YB-4 Fretless

Hello all,

I'm interested to try both a project and a bit of playing fretless bass. I'm really a woodwind player and only dabble with guitar and bass but wanted to try something new.

Adam advised of a new "Fretless Maple neck with overside headstock" and it matches the neck pocket of the YB-4 kit. I'm hoping to end up with something that looks pretty much custom - and the YB body shape is not as instantly recognisable as some of the F and G shapes.

Pictured is the kit alongside my P-Bass (bit of an irony that it's made by Yamaha, a "Billy Sheehan Attitude" bass).

The scale length works out to less than the 34" of both the P-Bass and the YB-4 kit spec. I'm guessing YB has shorter body, longer neck but don't have a fretted YB-4 neck to compare to. Scale length will be 32" and of course there are no fret intonation issues when there are no frets.

Attachment 31837

Picture of the two side by side.

Next post I'll put what I've done so far on the choice of headstock.

Cheers,


David

Choosing headstock style:

I didn't want to go with the single side P and J Bass style. I like the two-a-side Yamaha shape and the three-up-one down Music Man style but didn't want to follow these too closely either.

I made up a dummy neck in scrap pine so I could try a couple of different headstock shapes before deciding.

Shortlist was an image I found on the web of a two-a-side, and a two-a-side variation of the Music Man idea which I drew up.

After I'd made the first two-a-side, I was satisfied with that, so in the end I didn't bother to mock up a Music Man variation. I lengthened it a bit and got out my french curves from high school (quite some years ago that) to get the sweep I wanted, and have cut the real neck accordingly.

The headstock is in parallel plane to the fingerboard, set back but not angled back. So in the same way that a Fender headstock needs a string guide for the D and G strings, I might need to fabricate a string guide to hold the A and D strings down to the nut when I get to that stage.

Photo attached of the two paper patterns, dummy in pine, real thing cut to shape.

D. Attachment 31851

Looking very tidy there mate!

Thanks bakersdozen,

tidy is not a word I'm usually associated with (unless it has "un-" in front of it).

I am looking at Tung Oil for the neck and fingerboard but have no previous experience with this finish, only Linseed and varnishes, so probably some trial applications on scrap timber first.

For the body I'm undecided at this stage between a natural timber look and a glossy opaque finish. I will probably go with a stain and Tung Oil over it, but could go with an acrylic lacquer as I have lots of clear on hand, and some nice car paint remnants - two metallics and a pearl. Or clear over rattle can...

Just received the Tung Oil yesterday so I'll have a play with it this weekend on some of the scraps of pine and pacific maple I have lying around.


David

So I had another look at the YB-4 listing, and more generally on the net.

The YB is a two octave neck - that is why the shorter body, and why my scale length comes out at 32" not the 34" of the YB listing.

A bit of a 'doh' moment when I worked this out.

However I'm fine with this, as I don't play bass much, and sometimes play a 3/4 size bass at a youth music group I'm involved in. That one is pretty much the size of a strat and very easy to get around on compared to the Precision fretted.

So a smaller stretch for the hands is not an issue for me, but thought I'd put the info up here for anyone else contemplating options for fretless.

Have stained the body and prepping for first coat of Tung Oil today.

David

I went with Tung Oil rather than Acrylic lacquer as I wanted the bass to have a natural materials vibe / appearance. I've always been impressed with how the violin family were all developed with traditional finishes and look so beautiful. Although have to admit that the body colour I chose isn't seen much in nature - inside a watermelon perhaps.

Anyway, since last posting I have been applying Tung Oil per the instructions.

For the neck, no stain or dye, just want the natural colour of the timber. Four coats and this has worked out fine.

Attachment 32046


For the body I've used a H2O/alcohol soluble aniline dye. This is on the theory that if the dye is not soluble in the citric terpene solvent used to apply the Tung Oil, it'll stay where I put it.

In practice, it leaves tide marks when applied with alcohol, and soaks rapidly into some areas of the bass wood and doesn't penetrate others much at all. I was unhappy with the look after the first coat of tung. I used some fine (800 I think) wet/dry paper with water to lighten the dark parts and blur the tide marks. Then followed with more Tung layers.

In the last few weeks the local ambient temperature has often been low and humidity has been high, including a snow weekend and a misty cold weekend. Blue Mountains NSW.

I've ended up suspending the pieces under one of the central heating outlets to get a bit of warm airflow to dry the solvent terpene out and help the Tung Oil oxidise. This oxidation is supposed to happen before it's ready for the next coat. The house smells like someone is cooking marmalade by the vat full.

