Violin Forum/Message Board

MikeCooper · Posted: Sat Jul 05, 2025 9:00 pm Post subject:

I finished the bass bar. Here it is clamped for gluing, and finished.

MikeCooper · Posted: Fri Jul 11, 2025 6:21 am Post subject:

Here's a video of me shaping the bass bar

https://www.youtube.com/watch?v=lxsDQq3Y-20

John Cadd · Posted: Sun Jul 13, 2025 6:46 am Post subject: first build

What I notice is the highest section of the bassbar is away from the bridge position . Is that for a special purpose ? There are several opinions about bassbars and you may have reason for that .

John Cadd · Posted: Sun Jul 13, 2025 6:49 am Post subject: Re: first build

[quote="John Cadd"]What I notice is the highest section of the bassbar is away from the bridge position . Is that for a special purpose ? There are several opinions about bassbars and you may have reason for that .[/quote]
The questions and answers about plate thicknesses will also apply to bassbar shapes and positions .

Michael Darnton · Posted: Sun Jul 13, 2025 1:24 pm Post subject:

Middle of the bar is pretty much standard in the restoration community (where people don't feel the need to leave their personal mark or eccentricity). The weakest spot on the top is the narrow isthmus between the tops of the f-holes and the most pressure is at the bridge, so this strategy more or less splits the difference, considering them equally.
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MikeCooper · Posted: Tue Jul 15, 2025 5:50 am Post subject:

I do a lot of research and reading and found this on Maestronet, so rather than typing it all out, I'll copy and paste from that post.

I used these measurements mostly although my height measurements may have been off a little bit because of all the different things I've read.

Also I read somewhere that the highest point of the bar is about halfway between the bridge position and the center of the plate.

Roger Hargrave also has a PDF document about shaping the bass bar which influenced me somewhat.

I try to learn from the best makers as much as I can. They share a lot of good information!

Here's the quote, I think it was someone quoting something that Michael wrote in another thread, maybe on this forum somewhere.

"I use a simple plan that is based on something I got from the Carl Becker shop, who get full credit for it. The basic idea is to measure the bar height including the top thickness, with a graduating caliper. Divide the bar into eighths (nine pencil marks, including the ends) and the thickness of top plus bar is 5.0mm, 7.6, 10.2, 12.8, 14, 12.8, 10.2, 7.6, 5.0, from one end to the other at each mark.

It's simple, gives exactly the right profile, and compensates for top thickness. I start the bar 40mm from both ends, and it's 5.5mm wide, 1mm inside the outside foot of the bridge, and 12mm from the center of the upper bout and 15mm from the center of the lower bout.

Michael Darnton · Posted: Tue Jul 15, 2025 9:19 am Post subject:

Yes, those numbers are from me, from Beckers.
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John Cadd · Posted: Thu Jul 17, 2025 12:11 pm Post subject: first build

Davide Sora has a video about bassbars. He finishes with a stylish final shape . G plan furniture makers must have been an influence there .

MikeCooper · Posted: Fri Jul 18, 2025 9:08 pm Post subject:

Davide's bar has a rather long flattish section.

I've been pretty busy with other things lately, hopefully I can get back to the build soon.

I need to find a good quality paper to make my label before I close the box. Last build, I used parchment colored resume paper. This time I would like to find some authentic hand laid paper.

I was thinking of using a dilute solution of chickory to darken the inside so it doesn't look stark white new.

MikeCooper · Posted: Sun Jul 20, 2025 8:38 pm Post subject:

Another lake pigment experiment.
These two pics are the same sample, in sunlight and in the kitchen under florescent lights. The red looks more red than in person and the brown looks more brown than in person. The real color is somewhere in between but it's hard to get it to show accurately in a photo. Ignore the writing, there are other lake samples on the other side.

This is a mix of red madder, yellow fustic, cochineal, and Iron sulfate. The iron sulfate is from a discussion with Davide Sora, 10grams iron sulfate in my usual espresso madder but then I had to add alum to make it precipitate.

MikeCooper · Posted: Sat Jul 26, 2025 10:47 am Post subject:

Someone posted a comment on my youtube channel asking how to make lake pigment for varnish so I am making a video to show how. You guys already know how but I'll post a link in case you want to see how I do it.
It's in two parts, so this is part 1. It will be a few days before I post part 2.

https://www.youtube.com/watch?v=53c2adtoTGo

MikeCooper · Posted: Thu Jul 31, 2025 8:16 pm Post subject:

Part 2 of my madder lake making.

https://www.youtube.com/watch?v=tZ1SAqv9U6Q

Rick M · Posted: Thu Aug 14, 2025 9:59 am Post subject:

Good videos, thanks for sharing. Makes the process a little more approachable. Will have to add this to my winter “need to try” projects.

MikeCooper · Posted: Sat Aug 16, 2025 5:06 pm Post subject:

Hi Rick,

Thanks! I'm glad you like them. I have been a little slow to make progress lately but I'll try to get some more done soon.

MikeCooper · Posted: Sun Aug 17, 2025 9:27 pm Post subject:

Applying a size of gum tragacanth and gum arabic to the inside. I may thin it down and use it on the outside also, especially on the end grain areas.

https://www.youtube.com/watch?v=E72NhTsZCEk