Finishing off the Minibass

Just about there now. I found a couple of old “top hat” knobs in my parts bin. In the spirit of using stuff I already had, these seemed to fit the theme.

As I was wiring it up and testing it out one of the biggest problems I found was that the string anchor holes were too close to the bridge which gave a very steep break angle. This had the effect of canting the bridge saddle forward, so that the main weight of the strings was actually pushing against the back edge of the saddle slot. This meant that there was very little downward pressure onto the piezo pickup. For now I’ve implemented a bodger’s solution of a rounded bar which forces a much shallower break angle over the strings. I may just live with it and call it the Sustain-o-Bar™.

Finishing with Danish oil

I’ve spent a lot of time experimenting with the best way of applying Danish oil and I think I’ve just about arrived at the perfect approach for me.

Day One

The first phase is all about getting the first coats to soak in as deeply as possible to give a good foundation to the top coats. I don’t know for certain but I’m hoping this deep soak, means that it will be a more durable and longer lasting finish too. I get the oil and piece to be finished good and warm as a start. Using a brush I apply a liberal coat, let that soak in for 15 mins and repeat. You can see the areas where it has reached saturation point because the surface retains the satin sheen. Keep going until the whole piece has got that satin sheen. Give it a wipe down with a lint free rag and give it an hour or two to dry. After the drying period, if there are spots that appear “dry” I do it again. Once you’re happy let it dry over-night.

Day Two

The second day is all about applying the thinner top coats to give it a deeper finish. For a long while I used 400 or 600 grit wet & dry paper to apply these coats. This helps flatten out any imperfections as you apply. It worked well but because the paper doesn’t hold any oil, you are continually dipping the paper back into the oil; inconvenient, messy and unnecessarily wasteful. The breakthrough came when I tried an old, well used, green nylon scouring pad. It went through the washing machine first to ensure that it was clean and grease free. This works brilliantly. It is gently abrasive and it’ll hold a decent amount of oil so that you’re not continually stopping to reload. Once the thinner coat is on, any excess gets wiped away with the lint-free cloth and allowed to dry. Throughout the second day I do this every 60 to 90 mins. I leave it to dry a minimum of 24 hours (48 is better) and then top it off with a good wax polish.

Here are some of the progress pictures from day two of applying oil to the minibass.

Minibass: Routing the body shape and laminating the headstock

I have still to design the headstock layout (awaiting the arrival of the machine heads) but I do know that the current headstock will not be wide enough. I cut strips of sapele and the unknown hardwood and glued them to the sides.

While the glue dried, I attached the body template with double sided tape and routed it to shape, first with the top bearing bit…

…then remove the template so that I can cut deeper…

…and then finish off by flipping it over and running round it with a bottom bearing cutter.

and then I just had chance to snap this shot before the rain came.

Minibass: Making a bridge, cutting neck and body templates

I started off making an acoustic style bridge. First I cut the slot, by mounting a dremel router bit into my drill press, with two fences to guide the piece through. It took me two goes to get it right.

I ran it through the table saw, with the blade tipped at 30 degrees, to chamfer the sides.

After testing it on the 1:1 drawing I decided it was too long so trimmed each end. I sanded it to 220 grit and then dropped it in the jar of brown aniline dye solution.

I cut out the neck template. I’m going to use a separate template for the headstock, but cannot finalise the shape of that until the tuners arrive and I can work out the smallest, most compact shape possible.

I then cut two different versions of a body template. I prefer the one on the left so the other will get scrapped.

I used the template to draw an outline onto the blody blank and trim it to shape. Here is what I’ve got so far.

Here you can see the scarf joint on the headstock, and the 12″ measure at the bottom gives you an idea of just how small this thing will be.

Minibass: Gluing up the body blank and making a scarf joint headstock

I assembled all of the pieces of scrap timber for the body and trimmed them to around 38mm thick. I then ran them through the table saw to make sure each jointing face was flat and true. I then shade the edge of each jointing face with pencil and use my flat sanding block to remove all the pencil marks.

