2nd scratch build - Carpathian over EIR

Take us through building your guitar step by step. Post pictures and tell us what you're doing.
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nkwak
Posts: 650
Joined: Sat Nov 13, 2010 9:55 pm
Location: Pittsburgh PA suburbs

Sides braces and initial neck tenon fitting

Post by nkwak »

I put in some side braces the other day. I made them from spruce bracing scrap.

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Then I had to cut away some space to admit the truss rod and took a little off the side of the tenon. Now it fits snug; not loose at all, but it's too early to do the full neck set obviously.

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I also have a case for it to live in when the RH starts falling, but it's been hot this week.

Image
~ Neil
Danl8
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Re: 2nd scratch build - Carpathian over EIR

Post by Danl8 »

Very nice, clean work, Neil. Looks like this guitar will sing.

-d
johnnparchem
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Re: 2nd scratch build - Carpathian over EIR

Post by johnnparchem »

Looking really good.
nkwak
Posts: 650
Joined: Sat Nov 13, 2010 9:55 pm
Location: Pittsburgh PA suburbs

Re: 2nd scratch build - Carpathian over EIR

Post by nkwak »

Thanks.

I've decided that I'm going to make a sound port in the upper bout. I will be putting in a maple veneer (for decorative purposes) and a rosewood patch inside before routing it out. I'm hoping it turns out well.
~ Neil
nkwak
Posts: 650
Joined: Sat Nov 13, 2010 9:55 pm
Location: Pittsburgh PA suburbs

Re: 2nd scratch build - Carpathian over EIR

Post by nkwak »

I recently notches the rims and the fretboard extension to accept the braces for the top and back:

Image

In order to locate where to cut for the A Frame I used charcoal to scribe the position. Then I used hand tools to cut/chisel. I don't get along very well with power tools. They require a bit of finesse that I do not possess.

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Now all the pieces are roughly dry fit and can live inside the case together in anticipation of the RH dipping now that the northeast US heating season has begun:

Image
~ Neil
nkwak
Posts: 650
Joined: Sat Nov 13, 2010 9:55 pm
Location: Pittsburgh PA suburbs

Re: 2nd scratch build - Carpathian over EIR

Post by nkwak »

OK, I upgraded my go bar deck - and discovered that the rims are no as ready to accept the top as I'd hoped. I'm concerned that this would result in the dreaded "14th fret hump" so I'm trying to think of way to shaped the upper bout top geometry at the rims/neck block before gluing the top on:

Image
~ Neil
Danl8
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Re: 2nd scratch build - Carpathian over EIR

Post by Danl8 »

What exactly is the situation with the rims vs top?
nkwak
Posts: 650
Joined: Sat Nov 13, 2010 9:55 pm
Location: Pittsburgh PA suburbs

Re: 2nd scratch build - Carpathian over EIR

Post by nkwak »

I sanded a radius around the entire outline of the top side of the rims, even across the lateral axis of the upper bout. Meanwhile the underside of the upper transverse brace was left flat. The result is that the upper bout of the rims wants to have the radius but the top wants to be flat in that area. Doing a dry fit with the go bar deck the soundboard doesn't want to flex - nor should it IMO.

It's been so long that I've forgotten what I did on my first build but I remember doing something different with the UTB; I butted the ends against the sides with no taper and it appears that the upper bout is flat on the lateral axis. So I'm thinking that I'm going to have make a jig so that I can sand that axis on the rims flat with a 1.5 degree slop from the sound hole to the opening of the mortise.

This is probably pretty basic but like I said, it's been 5 years or more since I was at this point last time. Too long. Once I close the box and set the neck angle I need to make notes so that I don't get tripped up the next time around.
~ Neil
ruby@magpage.com
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Re: 2nd scratch build - Carpathian over EIR

Post by ruby@magpage.com »

There are a number of ways to treat the upper bout so that you neck points in the right direction. Here is one by Hesh Breakstone that gets positive reviews every time it comes up. Hesh is no longer on the inner web as he has retired from guitar stuff:

http://www.luthiersforum.com/forum/view ... 17&t=25931

Ed

Hope it's not a problem ti cite another forum here

Nice looking box, by the way - very clean
Ed M
nkwak
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Joined: Sat Nov 13, 2010 9:55 pm
Location: Pittsburgh PA suburbs

Re: 2nd scratch build - Carpathian over EIR

Post by nkwak »

I’ve done a little searching around over at the OLF and think I know what to do thanks to post by Hesh that’s several years old. It’s actually a pretty simple solution;

- just mark a line across twhere the UTb will be,
- lay the rims in the mold top down on a flat surface with sticky back 120 grit sandpaper on the flat surface,
- place a 1/8” thick popsicle stick under the tail block,and
- (pressing down of course) pivot the rims just like if you were using a radius dish to “drive the bus” as John says.

I’m going to be overly careful of course but will report back on the results. I’ve got a LOT of sanding to do though so I may use my block plane to get started of course.
~ Neil
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