Double Bass Rib Bumpers

[gerry grable]

Two different luthiers independently suggested contact cement. Yes, it peels off my finish without leaving a trace. I scraped off the 3M adhesive on the Golihur bumpers, washed the rest of the glue off with a little lacquer thinner (wearing protective) gloves, then used the contact adhesive. I masked rectangles on the bass (slightly smaller than the bumpers) with masking tape, then applied adhesive to both the bass and the bumpers, let it get tacky, removed the masking tape, and pressed the bumpers into place. I also shaved two of the bumpers and built up the thickness of the other two, to accommodate the varying reveal between my ribs and the top/back, as well as to compensate for a twist in my bass. In other words, although my bass is slightly twisted, it sits evenly on a flat surface because I varied the bumpers' thickness.

One question, please.
My bass has strips (1/2" wide and 3/16" thick) of wood that run along the ribs with the strip edges butting against the top and the back plates.
Do the bumpers go on the strips, or on the ribs which would put them 1/2" away from the top and the back plates?
Thanks.

 

[Eric Hochberg]

One question, please.
My bass has strips (1/2" wide and 3/16" thick) of wood that run along the ribs with the strip edges butting against the top and the back plates.
Do the bumpers go on the strips, or on the ribs which would put them 1/2" away from the top and the back plates?
Thanks.

I think you are referring to your outer linings. I put the gollihur bumpers on the outer linings of my bass to get the height correct. If I had put them on the rib itself, a couple of the bumpers would be too low.

 

[gerry grable]

I think you are referring to your outer linings. I put the gollihur bumpers on the outer linings of my bass to get the height correct. If I had put them on the rib itself, a couple of the bumpers would be too low.

Thanks. I didn't know they were called outer linings.
You confirmed what I thought, besides, I think that that would be the stronger of the two locations.

 

[drurb]

Two different luthiers independently suggested contact cement. ...In other words, although my bass is slightly twisted, it sits evenly on a flat surface because I varied the bumpers' thickness.

Yes, Eric, excellent info! Took me a second to understand that you meant this type of stuff:

Just think, as you do the job you can have fun breathing the vapors. In my case, both bass and player are "slightly twisted." Too bad they don't cancel out each other.

 

[Jake deVilliers]

One question, please.
My bass has strips (1/2" wide and 3/16" thick) of wood that run along the ribs with the strip edges butting against the top and the back plates.
Do the bumpers go on the strips, or on the ribs which would put them 1/2" away from the top and the back plates?
Thanks.

The bumpers go onto the linings. That way the weight of the bass is transferred to the strongest part of the rib - the outer linings, the rib and the inner linings are all glued to each other and to the top right there.

 

[SunneyBoy]

Specifically, Paul Warburton introduced them on TB and they do work. However, if I am seeing your pic clearly, you used notched fan belts. I think P.W. suggested smooth, unnotched belts. Also, I believe he used hide glue.
Of course the notched belts will work great for outdoor gigs in snow country

Yes that's right it was Paul Warburton's thread. We don't get much snow down here on the southern Tip of Africa but the notched belts are great when bush bashing. : )

 

[Bassguyrob]

Is it just me, or does it seem a little redneck to put rubber on a wooden piece of art that would value in the low ten thousands? I paid less than 300 for each set on my two basses, and one has maple, and one has ebony. Would I do it again? Absolutely. They are asthetically pleasing and durable, as long as they are fitted properly. Just my two cents....

 

[Eric Hochberg]

Is it just me, or does it seem a little redneck to put rubber on a wooden piece of art that would value in the low ten thousands?

Maybe, but Patrick Charton uses rubber in the edges of his >$30K custom basses.

 

[Jake deVilliers]

Maybe, but Patrick Charton uses rubber in the edges of his >$30K custom basses.

I prefer leather or rubber for the resilience - there's less shock transmitted to the rib join than with wooden skids.

 

[drurb]

I prefer leather or rubber for the resilience - there's less shock transmitted to the rib join than with wooden skids.

This would be an important consideration to me. Thanks, Jake.

 

[Eric Swanson]

I have seen basses where the ribs cracked from the wooden bumpers transmitting the shock of being set down, over and over. If there isn't internal lining, directly supporting the bumper, the force gets transfered to a pretty thin piece of wooden rib...

Even if there was an internal lining, I would still want the easy fit, the ease of replacement, and the shock absorbing action of leather or rubber. Maybe it is easy for a skilled luthier, but for me (a non-luthiery woodworker), fitting a wooden bumper looks like a time-consuming pain in the neck, with a result of dubious value. My brown leather bumpers match the color of my bass exactly, so, for me, there is no aesthetic reason to use wood, in terms of "blending."

Hence the leather. When I set my bass down I can feel the leather "give" just a bit, which is reassuring. Rubber would be groovy too, for the same reason. If I liked the look of a black accent, I might have used it. I liked the leather's brown cause it nearly disappears against my bass' finish...

 

[powerbass]

My bass also has a twist, noticeable when I lie it on it's side.

Two different luthiers independently suggested contact cement. Yes, the contact cement peels off my finish without leaving a trace.

To remove the agressive, factory-supplied adhesive, I scraped off the 3M adhesive on the Golihur bumpers, washed the rest of the glue off with a little lacquer thinner (wearing protective) gloves, let them dry, dyed them to match my bass a bit better, then used the contact adhesive.

To control the glue on my bass' ribs, I held the bumpers in place, then set masking tape just inside of the bumpers perimeters. In other words, I masked rectangles on the ribs, slightly smaller than the bumpers, then applied adhesive to both these rectangles (on the bass) and the bumpers. Then I let the cement get tacky, removed the masking tape, and pressed the bumpers into place.

Before gluing them on, I also shaved two of the bumpers and built up the thickness of the other two, to accommodate the varying reveal between my ribs and the top/back, as well as to compensate for a twist in my bass. In other words, although my bass is slightly twisted, it sits evenly on a flat surface because I varied the bumpers' thickness.

The whole thing was pretty painless and took about 1 1/2 hours, even with the leveling/shaving/gluing up of the bumpers. Tools/supplies used were: masking tape, contact cement, a razor knife (for splitting some bumpers to the right thickness), Titebond (for leather-to-leather bumper buildup/lamination; gluing the waste from two bumpers onto the other two), lacquer thinner, leather dye, shoe polish, a flat surface large enough to lay my bass, paper towels, gloves, tape measure, and a pencil. If I can do it, anyone can...

 

[pnchad]

Wow - I'm the OP - I had no idea the amount of interest by you guys.

TB is the BOMB!

Thanks all - now I have something to read tonight