Reducing neck thickness

[Fishman]

I want to reduce the thickness of a baseball bat 70s Aria Precision neck – the truss rod sits some way up from the back of the neck and I'm wondering how much to safely remove and what method would work best, and are there any potential problems such as warping or whatever

I saw somebody on youtube doing this with a roundover router bit which looked quite straight-forward: 

 

Any advice greatly appreciated

Cheers

[mybass]

Are you an experienced woodworker, because If you already have this router setup and are used to it, then you might be okay but I would think that if you are a novice a hand held router could be dicey, they can ‘kick’ like crazy dangerous. Heavy duty sanding down may be a safer approach and easier to gauge how much wood / neck thickness you are taking off.

[Manton Customs]

Ok here goes. I don’t know your experience and don’t mean to sound like I’m not giving you credit of having any knowledge, so please don’t take it that way!

How do you know the depth of the truss rod and are you aware they are routed into a curved channel on the vast majority of basses? So if it doesn’t look close at the adjustment end, it may get quite close at the middle of the neck.

Its most likely the profile shape which makes the neck feel like a baseball bat rather than the actual thickness, so you can safely alter this without touching the wood directly above the truss rod rout. Though you would probably be safe to reduce the thickness by a mm or two above the rout, you should take great care and check with a magnet throughout. Some Fender necks have as little as 3 mm of wood above the rod at the middle. If you go through to the rout the neck is finished.

Whatever you do, do not use a router. It’d be complete overkill and would not create a finished shape. Some people use a round over bit as the very first step on an uncarved blank  just to remove some bulk and then continue with safer tools to get the profile right (but the video above has taken it a step further). The actual amount of wood you’ll need to remove from your already carved neck will be surprisingly small and it’d be very easy to take too much off, slip up etc with a router. It’d only take about an hour using hand tools anyway. If you did want to use a router, you’d have to come up with a jig for the bearing to ride against like the one in the video (may even be a pin router) and it’d still need finishing by hand.

So if you’ve got some experience, you could definitely do this with hand tools but leave the router alone and don’t try and take too much off the middle. You shouldn’t have any problems with the neck warping, I never have on the necks that I’ve shaved down anyway.

Hope this helps without sounding too condescending

 

 

Edited March 12, 2019 by Manton Customs

[Fishman]

Thanks @Manton Customs and @mybass – in the words of David Bowie, I am an absolute beginner – if I can be bothered with this I will take the cautious, sand-paper-based approach

Interesting info about the depth of the truss rod in the middle – I didn't realise this, so thanks for that

I will certainly post here if this project takes off

Cheers!

[bertbass]

Just done this myself on a Harley Benton PB Shorty using spokeshaves and glass paper.  Worked a treat!

[dyerseve]

depending on how precious the bass is to you, could you not drill 3 small holes in the back of the neck to take the guess work out of how much wood you have to play with. If you drilled the hole(using the smallest drill bit you can find) at even intervals above where the truss rod would sit then you can check how deep the cavity is along the entire length of the neck and then go from there. You could easily fill these holes at the end of the project and colour match to suit.

[Andyjr1515]

I agree absolutely with @Manton Customs above.

Most of the time with 'brickbat' necks it is the shape either side of the central spline that makes most of the difference to the feel and playability.

I regularly reshape necks for my own basses and guitars to take them from a 'U' shape, to a 'C' shape and, for my personal preference towards a soft 'V' shape.  Also, when I do full builds, although I start with templates, etc, I finalise the final feel of the neck by subtly reshaping the sides either side of the spline by taking a little off, 'air-guitar; playing and then so on until it feels right.

So, reiterating @Manton Customs points and adding a few of mine:

• Be aware any mod like this will destroy the re-sale value of the bass, however much of an improvement it makes.  ONLY do it if it is an absolute keeper or has other factors that have already dented severely the value.
• I think most Arias have a light stain on the neck?  If so, bear in mind that you are unlikely to be able to match this colour.
• Investigate the sticky thread here of basschatters willing to help other basschatters.  It is not really something for someone with no experience to do.  But, if you are going to do it anyway...
• Never ever use a router
• I would say never even use other tools like spokeshaves, etc - they are far too harsh and can take too much of the wrong material off too easily
• I use nothing more than the humble cheap cabinet scraper.  Because this is a 'one off', just buy a cheap set and throw away (recycle) once blunt or when the jobs done:  https://www.ebay.co.uk/itm/Carbon-Steel-Cabinet-Scraper-Set-x-2-Rectangular-Scrapers-1-x-Goose-Neck-W8014/113128438340?epid=1475244966&hash=item1a56fafa44:g:e9cAAOSwzlFbPKmu    (you can get similar from such as Homebase B&Q etc)
• The scrapers take tiny, tiny shavings.  Means you can creep up very gradually on the shape you want. 
•  I personally hold the bass, while sitting down, holding it like a back to front cello.  Personally, I do this when the bass is fully strung up so I can turn it round and play it at regular intervals and really feel if I'm getting there. I take long light strokes along the whole length of the neck.  I sometimes need to do extra strokes closer to the nut where the curve is often tightened
• I am scraping away some of the curve between the fretboard /neck joint to the spline - without scraping away the fretboard side OR the spline itself
• When I have a shape I am happy with, I smooth it off with sandpaper and then refinish 

So yes, it can be done, but I think the general advice would normally be to sell the bass and buy something that suits better.

Hope this helps

[Fishman]

Thanks everyone – I will just give it a quick rub down with some sand paper and hopefully that will satisfy me – there's obviously quite a lot to consider and as I have around 10 other basses to choose from this will be low on the priority list 😎

[Islander]

Also remember that removing wood can cause movement in the remainder...