Prostheta

29 minutes ago, Bizman62 said:

At first I was going to mention the force used but then I read further.

A fellow builder was just leveling his neck. He simply attached a couple of sandpaper sheets on the true table of the big planer. An important part when leveling by sanding is to not to move back and forth. Strokes only just like with a hand plane!

Perhaps a better explanation here is that all parts of the surface should receive equal "time" on the sandpaper with equal pressure. Pushing a workpiece down in the centre or only at the very ends changes the rate at which material is removed at different places. To a degree this becomes a mental ability along with muscle memory. I have a large flat plywood board onto which I glued a wide sheet from a thickness sander.

It's similar to sanding a fretboard with a radiusing beam. If you run the beam right off the ends, you end up with a curve rolling off the ends. If you dwell entirely on the board, the centre is always getting abraded. With my (500mm?) beams I apply light-medium pressure in the middle of the beam (so I'm not deforming the workpiece or the beam) and only move my hand between the middle third, or maybe middle two quarters.

The main thing is that you have a flat reference surface to check progress continuously and adjust accordingly.

There's a fourth way, however I don't know if magazines and battered VHS tapes are still an allowable thing in a professional medical institution. It's probably a ten year old copy of Top Gear and the latest Koti ja Keittio.

43 minutes ago, henrim said:

Not knowingly, although some of the small “ebony” pieces I have collected over the years may as well be African Blackwood. 

Cheers

It smells beautiful, as though it is made from pure Oreo smoke. Ebony smells like sneezes and black boogers.

37 minutes ago, henrim said:

Funny commercials! Although nothing is funnier than the truth. I’d suggest to watch the 2011 black metal documentary called “Eternal Flame of Gehenna”.

I haven't seen that one! I presume that you're aware of the local Turku parody band The Black Satans? I think they were more of a joke between friends than a band. This one was filmed at Turku Castle of course

edit: Oh man, I forgot that they formed Suamenlejjona and have toured a bit. "Urheilu ja Isänmaa" ("Sport and Fatherland") is probably their most known track. Beer, sausage and ice hockey.

13 hours ago, Professor Woozle said:

Thinking about it, I suspect variability in the solution  is more likely down to the vinegar than the wire wool - you might be better off using non-brewed white vinegar, which is basically dilute industrial acetic acid! The steel wool will most likely be general purpose mild steel, so around 0.2% carbon and probably similar amounts of things like manganese and silicon in it.

Going off on the tangent of "not black enough"...

https://youtu.be/Ul72F0YaAcU

Thanks to the recommendations off that video (I remember this advert!) there's an entire rabbithole of metal band parody videos and adverts to go down. Even though the Persil advert has its own cringe value associated with it, I am thankful that most metalheads such as myself can laugh at the hypocrisies and sillier aspects of our favoured musical preferences. This Fedex advert seems to have been made by a team that clearly understands the existence of Slipknot and Alice Cooper as part of their sendup.

I haven't worked with it myself, even though I tried opening a conversation with the makers when they first introduced the product to the market. I can imagine exactly how it works though, especially based upon your description. Have you worked with African Blackwood before? This has very similar properties in that it is like machining a homogenous composite or resin-based product. Cutters gum up, heat is generated very easily and cutters blunt quickly as a combination of that heat and the toughness of the material. I imagine that it would be very good under a laser though, however the smoke might be somewhat oily and contaminate optics very quickly if not exhausted with prejudice. Looking at your cut edges and the quality of them feels very familiar. You have my condolences, and beer tokens are in the mail.

12 hours ago, avengers63 said:

In other words, fuck around and find out.

The Internet keeps saying that we shouldn't do that, or that somehow this is the bearer of poor consequences! In my experience it is simply....experience. You can't learn anything from things falling into your lap, you've got to test, experiment, compare and derive better understanding from things not going entirely how you expected them to. "FAFO" is a bit of a dumb term, or at least I see it used by people enough that it underscores how dumb and nuance-free their thought "processes" are.

In this instance, I agree. Fuck around and find out. On your own terms with the objective of raising your ability and knowledge. This is fine.

Whilst I'm unsure whether it'll improve matters significantly, it would be interesting to see how a more chemically pure application worked out simply for comparison. The stuff we make is proper bunk chemistry, but probably more fun because of that

The best information I have is to use a pure iron source such as old nails or whatever. Steel wool isn't the best, but it's the easiest. Spirit vinegar is 5% acetic acid or thereabouts. I don't think it's an accurate process without going to the point where concentrations and processes become less safe. @komodo had fantastic results using Quebracho tea as a source of tannic acid though. 

Technically what you want is Iron (III) Oxide. Clean your wire wool with acetone to remove grease and contaminants. Steel wool isn't ideal, but it's quick. Heat the vinegar first and keep it warm. Strain through a coffee filter or two. It's probably what you're already doing anyway!

Edit: Brain dumb. Iron iii acetate.

Epoxy doesn't need to be a thick layer. Just a consistent film on both surfaces. Clamping does not need to be too tight, just enough to close up any glue line. I used to hate it as well, however once I started planning ahead and staying in control of the job (doing a dry run, putting everything in place to hand, etc) it became much nicer to work with.

Yes, if you have a CNC and can cut HDPE cleanly then that works out really nicely. Just remember to drill holes through the base of each inlay, tape them up during casting and push the inlay out from the back. I forgot to do this....

