honza992

Top. Glued.

In another thread @Wookiebass mentioned CAD drawings and thought you might be interested to see my process. I use CAD in the followng way. 1. Fire up the Windows laptop. 2. Wait an extraordinary amount of time for it to start up. (Man I love my Chromebook). 3. Wait while it updates windows, then restarts. Wait another extraordinary amount of time. 4. Fire up CAD. 5. Try to draw a straight line. 6. Fail. 7. Get out a very large piece of paper and draw two views, one top view and one side view. I don't know if you can see those, they're a bit feint. They are the two full size drawings I do for each build. I refer back to them all the time, there's no way I could build without them. The side view is particularly important as it helps dial in the neck geometry. I find drawing by hand a deeply relaxing activity. It's a zen moment when the build is still perfect. Before the realities hit of trying to persuade a tree to adopt a deeply unnatural position... Having said that I would LOVE to be able to have 3D drawings done in CAD, and 2D drawings for templates etc. My brain is deeply 80s, unfortunately. I blame the video of Duran Duran's Rio.

I would love to be able to use CAD. I've tried several times, and even had a few lessons. But I just can't get it, my brain rolls it's eyes and looks away in disgust. So, I do everything on paper, full size. One top view and one side view. This is for an acoustic bass and the side view is really important for getting the neck joint and neck angle dialed in. Here's my current build that goes with the above drawing: You sir have PM!

Thanks Richard. Still a long way to go though.....🤪

Mornng all. A few random jobs to report on. First I glued the braces to the back. And just to prove to @alittlebitrobotthat in fact I am not a machine man with a machine mind, but a free man with freewill, I glued the four braces on in two halves. 2 at a time. I guess that's a brace of braces at at time...Anyway, it's a big help in getting the glue squeeze-out cleaned up. Next up...sledgehammer, meet (wal) nut..... This is some scrap from after I cut out the back. I'm going to joint/join two small pieces together and glue them on the back of the headstock. I may even try to inlay the same stripe that's on the back into it.... Also, the new wood arrived to replace the one with the fish-shaped knot. And here it is: And this is what I found when thinning it down: ARRGGHHHHH! The mother of all pitch pockets, full of the stickiest resin you can imagine! There was no trace of it on the outside, but magically appeared as I bandsawed away the excess... Luckily if I push the template all the way to one end, the defect is positioned right where the neck pocket will be routed out. Phew.... Finally, I bent the last piece of side, the cutaway. It's quite a tight radius and what I had intended to do was sand it slightly thinner at the peak of the curve just to help with the bending. But of course I forgot. Oh to be a machine man with a machine mind.....anyway, it's close enough. I lost my nerve and left it there. Breaking the sides on the last bend would have been annoying, to say the least:

Yep. It's far too clever, simple and cheap a solution to have been invented by me....

You probably want to avoid adding too much weight to the bridge area. I did think about putting them under a pickguard like archtops often do, but in the end the pickguard just didn't look right on a bass. I may well re-think for the next one though.

And that's it for today. Those two jobs took quite a few hours. You can see why a custom made archtop from a real luthier is 5 grand! Thanks everyone for the kind words. It's really appreciated😊

Also today I managed to get the back-seam-joint-inlay-thing (BSJIT for short) done. You can buy these for a fiver....But....it then won't exactly match the binding that I use for the perimeter of the guitar. And if I did that you'd all throw things at me. So I take the slightly slower option and do it myself. Basically it's a strip of the bindng, then a 0.5mm strip of white veneer, then a strip of 0.5mm black veneer. They'll get glued vertically into a channel routed into the back: You Routing the channel I use simply run the router along a straight edge taped down to the back. It's difficult to get it exactly centred so one trick is just to keep adding strips of tape to the side of the router base till you get it exactly right. You can see from these test routs that I got it right on the 3rd time (ie 2 extra pieces of tape). You can then happily rout knowing it's going to be exactly centred... Once the channels done, it's they just a question of sticking the strips of wood into the channel, then gluing it all generously with superglue. Then make some lovely shavings: And hey presto! It's done..

The braces for the back are approx 8mm wide, 20mm high. The back though has a dome shape, the radius of which is 15 feet. Putting the flat braces onto the radius dish you can see that they need to be curved. Putting a pencil through the hole of a washer, I can trace the curve of the domed dish onto the brace: You can see here the dome a bit more clearly: I cut to the line on the bandsaw, then put sand paper in the radius dish and sand them to get a good fit. Then onto the router table with a roundover bit, and they end up looking like this: The shape will be refined a bit before gluing, but for the moment, they're good.

A robot after my own heart. If you like a veneered scarf, here's one I did earlier...

You are very welcome. 😊 Shout up with any questions if the have any. I've learnt so much here!

Yeah, the sharpening is a pain. But diamond stones have made it much less boring than it was. I first used whetstones which I hated, then tried the scarry system which I hated, now I just have two diamond plates, a 600 and a 1200 (I think) and it's great. No mess, no faffing about. I guess there's a continuum between using just hand tools at one end, and using CNC for everything at the other. I'm somewhere in middle. No CNC, but if I can use my RAS to cut 300 slots for the kerfing, then thanks, I'll take the technology....