Allowing three or four days between coats it still does not seem to get bone dry. Nor is the dye staying put. Theory would have it that the dye should be under the oil and not really present on the surface, but in practice some of it rubs off onto the application rag.

After the fourth coat I have run a wool buff over it and got the beginnings of a sheen. Have also done a test spot of beeswax (under where the neck plate will go, in case it was a bad move, but it looks good). More than five coats of Tung is not recommended. The fifth coat is still drying and has a few days to go.

When I put it in the sun or when the warm air is on it for a while, it sweats tung oil. I'm a bit stunned at how porous / absorbent this bass wood stuff is, especially compared to the neck timber. Live and learn.

Here is what it's looking like after its fifth coat. I will be putting a beeswax polish on next and hopefully that buffs up to the soft shine I'm looking for.

Attachment 32047

I believe it will still be a bit patchy to the critical eye, but end result should be acceptable. Close up: Attachment 32048


David

So I showed the body to a fellow I know who does a range of timber and instrument work, his verdict 1. the tung oil has not been drying properly between coats. 2. don't go trying to get a final finish by waxing or similar until the Tung has definitely dried out and fully oxidised.

Makes sense. Yesterday was one of our first sunny spring days so put the body out in the sun. Not too hot but enough to warm it up nicely. This resulted in a fair bit of oil coming up out of the wood, and most areas of the body drying out. There just wasn't enough heat in the central heating airflow to get it dry and oxidising. Clearly it won't be fully dry and ready to polish for a while yet.

I decided I was tired of waiting to see how it sounded and played, and assembled it just with the essentials - neck pickup wired straight to the output jack, no bridge pickup, pots or strap pins. The strings are Picato nylon tape wound and very smooth under the fingers.

Attachment 32105

It sounds good, and is an absolute ball to play with, slides are easy, finding notes is not as hard as I expected although obviously I have a lot to learn yet. With fretless the fingers have to get to the note position rather than just behind the fret position. So I was expecting it to be a stretch, that is why I was fine with ending up at a 32" scale length. So far I'm finding the stretch to be same or slightly less than playing the fretted P-Bass.

The nut appears to be the correct height for frets i.e. much too high for fretless. So it will need its slots deepened. I ordered a bone nut, but received a six string one, I'll have another look at it in case it can be adapted easily. The neck, finished only with Tung Oil, feels great.

One unexpected issue is that the player's fingers have no electrical connection to the strings and bridge due to the nylon wrap. This means there is none of the hum suppression that you get with exposed wire strings, where one hand or the other is in contact pretty much all the time. My plan for this is to make a thumb rest in metal and run an earth from this. I will probably make a string guide in a similar style, although as the A and D strings seem to have enough downforce at the nut to play cleanly, this will mainly be for cosmetic reasons.

For the body finish I will wait until there is absolutely no oiliness, give it Tung one more time :), then see if I can buff up a sheen on that. If not, experiments with beeswax polish will be next.


David

Not much to report, we have had lots of humid weather including snow and some very welcome rain.

The last oily spots on the body have still not completely dried off. The Tung oil dries and oxidises really well on a warm day with a bit of sun, but inside the house, even with a warm lamp on it, it is slow going.

I have some stainless steel rollers from a defunct computer printer which I think will cut down into a nice conductive thumb-rest/earth. May get onto that task tomorrow.

David

It took me a while to decide on how to do the thumb-rest, plus there was another project which got in the way for a while.

I made the thumb-rest from a piece of aluminium extrusion and screwed it down on top of an earthwire in the same way that the bridge assembly is earthed. It was worth the trouble, it makes a definite differnce to how much hum is picked up.

I made up a beeswax / tung polish with some citric terpene to thin it, this went on nicely and produced a very low sheen.

Attachment 32818

I put it all together two weekends ago. The D string was buzzing at first, which had me thinking I had cut the nut down a bit too deep, but on close inspection the neck had a bit much pre-load in the truss rod for these particular strings, and was convex. Backed the truss rod off a little and now it has had two weeks for the neck and strings to settle into each other. It is stable and holding its tune well. The action seems pretty good to me.

Attachment 32819

It looks a bit different to what I had envisaged, the stain is supposed to have more of an orange look to it, and went on less evenly than I had hoped. Beware the spongy behaviour of basswood. Overall I am pleased with how it came out and especially with the effect of the Tung Oil which brings the neck grain out beautifully.

In the hands it feels like wood in its natural state, not better or worse than the glossy varnish feel of other guitars, just different.

I am very happy with the tone as well, there's quite a bit of life in the sound with the standard pickups, almost like it has a touch of reverb on it.


David

Great job.