5-string Rickenbacker 4003-ish bass

[Prostheta]

This one has been boiling under the surface in one form or another for a good six years....for a number of reasons. I'll do a bit of background so the project can be understood, go through the design process and bit by bit document the build itself. This is also cathartic for me since the SG project running concurrently was almost "designed for me" due to its own specifics. An end-to-end, ground-up project is important!

The motivation to pick this idea back up was in no small part due to losing Lemmy. I'd always wanted to build a Rick-style bass, but building in the design aspects that they are simply unwilling and unable to do. For starters, their 5-strings are notoriously-shitty, mostly being cobbled together from parts and specs from their 4-strings. The kind of decision-making that casts Gibson's in a great light you know?

Anyway. Enough of the bashing. Making a 5-string analogue of the Rickenbacker 4004LK model tempted me for a long while:

 

The challenge of the tooled-leatherish carving within the wings was appealing, however I always preferred Lemmy's #2 bass....

 

....However I've not managed to find much out about it. It's weird because even as modded as it is, certain fundamentals don't seem to conform to standard Rick design aspects. In spite of how much I love conundrums, I'm not aiming to slavishly copy any particular bass anyway, however certain aspects will influence the final design. Perhaps a 5-string 4004LK might be on the cards in the future beyond this one....

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It's probably as good a place as any to put pay to the typical overly-litigious nature of Rickenbacker and its legal scumdogs. Firstly, this instrument is being made for personal use and is in no way commercial. Secondly, describing the design process and how I make the instrument is not breaking any sort of copyright since it squarely qualifies as Fair Use. Neither am I planning on utilising trademarks held by RIC beyond a simple factual and referential basis. Looking into a mirror and saying RICs name three times seems to attract all manner of cease and desists. I'm not interested. All baseless legal bullying will be redirected to the round file.

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The design spec floating around in my head at the moment is a neck-through, but using locally-sourced materials for everything other than the fingerboard. Birch grows on trees around here, so a combination of different Birches (flamed, plain, spalted Karelian) is personally-appealing. It also suits the thinner nature of Rick-style basses; nominally 1-1/4" or 31,75mm. Birch is a pretty heavy wood so a lighter body style is welcome.

The neck-through design of Ricks is simplistic comprising a central block running the entire length in line with the neck taper. The headstock is bulked out with a pair of glued-on wings, whilst the body is more or less the same construction. Depending on how available stock pans out, the neck will be a three-piece made up from flatsawn wood flipped 90° onto the quarter. Flame expresses itself stronger off the quarter in Birch also, so this makes sense.

Finishwise, I am going to work on some samples. The ambered colour of Lemmy's #2 is pretty cool, however I don't want to achieve it with dyes since I'd like the flamed and figured sections to pop. I'll update with how my test using linseed oil, shellac and some sort of clear goes....

Undecided on pickups also. 5-string toasters just don't exist (update me on this if you have ideas!) however I might simply opt for something more or less standard. The idea of milling out an undrilled metal P-90 cover crossed my mind, however it would need replating. Too much work and money. I'm currently investigating the dimensions of Dynasonic covers....

[Prostheta]

I'll certainly want to implement a dual output. Being able to assign a signal path per-pickup is a nice option. Unsure on where I want to take the electronics side since that isn't of huge importance right now.

[Prostheta]

Bridgewise, I like Hipshot's B-Style. Its got a certain appeal that seems to tie in here. I'm looking into alternatives, however I provisionally added this into the design. The headstock needs tweaking for a good 3+2 configuration. I won't be going for the full 24 frets; more than likely 22. Scale is 35" even though I'm slightly tempted to add in a light compound scale of 35" over 34".

[Prostheta]

The pyrography Oak leaves around the outside are a nice touch. Binding will be simple cream/white or I might consider black-white-chequerboard. It's just awfully expensive. Perhaps a good opportunity to try out radial purfling with Kingwood, @verhoevenc?

[Prostheta]

Adding in these special appointments are tempting. There is a lot to be said for a more stripped-back approach though.

[verhoevenc]

If it's got striped grain I see no reason why not?!

I've done stripy EIRW and zebrawood to date; about to do some amboyna burl with alternating sap/red

Chris

[curtisa]

14 hours ago, Prostheta said:

I'll certainly want to implement a dual output. Being able to assign a signal path per-pickup is a nice option. Unsure on where I want to take the electronics side since that isn't of huge importance right now.

Interesting. Not sure if it's the way you've drawn it or I've just never noticed how a 4003 is actually made, but I almost want to rotate the body clockwise a degree or two around the heel. It just looks ever so slightly like it's pointing uphill

[KnightroExpress]

I'm pretty sure that's just how the 4000's are made, but I could be wrong. Either way, I'm looking forward to this one as well! 

[Prostheta]

They certainly are. Once all that real estate starts getting populated with parts, it becomes less weird-looking. Basses, eh?

[Prostheta]

9 hours ago, verhoevenc said:

If it's got striped grain I see no reason why not?!

I've done stripy EIRW and zebrawood to date; about to do some amboyna burl with alternating sap/red

Chris

 

I get the distinct impression that we only see maybe 1/10th of your output! 

