Mandolin Builder's Super Summit

Subject: Mandolin stain and finish

QUESTION: Where can one acquire potassium dichromate and what are some safe handling procedures? Is there an available substitute?

Lynn Dudenbostel: I found a local chemical supply here in Knoxville that ordered it for me. They sold me a small quantity (fortunately) and it's probably a lifetime supply. Charlie Derrington uses another strong oxidizer, but I don't remember what it is. Since it is a strong oxidizer, always store it away from flammable or combustible materials, I understand it's fairly toxic too, so I always wear rubber gloves when handling it. You can also use a dilute stain to wash coat your maple, then sand it back (with your final sanding) to accentuate the figure in the wood. I've used this method too (usually by accident when I get a sunburst I'm not happy with and have to sand it off and start over again!). It does the trick. Pot. dichromate is an old trick used by furniture builders to artificially age cherry and mahogany, especially in repair work when trying to match an old piece. It gives and absolutely beautiful patina to these woods.

QUESTION: What sort of dyes or stains do you use? Are they applied directly to the wood? By hand or sprayed?

Will Parsons: I use primarily Stew-Mac's Color Tone Liquid Stains because they are soluble in lacquer, alcohol and water. I start with water-base stains applied by hand and I basically do the entire sunburst a little bit lighter than it will eventually be. I then over spray a slightly darker color in a lacquer base and finish up with a fairly dark lacquer base to accentuate the points and edges. Then I spray a clear coat and then scrape bindings. I have found that analine stains bleed onto the binding throughout the finish process, so I avoid them.

Charlie Derrington: Water stains. I prefer to apply by hand (boy, is that ever hard to do on a porous spruce top), but the production dept. water stains by hand and touches up by air spray (Particularly on the top and dark joint areas).

QUESTION: I have built a few carved top mandolins, and I have trouble staining the top plate evenly. The stain tends to wick heavily into the curved area where the end grains are more exposed. This can make a fine looking piece of spruce look pretty nasty. I don't have any trouble with the maple back plates. Do you have any suggestions for me?

Hans Brentrup: Some builders shoot a thin coat of shellac first to seal the end grain a bit, or some airbrush the stain. I apply dye by hand, and it does wick a bit more into the end grain. Maybe your concentration of stain is too heavy. I do get some variation, sometimes very striking grain patterns, but we're talking about wood here, not formica. In our homogenized society, evenness of wood stain is achieved by masking the wood grain with muddy stains, which contain a lot of particulates. Folks forget what a beautiful piece of wood looks like. Take a tour through a couple of high end antique shops and look at the furniture. You'll see a lot of variation in the stain. You might also consider that a freshly stained mandolin looks really bad in just the respect that you are talking about. It looks really black in the end grain, but when you have applied several coats of your favorite finish, and polished the instrument out, That black will turn into the right color, and the instrument will not look as splotchy.

QUESTION: There is a big demand for varnished instruments, but some builders are having trouble with drying and hardening, and I'm leary of diving in. Please discuss this topic.

Charlie Derrington: You should be leery. It's a bear. Research and experimentation are the key.

QUESTION: To those using oil varnish, what preference do you have as to brand/formula/ resin content? Any pointers for application or suggestions for written references?

Charlie Derrington: I mix my own from some very old recipes. I use existing, available formulations and mix those together to come up with what I believe is the Loar period formula.

QUESTION: Do the forum members recommend finishing with french polish, or applying finish coats over varnish? What commercially available products do you recommend? Do yo recommend the use of hardeners? If a hardener is used, should it be used throughout the entire finishing process or just the final coats?

Charlie Derrington: Yes. I used to melt my own flakes, but, thanks to Frank Ford, have found a very good French base that is commercially available. It is called "Zinsser Bulls-eye Seal Coat Universal Sanding Sealer" Product # 00854. It is about a 2lb cut with an Ethanol base (which I always used as I don't like Methanol). Great stuff. I do add some other resins. Again, experiment until you find what dries quickly and hard and applies easily. I don't use hardeners. However, on the oil varnish, I use UV lights to speed up the curing process. The sun works just as well.

