Big Back Brace

[Maaaven]

I have a old 5/8 flat-back gamba style bass with a 40-year old restoration job.
The back bracing includes 5 separate vertical cross braces. The two lowest
braces appear to be made from 1" * 1" lumber (approx). The brace under the
sound post looks like a slab of 1/2" * 4", basically left whole. The taper on the end
is done inward to a depth of 1/2 inch. The two upper braces are about 1/2" * 2"
nicely rounded and again tapered at the ends in about 1/2 inch.

This seems like a lot of lumber for back bracing compared to my larger 3/4
bass, which is also 3# lighter, with one less brace, and everything nicely tapered
and shaved to minimum thickness all around.

Any expert opinions on bracing flat backs?

[KSB - Ken Smith]

Well, you can open that Bass up, replace those and start your own lumber yard with what comes out of it...lol

Too much wood will kill the sound. Plain and simple.

My best sounding Bass (Storioni) has the smallest cross bars I have ever seen height wise. I don't think they are over 1/4" in thickness. The center Brace maybe slightly over 1/2". The Bass has a lower, 2 uppers and a center brace. The widths are about 1 3/4" just guessing and maybe 3 1/2" on the center one. When this Bass goes into restoration soon I am going to suggest using similar braces in size.

My Loveri had the inner Linings doubled up on the Top edge and 2x wider on the initial strip. I had the Linings 'normalized' and also had some cross strips removed from inside the Ribs. The Ribs couldn't move and passed all the tension to the Top and Back.

If the Bass is worth fixing value wise, have it opened up and trimmed. I don't think 5 braces are needed unless the Bass is way way over sized. I have one huge Bass in restoration and both sets of various Crossbars put in from original to over the centuries were replaced with a single X-Brace in 3-pieces (no Lap joint). The current restorer added some wood in the X-joint area for support as there is a crack in that area.

My Hart Bass now has one LESS Brace then when it was made. The upper one was left out when the Back was restored and only stud patches put along the angle break. The Back has a deep boooomm tap tone in the upper bout.

[chris clay]

i am in the process of building myself a 3/4 flatback bass and gleaning information as i go from this forum...hopefully will learn enough on my way to be able to give the benefit of my experiences to others but for the time being all i am fit for is to ask questions.

as far as back braces are concerned i can reason that what would be optimum would be the least needed to give enough strength and support without unduly impeding the free vibration of the back plate..what does this equate to in practical terms taking account that all joints are to be hot hide glue done as carefully as i can... back is 7mm sycamore

is it neccessary to have a longitudinal cover beading over the centre join of the 2 back boards

[KSB - Ken Smith]

Originally Posted by chris clay

i am in the process of building myself a 3/4 flatback bass and gleaning information as i go from this forum...hopefully will learn enough on my way to be able to give the benefit of my experiences to others but for the time being all i am fit for is to ask questions.

as far as back braces are concerned i can reason that what would be optimum would be the least needed to give enough strength and support without unduly impeding the free vibration of the back plate..what does this equate to in practical terms taking account that all joints are to be hot hide glue done as carefully as i can... back is 7mm sycamore

is it neccessary to have a longitudinal cover beading over the centre join of the 2 back boards

Well, they say it's the weakest link that goes first so when the Back moves or shrinks, something's gotta give. Myself, I prefer the seams to open or the Ribs to crack and not the Top or Back plates. On two old Bass I bought and had restored the Back center seam was open up into the bend of the upper bout. Both Backs were in amazing condition. I can only imagine that if the Back center didn't open, something else would have split if not a Rib seam. These Basses dated from about 1820-1830 each.

Most Backs are studded with Maple from top to bottom. Some even have linen strips over the Studs and joints all the way, block to block. I think that's a classy touch. I don't like seeing a solid Strip up and down the joint. I think that chokes the Bass not letting it breathe when it needs to move. Less is more I guess because the Basses with less wood inside tend to sound better in my experience.

[Bob Branstetter]

Originally Posted by KSB - Ken Smith

My best sounding Bass (Storioni) has the smallest cross bars I have ever seen height wise. I don't think they are over 1/4" in thickness. The center Brace maybe slightly over 1/2". The Bass has a lower, 2 uppers and a center brace. The widths are about 1 3/4" just guessing and maybe 3 1/2" on the center one. When this Bass goes into restoration soon I am going to suggest using similar braces in size.

