Winter Build-Off 2022: Bamboo EUB

[Max Bogosity]

I think what I’ll do is just fill and clear coat it for now, and live with it like that for a few months until I’m sure I don’t want to reshape the neck or make other major changes.

Ordered a can of that Varathane Ultimate that all the cool kids are using these days, but what showed up was Varathane Diamond Floor Finish instead. I sent it back. I have used that in the past and it’s just OK. Probably user error, but it seemed like the coats didn’t bind together well and there were always witness lines when sanding through one coat into the next.

 

[Max Bogosity]

Started on the tailpiece. It would be nice if it were ebony to match the fingerboard, but I don't have any ebony so it's going to be walnut.

I've tapered it front to back and side to side to approximate the final shape, then drilled the holes for the tailgut with the extremely Mickey Mouse setup in the picture. I think the next step is to round the top, then cut out the outline, then tape the offcuts back on to help hold it while I hollow the back, then finally round off the edges and make it look pretty. Drilling the holes for the strings comes some time after rounding the top surface so I can get them perpendicular to the surface.

Most of the wood will end up on the floor. I've already started so I'll carry on this way, but if I were to do another one I might try coopering it.

 

[Flamingo21]

What is coopering?

 

[Videojunkie]

What is coopering?

Barrel making.

 

[Max Bogosity]

What is coopering?

A cooper is someone who makes barrels, so by extension coopering is making curved objects from a series of straight tapered ones. For example, a chest lid.

 

[Flamingo21]

Well that's interesting. Thinking about it, I think lutes are made using this kind of technique.

 

[Max Bogosity]

The facet technique for shaping necks works even better for tailpieces. With no inconvenient heel or headstock in the way, you can do most of it with a saw and a plane.

This is a weird shape and hard to hold. A tail vice would be handy. A parallel jaw clamp works in a pinch.

Hollowing the back using the drill press to establish the thickness. Similar to the way you might lay out the contours for a carved top. I started each hole square to the surface, then let the tailpiece orient itself.

Still a long way to go, but it's starting to look like something.

Probably would have been smarter to drill the string holes before starting to hollow the back side in order to avoid the holes blowing out, but I'll do it before going any further so any damage will clean up.

 

[Max Bogosity]

 

[RichterScale]

Nice

 

[Videojunkie]

Dude!

That turned out amazing! When you get some finish on it it's going to look gorgeous!

 

[1n3]

Nice job on the carving. If you're interested in matching the ebony fingerboard, walnut responds fairly strongly to vinegaroon dye.

 

[Max Bogosity]

Nice job on the carving. If you're interested in matching the ebony fingerboard, walnut responds fairly strongly to vinegaroon dye.
View attachment 4819045

Nice! That's worth checking out.

 

[Max Bogosity]

Started a batch of vinegaroon dye this morning which is now bubbling away. Apparently the bubbles are hydrogen gas. I will try not to explode myself. There are holes in the lid of the jar to allow the pressure to release.

And a bass-ackwards update on the holes in the tailpiece, which took an embarrassingly long time to lay out correctly. I wanted them all offset by the same distance from the curved front edge of the tailpiece, which is easy enough. But then I went down the wrong path trying to distribute the hole centres along that curved line. The tailpiece is tapered and the curve crosses the centreline at an angle, so the left side is longer than the right side, so equal spacing results in the holes being skewed toward the left. Then I was trying to vary the spacing along the curve to get them back on centre.

Finally I did what I should have done in the first place and laid out the string paths on the surface of the tailpiece and just marked the intersections.

Drilling the holes square(ish) to the surface.

 

[Max Bogosity]

Vinegaroonilicious.

 

[Crawforde]

Nice that darkened the walnut nicely but the grain is still pretty. I bets it will be sweet with the finish on it.

 

[Max Bogosity]

Nice that darkened the walnut nicely but the grain is still pretty.

That’s it exactly. If it came out uniformly black it wouldn’t be nearly so nice.

The dye did raise the grain, though, which I ought to have anticipated. I probably should have wet it and sanded back a couple of times first.

 

[1n3]

That was fast! It took my vinegaroon dye a couple weeks to reach full strength. Maybe you had stronger vinegar.

There are dyes that will give a more solid black, but I think the vinegaroon looks more natural. It does raise the grain, which sucks, because the penetration is usually pretty shallow. A trick, if you're going for the darkest effect, is to raise the grain with strong tea, which adds tannin to the wood. Guess my last post would've been a better time to mention that. But you can also add tea over vinegaroon if needed.

 

[Will_White]

What's vinegaroon?

 

[Slidlow]

What's vinegaroon?

Maybe they are refering to ferric acetate (iron acetate) which is what you get when you dissolve steel wool in white vinegar.

 

[Will_White]

Maybe they are refering to ferric acetate (iron acetate) which is what you get when you dissolve steel wool in white vinegar.

That's what I was thinking but that doesn't release gas, or maybe I got lucky