Gibson Army Navy question

[peter.coombe]

I quite enjoy repairing vintage mandolins and giving them a new life, but this time someone has been there before so has not been so enjoyable. It has been glued together with some sort of unknown stubborn glue, definitely not hide glue, and finished with a thick black lacquer. It is a Gibson Army Navy with the usual crack and sunken top. Got the back off with difficulty and the cause of the problem was then obvious. End of the brace under the bridge had come loose. The previous person had replaced it but had not tucked the ends into the linings. Have managed to get the brace off and flattened out the top. In the process of getting the back off the lacquer blistered due to the amount of heat required to loosen the glue so I stripped it off the back. I am fairly certain there is a layer of epoxy under the lacquer.

First question - do these flat tops have an induced arch in the top? The back still has the original brace and it is dead flat. The previous person installed an arched brace on the top with the arch fitting my 15in arch template. Not sure if it is correct, but suspect not because the top relaxed to flat once the brace was removed. There are also large Spruce patches glued to the top to cover other earlier splits. but appear to be stable so I don't want to touch them.

Second question - What were the colours of the finish. Looking at pictures it looks like a dark brown top and either very dark brown or black back and sides. Can't really tell if the back and sides are black or very dark brown from the pictures. I would like to strip that thick lacquer off and refinish with varnish and make it look much more like it was originally.

When I got this I thought tricky, and quoted a large sum. The owner swallowed a couple of times, consulted his other half and said go ahead, so I can afford to spend a fair amount of time getting it right.

[sunburst]

The only color I've seen on them is Sheritan (sp?) brown; whole thing.
I restored one a couple of years ago. I'll look at the pictures and see if I used the original top bracing. As i remember it, there was a slight induced arch top and back, but I'll get back to you after I look up the pics.

[sunburst]

Looks like I kept the top braces in place and replaced the back brace. I can't really tell from my pictures, but the reflections in the finish of the restored mandolin seem to show some induced arch.

[peter.coombe]

Thanks John. It does look like an induced arch. Sheritan brown makes sense. I have an A1 in Sheritan brown about the same vintage so I should be able to match the colour to that.

[Tom Haywood]

Maybe contact Terry Majewsky at Crystal Forest Mandolins to see what he knows. I researched the induced arch for these about 4 years ago. The best info I could find at the time, as I recall it, was that Terry's "campfire" plan is based on the plan that Stew Mac used to have, which is based somehow on the Gibson Army/Navy. His plan indicates a 10 foot radius for the top brace, but his internet listings discussed an 8 foot radius and I think the math on his plan works out to 96". All the info I could find indicated that the top and back braces on the A/N have the same radius, but that may be wrong based on what you have. FWIW, I use a nine foot radius on my new build campfire styles because the math makes more sense to me for good projection, but it does affect the bridge height. Please post whatever you discover or decide about this.

[MarkELynch]

The DY is described in this Cadenza advertisement as having back and sides finished in “Adam brown” and the top finished in “golden brown” with a satin polish throughout. I have two examples from the same 1920 batch (FON 11346), both match this description.

[peter.coombe]

Interesting. The one I have does not have Maple back and sides, it looks like mahogany to me, definitely not Maple. Also I don't think the headstock is veneered, it looks like it has been painted black.

[sunburst]

Yes, lots of Gibson pegheads were painted black.
Perhaps it was a situation similar to the J-45 guitars. Those were made with several different woods for back and sides, and the top could be either spruce or mahogany.

[rcc56]

I haven't seen an Army-Navy in years, but a mild arch certainly can't hurt anything. It's more stable structurally. Even most Chicago made "flat tops" have a little bit of arch. Sheraton brown sounds like a good choice to me. It's an appropriate Gibson color for the period.

For what it's worth, the old edition of Gruhn's guide describes the A-N model as having a "brown stain finish."

There used to be a guy around here that would reglue braces, cracks, and open seams with a department store hot glue gun. I hope I've seen the last of his work.

[sunburst]

There used to be a guy around here that would reglue braces, cracks, and open seams with a department store hot glue gun. I hope I've seen the last of his work.

