The Golden Years Myths & Truths of 50's Guitar construction :

[zeppelin101]

sorry guitarmaker i dont take lessons from the guy anymore so i doubt he would let me take pics of his guitar

[Greco]

While i'm here, here's some of the weirder things I've learnt in the last year or so. No idea what's true:

- The scale on many 50's Les Pauls follows 1 of 2 'hybrid' scales.

- The truss rod channel is straight (not curved) getting deeper at the heel end.

- Brazilian rosewood looks a lot like other rosewood

[gtrmaker]

Originally Posted by GooCart

When you talk about heating the unmixed lacquer, what temperature would you think you need? I talked to a guitar builder here in Sweden and he use to put a can of nitro in heated water to make it "softer", but he doesn't use it without thinner.

Originally Posted by Greco

Also - hot lacquer: So I stick a can of lacquer in hot water, what's the worst that could happen? At what point would things become dangerous?

Magnus and Greco - I am currently away from the shop, but when I return I'll post the C.F. Martin heated lacquer procedure as I learned it since you are both interested.

Originally Posted by Standard_59

Would this one do both - its a Solvent/Plasticizer?

Good observation as they state that it's use with nitrocellulose lacquer. I don't know. However, I will contact them to get their take on the topic.

Originally Posted by Standard_59

Was the Nylon nut 4/6....or....6/6

I read in another thread that it was 6/6. I have not been able to find any.

Originally Posted by Sgt.Pepper

This is how myths perpetuate. Your mention of a red stain shows you're thinking of bursts....

Yes, I was thinking of bursts which is why I mentioned the red stain. Thanks for clarifying that it was used primarily on the '52 LPs. I agree that visually one would be hard pressed to tell the difference under a finish and you would have to catch a whiff of it in order to be sure. Although I have not worked on hundreds of '52 LPs as you have, I have reset thousands of vintage Martin guitar necks and the smell hits you when your steaming one out that instantly identifies it as a Cedar neck.

Originally Posted by Greco

Brazilian rosewood looks a lot like other rosewood

The term Brazilian rosewood is now used as a sales gimmick for anything rosewood or even close to rosewood coming from S. America. That's where the money is! The Brazilian rosewood (Dalbergia Nigra) that is what most everybody is looking for and was used in the 50's is very hard to find these days due to the '69 embargo and the current CITES regulations. There is a lot of hybrid stuff out there and you shouldn't have to pay premium prices for it. Functionally, I don't believe most people will know the difference. Some people like Cocobolo as a BRW substitute, but I find most of it too orange colored and some people are allergic to the stuff. You will know Dalbergia Nigra instantly by it's great odor which is a pleasure to work with and you can instantly smell through the soundhole of an old acoustic guitar.

[Standard_59]

Originally Posted by gtrmaker

I read in another thread that it was 6/6. I have not been able to find any.

There was a thread a while back I read on another forum - and here.

LPF

Its one or the other.

[bfcg]

Originally Posted by Sgt.Pepper

Well, here are some facts that I know to be true. The tops on all production 1950's Les Pauls were glued to the mahogany back with phenol formaldehyde glue. Gibson used microwaves to cure this glue both for the Les Paul tops as well as for laminating archtop plates. At least some of the centre joints of the maple tops were glued with urea formaldehyde glue. The neck joint, headstock ears and most fingerboard joints seem to be hide glue and the frets were glued in with a mixed animal glue which replaced shellac. Many 1955 guitars have a random number of pieces of nickel silver hammered into the maple truss rod fillet under the fingerboard! Other years do not seem to have this.
Not all 1950's Les Pauls are made from Honduras mahogany - some are Cedar and some are African woods and not all 1959 - 1960 Gibson Fingerboards are Brazilian Rosewood - some are other South American woods such as cocobolo!

Look out your window, see that line of torches off in the distance ?, that is the pitch fork mob coming to your house
One thing though, I think it was RF(radio frequency) curing not microwave, hence the Radio glue.

[gtrmaker]

Originally Posted by Sgt.Pepper

The tops on all production 1950's Les Pauls were glued to the mahogany back with phenol formaldehyde glue....At least some of the centre joints of the maple tops were glued with urea formaldehyde glue.!