QUESTION: What are the various merits and disadvantages of varnish and lacquer? To those using varnish, what varnish do you use?

Charlie Derrington: The advantage to varnish is the tone. Everything else about it is a negative. It's hard to mix, almost impossible to apply correctly, takes years of training to get it right. You almost have to become an alchemist. It's fragile when cured, is easily bruised and scratched, turns white with moisture, prints in the case when warm. But, it's all worth it with the tone. You can't beat it and I would recommend going through the hassle if you want your instruments to sound the best they can.

QUESTION: I would like our guests to comment on a couple of questions related to varnish or spirit finishes, assuming they use it on their instruments.

1. If they french polish, what formulation or product do they prefer? A homemade mixture or a premanufactured product like Behlen's offers? Would they mind telling us whose they favor and why?

2. If they use an oil varnish, what steps do they go through in applying it?

Charlie Derrington: I think I have already answered this question. I don't like the Behlen's. In reference to the oil question: Always use a sealer (shellac works good) before applying oil. Remember, each coat will be a mechanical bond (non-chemical) and as you apply each coat, the previous has to be scuffed to accept the next. We used to brush the oil varnish but I have found a way to spray it. Very, very, thin coats and you have to experiment with the varnish/turpentine mix to get it right. You also have to try different air/mix settings and gun proximity to get it just right. It is very difficult to spray and you'll have to do a lot of tests to make sure you don't get it too thick or thin in application and coat thickness.

Subject: Binding

Qusetion: What advantage do you find in using the double course method of binding, considering that it requires twice the work?

Lynn Dudenbostel: Yes, it is more work, but I find it very difficult to get the clean bends I want in the scroll with b/w/ivoroid binding made up in one piece. I'm sure some of the other gentlemen on the panel have mastered this technique, and I'd love to bind in one step. Maybe I just need to experiment more.

Subject: Mandolin design experimentation

QUESTION: Since most - if not all - of these master luthiers have taken custom orders and experimented with designs, here's the question: What would you never do again for any amount of money?

Corollary question: As consumers with ideas of our own, what kinds of things should we avoid in creating our dream instruments?

Lynn Dudenbostel: I'm not sure I've done anything (yet) that I wouldn't do again, for the right money. I know I probably wouldn't do another full blown 45 style guitar with abalone up the sides of the neck and around all edges of the peghead, plus a tree of life fingerboard, without a substantial amount of money being involved. Also, I can't ever imagine doing a 45 style mandolin, although I've seen photos of a striking instrument of this type made by Mike K. I've been asked, and I think I'm real happy I said "No!".

As for your consumer question, I'd highly advise not asking a luthier to do something he doesn't have his heart in. If the builder doesn't seem enthused about the project or feature in question, don't push him into it. Also, asking a luthier to experiment in an area he hasn't ventured into can result in less than desirable results. It can also have a positive outcome, but not always. Luthiers (especially ones new to the business) usually want to please the customer by fulfilling almost any request. Well, it often results in what I call a "learning experience" for both parties. For the luthier, it's learning to say "no!" the next time!

QUESTION: Gentlemen, we know that our panel includes some died-in-the-wool traditionalists like Charlie Derrington and Lynn Dudenbostel, who feel that the Loar is the consummate and ultimate design for the mandolin. We also have John Monteleone, who was one of the first to break out of the Loar mold and Pete Langdell, who has blasted the mold all to hell and back. Where would the rest of you fall on the scale between the Loar traditionalists and Pete's Killer Bee? How much do you vary from the Loar specs?

Lynn Dudenbostel: As traditionally rooted as I am, I really respect the luthiers who have stepped out and "broke the mold". The Grand Artist and Radio Flyer mandolins are works of art, and I think there is room for all of these designs in the mandolin world. These instruments inspire me to think that someday, I may attempt something besides a traditional style F-5. Probably not any time soon, but someday. I think any departure from the traditional F-5 must look like it was designed from the "ground up" to be something new and exciting, and not just an F-5 that's been changed for the sake of change. I believe that's why John M.'s designs and Rigel's instruments are so well received. Not to mention, they sound great too.

