build thread Project: "some Les Pauls"

[Prostheta]

Relatively simple project remit - two Les Pauls made from Khaya Mahogany and Karelian Birch. One is to be receive a relic'ed "Gibson-ish" look with a black headplate, faded honeyburst, etc. whereas the other is to be more or less natural and is being made as a surprise birthday present for my wife. Shhh!

There are many threads around the net which detail "vintage" Les Paul builds better than I can so I will merely make reference to these rather than rehash the information in them or worse, duplicate contentious information and create more confusion over certain details. The greatest resource of information by far - especially for the carved - has to be Scott Wilkinson's vintage burst build from MLP. Google "exnihilo les paul"!

The build is more or less by the numbers according to both Scott's and other people's reference plans such as John Catto, etc. As usual, I redraw all plans in CAD to rattle out any inconsistencies within and between people's measurements to leave myself with one reference source. Variations exist because of people's own interpretation of the "ideal" Les Paul from the instrument(s) they happened to be measuring at the time, plus Gibson's own adjustments and inconsistencies. This really means that there is no real gold standard as such. Apart from a Standard Goldtop which goes without saying.

A unified CAD plan also gives me perfect opportunity to take arbitrary measurements during the build process and to tweak things as I want without breaking the way things work together in one design or another. A specific change introduced was my usual inclusion of a zero fret. Apart from being a purely personal preference, I do believe that done well they improve an instrument's playability to a significant degree. Beyond that we are looking at a very Les Paul-ish pair of Les Pauls.

Two Khaya body blanks and two Birch tops were glued up and thickness sanded to 46mm and 17mm respectively. I prefer to scarf my headstocks as opposed to creating weak short grain, plus this happens to be more economical in terms of stock availability. The quartersawn Khaya neck blanks were cut slightly long and wide at 612mm x 80mm x 45mm.

First order of the day was to get templating. Complicated builds like LPs tend to collect large template sets and I like to spend time making sure these are treated as well or better than the instruments built from them. The first body template locates the centreline (which is on the glueline anyway...a luxury), the upper switch hole location, wiring channel path and the control cavity layout.

Rather than cutting these in the template and using a bearing-guided router bit referenced by the template, I transferred the locations and centrepoints and sunk these completely through the Khaya with a 40mm Forstner bit. This deviates from "vintage correctness" but that is not a specific priority anyway. My templates indicate where to draw crossed lines in order to cross-reference the centre point of each drilling location. In the case of the electronics cavity this consists of four lines drawn in a "hash". A simple straight channel connecting the switch hole to the control cavity was routed into the top of each body blank. This also intersects both pickup cavities to facilitate wiring.

Two screw locating holes were drilled through the Birch tops in the areas where the bridge pickup and neck tenon will be routed out. Immediately prior to glueup, the mating surfaces of each top and body were thickness sanded down to their destination sizes of 44,5mm and 16mm and blasted clean with compressed air.

A good coat of Titebond I was applied to the underside of the top with a notched plastic spreader and dragged over the surface several times with excess glue removed. This helps to ensure the surface is fully penetrated and wetted. The mating face of the Khaya was very lightly misted with water to improve glue penetration. I've found that this method of glueing also reduces the tendency for parts to skate under hydrostatic pressure which is the source of much self-kicking and flying body parts.

The centrelines of the tops were aligned to those of the bodies and allowed to set up slightly for a couple of minutes to reduce any movement in the press. The tops were then screwed through to the body and clamped for 30 minutes in the hydraulic press at a pressure of around 50kg/cm² (720psi) and subsequently left at a lower clamping pressure for as long as the timer would allow me to.

The clamping time gave me ample opportunity to hunt down a longer bearing-guided router bit. As can be seen, I was only able to work through to around halfway in the Khaya. No matter, and certainly nothing to stop me from moving processes forward.

Apologies for the relative lack of photography at this stage. My phone has been deciding to crash at inopportune moments such as during photography. I soon get bored of waiting for it to reboot and crack on with work instead. Standing-Around vs. Busy-Working is little to no competition.

[ScottR]

Let's see if the clamp police get excited. Two bodies with just one clamp. (Yes technically a press, but that is just semantics)

SR

[Prostheta]

The press is technically four hydraulic clamps. Two at a time ensures that the pressure is equal above both pairs of pistons. Any excuse to make more than one at a time?

Incidentally - since one of these builds is for Nina - one of the bodies has been reduced in thickness to make it a litter more slender. Ultimately the length of the switch and jack placement are what limit this. I decided to leave this part of the thicknessing until after the press was out of the equation.

[ScottR]

More than one at a time? You could put dozens in that thing.....but you bring up a good point. They would all have to be of equal thickness, or you would need a pretty good supply of accurate shims on hand.

I have learned about switches and thickness requirements. My current use of a blade style 5 way influenced the thickness on my current build much more than I anticipated.

SR

[RestorationAD]

Ummm... the clamping police give up. That thing is awesome. I might put one in my budget.

