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How many of you pros are using Baltic Birch for your end blocks? I have some 3/4" Baltic Birch sitting around and was thinking about using that on my next build instead of Mahogany.

I use 1/2" of birch ply with just over a kerf's worth of Mahogany against the sides.
Mostly same reasons as Todd, splits etc. It's just I like to have the reassurance of solid wood to glue the top and back to, avoiding the ply glue lines, didn't know if it would hold as well.
But from what Todd says, it should hold pretty good.
I taper the ply part at the four edges to around 45 degrees, it is not in contact with the back or top.

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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.

I use 1/4 in and 1/8 russian baltic birch veneer as caps for the tops and bottoms of my rear and frontal blocks. The reason is that the long grain of the back and top makes IMHO a better glue joint when mated to the long grain of the baltic birch blocks. My 2 cents ernie. The conventional method has the long grain of the backs and tops glued to endgrain. Not a good gluejoint. End grain sucks up a lot more glue.

I made up a few end blocks out of two pieces of mahogany with the grain running perpendicular to each other. Looking inside the guitar, it will appear that it is a solid block. Is anyone else doing this?

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Good judgement comes from experience. Experience comes from poor judgement.

I made up a supply of rather thick mahogany end blocks (tapered back where they join the top and back) some time ago, however since I'm interested in adding a bit of mass to the guitar at that end, the Birch stock I got from Martin a while ago is looking good to me once the current supply runs out........

I'm certainly no pro but I used them on the last two bodies I put together.

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Steve Smith
"Music is what feelings sound like"

Me too for 1/2" BB tail blocks

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JJ
Napa, CA
http://www.DonohueGuitars.com

Me three. (isn't three one more than too????)

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

I use 'em.

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Rian Gitar og Mandolin

Do many people orientate the end blocks that way?
I keep the end block grain the same orientation as the sides.

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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.

No "Pro" here either, but, me four!

I use 1/2" BB too. So far i like it.

Thanks all! I'll hang on to the 3/4' Baltic Birch that I have for making moulds and jigs and get some 1/2" BB for the end blocks. I was initially a little concerned with how well the glue would hold the top and back to the "end grain" of the plywood, but it sounds like that isn't an issue.

Thanks again!

"I was initially a little concerned with how well the glue would hold the top and back to the "end grain" of the plywood,"

What is traditional with steel strings? On classicals it is oriented so the surface bonded to the top and back is end grain. I notice that C and N in their book make a case for the opposite, though their reasons probably wouldn't be telling today. One was the difficulty of leveling end grain which is no longer a problem. And the other is the mistaken perception on gluing end grain, see below.

Anyway, end grain gets a bad rap. I think the reason is that if you glue two ends together the joint is not full strength, while if you glue side grain together the joint is full strength. What is overlooked in that is that side grain to side grain is weak, and in most cases if you glue side grain to end grain it will still break outside the glue line in the side grain. Cored composites are extensively glue to end grain and the result is a stronger overall product, though the reasons for that aren't relevant here.

Where do you guys find your BB ply? I haven't had any luck finding it locally.

Just to toss a wrench into the works... I've been using BB for end blocks for a while now without any issues cropping up. At a recent builders get-together, one of the guys mentioned he had a couple of glue failures on the "end grain" where the back & / or top pulled away.
Since I heard that, I have been epoxying (is that a word?) a mahogany or walnut strip on the top & bottom of the blocks.
The grain is oriented so that the top & black glue to the flat sawn surface. The quarter sawn face glues to the sides.
Probably overkill, but it makes me feel better.......

Just to pile on, I use BB too and love it!

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http://www.presnallguitars.com

I came across what was once an up market 1960's black and white TV a few years back. It was an Aussie made Kriesler TV and it even had a cable remote. I stripped it down keeping the excellent quality pre-tinned hookup wire in all base colours with a white barber pole twist and all the braiding shielded wire for my repair stock. I also salvaged a few valves which I sold to cover my efforts (not many prized enough to be worth selling but sold in as a single lot they went fast and covered a few beers). But the main prize was the really high quality ply. At 5/8" total with thick mahogany face veneers, the stuff is just made for tail blocks No one sells that kind of ply any more but if you stumble across an old TV, keep this in mind because its far too good for land fill.

Cheers

Kim

Maybe I don't quite understand; it sounds like your mahogany or walnut strips are glued to the "end grain" so what's the difference?
pvg

Presumably that the situation is more controlled, and that he can choose whatever glue he wants with reference to the "end grain problem".

If one wants brown end block wood, you could get mahogany marine ply. Exactly what is in it varies in various unpronounceable forms, but it is all pretty much up to anything you could want of it.

Epoxy

Can you recall any known maker/design that has endgrain-to-top? I saw a Hernandez y Aguado like this, and at that time I though it is an oddity. One interesting approach is Fleta's, with a three piece block. Most of the center is perpendicular grain to the sides while the ends (about 3/4" tall or so) are parallel grain. The 2 joints even have tenons or biscuits(!!)

In the end, end grain should work at least decently, provided it is sealed in advance (=hide or fish glue) like they do for the violins. The corner blocks in violins are indeed top to end grain but sealing is mandatory.

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Build log

I wasn't able to find it locally either, so I ordered it online.

http://woodnshop.com/Hardwood/Baltic_Birch_Plywood.htm

Thank you Alan!

The assumption here being that- at least in this situation- epoxy makes a stronger bond than other glues? Specifically, stronger than the glue being used to assemble the box?
Thanks
pvg