Aria Pro Ii Rsb-600 Restoration

[Prostheta]

In exchange for some work I have taken onboard a 1981 bass which....has seen better days....

From 1977 to 1986, the Matsumoku factory (actually part of a larger complex, Singer I think) produced the best instruments Aria Pro II ever put out. The RSB-600 is a relative of the more commonly recognised SB-1000 bass played by John Taylor of Duran Duran, briefly by Cliff Burton (bigger backstory here), Trevor Horn and numerous other bassists of the era.

Like the "big brother" SB-1000 this bass is a 7-piece laminated neck-through design with Oak wings. According to the catalogues, the neck consists of Maple and Mahogany although I highly suspect that it is actually Walnut. Cosmetically the RSB basses were identical to the SB basses but with a 4-in-line headstock as opposed to the 2+2 Batwing or "open book" shape. The bridge on the SB-1000 was brass whereas all other models used a cast Zinc alloy.

Unlike the MB-1 16-pole ceramic pickup of the SB-1000, the RSB-600 has a single AlNiCo pole MB-II. Internally both of these pickups were identical in that they consisted of two interlocking plastic bobbins, wound, loaded with slug/mags or poles and then epoxy cast in a thermoformed case. Interestingly, despite using the same full-width bobbins as the MB-1, the MB-II was only loaded with four poles corresponding to two strings per bobbin. Essentially a P-Bass sensing pattern with full width Jazz-size winds!

We join our hero as I received her from Japan. Yes. Covered in bright blue paint. Very very very bright blue paint that we will call "Tepco Blue".

[RestorationAD]

Don't sand all the way through that polyester coat if you don't have to. You might lose an arm trying to seal it back up.

[Prostheta]

Appraisal

The bass was in surprisingly playable state given its age and state of wear. It was immediately obvious that the brass nut needed maintenance as the strings ran about 1,0 - 1,5mm too high to the first fret. The neck was straight with no signs of abuse or cracking. The truss rod operates smoothly and as it should. Capo'ing at the fifth fret, the bridge showed that it would benefit from being recessed slightly further by around 2,5 - 3,0mm. The fretwork is quite worn and will see a complete refret. This will allow me to remove the Tepco best ingrained in the Rosewood.

Since the restoration will require aggressive removal of the offending colour I have decided to refinish the bass from scratch including repro decals to replace those that will be removed during refinishing. If the decals will survive being doused in alcohol then the finish will likely be a blonde French polish. If not, it will be shot with nitro. Hopefully I can also replace the bridge with a newly-milled brass or aluminium reproduction. The original tuners will be kept but replaced with a new set. The electronics cavity will be enlarged to include provision for 2x PP3 batteries so the circuit can be upgraded to that as found in the SB-1000.

Right. Let's get to it.

[Prostheta]

If I go the route of French polishing I'll be filling the grain using a "ponce" bag which is a small cloth wrapped amount of pumice. Poncer is the French verb "to sand". The Shellac fills the grain up, however I may use something like Brummers on the Oak wings/headstock veneer and mask the neck.

[sdshirtman]

If you do the French polish method please do document the process for us.

[Workingman]

MY APII RSB Deluxe has beeen my main bass for 29 years. This is a very worthy project.

[Prostheta]

Matsumoku era instruments were something else, totally. Japanese quality just sells itself. No wonder Jackson shut down the factory over there that was producing their "budget" line when they started producing better instruments than the "premium" US-made instruments....thereby laying down the foundations for Caparison....

Today was stripping day! Nitro Mors totally removed the existing finish no worries. That stuff is seriously nasty too! Remember to turn the extraction on in the paint booth or do this outside. Wearing ten layers of clothes and rubber gauntlets!!

"You cursed brat! Look what you've done! I'm melting! melting! Oh, what a world! What a world! Who would have thought a good little girl like you could destroy my beautiful wickedness?"

[Prostheta]

After some unpleasant incidents involving Nitro Mors and bare skin I managed to wash this lot off, scrape off the blistered finish and sand the bass back. This greeted me with the wonderful smell of Oak. Fantastic. Unfortunately the headstock veneer tapers to a thin edge so this might need replacing. Oh well. Thankfully the serial number on the rear of the headstock was stamped deeply and wasn't damaged by sanding!