[Prostheta]

There's nothing wrong with a good old cast iron "cider press" style clamping setup. This might not generate sufficient overall pressure but the principle is sound. Plus the clamp police would say "add one to each corner too".

http://www.ebay.com/itm/ANTIQUE-VINTAGE-CAST-IRON-BOOK-BINDING-PRESS-BEAUTIFUL-/321185367436

[Prostheta]

Here's a photo update on prepping the neck blanks. It shouldn't require much explanation.

The blanks were cut and jointed perfectly square. The top surface has two mm of slush which is destined to be planed off immediately prior to glueing on the fingerboards. This is to give myself room to remove any dings and surface oxidation in the time between initial cutting and final glueup. Breathing room makes all the difference sometimes. The side and profile was marked up with a 14° scarf at the top end, neck taper and recovery piece for the headstock.

The tenon is parallel to the sides and bottom of the blank. To remove the material, the majority is cut on the bandsaw and the remainder on the router table.

This leaves minor machining marks which are easily removed, although this is not 100% necessary in a snug neck mortice since they are the smallest fraction of a mm. Any additional playing around with the tenon risks it becoming uneven. Caliper measurements showed both tenons a hair over the desired 38mm after the final pass.

I am the first to admit that I need more practice with a razor saw when cutting tenons. I approach these cuts with a bit of a margin which I intend to clean up with chisels. The first step in a cross cut is to start either end to slice the grain and prevent it blowing out. This isn't too important for this work since the blank is quite over-width. All that matters is that the final surfaces where seams show around the heel are square.

Completed tenon after cleaning up with a sharp 12mm chisel. A fraction of a mm remains to be removed which will be finessed at fitting time. I will also lightly "undercut" the inner face of the heel towards the tenon corners so that the bearing edge against the body is the outer seam. Ultimately, this part of the heel is only end grain and provides little to no glueing strength. Pulling in the outer seam tight is far more important.

[sdshirtman]

You've got some monster equipment there.

[Prostheta]

Not mine, the schools. The bandsaw turns out to be a little sloppy and fractious, plus the router table sucks. No fine lifters. I'm grateful but it is not what I would choose.

[verhoevenc]

I've never built a heel like that. But I've always wondered if folks are back/cutting the heel, like when fitting an acoustic neck, to make getting a tighter neck joint easier? Like so, so you're only sanding a small area to get the fit right:

Since that surface isn't structural and all.

Chris

[Prostheta]

That's exactly it, Chris. Like you say, even the flattest most airtight mating work between the heel and the body with the best glueup has no practical advantage structurally, tonally or even bragging rights-ly.

Any advantage I can get in making the seam as cosmetically perfect as possible is far more important. Currently that angle is shy of what the neck angle will be on the body, so it will be cut back after I transfer that across. The intention is for a target of about 4,4° however this may vary after carving the top and taking a read on the bridge height.

It's a shame that dovetailed or bolted necks have the advantage of mating pressure which LP necks do not. The mortice will be cut a hair longer than the tenon so that I can comfortably draw the neck backwards into the mortice using pressure against the inner face of the heel. That should be a job that will need concentration and organisation since glue will be setting itself up on the final run!

[RestorationAD]

That's exactly it, Chris. Like you say, even the flattest most airtight mating work between the heel and the body with the best glueup has no practical advantage structurally, tonally or even bragging rights-ly.

Any advantage I can get in making the seam as cosmetically perfect as possible is far more important. Currently that angle is shy of what the neck angle will be on the body, so it will be cut back after I transfer that across. The intention is for a target of about 4,4° however this may vary after carving the top and taking a read on the bridge height.

It's a shame that dovetailed or bolted necks have the advantage of mating pressure which LP necks do not. The mortice will be cut a hair longer than the tenon so that I can comfortably draw the neck backwards into the mortice using pressure against the inner face of the heel. That should be a job that will need concentration and organisation since glue will be setting itself up on the final run!

You two better watch it the voodoo police might come snatch you up! 999 Emergency.

[Prostheta]

Well you know I am not one to take these things on faith. Refer to my signature.

[Prostheta]

Oops. I wrote a massively long post update and hit BACK. Cue swearing. Here are photos so you can fill in the blanks. Sorry. I scaled back this project to one Les Paul on the basis that I am not sure I can afford to pour money into two sets of pickups, two sets of tuners, two sets of hardware, etc. This Les Paul will be my wife's xmas present, potentially birthday present if it needs to sit curing through New Year.

Using the thickness sander and a sled to cut the neck and pickup planes. The natural wood knot "defect" was added in specifically. Since my wife and I believe that it is important to remember and be reminded that something was a tree once, these kind of things matter.

Neck plane (4,2° starting at the very top of the binding)

Pickup plane (angle describing a plane intersecting the line where "the scale ends" and the end of the fingerboard).

[Blackdog]

Looking great !

I see you're in Finland, if you're still looking for longer router bits have a look here.

[Prostheta]

Actually that is where I bought the binding and my new cutter from. I'm thinking of putting in a more sizeable order when I get my student loan through (that makes me feel half the age I am, saying that) and a flush cut trimmer has crossed my mind, certainly. Cheers :-)