[Prostheta]

Okay, this morning I decided to do a bit of testing on the proposed finish with a bit of scrap. In spite of this Birch being lightly spalted, it isn't hugely weak or punky. Soft enough that I would call it "Alder-ish" when pressed with a fingernail. Certainly not strong enough for anything structural, but fine for anything that you would perhaps use Koa for. The body will be bound anyway, so edges won't be exposed to wear.

The finishing schedule will be raw cold-press Linseed oil (as opposed to "boiled" or polymerised) which is a drying oil. Alternative drying oils would be things like Tung, Poppy, Walnut, Safflower, etc. Safflower is the least ambering of the lot, if that helps.

Danish oil tends to be Tung or a mixture of other drying oils with varnish. I chose Linseed purely because it's readily-available, ambers with age and doesn't build a film unlike oils mixed with varnishes. Being unpolymerised, without dryers or varnish additions its curing is in the order of weeks rather than days. I can wait. Once the oil has cured, shellac is rubbed over the top using the typical French polishing approach. This can also take weeks, but that's fine too. The option here is to either go for the labour-intensive French polished finish (beautiful but not heavy duty) or to simply apply a light amount shellac and shoot a clear of some description over the top of that. Shellac provides an excellent intercoat between oil (which most things refuse to play ball with) and any other finish. This could be nitro, a brushed varnish (I'm looking at you, @Andyjr1515!) or auto 2k. At this stage, that part of the schedule is not important to decide on.

 

Okay, an offcut which contain a knot. This is straight off the bandsaw, so contains plenty of deep cross-grain saw marks. There's a bit of spalting across the top edge, whereas the rest is typical Karelian/Masur Birch figure, albeit light in this piece. Contrary to what was originally thought, the figuring is a genetic byproduct rather than disease or damage to the tree. It's somewhat similar to how birdseyes appear in Maple, but looks very very different.

 

Starting out with 100 grit to get some flatness to the piece. Getting out the saw tooth marks aren't a priority. 20 second work with the grain. Nothing more.

 

Step it up to 150 grit. You really don't need to slavishly go through every single grit sequentially. Every other grit is perfectly fine.

 

By this point (240 grit) we can see a lot more clarity and differentiation appearing between the spalted and figured areas of the wood.

 

Finishing up with 320 grit is as far as it needs to go at this stage. For the actual workpiece I might consider going 600-800 grit or hand burnishing with sawdust since we're using a fine finish.

 

The surface was wiped down with DNA (denatured alcohol....not "Multiple Miggs") to check for anything I've missed. Plenty of marks from the saw still exist, but enough has been sanded to make it an acceptable test piece.

 

It seriously drinks the oil. The first flood coat was accepted readily.

 

I tried an "oil dam" by applying tape around the outside. It doesn't seem to be working very well, however it holds enough oil to keep it flooded whilst it takes what it wants.

 

This is what I'm wanting the oil to maintain. The chatoyance, or movement of the rising/falling grain is super-high under oil. On its own, the oxidation of oil leaves a duller satin sheen as it microscopically expands from having taken on oxygen into its mass. Something like that. The main objective is to permeate the surface fibres that create the chatoyancy and add in contrast. This can be done with the dye/sandback method, however that is a big tradeoff of the natural movement vs. artificially adding contrast.

[Prostheta]

After letting the oil chooch into the wood, the excess was wiped clear and a flatter satin surface returns. Once cleared or wetted, the chatoyance in the Birch returns very strongly. The oil will be a left a few days, then a light film of oil will be added and wiped back. I'll do this for a week, then let the whole thing dry for a week or two. The oil will have cured satisfactorily when a white cloth rubbed over the surface doesn't return an oily amber mark and a Linseed-y smell.

So to recap; this initial stage of finishing will be done over raw Birch sanded up to a high grit. The oil is flooded and left to soak in wherever the wood wants to take it. Any areas that dry out during flooding are re-flooded. After a period of time (anything up to a few hours if you want) the excess is wiped off and the surface left to cure with periodic film applications. Once cured, we can move on. I'll pick this schedule test back up in a week or two unless anything worth mentioning shows up during the film application or curing.

[verhoevenc]

Hahahaha. I wish man! You've seen the EIRW. The zebrawood has been in finishing stage for... well... 5-6 years? Lol. I lost interest in that project but it's on the block to complete. The amboyna one is in progress.

Chris

[Andyjr1515]

There is a new term for me to try not to forget...chatoyance!

Very interested in your approach to applying the oil

[Prostheta]

This is pretty much on the mark.

https://en.wikipedia.org/wiki/Chatoyancy

Quote

In woodworking[edit]

Chatoyancy can also be used to refer to a similar effect in woodworking, where certain finishes will cause the wood grain to achieve a striking three-dimensional appearance; this can also be called pop-the-grain, wood iridescence, moire, vibrancy, shimmer or glow.^[4] This effect is often highly sought after, and is sometimes referred to as "wet look", since wetting wood with water often displays the chatoyancy, albeit only until the wood dries. Oil finishes, epoxy, and shellac can strongly bring out the "wet look" effect.