...and then there are those who just pour glue all over cracks and loose braces.

[sunburst]

They didn't make it as far as the "thick black lacquer" because they didn't finish stripping the original finish, so I guess i got lucky only having to deal with "stubborn glue".

[rcc56]

...and then there are those who just pour glue all over cracks and loose braces.

Awww heck--- that's just "mojo."

Tell me? Exactly when did "mojo" become a positive term for "beat to hell and abused by Neanderthals?"

It should be a term that means "run away."

For those of us who work on instruments, some might call it job security. But when I give an estimate on one of these jobs and watch the customer cringe, even though I might end up making less than minimum wage in hourly labor, I don't feel very secure at all.

[Walt]

Where is the top brace positioned in relation to the bridge? In front of, directly under, or behind?

[sunburst]

The bridge sits essentially directly over the main top brace.

[peter.coombe]

Thanks to all, has been useful. I have started to strip the lacquer off the top and sides. Looks like there is a layer of epoxy under the lacquer even on the top. Will have to be scraped off. Back and sides not too difficult, but the top is tricky. Groan. I am a bit worried how the staining will go if I can't get all that crud off. The large amount quoted is starting to look like an underestimate. Anyway it has been carefully measured and just for a bit of fun I might make one. These mandolins certainly do embody the KISS principle.

[oldwave maker]

Traditional Army-Navy crack repair in Oblivione, South New Mexistan (sister city of Alice Springs) requires sufficient quantities of popsicle sticks and ample flow of resorcinol marine glue, at least for the navy part. Wish I'd had a few before shots of this wreck. Any induced arch had been baked out of it decades ago. The reranch goldtop spray can finish and a 2 kilogram cast tailpiece draw the eye away from its KISS roots!

[Tukanu]

The A/N that I am working on has an arch of 8' to 10'. Seems like a lot for such an old instrument, but the braces look original.

[peter.coombe]

8 or 10" is a lot. Is difficult to know if that really is the original arch after 100 years. I did see that one for sale and was tempted, but when I worked out the transport costs, declined.

Any way has been progress. The crack is glued and new brace is glued in. Have also got all the thick lacquer off. I can barely believe it was so thick. Was like peeling an orange. Unfortunately some slivers of Spruce came off with the lacquer, but the back and sides came off reasonably clean. At first I thought scrape it off, but after a few minutes of scraping I had a very blunt scraper and not much to show for it. So another approach was needed or I would be scraping until Christmas. A hot iron did the trick, but still needed to scrape off the epoxy that was under the lacquer. The epoxy was on the top as well as the back and sides!

Now all the crud is off, I think the back and sides are American Cherry like the Alrite in the other thread, not Mahogany as previously stated. The two halves of the top are not matched. One half is dead on the quarter with medullary rays, the other half is off the quarter.

Back is now glued on. Need to work out how to treat those dimples where the Spruce peeled off and then stain.

[peter.coombe]

Now stained with water based analine dye and first coat of shellac. This one will be a shellac finish, French polished. Is starting to look like a Gibson Army Navy mandolin now instead of a shiny jet black blob.

[Tukanu]

I just noticed the triangular maple neck re-enforcement barely visible in the peghead. Mine looks the same.

[peter.coombe]

Now finished. Has been a bit of a marathon, but the end result looks quite good. With light strings, sounds ok. I have also finished my copy and here was the surprise. Mine sounds way better than the original. I was hoping for better sound, but it has far exceeded my expectations. Why it sounds so much better I am not sure, but I do have a few theories. I have been quite enjoying it and will probably make more. The top is Red Spruce from a guitar top that split, and the back and sides are Tasmanian Myrtle, neck is queensland maple stained to look like mahogany. Bits of wood that have been sitting around for a long time waiting just for this project. The changes from the original have been a couple of extra braces each side of the soundhole and 3 braces on the back, plus a few modern features such as carbon fibre in the neck, radiused fingerboard, bone nut and adjustable Brekke bridge. Can't get those cloud tailpieces any more so used a clam tailpiece from Stew Mac.

Here they are, the Gibson on the left