-sealing and pore filling with two coats of epoxy. It does a pretty good job of filling pores, and the great thing is that once cured, there's no further shrinkage. It' NOT the traditional dyed pore filler look as per Martin, but I'm not trying to do that.

Over the epoxy I'm using either Simtec's "Adhesion Promoter" or now the Cardinal equivalent urethane. These are "isolator" coats...sealers...particularly needed over rosewood or cedar, both of which have oils that are also "anti-catalysts" for the polyesters I like as build and top coats. They are also superior sealers under nitro, as Addam Stark is finding out.

The real key here is getting great adhesion, and sometimes you have to graduate from one material to another to another to get this. It's like the very best chrome plating over steel. It has to be copper, then nickel, then chrome to really get fantastic grip and the great look.

For those who want to try varnish, take a look at the Epifanes line. They have a formula that does not need to be sanded between coats as do normal spar varnishes. Behlen's Rock Hard is also favored by some American luthiers. I see no reason why these varnishes would not work really well over epoxy, and the finish could be brushed on in a simple clean room.

Another nice look is Waterlox tung oil (really a long oil varnish) directly over epoxy sealer/pore filler. It's not the music store finish glossy finish that so many expect, but it's a really superior take on an "oil" finish.

Yes, I'm a big fan of epoxy as the basic sealer. It adds a level of moisture resistance that no other coating can, it works nicely over a lot of stains (Behlen's SolarLux or US Cellulose MEK soluble dyes), and I do believe that it makes for the best adhesion of subsequent coats of anything that you can do. The thin epoxies also have fantastic wetting out properties and will really pop grain figure and natural wood colors. They'll also find any hidden flaws in the wood and help keep it together.

A number of American luthiers do a whole inside and outside treatment on Brazilian rosewood stump wood which can be problematic using epoxy on the joined but raw parts and then run the wood through a drum or wide belt sander. The epoxy penetrates well and helps to stabilize the wood. Look inside the guitar, and you cannot tell that this was done. The Smith CPES epoxy is practically water thin and is great for this.

I also know that a number of high end classical guitar makers are epoxy sealing guitars under French polish...and they aren't talking about it. It cuts down the FP time by at least 50% because all the basic wood prep and pore filling is done and stable in two days, and the FP can be less than half the number of coats.

Another more traditional technique comes from Romanillos who uses egg whites as a ground (sealer) particularly on tops underneath FP.
Click to expand...
 
No, Waterlox is no where near as hard and tough as other film finishes, but it has the advantage of being easy to do with minimal gear, and it's really easy to touch up with another coat. There are trade-offs with this simple finish thing. However, Waterlox is about the best I've tried of the so-called "oil finishes"...along with TruOil.

But try these over epoxy for a much tougher take on the oil finish look. No, it won't rival the glassy surface for nearly forever of higher tech sprayed finishes, but that's the trade-off.
 
I'm currently using up my last stash of McFadden's, and anxiously awaiting a shipping quote from Mac at Cardinal. Off the top, its insane - we need to get a distributor here in Hawai`i. In speaking with him (BTW, thanks Eric for bringing this up in another thread), seems my elusive 2-day finish (with lacquer) is not far away, once I'm done with West Systems (thanks Rick) pore fill.

One of the nicest finishes I've used is McFadden's polyurethane, which is different from their polyester. Of course, moot point, but I believe Cardinal has it as well. Problem is that I don't have the volume to support using urethane - the catalyst hardens in time (might help if I used bloxygen. . . ). Urethane over Epoxy, that was great. BUT, to me, just as, if not more, toxic than lacquer.

Personally, Nitro Lacquer is mild compared to the stuff I used to spray on my Motorcycles - urethanes, acrylic enamels, etc. . . and MUCH easier to spray.

Allen, I think one of the light bulbs that need to be lit for you is an HVLP conversion gun (if you haven't already). I know you like the compressor, so a nice Sata should do fine. You won't eliminate it, but you'll certainly see a reduction in the smell. Once the gun is set properly, if it doesn't hit the instrument, it usually falls to the ground (that's the LP part that prevents lift in the overspray). Of course, that's a $300 experiment should you wish to try it, but I don't think anyone whose gone to a gravity feed HVLP (a good one anyway) has ever looked back. I think Chuck may have used one, but switched to a full on HVLP system (as seen in his pic). I still like the convenience of the cleanup with Gravity Feeds, and I think that HVLP systems are now available with those guns...