Will Parsons: I have the greatest respect for Loar and his designs. I am glad that he did not adhere to some previously established standard, as if he did we may not have the mandolin we so dearly love today. He was a truly great genius but not the mandolin god. I have played some Loars that really blew my dress up and I have played some that I was disappointed in. Loar still holds the highest place of honor in my list of mandolin building heroes and probably always will. But, I believe, someone else will come along if they haven't already that will do as much for the instrument as Loar did or at least take it to another level. There are some builders in this group that I feel may have already accomplished this. I do not adhere completely to Loar's designs. I often use a radiused fingerboard, different sound hole shapes, different headstock shapes and different bracing patterns. Still, the basic Loar shape is beautiful, so though I am willing to incorporate new ideas I am not ready to make any radical changes.

Charlie Derrington: You know, I was going to rib Pete a little (just for fun), but I really have admiration for folks that don't resort to copying Gibson. If someone is going to really redesign the instrument, go for it all the way and break out of our mold. It just ain't for me.

Hans Brentrup: Personally, I have always felt that the asthetics (style) of the F model mandolin to be exceptionallly well proportioned, and that goes back to Orville, not Lloyd. Any changes externally that I have made are rather subtle, and in that respect, I have not strayed from the model too far. Internally, my red spruce instruments don't stray very far from the model either, but the German and Italian spruce mandolins are a different story. There are, after all (and I know this will shock some of you), folks that don't care for the "Loar" tone.

Michael Kemnitzer: I don't think of any one design as being superior. All other things being the same, mandolins of different shapes and sizes sound different. That uniqueness will inevitably be favored by some and not others. No one type of mandolin design is best suited for all types of playing styles or all types of music.

My F-5's have always been a mixture of the traditional design and my own touches. My Two-Points and A-model designs offer more freedom for innovation. In the future my F-5's may take on a more traditional and at the same time I look forward to pursuing my ever evolving 2-Point design. Mandolas, octave mandolins and mandocellos offer a great opportunity for innovation as a lot of players have less preconceived notions as to what they should sound and look like.

Subject: Scroll Ridge

QUESTION: The scroll of a carved F-style mandolin has a 'ridge' that runs down into the soundboard area. On a Gibson and many others, the ridge ends before it reaches the domed area. On my Red Diamond, and on Rigels, Webers (complete with forked tongue), and some others, the ridge extends down into the domed area. Best I can tell, the ridge is a styling gimmick. But what effect does it have on the tone/volume of the mandolin if it extends onto the soundboard?

Lynn Dudenbostel: I think it really depends on how far it extends into the soundboard. On a Loar top, it occurrs in a relatively thick part of the top, and I doubt it has any effect on the tone. It's mostly an aesthetic issue.

QUESTION: What are builder's thoughts on hollowing out the scroll block?

Will Parsons: I think that hollowing out the scroll block, and the scroll area of the top and back as much as is reasonably possible is a good thing to do. I have played some very fine instruments that did not have a very hollow scroll area but I think the odds of producing an above average instrument are improved by reducing the weight in that area.

Subject: Tricks of the Trade

Q - Most folks believe hat the Loar design is the standard to strive for. Do any of you stray from the norm in your designs? Should the bridge be in the center of the soundboard? Do most makers use the same neck angle, and is there an optium angle for F-5 type mandolins and another for oval hole mandolins? A very respected maker tells me that there are no secrets to making a mandolin, but do you think that there are important tricks of the trade?

Lynn Dudenbostel: I think the Loar is an excellent standard for design but I also think there is room for new ideas that may work as well or better than some aspects of Loars. I do like to see the bridge in the center of the top because I believe it allows for more efficient vibration of the entire top. Sometimes I think neck angle and bridge height can be confused. Mostly bridge height affects the drive to the top and neck angle affects playability.

The higher above the body the neck is at the body joint the less the neck angle is to establish optimum bridge height. There are too many rules and tricks to talk about now in one response but I'm sure we will hear a bunch of them before this weekend is over.

Subject: Top and back thicknesses

Q - What adjustments are made to the top and back thicknesses to accomodate bass? Treble? How do thinner sides affect tone and volume? As volume increases, does tone diminish?