I gathered together a selection of clamps that are large enough for the job.

My initial thought was to glue on the first two pieces, let that dry, glue on the next two pieces, etc, and then I realised that, even with cauls, the clamping pressure would deform the edge of the wood I was about to join next. This lead me to tackle it all in one go.

I left that for a couple of hours for the Titebond Original to do what it does so well. It doesn’t finish drying properly for 24 hours, but, as long as the join isn’t put under any stress, the clamps can be removed after an hour. I set to work on making the headstock scarf joint.

I marked up the angle of 17 degrees and cut it on the bandsaw freehand.

The headstock portion is flipped over to make the joint.

I glued and clamped that up and then I was in a position to go back to the body blank. I roughly trimmed the ends and then skimmed the surfaces front and back to level and clean them up. Here it is dry and then dampened to show the grain.

And in idle moments while that was going on, and now I know the size of the body blank I’ve got to work with, I took a spare sheet of MDF and drew a 1:1 scale image of what I’m shooting for.

The Minibass: Decisions, decisions.

Before I get any further into this build I need to firm up some design decisions. At the moment I’m just preparing the body and neck blanks which, to a certain extent, I can do without much regard to the config of the final instrument (other than know it is not a thru neck).

This post is really nothing more than me jotting down my thoughts about all of those decisions; the ones I’ve made and those I’ve yet to make. It is this latter category I really need to focus on, to make sure I don’t miss anything that would impact an early stage of the build. Some of the other decisions can be postponed, and be made immediately prior to the build step they impact. Normally I wouldn’t do this – I like to have a very clear idea of absolutely every minor detail before I make any sawdust. As something of a prototype this one is different though – and I will want to review and revise those design decisions based on current progress.

OK so let us start at the head of this mystical “Minibass” and work our way down to the tail.

Headstock

Should the headstock be flat and parallel to the fretboard (like a Fender) or angled back like a Gibson? On this one I’m going to go angled – only because I’ve never made a scarf jointed headstock and I’d like to add the skill to my “portfolio”. Because this bass uses these polypropelene strings the neck is not under as a great a tension as usual, so it should be a safe playground for me.

Type and layout of tuners? I really like the plain simplicity of the Fender style big-eared open tuners. Added advantage is that they’re not overly heavy and relatively cheap. For the layout I want the headstock to be as compact as possible, in keeping with the overall concept of a Minibass. I’m going to go in a staggered 2+2 configuration, aiming to keep the string run as straight as possible over the nut to the tuner post.

Nut

Because I’ve chosen a Gibson-esque headstock it makes sense to use a Gibson style nut too. The nut rests on the neck itself and butts up to the end of the fretboard, rather than the Fender approach of having a thinner nut that sits in a slot on the fretboard. The nut is going to be made from bone. If you’re interested in how I’ll be preparing the bone see this post.

Neck

This is the aspect that, at this stage needs the most careful planning. I need to decide scale length, whether it’ll be fretted or fretless, whether it flat mounts to the body or is angled back to clear a higher bridge, fretboard radius, width at the nut, taper, shape of the neck profile, type of truss rod, what fret markers I want. Phew! Lots to think about.

First off, because this instrument relies on a piezo pickup mounted in the bridge, I want a good downward tenson on the bridge saddle. This means a steeper break angle between the bridge and the string anchors, which in turn leads towards a higher bridge. Therefore it’ll be an angled back join with the body. As on many of my previous builds It’ll get a glued neck join, with a decent sized tenon into the body.

next is the decision about the truss rod. It probably doesn;t need one because of the low string tension but, because I may want to add relief to the neck (a slight bow forward) I’ve decided to install a double action truss rod. When I was building my Voodoo Tele I found this aspect one of the most difficult and I’d like the opportunity to practice and see if I can get it better this time.

