Search found 16 matches

by ChuckM
Wed Jul 17, 2013 12:55 am
Forum: Instrument Builders Forum
Topic: French polishing
Replies: 26
Views: 9571

Re: French polishing

I've tried both copal and sandarac, but honestly it was so long ago I couldn't begin to give any kind of analysis. I just remember that they took longer to dissolve than the shellac flakes did and that I wasn't that impressed, but I don't know beyond that. I wasn't aware of the less than stellar qua...
by ChuckM
Tue Jul 16, 2013 9:38 am
Forum: Instrument Builders Forum
Topic: French polishing
Replies: 26
Views: 9571

Re: French polishing

It looks like you finally got a decent result, really nice looking btw, so this post is a little late. It's important to note that French polish is not the same as just padding on shellac. The technique is very specific and the oil is the reason it works. FP technique layers the shellac on quite qui...
by ChuckM
Sat Oct 08, 2011 3:14 am
Forum: Instrument Builders Forum
Topic: Lacey Act again
Replies: 2
Views: 1243

Re: Lacey Act again

The suggestions make a lot of sense and would be very welcome to those of us with stockpiles of wood that date back well beyond the 1981 date mentioned in the NAMM document. There are still pitfalls for recently purchased wood though. Long years of opportunistic purchasing have trained many of us to...
by ChuckM
Sun Sep 18, 2011 1:37 am
Forum: Instrument Builders Forum
Topic: Exporting music instruments to the USA
Replies: 17
Views: 5430

Re: Exporting music instruments to the USA

Excellent post. Thanks for the time frames as well. The Lacey act also applies to interstate commerce within the US. I know that a good number (most?) luthiers in the US are sitting on piles of Brazilian Rosewood they paid a lot for and wonder if it's going to be possible to sell (or even advertise)...
by ChuckM
Sun Sep 18, 2011 1:37 am
Forum: Tutorials
Topic: Exporting music instruments to the USA
Replies: 12
Views: 6403

Re: Exporting music instruments to the USA

Excellent post. Thanks for the time frames as well. The Lacey act also applies to interstate commerce within the US. I know that a good number (most?) luthiers in the US are sitting on piles of Brazilian Rosewood they paid a lot for and wonder if it's going to be possible to sell (or even advertise)...
by ChuckM
Thu Sep 15, 2011 11:58 pm
Forum: Instrument Builders Forum
Topic: Analogue signal generator (and maybe more related questions)
Replies: 78
Views: 23516

Re: Analogue signal generator (and maybe more related questi

I figured a more complete set of data would be helpful. This is the back patterns. It's easy to see where the peak at 362Hz is coming from.
by ChuckM
Thu Sep 15, 2011 11:40 pm
Forum: Instrument Builders Forum
Topic: Analogue signal generator (and maybe more related questions)
Replies: 78
Views: 23516

Re: Analogue signal generator (and maybe more related questi

Hi Dom, I believe you are correct in your assumptions as far as the monopole modes go. The back appears to have the major resonance at 362Hz (tapped in center of lower bout) When tapped in the upper bout a co-peak shows at 249Hz. The back is 3 piece American Cherry. I guess it ends up being what you...
by ChuckM
Wed Sep 14, 2011 11:23 pm
Forum: Instrument Builders Forum
Topic: Analogue signal generator (and maybe more related questions)
Replies: 78
Views: 23516

Re: Analogue signal generator (and maybe more related questi

Thanks for that information Trevor. That is the person I was thinking of. The following plot shows the top tap analysis for the round bridge guitar before and after the bridge was glued on. Two peaks below the main (coupled) air resonance, 37Hz and 59Hz, show up better after the bridge is on. I shou...
by ChuckM
Wed Sep 14, 2011 1:57 pm
Forum: Instrument Builders Forum
Topic: Analogue signal generator (and maybe more related questions)
Replies: 78
Views: 23516

Re: Analogue signal generator (and maybe more related questi

My experience is that small and bass in speakers don't mix. I end up using the larger speaker for up to 100Hz or so. Above that I use the smaller one. It's not that the smaller one won't excite the lower frequencies, but the volume has to be turned up and it doesn't really do much below about 50Hz. ...
by ChuckM
Wed Sep 14, 2011 6:29 am
Forum: Instrument Builders Forum
Topic: Analogue signal generator (and maybe more related questions)
Replies: 78
Views: 23516

Re: Analogue signal generator (and maybe more related questi

I find that speaker size (and placement) is important, but it depends on what you're trying to do. I've used 2.5 inch (~6.4cm) and 5.5 inch speakers and found that the larger one tends to make everything look like a monopole. I tried a 12 inch and all I could get was monopoles. With the smaller spea...
by ChuckM
Wed Sep 07, 2011 12:34 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Mass Loading Sides
Replies: 7
Views: 2970

Re: Mass Loading Sides

Yes, going up is hard, but when you're just shy of the target on the downward side, it's difficult to justify dropping 10 or 20 Hz (in the case of skipping over a doubled air resonance) to get down to the next target frequency. The guitar I mentioned raising 15Hz (uncoupled) had laminated solid lini...
by ChuckM
Wed Sep 07, 2011 6:41 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Mass Loading Sides
Replies: 7
Views: 2970

Re: Mass Loading Sides

If I may ask the obvious followup question... Can we then raise the Top resonance, even if just a little bit by removing mass from the sides ? When using a heavy wood like rosewood or ebony this may be a viable option if the desired change is small and the amount removed doesn't weaken the structure...
by ChuckM
Wed Sep 07, 2011 3:10 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Specific vs Monopole mobility ?
Replies: 4
Views: 2008

Specific vs Monopole mobility ?

It seems that the terms Specific Mobility and Monopole Mobility are used interchangeably in the book. Is this the case or did I miss something ?
by ChuckM
Tue Sep 06, 2011 1:11 am
Forum: Instrument Builders Forum
Topic: Yellow Cypress.
Replies: 15
Views: 3949

Re: Yellow Cypress.

Thanks, Glad to be here. I've been meaning to join since someone here linked to my web site a few months ago. I didn't know this forum existed before that.

I've always wanted to visit/emigrate down under and this may be the closest I ever get. :D
by ChuckM
Sat Sep 03, 2011 10:29 am
Forum: Instrument Builders Forum
Topic: Contemporary Acoustic Guitar Design and Build - Reviews
Replies: 15
Views: 5678

Re: Contemporary Acoustic Guitar Design and Build - Reviews

I'm going to be lazy and just repost a review I put on another site... I have read quite a few guitar making books over the last 35 years. I've felt that few of them really added much to Irving Sloane's book, slim though it was. In fact Sloane's is one of the few books that I've dragged with me over...
by ChuckM
Sat Sep 03, 2011 7:49 am
Forum: Instrument Builders Forum
Topic: Yellow Cypress.
Replies: 15
Views: 3949

Re: Yellow Cypress.

I've use quite a bit of it. I refer to it as Nootka Cypress, but everywhere I can buy it it's referred to as Yellow Cedar. In my local lumber yard it is one of the most expensive woods. I have purchased a few top sets, but otherwise re-saw it from lumber. I have used it on one top and 3 backs/sides....