Rib thickness.

[violinvic]

How thick do you make your ribs?

[sunburst]

For mandolin, I usually start with about .080" or less. The scroll and some of the other tighter bends are usually thinned to about .060", but sometimes maple that is very curly can be so hard to bend without breaking that I've gone to as thin as .040".

[violinvic]

John- Thanx. I take my fiddle ribs to .040" and when Siminoff recommended .100", I thought that was awful thick. I did thin the ribs in the area of the tight bends. .070-.080 sounds a lot more reasonable.

[Bluetickhound]

How much thicker do 'dola's and octaves go? I wouldn't think it would be much, if at all...

[sunburst]

How much thicker do 'dola's and octaves go? I wouldn't think it would be much, if at all...

I don't think so either.
.090" is about as thick as I ever make sides for anything, including guitars.

[Bluetickhound]

Funny side story... i just googled "mandola rib thickness" and it returned not much in the way of useful (to me, any way...) info but I DID get links to several restaurants around the country named with some variation of "Mandola's" that serve what are by all accounts some pretty good ribs!!

[buckhorn]

thought I was the odd one, taking my scroll area a little thinner then the normal .080....thanks John....I try to get all ribs uniform at the .080 but if highly figured, i will take it less...and the schroll I take thinner if it doesn't flex much and, to me, the hardest to bend, that little S piece between the last point and the neck heel....I've gone as thin as .050...other builders have voiced questions about rims I've supplied them about some areas not being all the same thickness and this is why...so my secret is out......

[sunburst]

...that little S piece...

Yep.

Any part of the rib that is glued to a block (head, corner, tail) can be veneer thickness and still be structurally OK, when you think about it.
Also, for those non-builders reading this, none of this; differential thicknessing for the scroll, the "S piece", has anything to do with building an A-style, so when you are wondering why an F costs so much more than an A, this is a part of it, but it's only the tip of the ice burg.

[barry k]

Mine are .075, but I know someone here will tell me I am wrong.......waiting

[buckhorn]

if you can bend it without breaking, then it's good...I've got a small hill full of material that I can use for other parts because it didn't make it thru the bending process without splitting...

[Larry Simonson]

Gosh, I wish I had seen this post two days ago when I bent ribs for my 2nd instrument, another two pointer. I had forgotten (I know, I know, I should have kept records) of what had worked for me 5 years ago. After creating a small scrap pile of broken rib stock I thinned to about .07" and with heat just short of scorching, the ribs were bent successfully.

[Pete Jenner]

Mine are .075, but I know someone here will tell me I am wrong.......waiting

I don't think it's a case of right or wrong Barry, just what works for you.

[Bluetickhound]

In Lynn Dudenbostel's photo essay on building Chris Thile's mandolin he noted that he thinned the ribs to .065". I guess it's like others have stated, you have to find what works for you and make adjustments as necessary.

[Butch Heath]

I just bought a few sets of red maple rib stock. I took them to a local fiddle maker for thicknessing and they finished at .078-080" (according to his dial caliper). I thought they were looking awful thin to be reading .080". After arriving home and checking the thickness with 2 other sets calipers, they read .054" with my digital caliper and 1.4mm with my dial caliper. This was enough to prove his caliper incorrect.

Now for my question. Do you all think these will be sufficient for building an F or A mandolin without worry?

Thanks

[HoGo]

Mine are .075, but I know someone here will tell me I am wrong.......waiting

YOU ARE WRONG, BARRY! You asked for it... :-)

Your (mandolin) ribs are in the range I'm using, though.

I start with 2mm (~0.08") and thin the problematic areas somewhat if needed for ease of bending.
1/8" (0.125") thickness recommended by Siminoff is way too thick for hand bending, perhaps safer with steam bending in jig of some sort...

[HoGo]

I just bought a few sets of red maple rib stock. I took them to a local fiddle maker for thicknessing and they finished at .078-080" (according to his dial caliper). I thought they were looking awful thin to be reading .080". After arriving home and checking the thickness with 2 other sets calipers, they read .054" with my digital caliper and 1.4mm with my dial caliper. This was enough to prove his caliper incorrect.

Now for my question. Do you all think these will be sufficient for building an F or A mandolin without worry?

Thanks

I think they will be OK. They may be prone to bulging with humidity changing but structurally thaty should be fine - notice that guitar ribs are as thin as mandolin ribs but 3 times wider and bass ribs are typically thinner than mandolin something like your stock and they are as wide as highway when compared to mando... (but they often show the bulging or waviness).
You can always add thin strips of veneer (0.04"x1/2" wide) across the ribs in the areas with less bends to keep them more stable, similar to what guitars have.
Or you can laminate thin veneer all around the ribs inside.

[Shelagh Moore]

My Taran Springwell has rosewood ribs but Rory Dowling then lines these on the inside with, I think, sycamore... thereby obviating the need for kerfing. Unfortunately I do not know the thicknesses used.

[tonydxn]

That seems a bit on the thin side, but they'll do. It's not critical.

[Karl Hoyt]

Long time guitar builder, rookie Mando builder. So I followed Roger's advice for these tight curves.... I pulled them out of the steam box and directly onto a hot pipe and they snapped no matter how delicately I tried to coerce them . My guts already knew .1-.125 was too thick.... I always do bent guitar cutaways at .060-070 and those bends are way looser. So I took my next batch of mando side woods down to around. 065 and life was better....and i thinned out the S curve and scroll even more on the belt sander.... I'm about to make up 2-3 more rims, so we'll see how my theory works.... I think it should be fine . (Famous last words)

[sliebers]

My very first build, I was able to bend plain looking maple at .100" Bent easily over a hot pipe. Thought that it would all go that way and couldn't believe how easy it was. I bought some highly figured maple for my next one and almost quit building mandos over it. Could not get it to bend without breaking. Took it down to .065" and it bent a lot better. Stuff still wants to break randomly it seems.
I don't see any advantage to having mando sides thicker than .080" anyway.

[buckhorn]

I'm not magic or anything but have been pretty successful bending mando rims.. In the beginning, I soaked the rims completely for quite a while before using the heated pipe and that gave me the biggest problems.. way too many cracks and splits.. I started misting both sides with just enough water to get a little steam going .. I use a very small pipe (1 inch) with a piece of metal in the end to keep the heat in a little better.. use as little water as you can get by with.. I try to make all of the parts well ahead and have used 2x6s and copy the forms in a way that I can clamp the parts together until dry.. I have a wood burner in the shop and just lay the formed parts on top until dried.. Sometimes I have to do this a couple of times until ready to glue up in the final forms.. I get into trouble when I try to go to fast so waiting a while for the parts to dry out between bending really does help.. The wood seems to bend easier.. At any one time ,I have a dozen or more parts already to go and some may still need a touch of the pipe to get a good fit in the forms.. The last few days, I have formed and glued 8 rim sets with only one rim part breaking (that S piece between the last point and the heel).. Just try and remember that the more figure in the wood, the less water to use.. hope this all made since and I'll try to add pics of the 2x6 parts forms Keith

[buckhorn]

here is a pic of what I was talking about... Keith

[sliebers]

I do a similar thing, except I bend my pieces in the forms using silicone heating blankets and stainless steel slats on each side of the wood. Strips of brown paper sandwich the wood and I wet a strip of paper shop towel. About 5 minutes and the bends are complete. I bend my scroll on a pipe and everything else with the forms. Can do figured wood up to .090" if needed. I usually hit around .085" to be more flexible and allow some sanding room. The S piece I thin to about .065".