Acrylic resin mandolin construction

[hipster]

I am interested if anyone has ever experimented making an instrument with the type of acrylic that dentures are made of. This is not a wind up or joke but I am a dental technician and feel that some high impact resins could give high strength and good sound qualities to a mandolin, similar to carbon fiber and Kevlar. All I need is a patern to go to, and I will give it a go using plaster as a mould. If anyone would like to suggest a design I will make a patern. The end result will be pink with possibly an ebony fret board Not sure? Any suggestions welcome. Reards Nigel

[TeleMark]

Different strokes, I suppose. I say go for it!

[hipster]

Hi telemark Im going to go for it! but I know nothing about the basic design of mandolins?. I have lots of stuff in my head 90% of which is absolutly useless and 10% is pure genius

[barry k]

Thats one we could sink our teeth into. I have been working on a mando for 12 years, that is 98% acrylic.
All except tuners, strings, frets and tailpiece. All clear so you can see thru it. That will be a trip

[Lee Callicutt]

Having been a dental technician for some years myself in the past, I would say it is well within the realm of possibility, depending of course upon the cost/benefit analysis of monomer/polymer vs. wood, carbon fiber, etc. I would think a stress to failure test would be in order before you put too much work into a finished product, and then of course the quality of the sound would be fortuitous at best. Polymer can be any color you like?

[Lee Callicutt]

Maccafferi experimented with resin bodied instruments in the '50s, flat-top guitars, ukes, arch-top guitars. Think: Bowling Ball styrene. I have one of the arch-top guitars. It's an interesting, innovative piece of history, but its acoustic properties are probably best suited to Delta Blues.

I don't mean to discourage you by any means, just sharing information.

Maybe the first, best experiment would be to lay-up a plate sized sheet of acrylic and see how it tap-tunes?

[Jim Rowland]

Anybody remember Billy Glass and his all-glass orchestra? Probably not. I'm one of the oldest geezers on the Cafe'. Billy made many of the instruments which constituted a full swing band including woodwinds and brass. He even rigged some of the instruments with internal lights which would be turned on when the houselights were dimmed during a performance. The band sounded pretty good. This was back in the forties,and I believe he actually used Plexiglas. Go for it Hipster! Don't forget Ornette Coleman's plastic sax.
Jim

[mandroid]

Maccafari's instruments were injection molded , and high pressure injected in highly polished molds, the money was in the tooling, the parts came out polished, because the molds inner surfaces were polished.
Plaster , probably better to learn metal tool and die making on the side.

find someone that has the injection molding machinery industry,
and make dies to fit their machines thats the big bucks ,
the dies are the interchangable parts.

Alternatively,
maybe think of acrylic slab electric mandolins ,
in the style of the electric guitars that have been made ..

that's more directly shaping the block of acrylic, then.


I 2nd JKs input , Thermo plastics ,
you need like a pizza oven and a beefy vacuum cleaner.

a framed sheet of plastic , ABS is used a lot,
and you make a form like the inside of the piece, typically, and drill a lot of holes in it .
its made the top of a sealed box that the Vacuum pump is sucking on.
the droopy hot sheet of plastic is laid on top of the form, and the motor is turned on.
when the sheet cools to a solid again.. there you are , one step closer..

[jk245]

I would go along with Mandroids last idea to go the sheet stock way. You can heat shape many of the available plastics. Get a type of plastic that can be heat or solvent fused ... some plastics can not be joined other than mechanically. The Sheet stock has an advantage in being uniform thickness which would be difficult with a cast. You can use a template intended for a wooden instrument rather than a difficult to make mold.

[markishandsome]

but I know nothing about the basic design of mandolins?

Do you play/own a mandolin? Have you ever seen a mandolin? Do you live near a music store? It's all right in front of you, unless you're looking for something you're not articulating.