 

[Prostheta]

It references this article: http://www.hobbywoods.com/start_to_finish.htm

Quote

Appearance
Staining, of course, changes the color of the wood, but clear finishes will also alter the appearance of the wood. Most waterborne lacquers and polyurethanes are completely clear to slightly blue-gray. They will add almost no color to white woods such as maple, holly, and spruce. Shellac and lacquer will add warmth and color to the wood. Oils (including Danish Oil, Tung Oil, and oil-based poyurethanes) generally add the greatest amount of amber tones to wood, especially when several coats are applied.

With figured woods, such as curly or bird's eye maple, you can actually use the finish to intensify the figure, or "pop the grain," even without staining. One of the best "grain poppers" around is boiled linseed oil but shellac, lacquer, and most oil-based varnishes will also do the trick.

By adding one or two coats of shellac to a piece of figured wood, you can achieve a stunning effect called "chatoyance," from the French meaning "like a cat's eye." If you've ever seen the semi-precious stone Tiger-Eye, you'll notice that as you change your viewing angle, the light and dark bands of color change places; this is chatoyance.

 

[Prostheta]

I mixed up some shellac today. 1-1/2lb cut which is medium-heavy. That means 1-1/2lbs of shellac flakes to 1 US gallon of alcohol. This translates roughly to 13,5g per 100ml, or in the case of my 150ml honey jar about 27g to a jar of alcohol.

 

Full jar, scales zeroed out. This doesn't need to be exact since a 1/2lb or 2lb cut is also a common thing.

 

27g of blonde dewaxed shellac flakes....

 

Leave 'er to dissolve. I'll shake it around when I remember. This will have a shelf life of a few months. Some say six, however I prefer less so I don't try using a bad batch unwittingly.

[Prostheta]

Second test piece using Liberon Finish Oil instead of cold-pressed Linseed.

Flooded, waiting for it to chooch.

[Prostheta]

After letting it soak in for half an hour, the excess was wiped off. This is likely a polymerised oil in solvents. It's thin and very penetrative.

(click to embiggen)

 

The Linseed test piece (left) looks slightly yellower and flatter than the Liberon oil (right) which retains more contrast with less ambering. I'm going to leave the Liberon to dry over the week and apply some shellac next weekend. I guess a foam brush is good enough for a test.

[ScottR]

48 minutes ago, Prostheta said:

 

The Linseed test piece (left) looks slightly yellower and flatter than the Liberon oil (right) which retains more contrast with less ambering. I'm going to leave the Liberon to dry over the week and apply some shellac next weekend. I guess a foam brush is good enough for a test.

Any oil finish that builds a film, however slight, should create illusion of more depth, when compared to an oil with no film build up, though both do wonders for the chatoyancy.

I'm really enjoying these tests and comparisons, Carl.

SR

[Prostheta]

Me too. I rarely have the patience to do anything like this. I know full well that testing on scrap is a mantra, yet I always have one specific finish in mine or at least, always do the first thing that comes into my head. Yay mental hiccups, eh?

[Prostheta]

The Linseed is catching my eye more. It has more body and warmth to it. The finishing oil is veeery thing. The MSDS states a large fraction of hydrocarbon solvents such as naphthalene which is pretty obvious when you use it. Horrible stuff to wash off your hands too. I had to wash my hands in alcohol.

[Prostheta]

Back to the mission in hand.

The central neck block can be built completely separate from the rest of the instrument. Primarily I want to establish the basic geometry of the neck/body relationship and figure out what (if any) neck angle I want to build in. This is established by figuring out the saddle height adjustment range of the bridge being used so we know how far off the body the strings will be at the bridge, selecting whether the end of the fingerboard sits low or high to the body where the neck coincides and deriving an angle from that.

Currently I am unsure of the adjustment range of the Hipshot B Style bridge, so I need to do some digging or simply asking. Normally it would be better to have the hardware in your hand and taking the measurements personally to cut out any potential error. I'm breaking the rules here by doing it arse backwards.

I suspect that we might be looking at no angle. The B-style bridge is pretty compact, and IIRC it was intended as a Fender-style replacement. I might be wrong here.

Anyway. Once I have this basic geometry sorted, I can draw up a side profile of the neck and start looking at the first real wood butchery.

[KnightroExpress]

I really really love the oiled birch on display here. Since you've posted these, I've been looking for a decent source of birch in the US, but nothing promising so far. 

[Prostheta]

Karelian Birch is expensive stuff, and isn't usually found in boards. Oddly, it is sold by weight similar to burls I guess. You might find it as veneer though. I think @Andyjr1515 used some on a Westone refinish however that might not have been Visakoivu ("vissa-coy-voo") which is the Finnish name for it. I got these spalty ones a while back mixed in some clear Birch stock, snagged them and resawed them into thinner ~1/4" boards. I've also got a bunch of solid board stock which I used for my spool clamps tutorial....

Unfortunately they are not quite wide enough for most bodies, so they suit neck-through ideas like this very well.