Ken - I will be curious to find out what the thickness of the back is under those braces. I believe that you have to consider that when installing new back braces. What works well on a relatively thick back may not be that good on a thinner one and visa versa. Do you agree? (I sure wish Santa had brought me a Hacklinger gauge for Christmas)

[KSB - Ken Smith]

Originally Posted by Bob Branstetter

Ken - I will be curious to find out what the thickness of the back is under those braces. I believe that you have to consider that when installing new back braces. What works well on a relatively thick back may not be that good on a thinner one and visa versa. Do you agree? (I sure wish Santa had brought me a Hacklinger gauge for Christmas)

Bob, the Bass is at home now so I can't even measure the edge. Before long the Bass will be up at Jeff's for the restoration and I will ask him to gauge it all out.



To me, the Back is not quite as thick as my Hart Bass is. The wood however is super hard Curly maple. By the color of the oxidation of the crossbars and knowing some of the history of the Bass in America I would say the bars are before WWII because of the Italian born Joseph Settin, NY repair label on the center brace. That would place it between the 2 wars 1920-1940 or so. It could also be after as he died in 1967 but the bars look too old for any later work. The Braces might be much older as well. Jeff will tell me more when he gets the Bass apart.

They are beautifully shaped.

[Maaaven]

I failed to mention that all of the vertical cracks were covered with
long, 3" wide, and carefully tapered vertical strips. With the combination
of all the vertical and horizontal wood installed, I would say less than
50% of the back is simple original single layer back without bracing.

A similar approach with wide strips was applied to the ribs. Square
cleats were only used on the front table. The extra weight seems
to come from a combination of the back and rib repair work.

[KSB - Ken Smith]

Originally Posted by Maaaven

I failed to mention that all of the vertical cracks were covered with
long, 3" wide, and carefully tapered vertical strips. With the combination
of all the vertical and horizontal wood installed, I would say less than
50% of the back is simple original single layer back without bracing.

A similar approach with wide strips was applied to the ribs. Square
cleats were only used on the front table. The extra weight seems
to come from a combination of the back and rib repair work.

My Loveri had a ton of wood on the Back and Ribs as well and was quite a heavy Bass. Most of the extra mass has been removed. The new patches and braces are more on the normal side to what the Bass should actually have. I expect the tone to go from great to fantastic when I get it back.

[chris clay]

Originally Posted by KSB - Ken Smith

Most Backs are studded with Maple from top to bottom. Some even have linen strips over the Studs and joints all the way, block to block.

Ken thanks for your advice but can i just ask for some clarification.
when you refer to backs being "studded with maple from top to bottom" are you referring to the cross braces, and that there can then be a linen strip(rather than solid wood) that covers the centre join and which runs continuously from top to bottom block over these braces.

also is it usual to have a cross brace towards the top of the c-bout, in addition to the ones across the top and bottom bouts and the one for the soundpost

[KSB - Ken Smith]

Originally Posted by chris clay

Ken thanks for your advice but can i just ask for some clarification.
when you refer to backs being "studded with maple from top to bottom" are you referring to the cross braces, and that there can then be a linen strip(rather than solid wood) that covers the centre join and which runs continuously from top to bottom block over these braces.

also is it usual to have a cross brace towards the top of the c-bout, in addition to the ones across the top and bottom bouts and the one for the soundpost

The Studs/linen I refer to is up and down the center joint (or joints like on a 3-pc back as my Martini is done this way). More seen on roundbacks than flatbacks. Also, the linen does not go over the cross bars. I see the linen actually in roundbacks but do see studs in both. Remember, flatbacks are often quicker made Basses so leaving off the studs are common. A center brace and bottom bout cross bar are usually there. In the mid and upper it can be one or both totaling 4 bars with the center included. Some French Basses have only a single center Brace under the soundpost but is much wider and covers most of the center bout to the lower block area.

I am not a bass maker but have looked inside quite a few Basses. Before making something, it would be good to see several examples and copy the successful models rather than the failed ones. Aim before you shoot!

[chris clay]

thanks again Ken for clearing that up for me..i understand now what you were describing

its difficult down here in the toe end of this country to get to examine examples of basses and almost no chance of getting to see inside them..so i'm limited.
lots of lovely photos on the net but not many that get beneath the skin so to speak

so i'm grateful for all the advice i can glean from this TB forum..long may it keep on sounding