DIY Workshop: Gretsch Anniversary to 6120 conversion (Part One)

Huw Price finally fulfils a long-held ambition as he takes a well-worn vintage Gretsch Anniversary and turns it into a 50s-style 6120 dream machine.

This is a project I have wanted to do for several years. The basic idea was to turn a derelict vintage Anniversary into my dream 50s-style Gretsch 6120. The first task was to source a suitable donor guitar that was structurally intact – and that took a while.

Many of these old Gretsches have been retro-fitted with other pickups, and holes have been routed to accommodate them. You’ll often see bashed-in sides where the jack socket has taken an impact, and you can be pretty sure any old Gretsch will need a neck reset at some point. Binding rot is another perennial problem with vintage Gretsch guitars – and, despite various theories, nobody seems entirely clear what causes it.

Patience was rewarded and eventually this Gretsch Anniversary was offered for sale on the Gretsch Discussion Pages by a minister in Tulsa, Oklahoma. He was selling it on behalf of one of his parishioners, Clyde, and it even came with a bit of a back story.

Clyde told how he had been looking for “an electrified Gretsch” many years ago and his brother bought this one for him after finding it in “the largest pawn shop in Texas”. When Clyde got the guitar it had already been refinished in black, and he proceeded to strip off the lacquer with the intention of restoring the Anniversary to its original two-tone green colour scheme. Clyde got as far as stripping off the black lacquer and, to be fair, he made a good job of it, but never got any further.

Pic 1 - Pre restoration
Before starting work, a set of Gretsch tuners, a bridge and a V-cut Bigsby from a Duo Jet were thrown on the husk to test if it was solid enough to tune up and whether it was playable. In both cases, the answer was yes, but only just

The grand plan

Although it had been painted black and Clyde wanted to go green, the amount of orange stain suggests that somebody else had intended to make this guitar look like a 6120. The back and sides are fairly uniform in colour, but the top has been heavily sanded and looks a lot lighter. Tell-tale scratch marks all over the body and neck show that course abrasives had been used, so a lot of sanding will be required to prep this Annie for a clear finish.

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Pic 2 - Scratchy surface
 You can see scratches on the surface of the top. The worry is whether the scratches can be sanded away without going through the outer layer of the plywood

Trestle bracing is a crucial feature of 6120 Gretsches that were made between 1958 and 1961. Trestles also featured on the top-of-the-range White Falcon, as well as the lowly Anniversary. We can discuss the minutiae of trestle bracing further down the line, but suffice to say it was Gretsch’s response to Chet Atkins’ request for a guitar that sounded and sustained more like a solidbody.

While Gretsch carried on installing trestle braces in the 6120, Anniversaries made after 1960 didn’t have them. Gretsch guru Edward Ball helped me date this guitar, and based on production batches he concluded it was made late in 1960 or very early in 1961. So no trestle braces in this one, which means I’ll have to put them in myself.

Late-50s 6120s and Anniversaries had ebony fingerboards, but Gretsch swapped the Annies over to rosewood when it dropped the trestle bracing. Early examples, such as this one, were not bound and the thumbnail markers continued to the edge of the board to provide a front and side view.

Although it’s in a right mess, this fingerboard is a lovely old piece of rosewood, so my intention is to re-use it.

Pic 2 - Fingerboard
This guitar has been played a lot and divots in the fingerboard have been packed with filler. To even up the colour, this area of the board has been brushed with black paint

However, the edges are so worn and damaged I will be adding binding. I’ll also keep the nut rather than install a 6120-style zero fret because, like Brian Setzer, I prefer the look and feel.

A single HiLo’Tron pickup would once have been installed at the neck – along with various other pickups, judging by the Annie’s assortment of filled holes.

Pic 4 - Extra holes
The shadow on the left where the fingerboard extension meets the body is glue squeeze out. This provides an opportunity to test what type of glue was used and whether steam can be used to loosen the joint

My plan is to rout the top and install a pair of Filter’Tron humbuckers. At present, I’m undecided about the control layout because I never use most of the knobs and switches on my Tennessean. So a stripped-down arrangement with a pickup selector, master volume and master tone would suffice. One of the F holes has broken and both will need to be enlarged and bound for that classic 6120 look.

