Search found 78 matches

by Jim watts
Sat Dec 05, 2020 10:01 am
Forum: Instrument Builders Forum
Topic: Nitrocellulose issue
Replies: 11
Views: 2401

Re: Nitrocellulose issue

You might try a solvent called Cellosolve. I believe blush eraser is Cellosolve, but you'd want to verify that.
Here's a link to Frank Fords excellent site on how he used it on an old crazed Martin.
http://www.frets.com/FretsPages/Luthier ... ator1.html
by Jim watts
Fri Nov 20, 2020 12:12 pm
Forum: Instrument Builders Forum
Topic: It’s not your fault but
Replies: 7
Views: 2142

Re: It’s not your fault but

You can also make your own for about 10 cents.
You can get as accurate as want by by making it longer and using a shallow angle.
After cutting the wedge I just measured it with my dial caliper and marked it.
IMG_3701 small.png
by Jim watts
Sat Nov 07, 2020 3:48 am
Forum: Instrument Builders Forum
Topic: Bridge plate
Replies: 3
Views: 1579

Re: Bridge plate

Bummer, at this point if the guitar is for you I would just carry on and if there's a problem down the road fix it then. It is possible to remove a bridge and put in a new one, although I've never done it. You also might be able to add to the existing bridge plate with a narrow strip, it might be wo...
by Jim watts
Sun Nov 01, 2020 9:32 am
Forum: Instrument Builders Forum
Topic: Double V Neck Acoustic
Replies: 23
Views: 11260

Re: Double V Neck Acoustic

Wowzer!!! Great job on an unconventional build. Glad it works well too.
by Jim watts
Fri Jun 19, 2020 10:27 am
Forum: Instrument Builders Forum
Topic: First attempt at video editing
Replies: 8
Views: 2615

Re: First attempt at video editing

That's really nice, great job!
by Jim watts
Mon Jun 08, 2020 10:49 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Trevor’s video by Robbie
Replies: 10
Views: 4296

Re: Trevor’s video by Robbie

I just watched these, they're a good supplement to the book.
Thanks to Robbie and Trevor!
by Jim watts
Tue Jun 02, 2020 1:06 am
Forum: Instrument Builders Forum
Topic: Moving to the Desert
Replies: 10
Views: 3010

Re: Moving to the Desert

Hi Lillian, I'll be one of you're geographic neighbors, I'm just NW of Santa Fe it's a fabulous area. I'm at about 7000 ft and weather is mostly mild, winters are cold with some snow but lots of sunshine. It can make a 10 deg F day feel not too bad. If your putting up a shed to build in I would reco...
by Jim watts
Wed Mar 18, 2020 5:21 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: 1. falcate braced classical
Replies: 17
Views: 7613

Re: 1. falcate braced classical

Route it off like you're routing for binding. Set the depth to the top thickness and the width off cut equal to the sides = linings. You might need to do a little hand work over the tail and heel block, but otherwise you're pretty much done.
by Jim watts
Tue Feb 18, 2020 4:18 pm
Forum: Instrument Builders Forum
Topic: Carbon fibre splinters
Replies: 2
Views: 2791

Re: Carbon fibre splinters

D - All of the above
by Jim watts
Sat Nov 09, 2019 11:24 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Bridge Rotation at 2.3deg
Replies: 15
Views: 8975

Re: Bridge Rotation at 2.3deg

Got it. I run VA on a PC so the live view is in a separate window.
Thanks.
by Jim watts
Sat Nov 09, 2019 7:51 am
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Bridge Rotation at 2.3deg
Replies: 15
Views: 8975

Re: Bridge Rotation at 2.3deg

JF, What's the green plot? Sorry I'm just trying to understand.
by Jim watts
Tue May 21, 2019 5:56 am
Forum: Instrument Builders Forum
Topic: Fly in Nitro Finish
Replies: 4
Views: 2327

Re: Fly in Nitro Finish

Let it dry, remove the fly, drop fill, wait a few days, level and move on.
by Jim watts
Sun Mar 24, 2019 5:47 am
Forum: Instrument Builders Forum
Topic: Alternative to a Stewmac buffer
Replies: 9
Views: 5362

Re: Alternative to a Stewmac buffer

Here's one I made. I works very well, spins around 700-800 rpm. My only issue is that every time I use it I think to myself "I need to a belt guard over that top pulley". I used a piece of shafting from an industrial supply store and had a machinist friend cut the thread on it. IMG_3391.jpg IMG_3392...
by Jim watts
Mon Mar 18, 2019 1:59 pm
Forum: Instrument Builders Forum
Topic: Rope bindings advice please
Replies: 17
Views: 7245