Hmmm....the trouble with 34" is neckdive which would be inevitable and the higher tension strings which may put too much pressure on the top. You've completely got me on the wine and gold though. Very nice. Mind you, now i think about it.....Oh b_gger it, why not. In your next dream thats what i'll be making....

Yeah thanks Andy, the more I look at this more I like the metal tailpiece....so now I've got to learn how to machine, bend and galvanize metal. Like I don't already have enough other things to do. So great, thanks.....🤣

Wow, that is nice! I've never heard of it but the resemblance is striking. Just goes to show there's nothing new in guitar making! Here's another one in stunning sunburst...

This made me laugh. It's a truism of guitar building that you can never have enough clamps, but you can also never have enough different types of tape🤣

Lastly, I did some prep work for the braces. There are made of quarter sawn spruce, like the top. They are all slightly wedge shape because that's how they get cut to preserve the quarter sawn-ness. It's not a practical shape to work with though so I set up my router table to act as a jointer and joint the sides so they are 90 degrees to the faces. To turn the table into a jointer all I do is stick a 0.5mm veneer to the exit fence, then align it to the router cutter. The entry fence is 0.5mm further back, so you end up with a beautifully jointed piece of wood. It took me years to discover this trick, I don't know why. I now joint pretty much everything this way. Square stock is always a million times easier to work with.

Next was a bit of work on the neck. Last week I glued the blank together. Just in case anyone is interested the neck is made from flame maple with a central strip of walnut. The lines are made from 0.5mm veneer, a dyed black one and a maple for the white line. That means 12 surfaces to spread with glue and align and clamp, all within about 10 minutes before the glue starts to set. It's very stressful. Every time I promise myself that next time I won't try to do it all in one go. I'll glue half and then glue the other other half the next day. But of course I never do😟 Next time though I really am going to do it in two halves.... Anyway, here's how it ends up. Before gluing the bits together, I always flip and rotate one of the pieces of maple. This means that the grain lines are now in opposing directions. ie like this: \\\\//// This means that when the neck inevitably wants to move due to changes in humidity, the two pieces are pulling in opposite directions and hopefully cancelling each other out. It really does make for a very stable neck. I've marked the grain lines in pencil which will hopefully make a bit more sense.... I cut the scarf joint on the bandsaw, then cleaned up the gluing surfaces with handplanes and sandpaper to get it ready for gluing. This is another one of those jobs where it's important to get everything lined up. Using a laminated neck means a slightly misaligned join will be really obvious like this: Gluing a scarf joint, especially with a veneer in the middle, is not straightforward. The glue makes the pieces slip all over the place, especially when the clamps are applied. I use 4 toothpicks drilled all the way through the join. It's the black veneer in the middle which means once the neck is carved, you end up with this beautiful fluid geometric pattern just before the headstock like this: OK, prep work ready and into the clamps. This is one of the joints where I use West Systems epoxy. It's strong, doesn't add moisture into the joint, doesn't sink and is forgiving of gaps. Not that there should be any, but it's more forgiving that titebond in that respect.

OK, I managed to get through a few things today. First up I bent the other side without snapping it or bending backwards, thus ending up with two left sides, and no right. Go on, ask me how I know this is possible....🙄

Thanks JPJ. I actually had a set of LB LTFs in my box of strings, took them out only to find they are medium not long scale. Next to try are Chromes. Then some Roundwounds.....I'd really like to try these, which are made in Italy from copper and sugar, if the marketing blurb is to be believed. On the other hand they 70 quid. Which seems almost comical for a set of bass strings. Just how good can they be? Something tells me I'm still not going to be Jaco even after handing over my cash..... https://aquilacorde.com/en/flat-spirals-bass-strings/

Thanks Andy. It was you that tricked me into making an acoustic in the first place. Not that difficult you said. Well it's been a journey! So thanks for that. I think🤪

Hi Owen, I know what you mean. F holes look great, and I thought long and hard about using them as aesthetically it's what you expect on an archtop. My thinking is that a bass guitar (much more than a six string) needs every square mm of the top vibrating as effectively as possible. And where the F holes usually go is prime real estate. Less so the oval soundhole positioned close to the neck. Here's how a guitars monopole vibrates - as I understand it this is the main way a guitar top vibrates - moving up and down as one - and the way that most of the volume is created. So that's my theory!

Thanks Ben. I'm really enjoying building acoustic. And playing. Bass players never get to just pick up a bass and sit on the sofa. There's amps, and wires, and annoying the neighbours. I hadn't expected having an acoustic bass to be quite such a joy. It's really inspired my playing. Which believe me can really do with some inspiration. Or some practise. One or the other.....

Last post for today. Thinning the top down a bit and this jumped out.... I like a fish-shaped knot as much as the next man, but I'm afraid not much use in a guitar top that (hopefully) will be only a few mm thick, and under a gazillion kg of compression from the strings. Time to go wood shopping, again....