Will Parsons: In general, a thinner top promotes bass tones, and a thicker top promotes treble. I don't think side thickness has as much to do with sound as it does with structural integrity. The wider the rib is the thicker it needs to be to maintain good strength and durability. Rib width does have a direct affect on sound.

Q - How does each builder go about graduating tops and backs?

Lawrence Smart: I rough carve the outside of both plates with a pantograph and finish the outside carving with various planes, scrapers, and sandpaper. The outside is carved to it's final shape before the inside gets any work at all. The inside of the plates are rough carved on the drill press and graduated with the same tools as the outside. All finished surfaces, inside and out are smoothed finally with sharp scrapers. It's a pretty basic approach, but I feel that it enables me some latitude in altering the shape of the arched plates to work toward desired tone and the ability to work individually with the materials at hand.

Subject: Action too high

Q - With a bridge lowered all the way, and still the action is too high, do you recommend taking off the bottom of the saddle, or resetting the neck?

Will Parsons: Reset the neck. Taking the bottom off of the saddle makes an already vulnerable part even weaker. Of course, cutting the bridge is the easy way and if the bridge breaks its not that hard to replace. If you don't need much you might look at cutting the base of the bridge down but you going to lose optimum bridge height if you don't reset the neck.

Subject: One piece neck

Q - What is wrong with a one piece neck/neck block?

Will Parsons: It looks to me like it is the hard way of doing the job. If the instrument needs a neck reset in the future your really in trouble. A lot of classical guitars are made that way but the neck angle is much less and the string tension is much less.

Q10

Subject: Bolt-on neck

Q - Could you comment on the use of bolt on necks rather than a dovetail? What kind of joint would you use, ie, butt, mortise and tenon, and would you glue the joint?

Will Parsons: I use a dovetail joint all of the time now but I used to use a mortise and tenon bolt on method because it seemed easier. I enjoy doing a dovetail and I like the idea of no metal in the joint.

Q11

Subject: construction techniques

Q - What construction techniques and materials would builders like to experiment with to promote the evolution of the instrument?

Will Parsons: There are a number of areas that I am working on, some of which I'm not ready to talk about. I haven't found a tailpiece that suits me yet and I am working on a few new things there. Also some ways of reducing the long term affect of string tension on the top and tone chamber without decreasing the drive to the top.

Q12

Subject: glue preferences

Q - What are your glue preferences, and applications (where applied), and why the adhesive is preferred for that application?

Will Parsons: I use four glues and they are; Aliphatic resin(yellow glue), cyanoe acrylate(super glue), epoxy, and ground hide glue. I construct the box with hide glue. I usually use aliphatic resin on all of the neck parts. Epoxy is for the inlay. Super glue is my general purpose do it all stuff. I use it on fret ends parts of the binding gluing on small parts like the heel plate and corners.

Charlie Derrington: I prefer hide, but the new LM FG glue is very good. There are some other modern alternatives that work just fine on headstock veneers and kerfing. 3M is making a new product (Jetweld TE 200) that really works great on any part that you'd never want to disassemble in the future. It sets by heat and moisture and is fast as anything I've ever used.

Michael Kemnitzer: I prefer to use hot hide glue for most of my construction; dovetails, kerfing, bracing etc. It dries completely hard, and will not "creep". It is VERY strong when used properly. I think its hardness and the thin glue line it produces have sonic advantages. I like to use epoxy for gluing inlay as it will dry hard like the shell but is not hygroscopic, minimizes movement and finish problems over the wood, glue, shell junction. When your epoxy is mixed.. mix, mix and mix some more to avoid the problem of it not setting up all the way. Like many things, I had to learn this the hard way. I use CA glue for fingerboard dots so long as there is no gap between the wood and shell. I also use super glue for side dots because it's quick and does a good job. I still like Duco cement for gluing most of the binding or better yet, Sigment which isn't quite as hot so is a bit less likely to melt the black line into your miters. For years I used hide glue to glue in frets, it worked very well but I now use CA glue which also works quite well.

Q13

Subject: experiments with designs

Q = Since you all have taken custom ordeers and experimented with designs, what would you never do again for any amount of money? What, in your opinion, should we avoid in creating our "dream" instruments?

