Outgassing dilemma

[Antlurz]

I'm working on a laminated binding for a fretboard, and had never used acetone for bonding the laminate before. As it turns out, the celluloid swelled much more than I had anticipated.

Now, I'm stuck with the board assembly being quite measurably wider than the neck.

Two immediate questions:

1) Any idea of how long before it shrinks back down to a stable size so I can mount it to the neck, and

2) Anything I can do to help speed up the outgassing?

Ron

[Michael Lewis]

Ron, you must have really soaked the bindings to make it swell so much. You can only let time and warm air do it's job. If you have more binding you can keep on working, but if not you will have to wait. Make sure the binding is hard before trying to scrape or level it or it will shrink further and you will end up with dips and dimples.

[Antlurz]

Michael...

As you can see from the timestamps on our posts, it has sit for a few hours, and is now about half way back to where it should be. If it continues at this rate, I should be OK fairly soon.

Maybe? http://www.mandolincafe.net/iB_html/non-cgi/emoticons/wow.gif

And yes, I doused it pretty good. Crazy eyedropper went batso on me. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif

Ron

[Jim Hilburn]

One way to avoid this problem in the future is to build the fingerboard first. I may build a neck blank and install the rod, but I don't cut it to shape until I can mark it out with the actual fingerboard.

[Michael Lewis]

Yes, fingerboard first, then shape the neck.

Acetone is rather difficult to control since it tends to run all over the place. It is better to brush it on the surfaces that are to be joined.

As to acetone soaked binding, it will take some time to completely off gas and get hard. Days and days maybe.

[Antlurz]

Well, I wiped it down almost instantly where it got where it wasn't wanted. After measureing it a few times today, it appears to be back to just about where it should be. I can kill some time with the rest of the binding, etc. first, so it should be fine by then.

Ron

[Dave Cohen]

The rates of most chemical processes, including outgassing of solvents from polymeric solids, follow exponential decay laws. linear rate laws occur only in so-called "zero order" reactions, which are very rare. Translated into lay English, that means that the outgassing will occur rapidly at first, and more slowly with time. It WILL continue, though. Your binding could continue to shrink for months, years,..., though the rate slows down as time passes. After the initial treatment which you described, you should probably give your binding at least a month to settle down.

[mrmando]

Hm. In that case, perhaps he should set it aside for the next instrument he builds.

[Jim Hilburn]

You can add acetone to Duco to make it thin but it will still cling to things instead of run like water.

[Antlurz]

Your binding could continue to shrink for months, years,..., though the rate slows down as time passes.
That's good. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/laugh.gif

At the rate this one is going together, http://www.mandolincafe.net/iB_html/non-cgi/emoticons/mad.gif that will work out about right!

http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

Ron