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I have recently started trying laminated my sides.
With the first set I made this seem to improve the response of the finished guitar compared to my previous builds with non laminated ribs.
The second set I've made the laminations slightly thinner, in EIR and Khaya (1.8mm/1.2mm) and I also decided to laminate both the top and back linings, stepping the back linings from around 18mm down to 12mm, partly to keep the insides tidy when seen thought the soundhole, my kerfing jobs were not the best especially with a tight cylindrical back radius.
The whole assembly is very stiff, meaning driving the bus to radius the top rim can be done without a mold, and it has a tap tone like a gong.
I'm fairly happy with the results so far, and looking forward to the rest of the build.

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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.

Should be interesting Colin. How did you do the lamination - vacuum?

And do I see the makings of a bolt on/bolt off neck?


Cheers Dave

I am interested in your process Colin,

I only just started on my 3rd acoustic build and am getting ready to bend the sides (some wonky Rosewood with a couple of small knots) and am not sure they will bend that well.

I have checked out other laminating threads with some interest but with these "not so great sides" I have been thinking more and more about laminating.

Since my focus has been mainly repair, I have repaired 4 guitars with split sides mainly due to improper jack placement. it seems laminating would be much more stable for all reasons. But I questioned what it would do to the sound.

The guitar I just started is a copy of a Panormo and I set up a jig to laminate the linings so your thread has me thinking...

Ill be interested to hear what you think about the results.

Cheers,
Bob

Yes and yes.

_________________
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 bend all the side laminations with a form and use the same form (which is suitably undersized by just over 3mm) for laminating them in a tube type vacuum bag using Araldite Standard Ultra for it's long open time (80 minutes?)
The triple linings are pre-bent in aforesaid form, each about 1.7mm thick, and are individually glued with titebond original using Bessey string clamps.
Everyone who has played the prototype thought is was a definite step up in terms of response, and volume compared to my previous efforts.
I must admit, I agree.
I put a lot of that down to the stiffer (and slightly heavier) sides.

_________________
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 suspect you already know this because I yammer on about it on social media, but…

For the last several years I’ve been using the tutorial from Burton LeGeyt here on the OLF to make solid linings. His method for sanding the taper into the back lining so that they come out uniform all the way is so sweet. It works like a hose (ever see a hose fail?)

Linking here in case anyone wants to investigate.

Double sides and solid linings tutorial
https://r.tapatalk.com/shareLink/topic? ... source=app


Sent from my iPhone using Tapatalk Pro

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Nice work!

I have been using laminated sides for a long time now. I also found the tone and volume to be quite attractive to most folks including myself. One good combo has been Maple outer Rosewood inner. Double Mahogany great as well. Double Rosewood maybe not so great.

With the laminate lining I predict a LOUD instrument

Keep us updated.

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

Brad, I got a "dangerous webpage" from my anti-virus when I clicked on that link.
I re-read the tutorial (found by a search), and it's really neat, but TBH it's too much work for me..................
I traced an outline for the sides from my prototype, and just used that to trace and bandsaw a "wavy block" out of poplar stock which I ripped for the linings.
I then thickness sanded and bent them in the fox side bender., off-setting them by the taper in the back.

_________________
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.

Nice one Colin. I’m a big believer in rigid sides, looks like you’re onto something.


Sent from my iPhone using Tapatalk

Here's a safe version http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=21455
I just spotted the topic ID (t=21455) in the tapatalk link and copied it into the URL of the page that we're reading
The forum ID (f=10101 for this "Guitar Building Forum") is technically incorrect since when you load that page you can see that it's in "Fixture, Video and Picture Tutorials", which is forum ID 10117. But as far as I can tell the forum ID is only used when browsing the list of threads, and has no effect in a link to a thread. You can even remove it entirely.

Weird. Must be because it’s a Tapatalk link. I’ll use the direct link from now on.

Regarding Burtons tutorial, it is indeed a lot of work. For my own use I’ve whittled it down to just laminating and slicing up the lining side and then sanding in the taper. I don’t use the rest of it, it’s involved, as you said.