Are you saying that they used both phenol and urea formaldehyde glues or was this just a typo?

Originally Posted by Sgt.Pepper

Many 1955 guitars have a random number of pieces of nickel silver hammered into the maple truss rod fillet under the fingerboard! Other years do not seem to have this.

What purpose would these metal pieces serve? Do you have any photos of this?

[geochem1st]

Originally Posted by gtrmaker

Who came up with this doozie of a myth? Outgassing plasticizers!

Originally Posted by Fletch

Are you a chemist by chance?

fletch

I am.

Originally Posted by Standard_59

Would this one do both - its a Solvent/Plasticizer?

Dibutyl Phthalate

Dibutyl Phthalate is a typical plasticizer for Nitrocellulose laquers.

Nitrocellulose lacquers are formulated by suitable blending of nitrocellulose resins and solvents.

Plasticizers are defined as “any of various substances added to plastics or other materials to keep them soft or pliable.”

Without added plasticizer, nitrocellulose does not adhere, since the binder forms a very rigid 3-D structure that cannot bend without cracking, and the internal stress is so strong that adhesion is not easily attainable.

Most plasticizer additives used fall within the chemical class of esters. Esters are made from the reaction of carboxylic acids and select alcohols. These include phthalates, stearates, citrates, and a large variety of other esters. The most common are Di-isooctyl phthalate (DOP), Di-butyl phthalate, and Tri-ethyl citrate (TEC). Esters have excellent solvency properties. Other plasticizer classes include ethers, oils, and soft polymers.

Catalysts or accelerators may be used to increase the rate of reaction between a resin and a hardener. They are usually added at levels between about 0.1 to about 1.0% and can be used to either reduce the curing time at a given temperature or alternatively, reduce the curing temperature. Typical catalysts include imidazoles, cyclic amidine, alkyl/aryl ammonium halides, and zinc alkyl/aryl thiocarbamates.

But to answer the question 'do plasticizers outgass'......no. For example Dibutyl Phthalate, even though technically it is a solvent, it has a boiling point of 340 deg. C, and no measurable vapor pressure at room temperature. If any degassing would have taken place it would have been during the RF curing process when heat was applied.

[Fletch]

Originally Posted by geochem1st

I am.



Dibutyl Phthalate is a typical plasticizer for Nitrocellulose laquers.

Nitrocellulose lacquers are formulated by suitable blending of nitrocellulose resins and solvents.

Plasticizers are defined as “any of various substances added to plastics or other materials to keep them soft or pliable.”

Without added plasticizer, nitrocellulose does not adhere, since the binder forms a very rigid 3-D structure that cannot bend without cracking, and the internal stress is so strong that adhesion is not easily attainable.

Most plasticizer additives used fall within the chemical class of esters. Esters are made from the reaction of carboxylic acids and select alcohols. These include phthalates, stearates, citrates, and a large variety of other esters. The most common are Di-isooctyl phthalate (DOP), Di-butyl phthalate, and Tri-ethyl citrate (TEC). Esters have excellent solvency properties. Other plasticizer classes include ethers, oils, and soft polymers.

Catalysts or accelerators may be used to increase the rate of reaction between a resin and a hardener. They are usually added at levels between about 0.1 to about 1.0% and can be used to either reduce the curing time at a given temperature or alternatively, reduce the curing temperature. Typical catalysts include imidazoles, cyclic amidine, alkyl/aryl ammonium halides, and zinc alkyl/aryl thiocarbamates.

But to answer the question 'do plasticizers outgass'......no. For example Dibutyl Phthalate, even though technically it is a solvent, it has a boiling point of 340 deg. C, and no measurable vapor pressure at room temperature. If any degassing would have taken place it would have been during the RF curing process when heat was applied.

Now THAT'S a good answer...

fletch

[gtrmaker]

Yee Haa! Thanks for your explanation geochem1st!

[Standard_59]

Originally Posted by geochem1st

But to answer the question 'do plasticizers outgass'......no. For example Dibutyl Phthalate, even though technically it is a solvent, it has a boiling point of 340 deg. C, and no measurable vapor pressure at room temperature. If any degassing would have taken place it would have been during the RF curing process when heat was applied.

