Mary's 7-String

[Akula]

I did the fretboard marking-up in my normal fashion - I mark two lines parallel to the centreline in pencil, then use a combination of a meter rule (with .5mm resolution) and digital callipers to mark out a "point" for each end of the fret line with a scalpel blade. Then, I line up my best and straightest 30cm steel ruler with those points by feel, and score a deep line into the board with the same scalpel. I end up with dead straight, dead perpendicular lines which are easy to follow with a saw.

Of course, the saw has a kerf of .55mm, whereas the scalpel gives a much smaller width. I find the blade of the saw still always finds the path of least resistance, and I dig the scalpel in deep during the mark-up process. In future, I want to try out a new technique - I reckon taking a sharp triangle file and bevelling the edges of the scalpel cut will make the saw almost fall into a dead straight cut line. Time shall tell. 

 

Naturally, I glued it onto the guitar.

 

Got out my bottom-bearing flush cut router bit and trimmed the ebony down to the same neck taper. It really surprised me how much tear-out I got on my first pass - I've never worked with ebony before, just so y'all know! I ended up taking much smaller passes, and had a grand clean cut in the end. 

Because the fretboard is sitting flush with the top plane of the body (for now), I had a conundrum on how to shape the part of the fretboard that sits on the body. Obviously my flush cutting bit just ends up riding around the horns, and I end up with a "lump". 

 

To remedy this, I got out my factory-straight edge of MDF. I've had this laying around for a while, and I check it periodically against a real straight edge, but since I coated the edge in CA it seems to be holding a decent true line. Laid this on the mostly tapered fretboard, and clamped it flush. Then I got my router set with a top-bearing bit at a depth of exactly 0.5mm above the body plane, by placing some measured layers of sandpaper on the body and setting the plunge depth, then taking the sandpaper away.

After the cut, I literally took one good hard look at that 0.5mm piece of ebony hanging off the fretboard - with a chisel - and all was well and true.

 

Radiused with a sanding block and some 60-grit. I got halfway there, and realised I wasn't wearing a dust mask - black nose for the rest of the day. Dammit, I'm better than this, and I'm aware that hardwood dust will kill me quick. Lesson learned, the mask now sits on top of my sandpaper drawer. Anyhoo, I got up to about 320 and took this shot:

 

Got the saw out again, with a depth stop of plywood bolted through the blade at 2mm from tooth-tip, and re-cut the slots to a good depth over the new radius. Above about fret 18 this became quite worrying, as the blade tip was getting too close to the horns, so I covered them up with a sheet of carboard each. I guess I just have to be mindful of where the saw is, but the cardboard definitely gave me the confidence to get the slots down to a good depth. 

Then I went up to 2500 grit on the ebony. I may still give the surface a quick coat of oil before fretting, but in case I don't, I wanted to make sure the ebony was up to the quality it can be on it's own. 

 

Fret wire cutting. In the past, I have used flush cutters to slice off lengths of this irregularly-shaped extrusion, as have I used rotary tools. This time, I made a simple jig... Wait, no, this isn't worthy of the title "jig". I made two sides of a clamp, one of which holds the tang, and the other holds the crown of the fret wire.

 

I lay the radiused fret wire over the fretboard, use a fine-line marker to mark out the length, then clamp the wire in my contraption with the mark laying flush with the perpendicular fret slot in the softwood caul. Then give it about two good pumps with a hacksaw, and you've got a fret - without the burnishing of a high-speed Dremel disc, and without the slight end crushing of flush cutters.

 

Speaking of rotary tools, I did actually use mine. With a cutter disc. To nip the tangs of the frets.

 

Ran out of time today to get them into the guitar - apparently hammering frets at midnight is anti-social. But, the frets themselves are done, and the timber's quaking at the knees ready for them!

[ScottR]

1 hour ago, Akula said:

Speaking of rotary tools, I did actually use mine. With a cutter disc. To nip the tangs of the frets.

That is a seriously clean nip job to have done it with a cutter disc.

SR

[Bizman62]

The triangular file idea for deepening the scalpel marks sounds interesting, I'll be waiting for your results before going to the file shop!

[ScottR]

3 hours ago, Bizman62 said:

The triangular file idea for deepening the scalpel marks sounds interesting, I'll be waiting for your results before going to the file shop!

The pics say they came out quite nicely.

SR

[Bizman62]

16 hours ago, Akula said:

In future, I want to try out a new technique - I reckon taking a sharp triangle file and bevelling the edges

@ScottR, the current slots look nice indeed but they've been cut the old way with just a scalpel mark.

 

 

[ScottR]

7 hours ago, Bizman62 said:

@ScottR, the current slots look nice indeed but they've been cut the old way with just a scalpel mark.

 

 

Ahhhh.

Nice catch. Missed that .......or didn't retain it for very long.

