2nd scratch build - Carpathian over EIR

Take us through building your guitar step by step. Post pictures and tell us what you're doing.
Post Reply
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 »

LOL, yeah there's something to be said about a well-sharpened chisel or block plane. Sawing, OTOH - well, my elbow doesn't like that so much!

FWIW, I'm finding that for rough cuts I like power tools but for fine work nothing beats a drawn line to whittle away with a fine blade toward. I'm really not a big fan of Dremels or sanding bone saddles. I guess I'm not cut out to be a dentist! XD
~ 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 feel like I'm continually making excuses for not making progress but I still enjoy working on this - even if I fail to meet even my own expectations.

Today I'm just going to vent about notching the rims. Just when I'm about to glue the plates on the temperature takes a nose dive and the furnace kicks on. I need to shift my focus to installing that humidifier because after a week my plates are acting like they want to become potato chips and are resisting the pressure of the gobar deck.
~ 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 »

From my other thread about spool clamps...

Image

The bigger one will come in handy to ensure that the upper bout and the neck block extension make 100% contact.

Image

Image

Once the RH gets above 35% I'll put the sides back in the mold and glue the back to the rims. That way I'll also get to clean up the excess glue that would be visible through the sound hole. Once it's a "boat" the waist should be stabilized enough to glue the top on with the sides outside of the mold.
~ Neil
Diane Kauffmds
Posts: 3246
Joined: Sun Mar 09, 2014 8:13 pm

Re: 2nd scratch build - Carpathian over EIR

Post by Diane Kauffmds »

I thought you got that humidifier in and running.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
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 »

Diane Kauffmds wrote:I thought you got that humidifier in and running.
I did, but because of the space considerations I had to mount it on the return duct. It's made a notable improvement in the humidity but it's not working to its full potential and during times of excessive cold it can't keep up - though I also need to find a more reliable means of tracking actual humidity. The portable hygrometer I put atop the thermostat is reading 36% at present but because of my wife's wine collection (which is stored beneath the work bench) I've shut the duct in the basement and it reads 27%.

Really though, I'm going by what my hands are telling me and they've gotten pretty dry and cracked from my efforts two days ago. Better safe than sorry, so I've turned my efforts toward working with treated lumber, plywood and MDF. I fact, I've been "jigging up" in anticipation of a future build, an OM:

Image
~ Neil
Diane Kauffmds
Posts: 3246
Joined: Sun Mar 09, 2014 8:13 pm

Re: 2nd scratch build - Carpathian over EIR

Post by Diane Kauffmds »

I was just joking. Besides, the humidifier can only work when the furnace runs. At our house, the furnace doesn't run enough to maintain the humidity. Tightening up a house and installing high efficiency furnaces is a double edged sword.

I like your mold. I need to make another mold too.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
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 »

Can somebody explain to me why we radius the rims? It seems like having a lateral arc (across the width of the body) is counterproductive to assembly somehow. Looking at my factory guitars I see a straight line across the neck block and tail areas. It was troublesome when trying to set up the initial geometry for the fingerboard slope on the top and with the back being tapered it's downright frustrating.

The issue is painfully apparent at the inlets of the first ladder brace from the neck. In trying to inlet the end of the brace into the rims I discovered that I have to practically deform the brace in the opposite direction where I painstakingly sanded a 15' radius.

*grumble*
~ Neil
Danl8
Posts: 733
Joined: Mon Jul 28, 2014 7:50 am
Location: Chadds Ford, PA

Re: 2nd scratch build - Carpathian over EIR

Post by Danl8 »

The back is typically made with a lateral/radial curve (for example, 15') for a variety of reasons, most popular of which is to mitigate cracking in humidity changes. The sides also taper longitudinally where the upper bout is usually more shallow than the lower bout. The sides at the waist are higher because they are closer to the guitar's longitudinal center line. The 15' dish in theory conforms the shape of the sides to the shape of the back, where, in an ideal world, the mating is perfect without any forcing needed. That's worked a few times for me and occasionally isn't a perfect fit, but forcing never needed. Be glad you're not building a baroque guitar -- 15' radius is comparatively child's play. Any way you can post a pic of your situation?

BTW, completely flat can work and is simpler with assembly. My $19 Sears & Roebuck Silvertone guitar was definitely done that way.
ruby@magpage.com
Posts: 1564
Joined: Thu May 24, 2012 8:03 am
Location: Chestertown Maryland

Re: 2nd scratch build - Carpathian over EIR

Post by ruby@magpage.com »

For a while, Gibson made the curvature of the back a cylinder along a curve. To sand it you would need a radius beam (like a curved 2X4) and you would move it up and down the length of the back without spinning it.

Also, it is not uncommon to see a ladder braced guitar with a truly flat top- no radius. I built one, and the geometry is very easy to visualize and create. Just like a ukulele.

Ed
Ed M
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 »

Danl8 wrote:The back is typically made with a lateral/radial curve (for example, 15') for a variety of reasons, most popular of which is to mitigate cracking in humidity changes. The sides also taper longitudinally where the upper bout is usually more shallow than the lower bout. The sides at the waist are higher because they are closer to the guitar's longitudinal center line. The 15' dish in theory conforms the shape of the sides to the shape of the back, where, in an ideal world, the mating is perfect without any forcing needed. That's worked a few times for me and occasionally isn't a perfect fit, but forcing never needed. Be glad you're not building a baroque guitar -- 15' radius is comparatively child's play. Any way you can post a pic of your situation?

BTW, completely flat can work and is simpler with assembly. My $19 Sears & Roebuck Silvertone guitar was definitely done that way.
What I'm seeing is a "hump" at the base of the neck block:

Image

Image

I've since gone at it with a block plane to level it out and feel better about it now.
~ Neil
Post Reply