Rib reinforcement

ctregan · #1 02-20-2010, 10:12 AM

Is this a good idea?

One of the ribs on the bass I built, split last week. I was thinking of reinforcing the ribs so it does not happen again. I have seen other makers use strips of wood glued perpendicular to the grain, in the upper and lower bouts, not sure if it is a good idea or not.

The rib cracked on a school orchestra trip; kids in the bus, the instruments loaded on a van. The bass is made of cherry wood, may not be the strongest, but it is pretty.

Here is the idea:

arnoldschnitzer · #2 02-20-2010, 11:04 AM

If you do install straps, let them into the linings, so you don't cause a new crack. I prefer to repair individual cracks, unless there are several next to each other.

**Matthew Tucker** · #3 02-20-2010, 02:58 PM

I used light cedar straps at a few key points, but i feathered the ends to nothing rather than letting them into the linings.

You could use linen strips; they are good too, and a bit more flexible. you can easily take them up over the linings.

james condino · #4 02-21-2010, 12:12 PM

Craig:

'Good to see that your boy is not afraid to take that new bass out and play it hard!!! I should have sent out a spare set of ribs with those tops headed your way!

As much as I don't like to repair side cracks, most of the best instruments I have ever played did not have any side reinforcements and were under built. I can't site the source right now, but I've read an old article by Carleen Hutchins where she goes into detail about letting the ribs vibrate with no extra material added and she also talked about how a choked voice with 3mm ribs opened up substantially when she thinned them back down to 2.5 or less.

I've had a few pre war Martin guitars in the shop recently and the ribs on them have all been incredibly underbuilt- around 0.060" or less, broken up and repaired in dozens of places on each one, and yet they sounded incredible- banjo killing cannons.

The day I was in the shop building my bass, five minutes after I cut the access panel in the C bout, a neck hanging the wall rack fell and crashed into one of the ribs on the new bass, puting a five inch crack in it. 'Stuck my arm in the new panel hole, turned on the hide glue pot, made a couple of cleats and in about ten minutes the whole thing was back in shape and ready to go again....

Did you have to pull the top of your new bass to fix the cracks?

j.

Ed Fuqua · #5 02-21-2010, 02:29 PM

I'm just looking at the article from DB #3 (spring/summer 97) on the Kelischek bass -

"The thickness of the ribs is controversial; just 2mm rather than the conventional 4mm. They are lined with linen, though, which Kelischek insists makes them both stronger and lighter than traditional ribs. He can support his claims thanks to numerous experiments - he conducted his own stress tests on various thicknesses of wood with and without lining and found 2mm of linen lined wood able to withstand several times the force of an unlined 4mm piece before cracking."

**Matthew Tucker** · #6 02-21-2010, 05:16 PM

I haven't seen many basses with 4mm ribs. 2.5mm is more the norm.

Ed Fuqua · #7 02-21-2010, 05:54 PM

In the immortal words of Rodney Dangerfield " Hey I don't write'm, I just read'em..."

**Matthew Tucker** · #8 02-21-2010, 06:13 PM

An' nubbudy reads 'em bedda dan you

1st Bass · #9 02-21-2010, 07:06 PM

"I've had a few pre war Martin guitars in the shop recently and the ribs on them have all been incredibly underbuilt- around 0.60" or less, broken up and repaired in dozens of places on each one, and yet they sounded incredible- banjo killing cannons."

I trust that was s'posta read .6 mm? or maybe another zero after the decimal, or something? Either that or those guitars would only kill banjos they are dropped upon. :-)

Jake deVilliers · #10 02-21-2010, 09:06 PM

Quote:

Originally Posted by 1st Bass

"I've had a few pre war Martin guitars in the shop recently and the ribs on them have all been incredibly underbuilt- around 0.60" or less, broken up and repaired in dozens of places on each one, and yet they sounded incredible- banjo killing cannons."

I trust that was s'posta read .6 mm? or maybe another zero after the decimal, or something? Either that or those guitars would only kill banjos they are dropped upon. :-)

Nice catch Chet - should obviously be .060", 60 thou.

james condino · #11 02-21-2010, 09:41 PM

.060" for the old Martin ribs.