Pic 3 - Broken F hole
Originally, there would have been four holes for the pickup surround, two for the pickup and one for the pickguard. We count three extra holes – and all have been plugged with wood

I’m also concerned that the top has lost so much of its thickness through over-sanding it may need re-veneering. The headstock will have to be re-veneered and bound too, and I’ll probably end up cutting a new logo and horseshoe inlay. But before any of that can happen, the neck will have to come off.

Glue test

Firstly, I had to determine whether the glue used to fix the neck was actually hide glue. This is important because steam can soften and melt hide glue, but it won’t have any effect on urea formaldehyde or epoxy glues.

Pic 4 - Glue Squeeze Out
The only damage to the body is a missing chunk of wood from the F hole on the treble side. This will have to be repaired and the F holes will be reshaped

Under the fingerboard extension,  there was a considerable amount of squeeze out. I applied masking tape to protect the body and eased a hacksaw blade under the tongue to saw into the glue.

Pic 5 - Sawing squeezeout
To obtain a glue sample,  masking tape is applied to the guitar body for protection and a hacksaw blade is slipped under the neck. The resulting glue dust dissolves in boiling water, so we are good to go

Before long, I had a nice pile of glue dust, which I put into a glass bowl and covered with a small quantity of boiling water. The glue dust dissolved quite easily, so I was confident that steaming off the neck was a possibility.

Screw removal

Gretsch had an unusual method of attaching necks. Actually, at the risk of appearing Python-esque, let’s try that again. Amongst Gretsch’s unusual methods of neck attachment, there was the infamous neck screw. Typically, vintage Gretsch guitars have a circular dot inlay in the vicinity of the neck join.

Depending on the model, this can be located on the back of the heel, the side of the cutaway or the rear of the body. Measuring half an inch in diameter, the plug conceals the head of a large wood screw that Gretsch would drive through the body or neck and into the neck block or the neck tenon.

Whether this was used to help secure the neck in position as the glue dried, or as a failsafe in the event of glue joint failure is a matter for conjecture. The actuality is probably a bit of both. Regardless, the screw must be taken out before the neck can be removed.

If the side dot is inside the cutaway, performing a neck removal is that bit trickier. Fortunately, the Anniversary and 6120 models all had plugs on the back of the neck heel, so drilling them out is easy. It’s recommended that you use a Forstner bit of the same diameter as the original plug – or slightly wider.

Mark the centre point of the plug, carefully position the Forstner bit and start drilling. Before long, the Forstner bit’s centre-locating tip should hit the screw head, and that will be as far as you can go. Swap over to a regular drill bit with a 3/8” diameter and drill slowly into the centre of the hole to expose the screw head.

Pic 6 - Screw head 1
We weren’t able to get in as far as we would have liked with the Forstner bit, so this will need tidying up later. The screw head can be seen inside the hole

You may also need to use a craft knife or dental tool to pick out any stray fibres. With the head fully exposed, take a large flat head screwdriver and turn the screw anti-clockwise – it should come straight out.

Pic 7 - Screw coming out
The screw came out quite easily and measures 1.75 inches long

That’s the theory, but on this guitar the screw head was located quite close to the surface. This prevented the forstner bit from cutting into the heel cleanly, so the plan is to tidy this up once the neck has been reattached and the screw reinstated.

Steaming the neck

Next to removing the top, taking off the neck was the procedure that worried me the most, because I had never done it before. When I write these articles, I try to use non-specialist tools wherever possible, but from time to time you are obliged to buy the correct tool, and if you’re planning to remove a set neck a steam needle attachment is essential.

You can buy steam needle attachments from luthier suppliers and they are available with or without a hose for attaching to a steam generator. I would suggest going for the proper hose because the problems are twofold – heat and pressure. If you use ordinary rubber tubing, you’ll probably end up blowing a hole in the tube.

I went to a car brakes specialist and bought some hose that was described as being suitable for up to 20 bar and 100 degrees C. Even so, I ended up blowing a couple of holes in the pipe and jubilee clips were barely able to keep the hose attached.

Pic 8 - Burst hose
Although rated for 20 bar,  the steam blew through the hose on a couple of occasions. Stay safe by wearing oven mitts and goggles

If, like me, you try to save money by buying the steam needle without a hose, you may regret it. Various appliances can serve as steam generators. Some people use the milk steamer attachment of coffee makers and others use pressure cookers. I took my feed from a Vaporetto steam cleaner.

