epoxy a neck?

[Urumiko]

so anyone who's been following my build will know I'm making a palmwood neck.
For anyone who doesnt know it's ammost impossibe to carve without this kind of thing happening:

The example above i filled with dust ad glue and it really doesnt look good.

I will be carving using sanding only to avoid this as much as possible but i still expect to have some tearout perticularly on the edges.

I was considering that rather than filling and spoiling the look of the wood, I'd preffer to use some kind of ultra clear high build resin and sand that back to acheive a smooth finish with the "3D" imperfactions underneath. I could potentially add a smokey black pigment.

Does anyone know if/how i could go about this/what to use?
Is there something i could brush on in thick coats and build up, or would i be better off trying to box in the back of the neck and pour resin, then carve this back?
The thought of trying to box in an already carved neck is not appealng.

Edited January 13, 2020 by Urumiko

[Bizman62]

That was one of the things I was worrying about...

Epoxy/resin is a valid option - you may have watched Ben's River Table build, haven't you?

For such porous "wood" I'd use a vacuum bag to make the resin get really deep into the pores. The ones used for clothes work well enough. A cage of sorts around the mould to prevent the bag from collapsing into the resin will help. Something like a plywood box with holes for the airflow.

As for boxing the neck, use your creative imagination to make it fit as tightly as possible for less reshaping.

[Urumiko]

THank you both.. Damn.. I wish you could remember that vid title @norm barrows
Do you remember what viscosity he went for?

Thanks as always @Bizman62. You know me trying to source a vac bag is probably a bit more than id go for.
I havent actually been keeping up on youtube so much lateley but i did see bits of the river table build. He kept recommending some brand of resin, I guess my big question there would be what can I use to box it in that it will not stick to

[ADFinlayson]

I would have thought, if you're going to flood it with epoxy, you want the thinnest stuff you can find so that it soaks in further. If you warm up both parts of the epoxy seperately just prior to mixing, it tends to be a bit thinner too. Don't warm up after mixing because it will just harden faster. 

Some thought to the tools you're carving is probably a good idea too, a rough file is more likely to cause tear out than something like a fine micro plane, granted that would take longer. Be especially careful when you're starting that carve, removing the right-angle, I find that is when chunks tend to fall off if I'm not being careful. The fine side of a shinto rasp would probably be ok. 

Something else that might be worth while, remove some of the waste material on your belt sander or carve gently prior to epoxy, that way when you do flood it with epoxy, there is less waste to have to try and soak epoxy though. 

[Bizman62]

A vac bag is not hard to find, they most likely sell them at Sainsbury's or Poundshop or whatever you have close.

For the box basically any material would do, even cardboard. You can put cling film inside to prevent leaking and use styrofoam for fitting. Masking the fretboard is a must! One trick might be a variation of the masking tape trick: Several layers of masking tape should be easy enough to separate from each other even if the resin had solidified the uppermost layers.

House of Resin was the brand Ben used, IIRC.

Edited January 14, 2020 by Bizman62

[Urumiko]

Thanks all.

Yes I think perhaps waxing the edge of the fretboard then clamping sheets of polypropelene allong the sides would be good. i think the nut end would be tricky but i guess i could mock something up. if i can get a vaccum going i will.

if im going that route i guess i will prob end up finishing the whole of the guitar in epoxy. which given i dont have a spray booth yet might be a good idea.

Does anyone know if epoxy makes for a sticky neck?

@ADFinlayson yeah mate to be honest ill prob avoid blades completely and angle grind the extremeties, then either hand sand or bobbin sand the rest of the way. if it starts taring out uncontrolably i may just make a feature of it and try and get a rough 3d thing going below the epoxy.

I was looking at this

https://www.glasscastresin.com/glasscast-50-epoxy-casting-resin?gclid=CjwKCAiA6vXwBRBKEiwAYE7iSw4-A8FdsSKch-osF45CYE0BT0JybZLuXBVc1j9GC7UjZp6ocF8e8hoCPJkQAvD_BwE

possibly with some automotive black pigment.

 

Edited January 14, 2020 by Urumiko

[Bizman62]

6 hours ago, Urumiko said:

Does anyone know if epoxy makes for a sticky neck?

Not the slightest clue... But knowing that it's some sort of plastic and thus kin to the 2K lacquers some friction may be expected given your hands are moist by the right amount. And don't we all know how to make a sticky neck faster? Just sand it matte with 1000 grit wet'n'dry or steel wool and redo it when your hands polish it sticky again.

[Bizman62]

Sanding with 1000 grit doesn't actually damage a modern finish and it can be done dozens of times without issues. It's more like preparing for a better polish although in this case shine is not the desired goal. Instead of reMoving, we're reFining.

That said, talcum is a valid option as well. Will it act as a sanding agent, I don't know. It's mineral (stone) although one of the softest but it's also one of the reasons why white paper tissue works for buffing and polishing oiled wood as the talcum makes it act as an ultra fine sandpaper.

Edited January 14, 2020 by Bizman62

[Bizman62]

I haven't played much with rubbing compounds other than the cheap stuff I once used for my red car and the swirl remover which I used for my guitar after 6000 grit sanding.

I still somewhat disagree. When you're rubbing the finish of a car you're aiming to a fresh shine which means removing an entire layer of material. When you're sanding a neck flat the idea is to scratch the very surface without reducing the diameter by a split hair and using fine enough abrasive to dull the shine. Just barely enough to get rid of the suction cup effect. Done right the scratches shouldn't be visible with bare eyes or even with a regular 5x magnifying glass.

[Bizman62]

19 hours ago, norm barrows said:

unless you do it to gloss, thereby turning it to satin.    but the sensitivity of human touch can tell the difference.   in engineering terms, it lowers the coefficients of friction of the neck finish vs human skin - enough that we can feel a difference.

Now we're talking the same language. From gloss to satin, enough to lower the friction, enough to feel a difference.

Could it be related to our age?

 

Edited January 15, 2020 by Bizman62

[Bizman62]

9 hours ago, norm barrows said:

13 micro meters - IE   0.13 mm.   (did i convert that right?).

0.013 mm is right.

And yes, 62 is my year of birth. High School, Commercial School - I'm a trained bookkeeper but I've never worked as such, IT evening school... After 18 years of being a sales rep I started my own one man IT helpdesk business which I've now run for 15 years. My musical awakening was alongside American Graffiti and the the likes in the late '70's. No metal...