Winter Build-Off 2022: Bamboo EUB

[Max Bogosity]

One more disaster averted. I finished routing one side of each piece, then flipped the template to the other side ... and found that the two sides don't line up. One side is offset by ~1mm to the other. Best guess is that I drilled the dowel holes crooked.

I should have caught this when I was drilling. My drill press has a larger auxiliary table bolted on (just a piece of melamine-coated MDF shelf) and I did notice that a couple of the bolts were loose, but I just tightened them up and kept going. Maybe there used to be some shims in there to level the table, I don't remember. Or maybe I got some chips stuck in there. One more thing to troubleshoot.

Fortunately, I started routing the second side in a waste area, so the mismatch is in an area that will be removed later. No real harm done. I'll finish the routing from the first side if the bit will reach, or flip it over and finish it using a bit with the bearing on the other end. Then plug and re-drill the dowel holes before the glue up.

 

[BishopJP]

 

[Max Bogosity]

It was actually above freezing in my shop today. Luxury.

While cleaning up I found two abandoned projects that I had completely forgotten about: a Les Paul / Jazzmaster and a lap steel with a shell inlay fingerboard. If I quit working on the EUB now, I could probably finish the lap steel before the end of the build-off.


I finished routing the outlines of the three sections of the neck. Fortunately the bit was just long enough to complete routing from the same side as I started.

When I test-fitted the three sections together, I discovered that they line up pretty well at the scroll and heel, but not in the middle. Turns out that the alignment problem isn't exactly what I thought it was. The dowel holes were a bit crooked, but also I didn't have the neck oriented the same way when I drilled each hole, so the holes are crooked in opposite directions. As a result the distance between holes is slightly less on the hole exit face (bass side) than it is on the entry face (treble side). So the distance between holes on the template is slightly too long to fit correctly on the bass side of the neck pieces, causing the template to bow sideways a bit and create a different shape than the same template makes on the treble side. This wouldn't have happened if the template weren't so skinny in the middle.

The three sections aren't all out by exactly the same amount, probably because I didn't hold them in exactly the same orientation when I drilled. So the holes are out of position by different amounts, so the template bent by different amounts. But they're pretty close and I planned for extra material anyway, so I'm just going to go with it.

You might have noticed that the centre section looks different from the outer sections. The idea is to avoid excavating the channel down the centre of the pegbox by cutting it out before the glue-up. The janky looking extra strip across the top is there for a bit of extra support to hopefully guard against the centre section distorting; that will be removed after gluing.

Finally starting to look like something. Ignore the big ugly crack on the bass side. It's only one lamination deep and I think it will be completely removed when the neck is shaped.

This big ugly crack at the bottom of the pegbox channel won't go away, so it's getting filled before the big glue up. This will be pretty much hidden by the tuners and strings when assembled, so it's a good place to experiment.

 

[Flamingo21]

Step by step you are conquering the limitations of your material. I'm impressed.

 

[Max Bogosity]

Step by step you are conquering the limitations of your material. I'm impressed.

Thanks. It remains to be seen whether I conquer the material or it conquers me.

 

[Max Bogosity]

I filled that crack with CA glue. It's level, but doesn't look great. Every time I try to do something with CA it goes cloudy, then I go read up on how to stop it from going cloudy, then completely forget before the next time.

Thinking about how to avoid glue squeeze-out inside the pegbox. My first thought was to mask it off with tape, but I'm afraid getting tape plus glue out of the inside corners might be worse than glue alone.

Maybe paste wax on the inside surfaces to stop the glue from sticking? Maybe just give it a few minutes until the glue starts to set, then cut off the top 'scaffolding' while it's still in the clamps and dig out the glue with a chisel before it dries. Or glue the centre strip and just one side first, rather than all three strips, then I'll have decent access to clean out the glue on that side, then I can remove the scaffold before gluing the third strip.

 

[RichterScale]

I've learned that it's easier to remove squeeze out if you don't touch it (which is nothing short of a miraculous display of patience on my part, but I've done it). If you smear it into the grain, especially with a wet cloth that will thin it out and push further into the grain, then you have to sand away wood to the depth of the glue penetration, if you need to remove it for your finish.
I you are filling and painting then it's not an issue. But it's still less work to pop off the squeeze out with a chisel and sand clean if you let just sit on the surface and don't touch it. That's been my experience, anyway.
What if mask off the inside edges before glue up? Might still be a pain removing it all after it's together though. 6 in one, half dozen in the other.
Is the scaffolding in the middle 100% necessary?
And does the grain in that first pic look like tiny leopard spots? My eyes are all screwy right now. If so, that's really cool.

 

[Max Bogosity]

Yeah, it’s a good point. Every time I try to pull off the ‘remove the squeeze out while it’s still rubbery’ trick, I misjudge how much it has set and just end up bursting bubbles of glue that are still liquid inside and making exactly the mess you describe.

I suspect the scaffold isn’t necessary, but I’m a bit paranoid because I found some of the bamboo pieces moved quite a lot when I machined them flat and square before gluing. I’m worried that skinny bit at the bottom may change shape if left on its own. Unfortunately I can’t think of a way to be sure of that without just removing the scaffold now, which is a one-way trip. If I were to do it again, I’d put the scaffold higher up, coming off the very top of the scroll so it would be less in the way.

I think I’ll just go ahead and mask as I first intended. If there is any tape left in the corners, it’ll be very hard to see under the strings and tuner posts.