Time to mix some West System - guess you know what I'll be doing this week. . .

Speaking of Tru-Oil over Epoxy - that's currently on my personal bass, and I love it. I purposely didn't gloss the finish, but its filled nicely. Completely different feel from a lacquer neck.

Aaron
 
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Chuck, I notice that you are not using the 6' whip attachment on the Fuji. Do you have any problem with the air being too warm for nitro? I have the Fuji w/ the whip and gravity feed gun and have not had any problems.
 
My basic system for finishing for years has been an epoxy filler, one thin coat of shellac or nitro lacquer sealer, then six to eight coats of nitro lacquer for a uke, 8-10 coats for a guitar. After curing for one to two weeks I sand with 400, then 600 wet/dry and rub out with 0000 steel wool and Wool Lube. Since I don't like high gloss glassy finishes, the rub out brings the finish to a soft satin sheen that looks almost vintage and has a velvet smooth touch. This finish is always well received.

The ukes I have been building lately have been on the very simple side, that is, no binding or fancy inlays, just a good quality playing uke at a very reasonable cost. For these instruments I just give them one sealer coat and 3 coats of lacquer and then rub them out with the lube and wool. I don't use any filler. This leaves the open pores to show through, but I kind of like the look and again they have been well received.

For violins I use a combination of an oil varnish, pure Tung oil, turps and a small amount of cobalt drier. This finish is padded on like a French polish, it builds great yet remains very thin and is easy to touch up or renew. You can build the sheen to a high gloss or keep it at a softer satin patina. I may even use it on ukes in the future. The only problem I am having is finding a high quality oil-based varnish on the store shelves in my area. Most varnishes are now solvent-based or urethane products and I am not interested in any of those.
 
What do Kamaka and Koaloha use on their standard grade glossy instruments? To my untutored eye, it looks like lacquer without pore-filling but that is only a guess.
 
Further to using the Epifanes varnish Rick. I had a look through their website, but I could find scant information about procedure etc.

I gather that they are brushed on, presumably in a clean room with a high quality brush. One product needs to be sanded between coats, the other says it's fine to go over within 72 hours. Not really a big deal either way for me. What I don't know is how hard and durable these finishes are. Can they be buffed out like lacquer? Get similar depth of shine etc.

What sort of time frame are we looking at after pore filling to having an instrument ready to do set up? With the high gloss lacquer I'm at a minimum of 2 weeks with conditions being ideal. More like 3 though on average.
 
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Kekani said:
Allen, I think one of the light bulbs that need to be lit for you is an HVLP conversion gun (if you haven't already). I know you like the compressor, so a nice Sata should do fine. You won't eliminate it, but you'll certainly see a reduction in the smell. Once the gun is set properly, if it doesn't hit the instrument, it usually falls to the ground (that's the LP part that prevents lift in the overspray). Of course, that's a $300 experiment should you wish to try it, but I don't think anyone whose gone to a gravity feed HVLP (a good one anyway) has ever looked back. I think Chuck may have used one, but switched to a full on HVLP system (as seen in his pic). I still like the convenience of the cleanup with Gravity Feeds, and I think that HVLP systems are now available with those guns...
Aaron
Click to expand...

Been a autobody spray painter for 32 years Aaron and have been using HVLP for about 20 years. And it would be good to get a Sata for $300. The last one I bought was $600. The gun in the video is an old Optima that I've had since 1982 and is the clunker I have in the shed at home. But as you're probably aware, you don't see a lot of old spray painters and it has taken its toll on me.

As well, Australia along with many countries is putting in place much stricter regulations on VOC's. It won't be long before we will be forced to switch from solvent based paints at work to water bourn ones. Very tricky thing to do when you live in a place as humid as Cairns during the wet season.

I can't imagine going to a water based finish on my instruments. I've use quite a few over the years and not found one that I'm happy with. I need something that is durable, able to have a high gloss with good depth. Be at least no more time consuming to do than lacquer. Stand up to the very high humidity here in the tropics during the monsoon season, as well as the dry that the rest of the country gets. Thus these are the issues that have led me to start this thread.

I must say the quality of responses thus far have been great. Thanks everyone.
 
