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Hi Folks,

I’m building a 00 based on a bracing pattern I derived from looking at images of Gibson L00 tops from the 30’s and 40’s and the plan in American Lutherie #91 by Kerry Char.

Here is an image of the plan:


Here is an example I found online:


You can see in the plan that the bridge is really straddling the X and finger braces as opposed to the wings of the bridge just over the X.

I hadn’t spent a lot of time thinking about the impact of that until I braced the top today. It’s quite different than anything X braced I’ve built so far.

Anyone have experience building to this plan? Did you do anything special with the brace heights? I’m planning to taper the lower X legs and tonebars to zero. Upper X legs will be let into the lining.

Any thoughts are appreciated.

Thanks!
Brad


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I think it’d be fine as shown…

+1, looks pretty good to me.
My L-0 was braced similarly for the fingerbraces and it works well.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

The additional coupling of the bridge to the bracing "system" is part, very much part of the character of the tone of an authentic L-OO. It's also why when we see them they are usually in pretty decent shape. We had two 1937's in the shop at the same time from two different owners.

When I was building the prototype for my L-OO Black Tigers as mentioned I went though 10 tops. I found that I had to loosen things up more with less bracing to get the lush tone that I wanted from a finger style instrument.

Per this plan you will get an authentic sounding L-OO but they were were not like today's ring all day finger style instruments. They were more of a rhythm, strummer guitar with lots of middles and lousy highs and lows. That's my experience with them so now it's up to you if you want to be authentic or have it braced to sound differently. I went for differently and that lush finger style tone.

The L-OO is my all time favorite instrument and I covet them. I've been wanting an authentic 37 for years now but every time I find one the owner won't part with it...

GAL is good at getting the good plans. There are always little differences as these guitars were hand made. Some plans out there are no good
If you do this long enough you will see that the variances are not that much maybe +/- an 1/8 in . I had taken tracing from guitars that came through my shop for years.
start with the plan and you should do well. To answer your question the bridge location is going to be based off the scale length of the guitar and how that ends up on the guitar. The saddle will be set off the location of the nut . So look at the plan and figure if from that. the actual build may vary slightly.

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Thanks, all! It seems like a lot of bracing directly beneath the bridge.

Hesh, what adjustments did you make if you don’t mind sharing? Obviously I cannot shift the bracing now but if there are knobs to turn in the area of brace height, scallops vs tapered, etc… that can move the needle I would be interested to hear them.


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Regardless of the plans, it seems Gibson were not always found to follow them, and often placed the bridgeplates wrongly. You may find this video interesting, https://www.youtube.com/watch?v=X3HsGX8a2h0

I scalloped the hell out of the X legs where they intersect the tone bars. I did this tap tuning and I had and have my own tap tuning method that has worked fantastic for me and does not include all the BS that I read in other people's descriptions of the process. But I digress.

If you scallop the X-legs where the tone bars intersect it will open up. Also many builders if not most keep the X intersection WAY too high and that makes that spot on the top like the rock of Gibraltar... immovable and right in the center of the sweet spot of the top too so not good.

So I don't have specs for you and they would be different for every piece of wood anyway but scallop the X-legs and keep the X intersection below 1/2" and even less uncapped and you will get there.

I also almost went with patches for the intersection thinking that caps are more restrictive but I capped it.

By the way Tim McKnight once PMed me on this forum and very generously offered to me to keep the X intersection below 1/2" and man was he right. It was my first ever contact with Tim who later I got to know better. It was also very generous of him and exactly what has happened on this forum thousands of times. Good people helping us all out. Sorry for digressing I wanted to give attribution to Tim for the X-intersection height thing, I'm big on providing attribution on this forum and recommend it, we all learned this stuff from someone unless some of you were born to Luth...

Thanks, Hesh! I’ll post some pics of progress as I go for everyone’s benefit.

You’re 100% right about attributes. In fact, more than once, I’ve corrected folks on instagram where I know for 100% sure where they got the info and called it out in the comments. Nothing is new. Might as well keep it that way.


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Brad my Brother you are exactly right as usual!!!

If it were me and I had those plans I would open the X up a bit so that the lower half of the brace just kisses the lower half of the corner of the bridge. Tapering the ends of the lower braces to zero is a good idea imho and of course letting them in the the linings of the upper portion.

Another fun modification (if you want to vary from the plan a bit): Make it a 13 fret, not a 14 fret. That will nudge the bridge a bit toward the tail, which could push the bridge into a position relative to the X braces that is more like what we are used to for larger guitars.

IIRC, Tim also said that some of the ones that came through his shop had much thinner bracing. I think 3/16th maybe ??

Brad I just finished building this, my 7th, to this plan using black Walnut and Sitka spruce and I am very pleased with the results. Great tone either strummed or finger picking. I am using .012-.053 strings. My only deviation to the plan was that I chose a slothead instead of the solid peg head.
If you build to the plan, you will not be disappointed.
Patrick

The biggest influence in the tone of my few creations has been the product of moving the bridge closer to the middle of the lower bout, 12-fret and 13-fret intersections at the neck (short scale fingerboards). I'm a believer.

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Here is where I’m at, still needs sanded to 220.

The X height is .475 at the center and tapers to 0 at the lower legs. The tonebar height is .450 and tapers to 0. Finger brace height is .210. All the braces are .250 wide except transverse and tongue depressor.

I still need to glue in the cloth patch.

It taps nicely all around the lower bout. I’ll probably go ahead and close the box unless you folks see something needing addressed.



Brad


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Alright, we’re committed now!




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Looking good Brad.

Your bracing looks very good, excellent Brad nice and light. What was the top thickness? And do you thin the top around the edges to free it up?

I hope that some of the others here take note of your bracing because your's is much lighter than what we usually see on this forum and this is how it should be.

This little guitar will likely sound fantastic and be responsive as well. Very well done.

Also this is a pic of an actual 37 I think L-OO:

Thanks, Hesh. The top was initial thickness of .107 and I do plan to thin the perimeter.

Here are the all around numbers.



All the braces are peaked as much as I could get them. I use a 20 degree bevel chisel with safe corners as described in Gores book.


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FWIW, those brace thicknesses are very close to what I target on our Jumbo's (SJ-200 plans). I use a cap instead of cloth, but very similar... except for an additional finger brace on the two sides... which is the typical layout. FWIW, we use adi for the top and get a great tonal range with finger picking, though most of our players use a pick.

Brad's measurements are similar to what use on my Dreds, OMs and OOOs with scalloped braces. My measurements are based on measurements that came from a '37 D28. Makes a responsive guitar. I also use red spruce tops..

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