And yeah, the bamboo has huge pores that do kind of look like leopard spots in some places. Where it goes around a curve, they change shape in a kind of interesting way.

 

[Max Bogosity]

More leopard spots. They look like they're speeding up as they go around the curve.

Taped up and ready to go.

 

[Max Bogosity]

The obligatory clamp shot:

A couple of hours later I cut off the 'scaffold' and it looked not too bad inside. It's interesting how much faster the glue on the outside surfaces has hardened compared to that inside the channel. It wasn't completely closed, but I guess it was closed enough that the humidity was higher.

I decided to take a chance, do what I said I wouldn't do, and pull the tape while the glue wasn't fully dry. Here we go:

And it came out way better than I expected.

There are a couple of little shreds like this, but I was able to mostly pick them out with an Exacto knife. And a few little blobs of glue on the side faces because I was clumsy when removing the tape, but those will be relatively easy to clean up.

 

[TerribleTim68]

So, I missed the glue squeeze out convo since I was off being a rebel and gathering in groups in this area where that's highly frowned upon.
But here's my $3.57 (two cents after current inflation and taxes) - It's actually best if you can wait about 30-45 minutes for it to start to set up, it turns kind of yellow and rubbery, then scrape it off. It comes off way easier than waiting for it to fully dry and trying to scrape it off when it is cement, and it doesn't push it into the grain. The problem with this method is, I tend to do glue ups and then go to bed or I just forget to come back to it in 30-45 minutes. Because...you know...squirrel!

 

[Max Bogosity]

It's actually best if you can wait about 30-45 minutes for it to start to set up, it turns kind of yellow and rubbery, then scrape it off. It comes off way easier than waiting for it to fully dry and trying to scrape it off when it is cement, and it doesn't push it into the grain. The problem with this method is, I tend to do glue ups and then go to bed or I just forget to come back to it in 30-45 minutes. Because...you know...squirrel!

That’s kind of what I was trying to do here. It was rubbery on the outside surfaces but still runny inside the channel. I probably should have just put it down and come back in another twenty minutes, but fortunately it came out ok anyway.

Thinking about what to do next. I probably want to keep the neck square as long as possible for ease of clamping. So the order of operations looks something like:

1. Plane top surface for fingerboard
2. Carve scroll
3. Drill tuner holes
4. Cut heel tenon
5. Glue fingerboard
6. Trim neck sides flush with fingerboard
7. Carve neck

And at some point I might even make a body to go with it.

 

[Max Bogosity]

I couldn't wait for step 2, so I started laying out guide lines for carving the scroll. I guess this is step 1.5. The Hargrave book has a great description of how he does this (~ page 19) and I've basically copied it. Using my King bass as a pattern, I measured the width at several locations, transferred those measurements to the new neck, and connected the dots. Hargrave says he uses a length of spring steel as a flexible straightedge, but I used tape. Mostly because that's what I have, but also it's convenient that it sticks to the surface and allows gentle sideways curves, which helps to connect the dots smoothly.

I also stole this method for transferring the spiral shape to the sides of the scroll. Just lay the pattern on the surface, jab a pin or scriber right through it, and connect the dots again. After I plane the fingerboard surface but before I start carving the scroll, I have to add two little 'ears' to extend the width enough for the last turn of the scroll. They'll also hide the dowel holes.

Then comes a step I forgot about. The pegbox channel gets tapered slightly, wider toward the nut. That helps the outside strings make it down inside the box without rubbing the sides.

This is a good start, but I suspect I'll have to revisit it when I finally get some strings on. The camera lets you look from perspectives where you can't actually get your eye, like this. It doesn't look nearly as symmetrical from here as it does from above. I'll have to check if that's real or just the camera angle.

 

[Max Bogosity]

Getting set up to clean up the top surface. Sure would be easier if I had a work surface that was flat. Even my shims have shims.

This 2x4 and particle board monstrosity was here when we moved in and it is doing me no favours. A new workbench is going to be high on the to do list after this project.

 

[Bent77]

Getting set up to clean up the top surface. Sure would be easier if I had a work surface that was flat. Even my shims have shims.

This 2x4 and particle board monstrosity was here when we moved in and it is doing me no favours. A new workbench is going to be high on the to do list after this project.

View attachment 4586592

I was fortunate to do field service on heavy equipment onsite. It gave me opportunity to be at active commercial buildings before the cleanup phase. So I was able to collect 4x6 dunnage, rough cut 2x4s, and 3/4” plywood. 144”x30”x40” high with a deck 12” off the floor. I’ve moved that battleship 4 times. Worth every effort

 

[Flamingo21]

battleship

Pic?

 

[Bent77]

Pic?

mostly anyway

 

[DJ Bebop]

mostly anyway
View attachment 4586981

Odd, that looks almost exactly like the workbench I gave my son. We had to dismantle it to take it out of the basement of my home. Built with some of the same material too

We had printing presses shipped from Germany that came with a lot of 4x6s, 4x4s, and plywood so, home it went!

 

[Bent77]

Odd, that looks almost exactly like the workbench I gave my son. We had to dismantle it to take it out of the basement of my home. Built with some of the same material too

We had printing presses shipped from Germany that came with a lot of 4x6s, 4x4s, and plywood so, home it went!

It’s good to put stuff like that to use rather than wasting!

 

[DJ Bebop]

It’s good to put stuff like that to use rather than wasting!

Yup