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double post

For "solid" linings I like to use bending ply. It will bend in both directions and conform to the edge of the side without much effort. The decorative profile is optional. I have started sanding the inner ply thinner to mitigate the appearance of cracking that occurs from an outside bend.

Thanks for that link, That does seem pretty involved but it produces some nice looking sides.

Cheers,
Bob

Hi Colin, Can you elaborate on the vacuum bag material you're using? What is it? Where to get it? Seems like it must be fairly thin material if you only have to under-size your form by 3mm. Is it reusable or do you have to destroy the bag to remove the side?

I've been using a polyurethane vacuum bag for laminating sides and it's too thick and bulky to fit into my Fox bender as yours does. You'll probably think this is nuts but I've had the most success using a bag big enough to contain the whole bending form. I had to add a caul in the waist. If I could use the bending machine as you do I think it would all be a lot easier.

--Bob

Actually it's1/8" undersized, I have to account for the double slats underneath and the bag. It's a single use 10" tube for vacuum bagging round items like boat spars. Brian Coombs earlier in this thread may be able to help you source something stateside, My source is UK.

_________________
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’ll do some searching too. Thanks.

Brian!?! Hahaha

I cannot help with a single use solution. What I use is a custom bag I made from a sheet of vacuum material from veneersupplies.com.

I made a tube bag that I shimmy around the lining and then use a form that is offset the correct amount and in the bender just like Colin. Here is a pic. You can see the PVC closures that Veneer Supplies sells on the ends of the bag.






I use the same epoxy that Veneer Supplies sells and use it at slow set mix to give me time to get the layup into the bag. I keep it under vacuum for 3 hours and then left in the bender overnight with the ends of the bag opened up. Let me know if you have questions.

Brad (Brian)


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One other thing, I slip a piece of breather mesh in with the lining. That keeps the bag from closing itself off.


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If it might help, here's my UK source - either the 250 mm or the 150 mm widths my be of use to you.
Self-releasing Tubular Bagging Film - https://www.easycomposites.co.uk/Tubular-Bagging-Film
My layups don't seem to require breather mesh, it may be that the wood itself is porous enough to prevent the bag sealing off.
However as a hack, I used an overlap of ~ 4" square of non woven scotchbrite type pad at the end of the ribs with a small wrap of microfibre cloth around the end of the vacuum tube so the bag doesn't get sucked into it.
A quick search found what seems to be a source for the same brand of Self-releasing Tubular Bagging Film in the States - https://www.diatex.com/diatex-produit/po160-tube-bagging-film/

_________________
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.

That's really neat Brad - misstype/autocorrect?

_________________
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.

Thanks Brad and Collin.

I also use a bag I made from Veneer Supplies material. I guess I just made it too big. In my first attempt I made a slim bag that I clamped to the form outside of the bending machine and I did use breather mesh. I tore out a bit of hair (that I can’t afford to lose) getting the bag to close properly so I could pull a vacuum. Then, the combination of a tight bag and too much glue left me with a side I couldn’t get out of the bag without cutting it open. That material is expensive so on my next one I just made a bag big enough to fit the mold into and put the waist caul on the outside. Easy to get stuff into and out of but it was still a pain in the butt.

I’d like to try the single use bag and the bending machine to cinch the waist. Thanks, Collin, for locating a source.

Oops. I should be typing Colin instead of Collin. Apologies!

What do you like, dislike about those combos?

Pat

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Pat

Double Rosewood was plenty loud but I was a little lukewarm about the tone. Seemed a little muddy to me. Maybe too much mass.

Mahogany/Mahogany, Mahogany outer/Rosewood inner, Rosewood outer/Maple inner, and vice versa have all been well received. Thickness of lams roughly.040-45 inner .050-060 outer.

I use double Maple on archtops.

I repaired a guitar a long time ago that took double sides to an extreme. Double Rosewood with a layer of lead mesh between and lead lined kerfed lining. It was LOUD, but the tone was unattractive.

I think there is some point where there is just too much weight and stiffness.

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