I'll let Rick answer but a modern oil varnish ticks many of those boxes. Some people brush, some spray. From my experience of Behlens they are tough and durable. I even tried scraping the Behlens from one instrument and it's not something I would want to do again. Epifanes is similar in nature to the Rockhard.
I think you will be fine with the Humidity and human sweat issue. Oil Varnishes are pretty good at resisting very hot water. I know a Lute maker who uses near boiling water to release Soundboards without damage to the finish.
The one issue that does crop up with these types of finishes is the visibility of witness lines. There are methods of eliminating these.
 
This is a great topic, Allen, and indeed, some of the replies are interesting. I've worked with furniture finishes all my life, much as it appears you've done with auto work. In developing techniques for musical instruments, I've tried most everything suggested here (no experience with Cardinal or Epiphane).

The one thing that helped me sort it out, was that I had some specific goals in mind from the beginning. The last few posts have included some of the finisher's goals as well. It seems to me that the replies would be more instructive if they began with what end result you are looking for - in other words, the qualities that make a good finish in the first place.
 
Allen said:
The gun in the video is an old Optima that I've had since 1982 and is the clunker I have in the shed at home. But as you're probably aware, you don't see a lot of old spray painters and it has taken its toll on me.
Click to expand...

I stand corrected in my response - you're right, it was based on the Optima in the video.

Some days I just wish I could Tru-Oil everything and be done with it.

On another finish, I have spoken to a well known Guitar maker in CA (deals Cedar and Myrtle), and when I asked the finish on his instrument, he stated, "Shellac." I responded, naively impressed, "Oh, French Polish?" He said, "No. Shellac."

We can all be like the manufacturers selling Laminate Koa `ukulele as "Koa" - we'll say "French Polish style finish", but it'll be epoxy fill covered with Shellac (sprayed, or better yet, rubbed), buffed out.

This would be what big industry calls "consumables" - not only do we sell an instrument once, they come back in for finish repair once in a while!
 
southcoastukes said:
It seems to me that the replies would be more instructive if they began with what end result you are looking for - in other words, the qualities that make a good finish in the first place.
Click to expand...

Dirk, you have done me the favor of explaining the question that I asked above about what some of the major 808 builders use for their standard finish. Beginning builders have been advised time and again to avoid the more decorative features and to concentrate on the sound. Mirror finishes fall in the same category as complex binding, purfling and inlays - wonderful displays of the luthier's art but not essential to building the basic skills that enable a builder to improve the sonic quality of the instrument. In short, Kamakas and Koalohas are beautiful and appear to use relatively simple finishes that some might find suitable for builders with less flashy goals. Thus, I wonder how they are done.
 
I brush, then pad out shellac on the inside of my instruments to help buffer drastic swings in humidity, and have tried it on the outside of a couple. But on one of them the person who had it has "toxic sweat" and as you can imagine if you've ever lived somewhere during the monsoon season, is not a good look on an instrument. So for me this finish isn't an option, even though I really like using it.
 
saltytri said:
.... Beginning builders have been advised time and again to avoid the more decorative features and to concentrate on the sound. Mirror finishes fall in the same category as complex binding, purfling and inlays - wonderful displays of the luthier's art but not essential to building the basic skills that enable a builder to improve the sonic quality of the instrument....
Click to expand...

I was wondering if anyone was going to mention this. To me, sound is the most basic consideration in any aspect of an istrument's make-up.

There are reasons why some finishes are referred to as "production finishes". I don't think many of them aim much at all at this primary goal. I think small builders make a mistake if they try too much to mimic the look of factory finishes.

Start with the idea of sound!
 
dustartist said:
Chuck, I notice that you are not using the 6' whip attachment on the Fuji. Do you have any problem with the air being too warm for nitro? I have the Fuji w/ the whip and gravity feed gun and have not had any problems.
Click to expand...

I really don't see the need for the whip hose. It only takes me five minutes to spray for ukes. My wrist can handle that.
Re the warm air from the turbine. My lacquer is stored at about 75 degrees, my spray booth is about 85 degrees. The air from the Fuji turbine is warm but I don't think unreasonably so. I keep it mounted high (as recommended) and keep the intake filter clean. I'm only using it for very short periods at a time so it doesn't get a chance to get real hot. (although I've used it on a kitchen cabinet job without a problem.) If anything I think the warm lacquer/warm environment helps everything flow and spray better. The Fuji Q4 works beautifully once you've got your mix down right.
 
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