Reprofiling A Neck

Nomad

For my kit-based 12-string Tele build, I'm considering reprofiling the (maple) neck. It's quite chunky, and I'm thinking that offsetting the profile so that the deepest part is biased towards the bass strings might be better. Not intending to make a V shape, just offsetting the C shape a bit.

My first thought was to tale a belt sander to it, one of these, which has an unsupported belt, so has some give...

https://www.machinemart.co.uk/shop/product/details/cbs1-5-belt-disc-sander

It's a 1" belt and can be used for some fairly delicate work (shaped a knife handle with it, which came out rather well).

I guess there are probably proper luthier-style techniques that one might use instead. Any suggestions?

Misterg

I'm sure the real builders will come up with some suggestions, but I would just use a single edged razor blade with the edge 'turned' to make it into a scraper. Doesn't feel like it's taking much off, but I found it amazing how much difference it makes in a short time. It makes it easy to blend the new profile into the old, and difficult (but not impossible) to dig big holes / create flat spots.

(For reference, I have tried a spoke-shave, a belt sander, a small orbital sander, rasps, files, sandpaper, etc. when making a neck.)

Nomad

Is this where those cabinet scraper things come in? (Been looking at them, and thinking of getting a set.)

WezV

do it by hand.   you won't need to remove much wood to change the feel.  I like using fine rasps and scrapers followed by shoe shine sanding.  i don't like spokeshaves because i often use laminated necks and grain direction becomes an issue unless I am sharpening it every 5 seconds

When recarving necks i make every effort to avoid the center line, unless you know where the truss rod sits its quite risky.  I never take more than a mm off this sections unless its a recarve of a neck i built.

so you want it asymmetric.  start by  attacking the cheek of the treble side with your harsher tools then tidy up and round over onto the bass side with your finer tools

  

Andyjr1515

Hi, @Nomad

I fully agree with what @WezV advises.

I did the same with my 2014 Summer Challenge offset - I use a cabinet scraper and then progressive medium to fine sanding until I have the shape that 'feels right'.  The bit of the thread showing this is here.  Note on one of the photos, as @WezV says, that the spine remains untouched.

Incidentally, I always do this with the neck in situ - I just put a bin bag over the body with elastic bands around the top to stop the dust getting in.  That way you can really feel what the shape is going to play like.

Andy

Nomad

Thanks very much chaps. I think it makes sense to try the gentler method first and see what the rate of material removal is like (belt sander is probably a bit over the top). So, some cabinet scrapers would seem to be in order.

I was looking at these a while ago...

http://www.ebay.co.uk/itm/High-quality-miniature-micro-cabinet-luthiers-scraper-4-piece-set-/181319204220?pt=LH_DefaultDomain_3&hash=item2a37777d7c

...mainly because one of them has concave edges. I gather they're quite small - maybe 2-3" long, so are maybe more suited to small spaces. No idea if the quality is any good (less resharpening is good, I guess).

I notice that Andy used a straight one - is the concave thing really needed?

Any suggestions for good quality scraper (or set)?

 

 

 

Andyjr1515

Nomad said:

Thanks very much chaps. I think it makes sense to try the gentler method first and see what the rate of material removal is like (belt sander is probably a bit over the top). So, some cabinet scrapers would seem to be in order.

I was looking at these a while ago...

http://www.ebay.co.uk/itm/High-quality-miniature-micro-cabinet-luthiers-scraper-4-piece-set-/181319204220?pt=LH_DefaultDomain_3&hash=item2a37777d7c

...mainly because one of them has concave edges. I gather they're quite small - maybe 2-3" long, so are maybe more suited to small spaces. No idea if the quality is any good (less resharpening is good, I guess).

I notice that Andy used a straight one - is the concave thing really needed?

Any suggestions for good quality scraper (or set)?

 

 

 

Yes - belt sander would probably be over the top and through the bottom!  )

For the job you are doing specifically, I'm sure those would be fine.  If you also wanted to use them for - say - scraping dints out of the back of a guitar, then you need the better grip you can get with a full-sized one.  