Once you have your equipment sorted, you’ll need to drill holes into the guitar to insert the steam needle. Gretsch Anniversary necks are attached via a traditional dovetail joint. The procedure is to remove a fret then drill down into the joint through the fret slot. Replacing the fret should conceal the hole.

Pic 9 - Drilled board
The 14th and 15th frets were removed and 2.5mm diameter holes were drilled into the slots to insert the steam needle. Of the two, the 14th fret seems to be the best location, and both holes should be about 3/8” away from the fingerboard edge

Opinions differ as to whether you should drill through the 14th or 15th fret. Noted Gretsch specialist Curt Wilson (www.oldschoolguitar.net) advocates the 14th, right where the neck joins the body – and having tried both I think he’s correct. Two holes are recommended because steam injected through one hole can vent out of the other.

The diameter of the drill bit should be slightly larger than that of the needle and you should start the holes about 3/8” from the edge of the fingerboard. Try to follow the line where the heel meets the body, but angle the bit very slightly towards the centre to follow the shape of the dovetail.

If you strike lucky, you’ll feel it when the bit reaches a void in the joint; that’s where you want the steam to be. Steaming off a neck is a messy business, so if you can’t carry out the process outside try working over a sink.

Pic 10 - Steam-in
Steaming a neck joint is a wet and messy business, so work in an area where the water isn’t going to be an issue. Here, you can see steam venting out of the side of the neck joint

If that’s not possible, put down loads of towels to soak up the water. It’s also worth protecting the top of the guitar and the fingerboard with towels and continually mopping the water off the guitar rather than allowing it to pool up. Protect yourself, too, with oven mitts and goggles.

I found pushing the needle too far into the hole created excessive back pressure. Starting shallower and gradually increasing the needle depth as the glue softened up produced better results. Also remember to insert steam in both drill holes and move between them. It takes quite a while before the glue gets hot enough to begin softening and loosening. In this case, it took well over 20 minutes before things started moving.

When the steam really begins to penetrate, you may find that it shoots out from the sides of the heel. I was able to hasten the process by easing a very thin bridge removal knife into the gap between the heel and the body. It was particularly easy on the treble side because the glue melted away to reveal a 2mm gap that had been packed with glue and sawdust.

When the time feels right, you can remove the needle and try wiggling the neck back and forth. If the glue is soft enough, you’ll feel it move. Some luthiers who do this job regularly use special neck removal jigs to ease necks out of pockets.

I eased this one upwards using a side-to-side motion and eventually it pulled free, but if I had a jig I would have used it. Scrape away the glue while it’s still soft and wet to clean up the joint.

Pic 11 - Dovetail cleanup
Knife blades and a chisel were used to clean the old glue from the dovetail joint. It’s best to do this while the glue is still soft from the steam

Any old glue left inside the dovetail will weaken the repaired joint. When I was cleaning up, I noticed two types of glue. The original hide glue was easy to clean up with a chisel, but there was also a rubbery and gelatinous glue residue at the bottom of the joint. Somebody may have forced PVA glue into the joint at some point, presumably because the neck was pulling away from the body. Unfortunately, a chunk of neck block came away along with the neck.

Pic 12 - Chunk off
A piece of the neck block came away from the body along with the neck. Fortunately, it was a clean break and the repaint will be undetectable. The glue joint will also be stronger than the original wood

This doesn’t appear to be uncommon with Gretsch neck resets, and this clean break means the chunk will glue back on quite easily. I was also surprised to find a mahogany shim on the bass side of the dovetail that was a quarter of an inch thick.

Pic 13 - Mahogany shim
Gretsch’s dovetail joints weren’t exactly precise. A mahogany shim was used on this guitar, but you will sometimes see pieces of cardboard

Then again, the shim my mate Daniel discovered when he removed the neck of his ’59 Anniversary was actually a piece of cardboard. Old gold my foot!

Pic 17 - Thumbnails
After a few seconds under a hairdryer, the thumbnail markers could be lifted straight off the board. I placed them onto a piece of masking tape, put another strip across the top and numbered them up accordingly

After steaming off a neck you should put everything to one side and let the guitar dry off. I also removed the thumbnail markers and put them somewhere safe. The next job will be removing the top, and work will then begin on the neck restoration. But that will have to wait until next time.

Check out the other parts of this project here.

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