14 Fret Nationals Laminated 1/4 inch support

[The Beltona Kid]

I am again in communication with a seller, this time on reverb who has a repainted blue 37-38 Supro Collegian. Based on pics from 4 years ago and today, there is a line approx 1/4 inch below the fret board starting at the heal extending out on both sides toward the front of the neck. His explanation is as follows:
 
Quote:

That is not an issue. The necks on 14-fret Nationals and Dobros have a lamination of 1/4" of hard maple under the fingerboard. That was what replaced the truss rod. That line often shows up in the finish and is often seen on the face of the headstock, too. It is a glue line between two materials that shrink at different rates. The only time you can't really see it (if you know what you are looking for), is when it is hidden by a refinish. But as the wood and lacquer continue to dry, it will show up. That is not a defect. That is how they were built.

Vintage Style Guitars Mar 23, 2022 02:48 PM

Wondered if this is correct.

Best,

Malcolm

Las Vegas, NV

[snakehips]

Hi there ,

That explanation is entirely correct. It is often referred to as a sandwich layer - and was common on Nationals from around 1935 onwards.

I have two 14 fret Duolians - one from 1934, with a one-piece neck.
And then when I BOUGHT the1935 Duolian on ebay.
When I got it home, I noticed a line across the front of the headstock, parallel with, and about 1cm from the nut.

My instant reaction, having never seen this sort of thing before, was that the headstock had had broken at some point in it’s past, and it had been rather expertly glued back together, and there was just a tell-tale fracture line still showing - AND that the seller had omitted to tell me, rather sneakily !!

Of course, this was not the case. It is one of the guitars with the sandwich layer, between the main bulk of the neck and the fretboard. These ones can be absolutely fine BUT I think this way of strengthening the neck was never as successful as National hoped, compared to installing truss rods, like most guitar companies were beginning to do.

This guitar’s neck was rather banana’d BUT my luthier managed to sort it all out - by removing the fretboard, planing the neck flat, and installing twin carbon-fibre strengthening rods inside, then a new fretboard over the top.
NB. I have had a few Nationals restored this way, and a few Nationals restored with a hidden adjustable truss rod installed into the necks (adjusted from the body end, through a small hole drilled through the side of the resonator well, under the fretboard extension, by stilling an Allen key through the hole into the trussrod end).
Comparing the sound of those guitars, my personal experience is I feel the carbon fibre rods deaden the sound of the guitar a bit.

[The Beltona Kid]

Richard, Wow! I can't thank you enough for the history lesson. I put an offer in on this blue Collegian about 3 hours ago. I think it is the same one referred to as the Mike Eskimo Pontiac Engine Block Blue Supro; as it is in Seattle and a forum link by Damflask lead to a comment by Ric Besser that he had worked on this guitar in the past. The last all original Collegian went for $2500 on Reverb 10 months ago. I based my offer on that price; this guitar not having the original paint. Mojo not withstanding, I will not overpay for a refined guitar. Take Care, Malcolm

[snakehips]

I've just arrived at work, but when I get a chance (probably tonight) I'll post some photos of my two Duolians to show that sandwich layer.