Will Parsons: I have ran into a few uncomfortable situations by agreeing to some customizations without giving it enough thought. I remember once inlaying a symbol in the headstock of a mandolin that to me at the time seemed completely innocent. The mandolin was finished and a friend of mine pointed out that I had just inlayed the symbol of a very controversial group whose views and opinions I did not share directly beneath my name. Fortunately I was able to build the customer another instrument without that inlay and then I removed the headstock overlay from the original instrument and sold it as the fine instrument that it was with no religious or political affiliations. I also remember once getting stuck with using green formica as an inlay material and it looked as bad as I was afraid and believed that it would. I did not feel that I could refuse at the time because I had agreed unwittingly to whatever customizations the buyer wanted and also because the electric company wanted his money. Looking back at it now, it would have been better to have damaged my credit rather than my integrity. If you are building an instrument for yourself, don't avoid anything. If someone else's name is attached to the instrument you should be sensitive to what they feel comfortable with leaving as their legacy.

Charlie Derrington: Thin tops. Kiss of death. Bolt-on necks. (sorry, you guys that use this system, but, I speak from experience on this one)

Hans Brentrup: I would never make a top too thin on a mandolin. I've always felt that the fingerboard on a mandolin is a "working surface", and therefore feel that any inlay more than dots is superfluous. Come refret and F/B planing time, it's going to cost you a fortune.

Q15

Subject: most difficult part of building an F-style

Q - What do you find is the most difficult part of building an F-style mandolin? What is the single most important aspect of making a mandolin sound the way you want it to?

Will Parsons: I guess the most difficult part is carving the top and back. For me this is also the most enjoyable part. I don't use any carving machines, only fingerplanes, gouges, scrapers and sandpaper. I also think plate thicknesses along with bridge height and proper materials to begin with are the most crucial to tone quality.

Charlie Derrington: Graduations and air-chamber tuning are the most critical, with wood specie and glue types at a close second. The most difficult part is varnishing correctly. From the mixture all the way to application and final polishing.

Q17

Subject: How many mandolins did you make

Q - How many mandolins did you make before you felt really confident that you were getting the results you wanted?

Will Parsons: Building the perfect mandolin is the impossible goal that we are all shooting for. I started building when I was very young so my expectations and my abilities grew together. I would think that for most people at least 10 instruments are required for a person to feel like they are beginning to understand what makes a mandolin work. I thought that my first 10 instruments were great when I built them and I'm glad that I did as otherwise I may have become discouraged. Looking back I am glad I have the excuse, "Well, I was just a kid then".

Q18

Subject: Question regarding Virzi

Q - Where do you guys line up on the question of the Virzi? For the benefit of the listmembers, I sent around to the panelists earlier this week Tony Williamson's "The Virzi Vortex," as well as John, Lynn, and Charlie's posts pro and con on the Virzi which were made during John's week as CGOW in January. Phil Davidson says "Virzi schmirzi." I guess that is a thumbs down from Phil. Who else wants to weigh in on this controversial topic?

Will Parsons: The Virzi thing hmmmm..... It seems to me that a Virzi defies all rules for good acoustics. I have played mandos with them, lots of mandos without them and a few that they had been removed from and I believe them to be detrimental.

Charlie Derrington: As I stated in one of my CGOW responses... I am in the process of changing my mind on the Virzi. I'm still not sure if it is just my current mandolin that is tempering my opinion. I do notice I enjoy it much more during solo practice than in a bluegrass band context.

Hans Brentrup: I would like to try one sometime just out of curiousity, but building for orders is so time consuming that there is little time left for experimentation. From what I understand, they smooth out the tone across the strings, and provide a richer tone but cut volume. If that's the case, why not just use German spruce and keep the volume?

Q19

Subject: European top woods

Q - Are European top woods just different or maybe better in some respect, e.g. easier to work with?

Hans Brentrup: German or Italian spruce isn't really any easier to work with than red, Engelmann, Sitka...they're all about the same. I wouldn't say that they are better either, what they do is give a different color to the tone. Your basic red spruce gives you that Loar tone, fundemental, woody, some folks even say dry. German spruce warms things up considerably. It's the richest sounding, very complex with a lot of overtones. Italian seems a great compromise with a solid, rich bass, trebles with screaming clarity, and a moderate amount of complexity.

