Martin Jumbo - Rosewood Kit

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Selah
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Joined: Fri Jan 24, 2020 5:35 pm

Re: Martin Jumbo - Rosewood Kit

Post by Selah »

Top and back are on. I am trying out some shims to fix the neck joint problem. A couple of popsicle sticks seem to work. Should I glue the popsicle sticks to the neck part of the joint first?
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tippie53
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Re: Martin Jumbo - Rosewood Kit

Post by tippie53 »

I generally glue them all in when the neck is ready . So if you are done working the neck joint you may certainly glue them in. Use the neck and wax paper so you don't glue the neck in but do get the shims glued properly
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
MaineGeezer
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Re: Martin Jumbo - Rosewood Kit

Post by MaineGeezer »

I glue everything at once, but I see no reason why you couldn't glue the shims first. I think I would glue them into the pocket, not to the neck, but that is just my inclination. As John says, you have to be sure they end up in the right plaace.
Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
Selah
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Joined: Fri Jan 24, 2020 5:35 pm

Re: Martin Jumbo - Rosewood Kit

Post by Selah »

Back and top are on. I’ve routed in the binding and this raised another question.

The binding is perfectly flush on the top of the back yet sticks out a little proud on the sides where the back is really arched. I have the router bit that has multiple bearings. I could go a little deeper by changing from the 0.80” bearing to the 0.780” bearing. This may make the cut a slight bit too deep. Would it be better to do that and allow for a little thickness of glue or to stay as is and sand the binding down a bit? My thinking is to go a little deeper and sand the wood down to match. The thickness of my binding is 0.065” which is half way between the 0.060” and the 0.070” thickness noted on the router bit instructions.
MaineGeezer
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Re: Martin Jumbo - Rosewood Kit

Post by MaineGeezer »

I think I'd leave the binding a little proud and use a scraper to take it down to be flush with the sides. The sides (ideally) should be flat vertically, not tapered inward at the top and/or bottom.

You also want to be sure the binding is of uniform thickness, of course, which implies the binding channel that you cut is of uniform depth. A little shallow is fine, as long as it is uniformly a little shallow.
Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
tippie53
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Re: Martin Jumbo - Rosewood Kit

Post by tippie53 »

I set my binding just under the sides a thou the key no matter what technique you use is not to pinch out the binding. I like to see an even reveal all around the body. The back is the hardest area. I can't stress enough about prep and execution.
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
Selah
Posts: 55
Joined: Fri Jan 24, 2020 5:35 pm

Re: Martin Jumbo - Rosewood Kit

Post by Selah »

I’m to the point of putting on binding and purfling. The kit came with two bigger pieces of binding, both 0.063” by 0.21” and one tiny one at 0.027” by 0.063”. One of the big pieces is the binging. The tiny piece is the purfling. What is the other bigger piece for?

Second question: the top also came with two bigger pieces with the same dimension as above. The tiny piece measures 0.070” square. Again, I assume one of the bigger pieces is the binding. For the top, I have ordered one of John’s herringbone purflings. Should I just use one of the bigger pieces for a binding and the herringbone purfling? Should I put the tiny purfling between the binding and herringbone? Does it even matter, or is it just personal preference?

Basically, in my research, it appears as if you can use any combination of binding and purfling that you desire for you guitar. Is that true? Is there some overlap benefit provided by the purfling?
ruby@magpage.com
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Re: Martin Jumbo - Rosewood Kit

Post by ruby@magpage.com »

S

Many guitars have been built with no binding at all, let alone purfling. It is decorative. On a violin family instrument, it is set back from the edge of the top and back which overhang the sides,and they strengthen the delicate shape of the wood, but on guitars that is not necessary.

Ed
Ed M
MaineGeezer
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Re: Martin Jumbo - Rosewood Kit

Post by MaineGeezer »

Yes, you can assemble just about any combination you want. One limiting factor can be the width. If it is too wide, the channel will be wider than the kerfing strip. If you have a thin top or back and cut the channel a bit too deep, you may find thaat you have just cut the top or back loose. If you are careful you can install wide purfling. Just be aware of the need to leave enough thickness when you cut thechannel. A 0.050" deep channel in a 0.085" top leaves about 1/32" .
Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
tippie53
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Re: Martin Jumbo - Rosewood Kit

Post by tippie53 »

purfling was for the back and herringbone on the top
square piece is the heel cap and the tapered piece is for the tail joint
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
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