jwcustomguitars

1933 National El Trovador Dobro

Rescue Mission

Pat. Number-1808756

Serial Number – K143

Manufactured for National by Kay for 8 months in 1933

Biscuit style bridge and cone 9-1/2” dia.

Inset in top for cone: 1-1/16” deep top to lip

Lip: 7/16” thick

Inset dia.: 9-9/16”

Fretboard Radius: 14” (unusual for a resonator guitar)

Fretboard width: @ nut 1-7/8” @ 12th fret 2-9/32

Neck: round “V” Thickness @ 5th fret 1”, headstock slotted

Original scale length: 25-13/16 Appears to have had no compensation but can’t be sure due to the condition.

Mahogany ply top and back, solid mahogany sides, non adjustable steel truss rod, mahogany neck.

Initial inspection: neck at severe upward angle, neck block broken along with side at block and around front bout. Sides and kerf blocks fractured at top just below binding around entire rear bout, and onto forward bout. Entire perimeter of top & back showed either resourcenol or stain on and around binding. Fret board severely warped, cracked and 50 % unglued, “finger holes” worn into board from playing, particularly at first few frets. Neck has been re-fretted at least once. Neck cracked on treble side of truss rod just below headstock, neck socket has “filler” in it from previous repair. Hardware badly tarnished. Finish water damaged white out showing. Earlier repair installed cross grain battens. Not sure if some existed in original. Some obviously installed during repair. Interior Center beam & blocking loose and “rattling”. Some screws missing in the cone cover. One screw missing from one of the machine gears.

Repair outline: Remove fret board, top and all hardware. Re-set, glue & clamp neck block using Gorrilla Urethane Glue. Glue & clamp side adjacent to block with Titebond yellow water proof glue. Glue & clamp all small splinterings around upper sides with titebond yellow, then glue and clamp fractures in sides with same glue. Install USG P-tape (fiberglass tape for skim coat plaster) across kerf block at back to upper reach of kerf block at top around the entire body on the inside, coat tape with thin coat (approx. thickness of the tape) of 2 ton structural epoxy to allow more even flexibility in sides and hold them together as well. Remove remaining hide glue from neck socket and neck dovetail. Wedge crack in neck open force yellow glue into crack and clamp. Use #4 x 5/8 screw under fingerboard to mechanically assist glue for crack repair. Glue joint is not inspectable so screw is to help ensure integrity of the repair. Reset neck using Gorrilla Urethane Glue, (this is a last resort as hide glue doesn’t stick well to filler in socket, causing the previous failure, and this glue will. Down side- neck can’t be removed again). I used a single washer head structural 1-1/4” screw from inside to lock neck tightly in place along with glue clamps. Straitened warped fret board by applying light clamping pressure in open air to equalize moisture in entire fingerboard over 30 day period plus or minus. Faired & fit back of fret board and neck & Re-set fret board using hide glue, future removal is possible in this case. Center beam & blocking was re-glued at all intersecting points except one where a small screw had to be used inside with glue as clamping was not an option. Polished chrome hardware using 3 grades of finishing compound. Cleaned binding. Polished original nut. Scale length not compensated. Some movement from the trauma of its last years is probably to blame for some of it. Scale needed to be nearly ¼” longer. Using all hand tools I mortised the resonator cone shelf back to accomplish the relocation of the bridge without affecting the outward appearance. Guitar is tuned to open E - (E,G#,B,E,G#,B). It would readily accept standard guitar tuning. We could at some point raise the nut to make this a bar only guitar, as long as the open E tuning is maintained. There is considerable distortion of parts from it’s baking, swimming, freezing past. The action on the neck will never be much lower than it is now without compromising the original character of the instrument. THE ONLY VISIBLE NEW PARTS ARE 2 SCREWS, ONE IN A MACHINE GEAR AND 1 IN THE COVER PLATE. Although not original to this instrument they are both at least 50 years old. Internally there are 2 structural screws and some 2 ton epoxy and fiberglass open mesh reinforcing. Everything else is original. Seems to be solid and is quite enjoyable to play. Sound is really nice.

"Original" Gaffed neck

Here are 2 very early resonator guitars I repaired. One was so badly repaired in the past we aren't even sure of the maker or the exact year. The only thing I have discovered with relative certainty is that it was made prior to the 1932 pat. application date. The tell-tale there is that it has solid top and back. All the units after the patent date according to all the info we've found were plywood top and back.

The other a 1933 National El Trovador would be a very valuable instrument had it not been stored in an attic where it baked then froze and then managed to be right under a leak in the roof. As you look at the pix you can see it was really beyond "normal" repair! I just couldn't see these fine old instruments go to the great Dobro home in the sky! I was always taught to respect my elders! And since I'm 64 and these are much older than that I thought I'd give it a shot!

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