SR

[Akula]

Yep, you're right, these slots were done without this novel idea of beveling the knife-marks. That idea shall take it's root in another build at another time - but I am very happy with how these slots turned out.

 

After beveling the slots themselves, and to clear up any confusion, I'm talking about beveling with a small triangle file *after* cutting the slots to proper depth after radius with a good saw, I installed one single fret.

 

One.

Then the neighbour reminded me of the time. Quite kindly, I must add! And, to be fair, it was just after sundown and they have a small child, so I said fair enough and packed down the tools for the day.

 

One fret!

 

I wouldn't want to be a fret in the block right now...

They must be terrified right now! Haha.

[Akula]

The rest of the frets have been out away from their anguish.

 

Trimmed these frets down to within 1mm of size before installing, which gave me a 0.5mm margin either end. I didn't want to end up with miles of wire to file through to get it flush with the board, but didn't want to come up short either. Worked well, except for one fret, which when I hammered down it came up 0.3mm short one end and 0.7mm proud the other end. To avoid chipping the ebony by pulling it out, I gently tapped it sideways in the slot to get it flush at one end. Can anyone see a problem with this? As far as I can see, this is merely an extension of the protocol of tapping over-bent wire in at the sides before hammering the middle - the tang has still moved sideways, allowing the barb to grab into fresh wood. 

It's been over a day, and I can't see any pop-up movement in that fret. 

Part of my fret install process, after hammering, is to flow some CA into the slot underneath the tang and gently clamp with a caul to make sure the ends sit down nicely, and I usually do this a day or two later.

[ScottR]

1 hour ago, Akula said:

To avoid chipping the ebony by pulling it out, I gently tapped it sideways in the slot to get it flush at one end. Can anyone see a problem with this?

My understanding is Fender does all their fretting by shoving it in from the side. @Prostheta tested that method recently and seemed to come away fairly impressed by the method, I I remember correctly.

SR

[Bizman62]

My memory tells the same stories. And your logic comparing the sideways tapping to the protocol of tapping over bent wire at the ends first to make the tangs go sideways seems solid.

[Akula]

Well, I'm glad I'm on the right track. Sometimes things can make perfect logical and physical sense in the world of engineering and carpentry, yet totally miss the mark in the finely specific world of making fretted instruments.

Tomorrow's all about the neck carve, and then getting those frets flush bevelled and nice.

[Akula]

Got the frets flush by hand with a "flush file" - read: a half-round that I've snapped in half. It works, to an extent, but besides flushing the fret ends it gets too messy. After this I went to sandpaper wrapped around a steel object to get the frets nice and flush and bevelled to 45'. Bear in mind that the fret ends still need some fine tuning that won't happen until after proper levelling and dressing, and that's when I'll properly polish the sides of the fretboard. It's a game of do some now, some later.

 

Carved the neck. Same way as I always do, rasps and files. Because of the uber-thin fretboard, I got to 20mm at the 3rd fret before starting the widen out the carve in a nice shallow shape. Honestly, the neck is still a whole mil thicker than spec, but it feels thin as hell due to the shape of carve. More material will come off during final sanding, which should hit the 19mm spec.

 

Neck heel join feels huge at the moment. The neck is 20.5mm at F20, but 45mm at F24 - that's a hell of a radius! So I'm going to take this area of the join to a lesser thickness, using a combination of router and grinder.

 

Besides neck shaping, I got the bridge recess done. I went to 9mm depth, which is insanely low for a T-O-M recess, but I figured it's better to have the adjustment room and not need it, instead of needing it and not having it. By my measurements, the bridge can now adjust to -1mm of zero-action.

 

Worked on the top carve, made it a bit deeper and more concave to the clients request. Angle grinder is one hell of a tool for carving, so I purposefully left a good margin of safety to be completed by hand-sanding. Once material is gone, you can't put it back.

 

Two words: gut carve.

 

I'm stuck at home again for another few weeks - besides being in lockdown, I've also been identified as a "close contact" with covid, so I literally can't even go grocery shopping. As much as that sucks, it means I can pour some time into this build and others. So expect updates!

 

In an unrelated note, my neighbour chucked me a decent-sized board of Ironbark over the fence the other day - reckon this will make some good fretboard timber for future builds? It's reclaimed, so who knows how old it is! Heavy as hell - I measured it at 1100kg/m3.

[Bizman62]

1 hour ago, Akula said:

a decent-sized board of Ironbark

And quarter sawn for that matter! That's a nice piece of timber! Looks like a dozen high quality fingerboards to me!

[Akula]

On 9/12/2021 at 3:09 AM, Bizman62 said:

And quarter sawn for that matter! That's a nice piece of timber! Looks like a dozen high quality fingerboards to me!