Very very cool! I guess that the inlays were cast-in-place rather than the inlays being cast in HDPE and inserted into the board?

26 minutes ago, Bizman62 said:

Richlite tells to use epoxy only, although other glues may be recommended on luthiery boards and videos. Thing is, how extensive testing has anyone made outside Richlite themselves. Just as an example, Ben at Crimson Guitars had at some stage used polyurethane glue for fretboards. Then all of a sudden one neck fell on the floor during a maintenance operation and the fretboard just snapped off! For reliability the shock effect was tested with other necks, both old and new ones with the same result.

I heard about that, and it absolutely does not surprise me. Polyurethane glues are absolutely not appropriate, and anybody that has a reasonable level of technical knowledge about adhesives would know this. Ben has always come across as somebody who plays a confidence game rather than somebody who has defensible ideas to bring to the table. I have a particular dislike for people who sell poor-to-dangerous ideas as some sort of acceptable method, let alone a standard for others to follow. That's the worst sort of "teaching", because he absolutely needs to take responsibility for the appropriateness of anything put out into the public sphere under the flag of "professional" luthier. Some kid copies his method and loses a finger? That's on him. I could never recommend anything that propagates ignorance over safe and defensible knowledge. Rant over.

Definitely not polyurethane!

19 minutes ago, nakedzen said:

I saw someone rub 80 grit papers together to get some grains mixed in the glue, as an alternative for the salt trick.

The only problem here is that aluminium oxide/silicon carbide grit will damage any cutting tools it encounters. Not hugely, but it won't improve them at all  Salt is resilient enough to stay granular in a normal glue film, but break when cut.

As for Richlite, I would use epoxy. Anything that is a composite of resins will have questionable wetting compared to wood, so reliance is going to be on a mechanical bond. That means breaking surfaces with 80-120 grit, cleaning with acetone, wetting both with epoxy and having non-excessive and equal clamping pressure. I've not worked with Richlite, so I would be cautious and go with what is guaranteed to work. 

Well, you always need clamps. Bolts, screws or anything that can draw two surfaces together are useful.

No idea about the salt. I doubt that a pinch makes that much difference, and if it did I am sure somebody more capable that I would comment on it. Mainly it's to help prevent surfaces skating about under hydrostatic pressure.

You can even put bolts with washers through to provide clamping pressure since tuner holes are mostly 10mm diameter. Of course, a plywood caul is needed either side. One or two clamps and it covers the lot. An old trick I learnt was to sprinkle a little table salt into the glue to provide friction between the two surfaces as the glue sets up. The grains bite into the mating surfaces like sandpaper.

Adding a drill hole next to a pad allows you to strain relieve wire connectors. It does add to the finished depth of the board of course.

That's all part of the fun, at least for me anyway. I enjoy the process and the mental exercise more than having to reach the end goal. Of course, that's always good, however I do think that upping one's abilities, trying new challenges and building on previous experiences and new information keeps life interesting. It's the journey, not about the podium.

The concept of Millimetric's is interesting, however I can't help but see a lot of potential short grain through the area where the neck meets the heel. It seems even less supported than how old 70s SGs were glued in close to the neck pickup. This is one of those situations where principles absolutely must come first, and viewing their gallery it seems they have a deeper heel to fix this weak point, which sort of defeats the objective of creating greater upper fret access. Hmph.

Yours has a much superior strength in that specific point, so I would say that you shouldn't get "too inspired"! Travis Beans are an excellent example, however they don't have the fend with the issues that wood presents.

Hey, have you ever wondered if a guitarist has ever wanted to change the profile of a Travis Bean? "A bit off the profile please!". What a nightmare

My thought processes altered maybe 4-5yrs back when I really delved into manufacturing process design. I couldn't start without a design these days! The Travis Bean idea is certainly one that I've seen before, and being aluminium the design of the neck attachment really suits the material. If you can pull it off in wood, that's a real trick. I think I now have that idea in the back of my head, where I have to design something so that I could make 10x, 100x or 1000x of something as well as I could make 1x. The real satisfaction for me is in designing the method, winding up the clockwork and letting her go  So autistic.

It's ambitious! Especially if you don't plan it out beforehand

What'd I miss?

Agreed. A solvent-based finish like nitro can be reflowed and repairs will burn themselves into the existing finish. Test the lacquer in an inconspicuous place, or if you have a chip of lacquer, use that. Drop a drip of alcohol and see if it softens. If so, that's way way forward. The simplest repair is with shellac sticks and an alcohol lamp, however a bit of practice will be required.

For catalysed finishes, those that were chemically-cured on initial application you cannot really burn in a repair so they'll always have witness lines around and drop fills. Additionally, thinner CA may discolour the underlying wood and make a repair visible. Again, test if possible. I prefer water thin CA for repairs like this since it wicks into the cracks of the existing finish, but may also wick into the wood more. Drop fill with toothpicks rather than direct application.

Adversity and performing repairs when things go wrong are often the best teachers. I broke so many things and did so many things incorrectly in the early days that it was almost completely unfunny. The thing is, that formed the basis of what is now my profession! If this repair doesn't work out, take as much from the experience as you can. Every thing you do, always better than the last.

The main trick is the hardware. You're not going to have the easiest job scaling an OFR down, or tuners. In that respect, it really depends on whether you're scaling the physical outline of the instrument down, or every last part.