Are you talking about the Glue or the Finish, Geo? Is the Finish also RF cured? Thanks.

[Sgt.Pepper]

My understanding of the RF curing is that it only works where water molecules are present, so would not work for curing lacquer.
I'm very interested to know about the heating laquer technique. I've spoken with ex-Gibson employees who say that the lacquer was supplied ready to spray but was heated to around 100 degrees F and that eight clear coats were sprayed. The colour coats were supposedly sprayed as normal. My personal view is that only the paint sprayers would know for sure and that heating cellulose lacquer to that temperature sounds dangerous. It's not something I would want to try and the only benefit would seem to be a faster curing time.
I am really curious to know about the Martin technique though, and from anyone who sprayed lacquer at Gibson.

[gtrmaker]

I'll post the Martin method this weekend. Until then, here's one finisher's description of how he does it:

"We are running a Grayco HVLP system with a fluid heater. We have been using this system for over 6 years and I am real pleased with the results I get. Depending on the conditions, we will heat the lacquer up to 120 to 135 degrees. Heating the lacquer will not make it dry faster. What is does is makes it easier for the air to break it up so you get a smoother finish. I pull my finish straight from a 5 gallon pail; I do not cut it with lacquer thinner. If I feel the lacquer needs to be thinner, I just raise the temperature a few degrees. When you thin with thinner, you lower the percent of solids. The solids are what help you get a smooth deep looking finish."

The link to this is:

Heating Finishes

[FLICKOFLASH]

Originally Posted by DoeringerGuitars

How about the "Lawsuit" Ibanez guitars touted (Myth) to be an exact replica of a LP? The truth was the lawsuit had to deal with the shape of the headstock ONLY.
I have one of these ($35 at a pawn shop 20 years ago), a lower end 2324 model bolt on, but I love it. I'm refinishing it now back to the original color since someone stripped it a sprayed it black. But it is mahogany topped and backed with a spruce veneer and plays like a dream. Doeringer Custom Guitars and Parts Home Page

The truth their never was a lawsuit IBanez changed on their own accord

[FLICKOFLASH]

Originally Posted by gtrmaker

Very interesting thread and it will be a great thread if those that know come out and play.

I'm not sure about the Cedar myth although I do have some "Spanish Cedar" neck blanks that could easily be mistaken for Honduras Mahogany especially with a red stain on it. Anything's possible!

Flick, when you say "the inlays are inlaided into a radiused route " are you referring to the route depth following the radius of the fingerboard? Also, pleeeeease get your museum contact to participate!

Correct on the routes & the contact has posted & with some very interesting statements I will not out him though

[gtrmaker]

Flick, thanks for the route verification. Any idea on how they did radiused fingerboard inlay routes back then? Do you think they used a pantograph style router with a master? Since the routes were quite shallow and the inlays quite transluscent, did they paint the cavities with light colored paint so that the dark rosewood doesn't show through before gluing in the inlays?

Originally Posted by FLICKOFLASH

...the contact has posted & with some very interesting statements

Ooh! Ooh! I know! I know! That was just enough of a clue for me to figure it out. I want to thank him for joining in and hope he continues to because his insight and knowledge is perfect for a thread on "Myths & Truths". Likewise, I will respect his privacy.

[FLICKOFLASH]

Not many luthiers have even seen a Stradivarius let alone are world reknown for refurbishing & repairing them as well as their own builds

[FLICKOFLASH]

nitrocellulose

a mixture of nitric esters of cellulose, and a highly flammable compound that is the main ingredient of modern gunpowder and is also employed in certain lacquers and paints. In the late 19th and early 20th centuries it was the basis of the earliest man-made fibres and plastic materials.