I'll be paying the man good money for any more reclaimed timbers he can throw my way. Only problem is, being the kind hearted man he is, he thought it prudent to grind off all the nail heads sticking out of the timber, so I don't cut myself.... And now I can't remove the nails! Bless the man, but probably half of that chunk of wood can't be used, for fear of wrecking blades and bits. But still, that makes about half a dozen fretboards!

 

Very little work lately. I've been downgraded from a covid "close contact" to a "casual contact", which means I have freedom to do grocery shopping again, but not much else. And the weather's been fairly crap, which has dissuaded me from venturing to the end of the garden. What a week. 

 

I did rout the pickup bay, though. 

 

Every time I make a new template, I eff it up and have to do it again. I'm aware of all the jigs that use a few pieces of factory-edge timber, but every single time I end up going: ah well I'll just make this one out of MDF with a jigsaw and files, then I'll do the rest properly. Never again.

 

Route came out pretty good. Just need to chisel out the "ears" a touch to make this Duncan Distortion fit.

 

Because we're all locked down, and the postal service here has quite literally fallen apart at the seams (along with public transport), I was getting quite worried about procuring the correct items for finishing this guitar. But then, I received two packages in the mail the other day - a can of oil, and two different flavours of "Prooftint" stain. Here be a test patch.

 

 

[Akula]

I always make my electronics cavities too small. Every single time, I end up trying to cram all the components and wiring in there, and this time I decided I'd had enough of it. So I turned a large part of the lower bout into swiss cheese with a drill bit.

 

Not quite a "bathtub" route, but there's definitely ample room there for any future upgrades. Specifically, if we ever want to add another pickup bay, there be room for a third potentiometer or a switch. Or a battery, for active pickups.

 

And a touch more shaping on the heel. Not quite there yet, not quite. But with a tool as aggressive as an angle grinder armed with a 120 flap disc, I find it's wiser to shut off for the day and have a feel tomorrow, instead of realising you'd gone a fraction too far.

[Bizman62]

Definitely a good idea to make the control cavity large enough, and close enough to the edge for the jack. Much easier to do it a this stage than enlarging it later. Redoing the template and trying to realign the unchanged parts is a PITA.

[Akula]

18 minutes ago, Bizman62 said:

Definitely a good idea to make the control cavity large enough, and close enough to the edge for the jack.

Just a few weeks ago, I installed electronics in my 5-string bass build, which I have yet to complete posting upon - I found that my electronics were so compact within a large hollow body space, that the input jack was actually fouling upon the tone potentiometer! How could I make such a mistake? Well, I did, and I've fixed it in a way, but I'll never have that issue again....

[Akula]

Drilled a lot of holes today. 

First up, let's attack the string-through ferrule holes. I marked out on both sides where the holes should be, and used a Drillmate to get the top holes drilled to the depth of the ferrules at 5mm with a brad point.

 

Lacking a drill press, I invested fifty bucks in a Drillmate a while ago - for those unaware, this is a kind of portable drill press set on a base and two pillars, with it's own chuck and bearings. It's fantastic for places a drill press wouldn't reach, for instance, if you need to drill a straight perpendicular hole in a wall stud or a bench top. It's no replacement for a good solid press, of course, but I definitely lack the space for a press large enough for my needs - I've just about managed to squeeze a 10" bandsaw into my shop, and it's getting very cosy! Here's the Drillmate mounted to a jig:

 

Let's take a closer look at that jig. It is a pretty standard thing used by a lot of people, albeit usually on a real drill press. The bottom layer has a "pinhole", in this case 5mm in diameter, through which I poke the shank of a drill bit and locate it inside one of the ferrule holes in the top of the guitar upside down. This should theoretically allow me to drill holes into the bottom of the guitar that line up perfectly with the ones on the top.

 

Even looking at that last photo now, I can understand why this jig system didn't work as well as planned. Think about a big solid floor-standing press - it's solid and heavy, and should travel downwards in a smooth fashion. This Drillmate has just the slightest "wobble", to the point where it is felt more than seen. And the MDF jig just was not stable enough. The distance between the two inside faces is the same as the guitar body thickness, so it doesn't lean over in use, but in future I would consider making a similar thing out of steel.

The bottom ferrule holes came out ever so slightly wonky. The strangest thing is that the 3mm holes going all the way through 45mm of rock maple to the other side, well they were fine! Dead straight and perfectly aligned when they popped through. But the 8mm holes that only travel ten mil deep? Nope, they wandered. 

 

The photo looks terrible. I measured the deflection, and we're talking about +/-0.25mm. But it only takes a tiny amount for the human eye to be drawn to it, and label it a mistake. So I enlarged the holes every so slightly, and will have to glue the ferrules in with dust and CA, using a jig to hold them in a straight line. Luckily, there's a good flange on the ferrules, which I'm hoping will hide the issue. Failing that, I'll route an opening and install a steel plate to hold the ferrules.

