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I have wondered about those figures for gluing pressure, which I've heard mentioned before (or at least 100 psi)
By my reckoning that means a 4 inch length of 1/4" bracing requires about 14 of Hesh's go-bars, or about 56 of them for a 16" x-brace. About 400 lbs total force
I haven't tried it, but it would not surprise me if that crushed a soundboard, and the brace, IF you could get them all on.
As long as the fit is near perfect, relatively little clamping force should be required, IMHO.
Surely the important thing is the thickness of the glue film itself?
IIRC, I normally use about 10/12 for an x-brace.
Anyone go other ideas?

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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.

Colin,
I agree with you. I can't see how one can generate 100-150 psi. I use about the same number of
bars as you do- one every 1 1/2- 2" or so. I'm not seeing any evidence of a too thick glue line
when I have to pare a brace end down to the top plate.

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Gene

Politicians and diapers must be changed often, and for the same reason- Mark Twain

I use about 4 or 5 cam clamps per side on an x-brace. That is probably in the 300 lb range per brace, 600 total. No crushing I'm glad to say. I suspect that the needed titebond clamping pressure is overstated in their charts but I still clamp them tight.

A lot of experienced people and some big companies have been gluing braces with vacuum clamps forever with no problems.

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Joe Beaver
Maker of Sawdust

Yup.

I think I may switch back to the stew mac style rectangular ones. At least they don't rotate...

My point exactly, 14.7 psi pressure maximum with vacuum.

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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 have two comments that should vastly improve your go bar experience. But, before that, let me remind you that the utility comes from buckling column theory. It's hard to get a more even application of force than through the natural physics involved in buckling columns. In fact, once the bar is bowed even a little bit, any more bowing produces no more downward force, and u are just exposing yourself to more possibilty of slipped go bars. 1.) cover ur go bar deck in a fabric, i used thin painters tarp from lowes. 2.) I do not apply force directly to braces. I set up two braces, one with glue, and place cross beams over them, and place go bar in the middle.

Ok, vacuum is most even application of force.

https://goodwinds.com Is a great source for fiberglass rods and vinyl end caps

+1 for Good winds with the vinyl end caps. I bought 72"x 3/16" FG rods, cut them down to 24", and ordered extra caps. Much cheaper too. I've never had one slip... Yet..

I've never had any problems with the go-bar sticks --- I bought the rectangular Stew-Mac fiberglass ones a LONG time ago, when they were MUCH, much cheaper than they are now, so I was able to get 36. I've never had to do anything to the contact surfaces to make them stay, nor have they ever spun around or popped out on me. I guess I've been really lucky. Before I got those, I was using wood dowels (I think, 3/16") and occasionally they'd explode (break) on me! I love my go-bar sticks.

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Kathy Matsushita
San Jose, CA USA
http://theamateurluthier.com
Facebook: https://www.facebook.com/kathy.matsushita

I have both vacuum and gobars . Havn't used the vacuum since I started using HHG.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Can't seem to locate the pics but IIRC when testing go-bars, deflection etc. I tested the Stew-Mac fiberglass ones, I have 24 of them and they exerted substantially more clamping force, in the neighborhood of 19 pounds again IIRC over the LMI metal round ones pictured in this thread. Since I have and use both the Stew-Mac ones are great for when you want more clamping pressure.

The one down side of the Stew-Mac fiberglass go-bars that I have directly and personally experienced a few times is mine shed splinters, very nasty, sharp, hard to see to get out splinters...

Happy Holidays Kathy too!!!!

Similar experience to Michael and Kathy.

I bought 3/16" fiberglass rods and caps from http://intothewind.com. I use about an inch of deflection, try my best to have the rod as well aligned as possible, and don't remember any slips.


Sent from my iPhone using Tapatalk

You need to wrap them in tape. Keeps the splinters in.

Same here.

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Steve Smith
"Music is what feelings sound like"

When u are cutting them. Use a dremel carbide blade, not ur bandsaw blade or u will be buying a new bandsaw blade. Once cut and in a vinyl end cap, they are worry free.

For those of us in the snow belt those orange and white driveway markers with a rubber thread protector from Ace on each end work well and don't splinter. I think they are 5/16"



Good for major braces, bridge plate ect. I also use the 1/4" kite rods with rubber caps for lighter clamping and closing the box.

I have not seen much slipping with the rubber caps. I have a ceiling mounted melamine deck.

I am a huge fan of go-bars.

If I was not using hide I'd definitely explore vacuum for braces. I do use it for other stuff.

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It's not what you don't know that hurts you, it's what you do know that's wrong.

I built this deck in 1982. Adjustable go bars with springs on top has worked great. I do the adjusting before installing. To install, I place the bottom end on the brace, then slide the top over until the go bar is vertical.

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John

Back in the day , I remember a couple "go go bars" I liked

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Never met a STRONG person who had an EASY past !
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http://www.facebook.com/groups/GatewayA ... rAssembly/

Great setup, John. I have been thinking about making adjustable go bars, or spring loaded go bars. and yours answers a lot of the questions I had. Now I can have both.

Yours should be called a "GOOOO BARRRRR" deck, since it can do some pretty heavy lifting.

Thanks for posting.

James

This is how I do it. I don't really see myself changing my method anytime soon

How do you deal with squeeze out if youre using a vacuum?

Also, to avoid a lot of the issues with go bars, could you make a rod with a turn buckle on it? (that was more of an idea than a question.)

I use the NU-2 by Quality Vakuum products (QVP). Runs off of the compressor. No sure of what the draw backs are.....I'm not experiencing any. high quality components, excellent support...these have been out there a long, long time.

Nothing if you prefer not to use go-bars.

For me though go-bars are way easier, faster, more reliable, etc.

I want to be able to exploit my radius dishes and glue stuff up in the dish. You can do it with clamps of course but it's harder, slower, more complex in positioning, etc. I also want to use HHG where it makes sense and I can position go-bars in a proper go-bar deck WAY faster than clamps. HHG is very unforgiving if you wait too long to have your clampage in place, with go-bars this is not an issue a least it's not for me.

You can put a go-bar deck on a TV swivel and slide like Kathy and I did and then it's in a corner out of the way when not in use and very accessible when in use. It also helps greatly to be able to rotate the deck so that we are not reaching though existing go-bars and risking knocking them loose and poking an eye out as a result... Always wear eye protection.

Sure, no one needs a go-bar deck, you don't need any power tools either, in fact you could do all this stuff with a pocket knife but most would not wish to go that route, me either....

here is my method for gluing in a gobar deck.
https://www.youtube.com/watch?v=NFkXpoWTBzk

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I hate go bars because they always seem to apply pressure at an angle but it looks like this setup should fix that. Great idea!

I have this one: http://www.veneersupplies.com/products/ ... 0-VAC.html

and it's about as loud as a normal person's normal speaking voice. Not compressor loud or anything but definitely noticable