The ribs on my bass are 2.4mm

Even though this is a bass forum, a lot of the folks around here work on and build more than basses, hence my guitar reference. Across the spectrum of instruments that build and play, I'm a strong believer in the idea that the ribs play an important part in the voice and I want / like them on the thin side.

I can also remember being sixteen and stuffing an old bass in the back of a 1980 Honda civc with the front wndow open, about two feet of the neck and the scroll sticking out the passenger side window, two more buddies, and a lot more gear all piled into the thing and the bass taking a beating as we drove like maniacs, tossing empty beer cans out the window as we drove along... It might not be such a bad idea to stffen up those ribs on your son's bass.

j.

**Matthew Tucker** · #12 02-21-2010, 09:47 PM

And then again, there are guitar makers that laminate great thick ribs and double backs to make the box as rigid as they can. Another approach, another result.

james condino · #13 02-21-2010, 10:36 PM

Quote:

Originally Posted by Matthew Tucker

And then again, there are guitar makers that laminate great thick ribs and double backs to make the box as rigid as they can. Another approach, another result.

True, but I've played a lot of them- probably close to 100 different ones- and never met one that I ever considered owning or that responded anywhere near the way a great old pre-war Martin or a new Jeff Traugott sounds. A good friend of mine is a great builder and author who is all about that double wall school of building, so I'm well versed in it. Working at Dream Guitars ( When I can balance it with my own busy workload. I'd post the website so you could take a look, but the thought police would come after me here...take a wild guess at it before you google) allows me to play hundreds of incredble guitars by the best builders in the world every month, and every one that stands out to me gets worked over with the calipers and Hacklinger gage to run the numbers and take notes on the construction.

As long as we are fading from the original post, I've been wanting to build a bass with Brazilan rosewood ribs for quite some time, but just haven't figured out how to do it without breaking the bank...'must be the guitar nerd in me...either way, I already know that I'll be doing a lot of regular crack repairs with those.

I 'd be willing to bet a pretty good wager that even with a great big, thick, overbuilt , double wall and double back bass, Ed would still be able to pull more tone out of the thing than most of us will ever be able to dream about.

j.

ctregan · #14 02-22-2010, 05:51 AM

I went with the singular cleats. No need to over complicate the job with extra bandages.

DavidMP · #15 02-22-2010, 08:52 PM

Quote:

Originally Posted by james condino

True, but I've played a lot of them- probably close to 100 different ones- and never met one that I ever considered owning or that responded anywhere near the way a great old pre-war Martin or a new Jeff Traugott sounds.

The Smallman classical guitars are very responsive and have a reputation for demanding very clean technique; they have laminated sides. All in all it's the luck of the draw.

If you play the bass and somebody rests their hand on the ribs does the sound change?

uprightben · #16 02-24-2010, 07:51 AM

Quote:

Originally Posted by DavidMP

The Smallman classical guitars are very responsive and have a reputation for demanding very clean technique; they have laminated sides. All in all it's the luck of the draw.

If you play the bass and somebody rests their hand on the ribs does the sound change?

You can do that experiment yourself, just use your legs and belly to press against various parts of your bass while you play. IME the answer is absolutley yes, the sound changes when you dampen any part of the bass.

One really shouldn't comapare DB with guitars, the mechanics and timbre are completley different.

Eric Rene Roy · #17 02-25-2010, 04:55 AM

Quote:

Originally Posted by uprightben

You can do that experiment yourself, just use your legs and belly to press against various parts of your bass while you play. IME the answer is absolutley yes, the sound changes when you dampen any part of the bass.

Your assuming that laminating ribs is the equivalent to dampening them. Not true at all IME. When done right...there are some real structural benefits of laminating ribs (I think we have paid a few salaries with the amount of rib cracks I have seen this winter) and I don't think the sound suffers at all.

ctregan · #18 02-25-2010, 05:13 PM

The repair is done, the only thing left to do now is make out the bill

. Here are the obligatory before and after photos.

forester · #19 02-25-2010, 05:31 PM

nice work ct! looks like it opened up at a texture change.

ctregan · #20 02-25-2010, 05:51 PM

Since the top was off, I also made an attempt to improve the bass, by re-working the insides. Changed the bass bar and also thinned down the top. Here some photos of my experiment at mode 5, and the new bar being installed.

Overall the bass sounds much better.