[FLICKOFLASH]

The switch tips are often refered to as being bakelite. They are actually Catalin

Catalin - Wikipedia, the free encyclopedia

[Ole'Lefty]

Flick--given the mess I had to go through Monday, can you get confirmation that logos were(are) installed with mastic(black), or now as part of a pre-made plate on some LP's? I did ask for confirmation up in the regular LP sub-forum, but had to find the discussion and add it. Otherwise, it is a matter buried here and there. Of course just about every build thread shows it. Thanks, Ole'Lefty

[FLICKOFLASH]

Originally Posted by Ole'Lefty

Flick--given the mess I had to go through Monday, can you get confirmation that logos were(are) installed with mastic(black), or now as part of a pre-made plate on some LP's? I did ask for confirmation up in the regular LP sub-forum, but had to find the discussion and add it. Otherwise, it is a matter buried here and there. Of course just about every build thread shows it. Thanks, Ole'Lefty

I always thought they were set in a route submerged in a black epoxy ( not preinlaid in a black board as they were later on

[gtrmaker]

Originally Posted by FLICKOFLASH

I always thought they were set in a route submerged in a black epoxy ( not preinlaid in a black board as they were later on

Ditto.

[Loserface300]

Originally Posted by DGNRepair

LOL

nylon saddles on some guitars

old style logos (gibson pre-norlin logo)

PAF pickups

P90s

Cotton sheilded wiring

bumblebee caps

[Sgt.Pepper]

Here's one. On some higher spec Gibsons, the white saddles were actually carved from bone! People usually mistake these for the plastic ones but if you look, you will find bone ones, mostly on Jazz guitars. My 1961 SG Custom has original bone saddles as does my friend's Byrdland.

[Ole'Lefty]

I used an old world/fashioned word-mastic. It is used to describe a glue like substance, often with a solid or colorant added. It is my understanding that some, but not all LPs, in more recent years have used a fiber headplate, precut for the pearl, and even in those, there is a black epoxy used. That has been the source of questions about seeing an additional "outline" of the logo-I asked about this upstairs, but no response. I found a discussion with photos and linked it in up there. Thanks,O'L

[Standard_59]

Originally Posted by Ole'Lefty

It is my understanding that some, but not all LPs, in more recent years have used a fiber headplate, precut for the pearl, and even in those, there is a black epoxy used.

There's a company in Germany selling a batch of those Headplates - from the 70's IIRC. You could ask them, Mike.

crazyparts@t-online.de

[ex-nihilo]

Here is some of the fascinating information I have on original late 50s bursts.



1. Virtually all of them were made out of wood.
2. Glue held the pieces of wood together.
3. Many were painted really neat, but they faded in the sun. But that is NOT why they are called "sunbursts".
4. Magnets were wrapped in wires and stuck under the strings. When plugged in, the magnet/wire thingies made the guitars MUCH loader (when an amplifier was used).
5. They are very expensive today.

Ok, maybe I should leave it to the experts.

Seriously, this is a great thread.

[geochem1st]

Originally Posted by Standard_59

Are you talking about the Glue or the Finish, Geo? Is the Finish also RF cured? Thanks.

Thanks for pointing that mistake out. I was looking into RF curing of glues, at the time that I wrote my response, "heating" was on my mind as thats how to best degass a solution (heating/vacuum), and the RF remark should not have been mentioned there.

The heating method used for 'thinning' the laquer is not high enough to degass the common plasticizers used. Plasticizers are just not volatile. They are known to migrate, but there is no degassing taking place.

[Standard_59]

[gtrmaker]

Originally Posted by Standard_59

There was a thread a while back I read on another forum - and here.

Thanks for the correction. The consensus seems to be 4/6 was the original composition and since it's apparently not available anymore then 6/6 is what's available now.

[Fletch]

Originally Posted by gtrmaker

Thanks for the correction. The consensus seems to be 4/6 was the original composition and since it's apparently not available anymore then 6/6 is what's available now.

Wasn't the story on the nylon nut that someone found an old hunk of nylon at Gibson that was marked "4/6" and then somehow it became nylon from the 50's? And then it was cut into blanks and guys were sucking them up for silly money like a few hundred bucks a pop because they thought they had something? But there wasn't really any reason to believe that that was the truth other than hearsay?

And isn't there really practically no difference between 4/6 and 6/6, and no way to prove which is which by looking at it?

If so I have a TON of 50's 4/6 nylon nut blanks I'll sell for $100 a piece...

I'm fully prepared to stand corrected on this.

fletch