Q20

Subject: fit and finish by hand

Q - Do you accomplish your fit and finish by hand, or is it necessary to use precision electric tools to achieve these results?

Hans Brentrup: If you call band saws or dremel tools precision electric tools, then I use them. Binding is hand routed, and in the scrolls, it's done by hand. Wish I had a CNC router, but that's a bit out of my reach.

Q21

Subject: tune the sound box

Q - Do you tune the sound box to a certain note or tap tune the top? Another way of asking is what kind of procedure/checks do you use to know that you are progressing toward your desired sound?

Hans Brentrup: I do quite a bit of rapping on the top in it's various stages of carving, cutting out the F holes, and carving the tone bars. There's also a lot of flexing of the plates going on, especially the back. When the box is together, time is spent scraping and rapping. When the instrument is strung up in the white, it is played off and on for a week or two, and final adjustments are made.

Q - Do you tap tune prior to assembly, and do you string the instrument up in the white?

Lawrence Smart: I have strung a few mandolins up in the white, but at the present I do all assembly and finishing before they're strung up. I do tap tune the plates prior to gluing the plates to the sides but I'm not usually looking for a specific note; but rather a tonality that is responsive and over-tone rich. I take notes on the tap tones of all instruments and as I look back at the notes I find pretty good consistency in similar materials.

Q22

Subject: marketing for beginning luthiers

Q - What advice can you give on marketing for beginning luthiers?

Charlie Derrington: Get it to the players. Everything depends on that.

Michael Kemnitzer: Listen to what good players want and do everything you can to learn how to provide it. Getting good players playing your instruments is the single most powerful marketing tool that I can think of. Travel. Try to get your instruments spread around. Consider selling some of your instruments through a store.

Q23

Subject: oval hole mandolins

Q - Who is offering oval hole mandolins, and does anyone have any new ideas about oval hole?

Charlie Derrington: Why go with new ideas, when the old ones are so good?

Q24

Subject: experiment with bracing patterns
Q - Is it worthwhile to experiment with bracing patterns that are alternatives to the standard tone bar or X-brace? Can one generalize about how sound varies with the relationship of top thickness to robustness of braces? How do the two extremes compare...thick top/lightly braced vs thin top/ heavily braced?

Charlie Derrington: No. Build it like a Loar. Don't vary from the model.

Q25

Subject: "duck" mandolin made by John Duffy
Q - Would anyone care to comment on the "duck" mandolin made by John Duffy? He claimed it had certain sonic advantages from the size and shape of the sound chamber.

Charlie Derrington: I only played it once, a long, long, time ago and don't have a good enough memory to comment.

Q26

Subject: weight factor in building mandolins
Q - How critical is the weight factor in building mandolins...does it affect the tone? What are your opinions on truss rods vs carbon fibre reinforcement?

Charlie Derrington: Very critical. I think (as a general rule) the less mass, the better. Particularly in regards to hardware. Of course, I'm going to say truss rods. The old Loar rods work so good. Why muck with it?

Q27

Subject: getting the results you wanted
Q - How many mandolins did you make before you felt really confident that you were getting the results you wanted?

Charlie Derrington: Ask Steve, Lynn, and John....I'm still not there. Remember, I don't really consider myself a builder. I build, sure, but research, playing, and repair are the things I really love.

Q28

Subject: tonal/color differences
Q - What tonal/color differences do you notice playing an instrument in the white vs. after the finish is applied?

Hans Brentrup: I wish we could just leave the instruments in the white. Applying finish takes out some of the richness of the bass and tinnys out the treble. That being said, an instrument just strung up sounds pretty funny: chords don't sound too good and the instrument still thinks it's a tree. After an hour or two it's sounding a bit better, and after a couple of days the bridge seats and it's on it's way. As it breaks in, the richness of the bass comes back in and the treble mellows again. With some breakin, the instrument starts to get that hollow sound that we're all looking for.

Mandolin Builder's Super Summit

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