 

We're doing an oval jack socket plate, which means it's an easy install - spade bit right through to the cavity. Had I the forethought, I would've done this before routing the electronics cavity. Not that there was much if any tear-out on the inside, but y'know, it can't hurt.

 

Tuner holes, standard stuff - measured out the tuner size, spacing, and string paths, then went at it with a handheld drill with some sacrificial timber clamped to the back of the headstock.

 

Knocked through some pot-holes, and set to it with low-grit sandpaper. As seen a few photos ago, the edges of the body are still marred with router scorch marks, the top carve has grinder scarring, and there are still tooth-marks on the neck from rasps and files. I purposefully leave all of this "shape-sanding" until the last step before finishing, because I have previously spent hours sanding guitars at every step of the way, just to accidentally slip while dressing the 24th fret, or something similar. So, thus begins the sanding mission. I do it all by hand, or shall I say, fingertips. There's always music and a few beers involved!

 

I've packed it in for the night - tomorrow I'll take it all to a higher grit, struggle with end-grain for hours, and hopefully get some stain done.

[Bizman62]

1 hour ago, Akula said:

the sanding mission. I do it all by hand, or shall I say, fingertips.

You mean no blocks? If so, I guess you like it because that way the dust doesn't clog the paper?

The reason for asking that is that I'm studying the mechanics of sanding, the how's and why's of doing it the most effective way without extra scratches. When I've finished my pondering I might type a tutorial...

[Akula]

7 hours ago, Bizman62 said:

You mean no blocks? If so, I guess you like it because that way the dust doesn't clog the paper?

Partly, yes. I also find it easier to tell when the sandpaper starts to clog, since I can't hear the sound change due to my blaring music. Another reason is that for a carved top I find it easier to follow contours. I can also move my fingers around on the piece of sandpaper, thus "using up" all of it. And finally, not to sound too artisan, but I feel like I'm more at one with the workpiece when I'm directly connected to it. This all applies to complex shapes such as guitars - I wouldn't exactly sand layers of paint off a cabinet without some help from blocks or power tools.

[ScottR]

Man, you work just keeps getting cleaner and cleaner.

Good stuff!

SR

[Akula]

On 9/28/2021 at 1:48 AM, ScottR said:

Man, you work just keeps getting cleaner and cleaner.

Thanks mate. There's always room for improvement, which is why I keep doing it! 

 

Did the finish-sanding, which I view as a seperate step to shape-sanding, in an afternoon. Grit numbers are hardly applicable here, as even 400-grit can be "shaping" when used on something like this mahogany, whereas you'd need 240 to make such a difference in physical shape on hard maple. But after a few hours I'd gotten the bulk of the body up to 400 grit, and then I raised the end grain and went 400 again, then raised, then 600. An interesting note here: the neck heel carve is essentially end grain, although not as oblique an angle as the bottom of the body, so I made sure to raise grain here as well and sand back - nobody likes a "fluffy" neck heel.

And then, when all was said and done, and I was happy with the smoothness all around, I applied the prooftint stain.

 

And, of course, nothing ever goes to plan when using a new finishing product for the first time. I knew that bleed underneath the tape where I masked off the neck-body and neck-headstock transitions would be an issue, so I went crazy light and dabbed it on. That worked pretty well for the heel.

 

Not so well for the headstock transition. 

 

I got that one fixed up by moving the tape-line a few mil further into the neck, and having another go. This photo shows some crazy difference in colour, but after some more blending an hour of drying, it's very hard to see the difference.

 

Only other issue I had was at the end grain on the bottom of the body. Hanging a guitar from a 200cm ceiling can definitely make for some awkward angles, and I quite simply missed a bit. Or just didn't rub the stain into the end grain. Or perhaps I didn't get the sanding quite thorough enough and left some low spots.

 

Fixed those bits up by dabbing more stain, then blending it in to avoid the two-layer colour. This is really easy to do with this particular product - I literally dab on the stain into the areas needed, then use a gloved finger to rub it in with the surrounding areas. Wish I'd gotten a photo of the result.

One thing I'm concerned about is the maple on the back of the guitar, came out rather blotchy compared to the front. I'm reluctant to sand it back and start again, because I'm afraid I'll never tone-match the top, and it's only this one area highlighted in this cropped photo - but it's enough to piss me off. It's one of those things where you're sure it's fine, just a result of timber being an organic material, but knowing it's there... Well, we've all been there.

 

 

[Bizman62]

40 minutes ago, Akula said:

One thing I'm concerned about is the maple on the back of the guitar, came out rather blotchy compared to the front.

I guess one reason for that is that the bottom is more like quarter sawn with basically all the growth rings showing while the top is more like slab sawn as the rings bend over on the top. I wonder if you could use the recommended thinner to blend the blotches in.