Re: Rope bindings advice please

Hi Pete, It's been a while since I made this rosette so the process is a little fuzzy to me right now but near as I remember lamanoditrento's description of it is spot on. It took me a couple of attempts, the failure with the first one was due to using a water based glue like titebond. You obviously...
by Jim watts
Tue Jan 29, 2019 3:55 pm
Forum: Instrument Builders Forum
Topic: Spectra question
Replies: 17
Views: 7396

Re: Spectra question

Trevor, The amplitude difference between the t1,1 and t1,2 was my first thought too after rereading the section. With the set up in the original configuration, I held a book (your book BTW) 5-6" in front of the sound hole to know the amplitude of the t1,1 down. But I still had the deep trough, so I ...
by Jim watts
Sun Jan 27, 2019 4:24 pm
Forum: Instrument Builders Forum
Topic: Spectra question
Replies: 17
Views: 7396

Re: Spectra question

Well, I spent part of the day trying figure this out and I believe I made some progress. Looking at Trevor's references of section 2.4.2 it appears that frequencies can interact with one another depending on their phase and strength. I won't bore you with a bunch of spectra plots unless you want, bu...
by Jim watts
Fri Jan 25, 2019 4:25 pm
Forum: Instrument Builders Forum
Topic: Spectra question
Replies: 17
Views: 7396

Re: Spectra question

Trevor, Thanks for the references. I've been pretty tied up with some other work stuff, so I'm still chewing on this. I'll get closer to having this figured out in a few days, I think.
Jim
by Jim watts
Tue Jan 22, 2019 3:12 pm
Forum: Instrument Builders Forum
Topic: Spectra question
Replies: 17
Views: 7396

Re: Spectra question

Ross, I just trashed my shop computer and my old amplifier a few months back, cleaning up the shop! Oh well :cry:
by Jim watts
Tue Jan 22, 2019 10:16 am
Forum: Instrument Builders Forum
Topic: Spectra question
Replies: 17
Views: 7396

Re: Spectra question

Thanks Trent, I'm one of those very few anti smart phone guys.
As I was thinking about it a little more this seems more than likely a phase thing with the back. I'll check the black book for some more info.
I'll try retapping in the next day or two and see if I can get anything different.
Jim
by Jim watts
Tue Jan 22, 2019 5:09 am
Forum: Instrument Builders Forum
Topic: Spectra question
Replies: 17
Views: 7396

Re: Spectra question

Thanks for the replies. This guitar is being built by a student over a long time period, a few years. I was just going over my notes, it appears we wanted to leave the top thick so we could bring down the resonances. The idea being he'd learn something from that exercise (me too of course) and he'd ...
by Jim watts
Sun Jan 20, 2019 5:15 pm
Forum: Instrument Builders Forum
Topic: Spectra question
Replies: 17
Views: 7396

Re: Spectra question

Ross,
It looks we posted at the same time.
The uncoupled top is at 222 Hz. I had planed to do some top thinning on this one, but this is probably more than I wanted.
by Jim watts
Sun Jan 20, 2019 5:12 pm
Forum: Instrument Builders Forum
Topic: Spectra question
Replies: 17
Views: 7396

Re: Spectra question

Hey martin, some addition information; - I used a Zoom h4 recorder for the mic. It actually has a pair of mics. - Recorded into Va, fft size of 16384 and sample rate of 11025. - The guitar was tapped with an eraser on a stick, lightly in the bridge area. - Averaged 10 samples. - The mic was little l...
by Jim watts
Sun Jan 20, 2019 6:47 am
Forum: Instrument Builders Forum
Topic: Spectra question
Replies: 17
Views: 7396

Spectra question

I'm currently working on a guitar and have a questions concerning the dip in the spectrum at 201Hz. I was anticipating the top to be there. The guitar is nearing completion, It's a fan braced classical, without a bridge at this point. I'd like to pull everything down a bit. So, what is it and why do...
by Jim watts
Sun Jan 20, 2019 3:16 am
Forum: Instrument Builders Forum
Topic: Hollowbody electric
Replies: 25
Views: 12845

Re: Hollowbody electric

She's a beauty!
by Jim watts
Sun Nov 11, 2018 4:26 pm
Forum: Contemporary Acoustic Guitar Design and Build - Trevor Gore
Topic: Predicting Panel Mass SS - Lookover
Replies: 4
Views: 3179

Re: Predicting Panel Mass SS - Lookover

John, you lost me on your area calculation. Pause.... .00119 is in Kg/cm correct? Now that I've considered the area calculation, that's an interesting way to do it.