In deciding the scale length I have a number of limitations. First this style of bass usually has an 18-19″ scale, although they can go up to around 23-24″. Secondly, the fretboard supplied by Steve Benford is pre-slotted for a 25.5″ scale length. That is too long for my needs so, if I chop it at the 1st fret slot, making that the zero fret, it would give me a scale of ~24″, at the 2nd fret, ~22.5″, at the 3rd fret, ~21.5″ and at the 4th, ~20.25″. I’ve dithered between 22.5″ and 21.5″ for a while but, making a decision right this moment, I’m going to stay true to the principle of, making it smaller at every opportunity (whilst still being playable) and go for the 21.5″ scale length.

I’ve also struggled with the decision about whether it should have frets or not. I would love a fretless, and I think this more acoustic sounding bass will really suit it. On the other hand, the shorter the scale gets the harder it is to play a fretless accurately. I’m also crap at playing a fretless, it would take a lot of practice to start maaking sounds that I like hearing and I’m worried that I’ll move onto the next project and this one will just gather dust in the rack. And that makes the decision for me. I’m going to save my first fretless project to be a 34″ scale. Sorted.

I want this neck to be of a medium width, but perhaps a touch flatter, both front and back, than usual. It’ll get a fretboard radius of between 12″ and 16″, probably erring towards 12″. I’m going to have a go at making either my own radiusing jig or, more likely, a radiused sanding block.

Last choice should be the easiest to make but is another one I struggle with. What sort of fretmarkers should it have? I’m not quite sure why but, stylistically, fret markers have taken on a huge significance for me, and I want to do something really cool. I really like the thumbnail fretmarkers on Gretsches so I’m going to haave a go at doing something similar in appearance. It will be a very different technique though. At the point where the neck outline is marked on to the fretboard and neck (before the fretboard is glued on), I’m going to drill 8mm holes centred on that line. This will get a darkwood dowel or plug glued in place. Then, when I trim along the line, it’ll just leave a semi-circle slice of that dowel in the fretboard, looking like a thumbnail from the front and a rectangular block inlay from the side. For the 12th fret I’m going to drill a 3-4mm hole into the dark wood dowel and glue in a light-wood dowel. When cut in halt this will make a double mark when viewed from the side

Body

Whereas the body shape is usually the first thing on the drawing board, this is completely different. I’m going to set myself some hard constraints (position of bridge, size of the blank, type of string anchors, position of neck pocket, position of control cavity, etc. I’m going to leave the design of the silhouette until much later.

Because the blank is of a sandwich construction and the neck tenon will be visible on the top, I have to decide whether to feature this or whether to add a thin cap of a single timber, such as a figured maple. This is another decision I’m going to postpone until I can see how it looks. If I like it I’ll feature it, if not I’ll cover it.

Bridge

As I mentioned earlier this will be a relatively high bridge, to make sure I’ve got a good break angle. Because it is an acoustic style bridge, and because I yet know exactly how these strings will react with regards intonation, I’m initially planning for this to be a floating bridge. once I am happy with the intonation, I’ll glue it down, and can finalise drilling the holes to properly install the electronics.

I haven’t yet decided what materials to use to make the floating bridge. In keeping with the rest of the guitar I’ll aim to use something out of my offcuts bin. I’ve got a few decent sized pieces of maple that will be used for the first attempt. Essentially all I need is a block of wood with a slot cut into it to hold the piezo element with a bone saddle riding on top of it. Turning that block of wood into something that fits with the guitar’s aesthetic will be the challenge.

Because I’m initially going with a floating bridge I need a separate method of anchoring the strings. For this I’m going to use a string through approach, but instead of coming through from the back they’ll come through from the tail end. Hard to describe, but you’ll see what I mean when I do it.

Electrics

I’ve ordered a piezo element and small on-board preamp. I’m waiting for these to arrive because it is difficult to accurately plan out installation until they’re on-site.

Finish

Regular reader of this blog will not be surprised that I’m going to choose Danish oil again. That was the easiest of the decisions.