You can get concave full sized ones, but it's easy enough to get a decent curve with a straight one just by faceting.  The final result will be sanded to a smooth curve anyway - the scraper is about getting rid of the bulk removal quickly but controllably

Andyjr1515

Just as a reference, I got mine from a thickish  'C'to a soft 'V 'in around 15mins - and that was taking it gently and stopping to try out the feel a number of times.  The whole job, including scraping, sanding, finish sanding and re-varnishing took around 30 mins.

After you've scraped an amount off (always along the neck), run up and down the neck with some relatively coarse sandpaper on a block to take out any inadvertant 'waves' where the scraper has dug in a little deeper in one part of the neck length than the other. 

Andyjr1515

Another tip...hold the guitar like a back to front cello and, holding the scraper with BOTH hands (my photo was because I was holding the camera with the other one!!!) pull it up from the heel to the headstock in one smooth movement.  Work your way round towards the the midpoint of the neck profile, leaving the top unscraped, then do the same with the other side.

Misterg

The thing with scrapers is being able to "sharpen" them - AFAIK you can't use them without first using a steel to raise a burr on one edge (but I've never done it).

Andyjr1515

Misterg said:

The thing with scrapers is being able to "sharpen" them - AFAIK you can't use them without first using a steel to raise a burr on one edge (but I've never done it).

The ones you buy generally already have the burr.  It will last a good few necks.  Now, if you're talking getting a decent burr back on one once it's blunt, there lies a whole new ball-game  

WezV

depends on how good a finish you are after.

you can simply run the scraper across a fine mill file.   This works well enough that you can still get fine ribbon shavings but the finished surface will need some light sanding.

a flat scraped surface from a  scraper with a properly turned edge should not need any sanding afterwards.

WezV

i think i have posted this before.  its totally bad form but it works so i don't care

Nomad

Got some scrapers yesterday, but haven't touched the neck yet. They're Footprint ones sold by Machine Mart, which are presumably decent quality.

I had some practice on a bit of 2x4 softwood, but only managed get dust and some very fine fibres - nothing like ribbon shavings. Might need more practice or learn to sharpen them. I tried the file thing, but it didn't help much. I'll do some searching and find out more about sharpening methods.

I'm not too fussed about finish as long as there are no gouges and any faceting is mild. Quite happy to sand the last of it.

WezV

Its as much down to the way you hold them as anything. Try at different angles and try flexing it with your thumbs... And try on proper hardwood!

Nomad

Just been practicing on a bit of meranti, and made some progress. I was still getting dust at first, but found that holding the scraper a bit more vertical helped - about 60-70 degrees. Also, a bit less pressure and a bit more speed. I tried rounding off the corners and did okay, although it seemed that there was a good direction on each edge, and the other tended to snag - I guess it depends on the line of the grain at the surface being worked. On the first pair of edges, after sanding, the rounded areas had a bit of a ripple feel when I ran my finger along. I did the other two edges with lighter and faster strokes and they had less ripple.

Not quite ready to start on the neck, but I think I'm getting a better feel for the tool.

Andyjr1515

Hi @Nomad

Yes - the grain direction makes a big difference.  Scrape this way:

Nomad

Andyjr1515 said:

Yep.

Garthy

Hi, I have a Carvin  thru necked DIY superstrat with a neck that is too chunky for my tastes and would like it reprofiled. As it's a thru neck and a mistake could/would ruin the whole guitar I'd rather an experienced pro do the job as for me to do it sounds like giving a newly qualified driver an old Lamborghini as their first car. It also has an enormous heel which I'd like reprofiled to a more modern shape (google images of any Soloist/ESP will give an idea).

Has anyone got any idea of the ball park figure this would cost please?- when I say ball park I mean is it going to be closer to £200 than £800 as when it comes to substantial and time consuming woodwork I have no idea of the labour rates and time involved. To complicate matters it has paint deep enough to swim in, but the whole instrument will be refinished in the future.

Thank you