Next task is to enlarge the control cavity to include an area for the pre-amp and 2x PP3 batteries. The bridge recess will also be deepened by 2,5mm to allow for better range of adjustment at the saddles.

The Tepco Blue persists in the open grain of the Oak leaving me with a decision - sanding it out or disguising the stuff. Since the Oak needs the grain re-filling I'll pick the most obvious pieces out with a pin, backfill with grain filler and use a fine technical drawing pen to hide anything that remains.

Time to buy some grain filler and get the decal order in!

[Workingman]

Hmm a bit surprised you say it is oak. All the thru-neck Matt's I have seen specs for say maple. The wings vary. Yours looks like the sycamore on my TS350. I don't know how sycamore smells though.

[Prostheta]

There was a long run of SB and RSB Mat basses '77 through to '86. If I recall, the wing woods commonly used were Chestnut, Oak, Ash and Alder. It certainly is not Ash though! The smell is distinctively Oak. I could check it with a little iron acetate which would react with the tannic acid and turn it black/brown however I have something different in mind....

Whilst I am thinking about it, does anybody have an immediate suggestions for a black grainfiller that is less likely to stain the wood? Easier availability within the EU is preferable of course. Cheers.

[Prostheta]

The bass is currently sanded to 320 grit with me vacillating on how and what to grain fill it with. The headstock veneer is in need of replacement and I happen to have a nice piece of flamed Oak kicking around one of "my piles".

Since there is still existing black filler in the grain I'm going to stick with that colour for the re-fill. Kind of tempted to try the approach advocated by O'Brien Guitars on YouTube, tinting some drywall compound black. At the very least it should be an interesting experiment. Certainly, the neck through laminations will need either masking or sealing with shellac first.

[Prostheta]

After testing various finishing ideas on scrap Oak, I decided that I liked the look of open grain on this bass rather than the "behind glass" appearance. Instead of grain filling level, I wanted to colour the grain instead as is common with Ash for example.

The schedule I decided on was to sand the body up to 320 grit, burnish out the wood with 0 through to 0000 steel wool to soften and open the grain, followed by a good old blast with compressed air. After masking the central section (tape is sufficient) the wings were liberally slathered with a 1-1/2lb cut of Shellac mixed with a cold hue dark brown pigment. After drying this was rubbed back out with clothes soaked with pure alcohol. This is enough to remove any surface shellac and pull any staining yet leave plenty in the grain.

To follow, the bodying sessions were applied with another 1-1/2lb cut until sealed. The headstock decal was then applied and gingerly sealed with light flashing coats so as not to disturb the print.

New Oak headplate:

Lower cutaway showing the open grain look I am aiming for:

Upper horn showing the contrast in the grain fill:

Working time so far:

Paint stripping - 1.5hrs hands on

Sanding - 3hrs

Grain filling - 2hrs

French polishing bodying sessions - 4hrs constantly on and off

Is it any wonder that people don't understand the cost of custom work when you factor time into these things. :hmm:

[ScottR]

That oak turned out very nice. Any idea what variety of oak it is? Years ago I had some captain's chairs of white oak that presented a very similar pattern as that bass side horn when stained and rubbed back. I always thought it was the best looking oak.

SR

[Prostheta]

I genuinely do not know. There is contention about some of the facts between reality and what was in the Aria Pro II catalogues. Things like Oak and Chestnut being mixed up. In some ways I am wondering if this "Oak" (as it was listed) is in fact Chestnut. Certainly, it is paler than most white Oak I have used and there was significant tonal difference between the new headplate and the wings before the grain was filled.

Since I've not specifically worked with Chestnut before I am in the dark. I could test it for the presence of Tannic acids by apply ferric acetate however since Chestnut and Oak are fairly well related I would expect them both to react to the test. The wood does *smell* like Oak when sanded (that fantastic whisky barrel smell) however this says nothing really. The grains are more or less identical as is the coarseness. Who knows?

[bob123]

WOW that looks gorgeous man!

[SwedishLuthier]

Very nice my friend, very nice indeed.

[Prostheta]

Thanks Peter. I'm aiming to bring the weight of shellac up somewhat, however since it is going to be open grain a gloss would be inappropriate. I'll be hitting it back with steel wool and maintaining it with a wax blend.

