Passive Mid control for a 5 string Bass

[LtKojak]

I've been using PU for fingerboards for about 10 years now and I love it.

David... what is PU for us non-english-speaking-population?

[Stealth]

David... what is PU for us non-english-speaking-population?

Polyurethane, maybe?

[David Schwab]

I've been using PU for fingerboards for about 10 years now and I love it, I can start machining in an hour. Before that I was doing hide glue. I don't use veneers at all if I can help it. I was always told the veneer was a good way to hide a bad joint. Not sure what Alembic would say to that.
In the old days I had to bring PU in from Denmark and eventually I could get it in France. Franklin's is about the best I've used and it's usually a lot fresher than the gorilla crap at the hardware store. I buy a new bottle every 3-4 months and keep it upside down.

I've been meaning to try some of that glue. Do you have an issue with it foaming?

I use veneers as accents, but I discovered early on that sometimes if you are going to have a visible glue joint, instead of hiding it, make it a feature! Veneer works great for that.

Like this:




But I was also putting veneer under the phenolic fingerboards. It made them stiffer, and you could actually get a tap tone from them. My inspiration for that was my building partner interned with Ned Steinberger building the first few double basses, and they were built from alternating layers of veneer and carbon fiber.

[mkat]

I have some PU. I first used it a couple of months back. Easier than epoxy to use and I had no issue with the foam which is relatively easy to sand and scrape.

[David King]

Yup
PU is moisture curing polyurethane. It has a very faint odor and probably isn't good to breath the fumes or get the stuff on your skin. Once it's cured it can only be scraped off, acetone won't touch it. It's so tough that the foaming is a good thing otherwise you would be hard pressed to scrape it off. Folks who have an issue with the foaming don't understand the first thing about gluing two pieces of wood together -they have to fit. You don't want to use it on dark woods with large open pores like wenge as it will foam up in the pores and look bad. That said I use it all the time for gluing wenge fingerboards and it doesn't foam out the pores for me.

[David Schwab]

It's amazing that we started out on passive mid chokes and got into glue!

But it's all very useful information.

I'll have to try some PU glue out.