[hipster]

Thanks for that....Thats given me something to get my teeth into:laugh: I like the idea of clear plastic and the sheet acrylic for uniform thickness.To answer markishandsome I have just started playing the mandolin and have just purchased a Martin A model off ebay which looks mint for a 1924 model. I think the thickness of the soundboard would be crucial and I thought you would get away with a thinner section soundboard by using a high impact resin. Some of these resins are amazingly tough and resilliant. I use one called acron high which is almost unbreakable, if above 1mm in thickness.Thanks again and I just need to retire now so I have the time to experiment???

[BlueMountain]

Hey, it's worth a try! As you are a dental technician, you shouldn't have any trouble removing the strings and tailpiece from your Gibson, covering it with something like Saran wrap, and making negative and positive casts from that, whatever you need. You should adapt the cast so you have a top piece that is complete (that is, there isn't a cut-out for the neck), and a back piece that includes the sides (one piece; again, you'll need to adapt it a little so there isn't a cut-out for the neck). (Another possiblity might be making the top and sides out of one piece with the back as a separate piece.)

What comes after that is a lot more technically difficult, but I'll bet that if you could make those two pieces, back/sides and top, you could find a luthier on here who would be interested in using them to see how it would sound. The luthier would need to make and glue in tone bars, neck-block, tail-block, kerfing, install a neck, tailpiece, etc. It's a lot of work, but worth a try. Why not start with your part, then show us photos of the results and ask if anyone wants to do the rest?

(Another option would be to spend a small amount on a cheap mandolin, make a model of its body, remove it's body, and put on your own.)

You have nothing to lose but money, time, body parts, reputation, etc. Why not?

[hipster]

Hi Bluemountain those are great suggestions. I have just collected the Martin. I have to say Im a little disapionted in the sound/tone/loudness.......... but it may need new strings and the action sorting. I will start playing about with some of this resin and perhaps proccess some and then see how it resonates. The interesting thing is that the odd bits Iv'e left in the dry heat curer for weeks and weeks take on the qualities of a very hard but lightweight wood and the long curing of the resin could be a way of making it more suitable for instrument making... almost like kiln dried timber

[jim_n_virginia]

I don't know many people who play or even own a bent top Martin mandolin. The few people I know that DO own one just has one or two for collecting. They don't have the tone nor the loudness of the standard archtop mandolin. I don't think changing the strings is going to make much difference.

What ever you build you will need a model for a prototype. Maybe you can pick up a inexpensive mandolin for a model and then tweak the design?

Or what about if you buy a disassembled mandolin kit like from Simonoff or Stu-Mac and then use each individual piece as a model and mold all the parts to a mandolin and then assembled it with epoxy or something?

Just an idea.

--jim--

[Steevarino]

I have a friend in California that is a dentist. #He used this same stuff to make handles for all of his kitchen utensils; spatulas, big spoons, big forks, etc. #He was able to mold each handle to perfectly fit his hands, so they worked quite well for him. #To me, the color was a turn-off. #Didn't really help to perk up my appetite, anyway...

Steve
www.CumberlandAcoustic.com

[MikeEdgerton]

If we can find people that are looking for sunburst teeth maybe the company would make the stuff in that color....

[Lee Callicutt]

You mean, like Jamie's Avatar? #

One thing's fer' sure, It would chop.

[hipster]

Hmmm|? Ive been offered a 1920s Vega cylinder back. got a feeling there is little to compare with these........ Thanks jim in Virgina have to agree with your coments on Martins..... Ive got the hots for Vegas. Had a few beers and its late, but on the subject of dentistry you may want to check out my website.....www.sharedental.co.uk

[Herb H]

Where can one purchase the dental acrylic resins? I had a source decades ago, but didn't have much use for it at that time.

[Lee Callicutt]

Check in the yellow pages for the nearest wholesale dental suppy house. They'll probably require you to have some sort of business license number, etc. before they sell to you.

[hipster]

There should be lots of manufacturers of resins in the USA but I am in the UK so cant recommend any.


What you want is methyl methacrylate and it comes in liquid and powder form.If anyone else decides to use this stuff make sure you are in a very well ventilated room or outside when you mix it