I'm sure that you can relate to this one....because we have hard floors, as soon as the sun hits the room it becomes a nightmare for dust ascending into the air! Total pain for French polishing....

[orgmorg]

That is most definitely not oak. The most obvious giveaway is the lack of visible medullary rays.
If it is chestnut, it is a variety I am not familiar with, not american.

[Prostheta]

I'm not familiar with the timber sourcing used by Japanese factories in the 80s, but yes you are perfectly correct about the lack of ray flecking. I re-examined the wings perpendicular to the growth rings and the most I can see in terms of flecking is no larger than you would see on quartered Maple.

Whether this wood is some relative of Oak (such as a Chestnut of some description) is totally unknown even though it possesses many aspects which Oaks do such as smell, etc. Thankfully the white Oak headplate matches up well after the grain colouration step. The slight darkening from the pigment I added to the shellac brought them down nicely.

In the catalogue photo I posted earlier, I would say this bass was an "RSB-600 O" where I presume "O" means Oak. The plot thickens (if you want).

[orgmorg]

Ya, in that photo, I think O, WA, and N stand for oak, walnut and natural, but refer to the stain, rather than the wood. The N actually looks like ash. The grain in yours looks a lot like hackberry, as evidenced by the zig-zag pattern of the earlywood pores, and its rays are similar in size to what you describe. Hackberry is vary pale, though, almost white, but there are a lot of species in that same genus spread out all over the world, including China and Japan, which may have different coloration, so I have a feeling it may be one of those. In any case, the headplate does look fine with it, and the whole thing is really nicely done, so no worries there, for sure.

[Prostheta]

Hackberry, interesting. I looked it up on Google Image Search and checked it out on Hobbit House:

http://www.hobbithouseinc.com/personal/woodpics/hackberry.htm

The photos of the veneer further down the page show a striking resemblance to the bass's wing wood, however some of the endgrain shots leave me umming and ahhing, although not unconvinced. Certainly, the flat and quarter grain ticks all of the boxes.

Hey Wes - are you not drying or working with a load of Hackberry at the moment?

[Prostheta]

Just carried out the third bodying session today, wondering whether or not my decision to go for an open-grained look is the right one. The areas that are glossing up are very very tempting. I could do with having pumice for grain filling available anyway and this is about the stage where the decision to pumice the shellac or continue through bodying/spiriting/glazing is the right one. Certainly, I would like to take what I learn from my foray into French polishing and write it up better elsewhere on the site. It genuinely is an excellent skill to learn judging by how forgiving the process is and the immediate results.

Crazy how thin the shellac goes on too. I burnt through on the headstock and slightly scuffed the decal slightly on the "II". Kicking myself and wondering whether or not to cut it back and apply a new one.

[SwedishLuthier]

I had a diskussion about french polishing with a lokal builder of classical guitars (and very fine such). I think that he summed things up quite good when he said: "You can learn french polish in a few minutes but you will need to spend the rest of your life perfecting it"

[Prostheta]

I couldn't agree more. I think that the common perception of French polishing being a very-difficult-to-perfect process is what puts most people off from trying it. At the very least it provides an immediate close-up education in finishing an instrument properly from the sanding stages upwards. I found a bunch of scratches in silly places which I had to go back through and repair. Shellac is at least very forgiving of backtracking through a finishing schedule should this occur.

I very much doubt that I will be 100% happy with this first foray into the field however I'm finding my feet and have found many to-do and not-to-dos. I'm also thinking that I might use French polishing techniques as the basis for future sealing and grain filling jobs since faults are immediately obvious and ridding myself of them prior to spraying whatever on top is always a good thing.

Yes, I'm taking a lot from it and hopefully I can feed this back through writing about it.

[Prostheta]

Progress on French polishing the RSB-600 resto. All of the primary bodying has been done. Sanded back flat using olive oil as a lubricant from 800 grit through to a 4000 grit pad. The photos highlight the open grain look with a little haziness left from the olive oil. Overall I am happy with how the shellac is progressing over the open grain so pumicing is out of the window now. The finish is getting really nice and slick. Time to start extending the time between sessions, allowing the shellac to fully harden off after spiriting the oil out.