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I have been busying joining tops lately and for some reason hot Hide glue will not join these redwood tops. I glued 4 redwood tops and all four joints failed when I flexed them the following day. Then I joined them with LMI white glue and voila, no problem-o.

It's not the glue nor is it the joint design. I candled each joint and they were perfect. I used the same batch of hide glue to join Lutz, Engleman, Adi, Sitka and Cedar (all at the same time and conditions). None of those tops failed.

There was some squeeze out of glue along the joint. After the glue dried over night I would scrape this off before I thicknessed the tops. One thing I noticed when I scraped the redwood, the scraper would pull the glue out of the joint seam in several places along it's length, an inch or so in length. This was not a huge gap or a poor fitting joint. It was only a hairline opening a few thousandths wide barely visible. It would not do this on the other spruces or cedar.

Hey Don Williams: These are your tops. Have you ever had this problem? It's weird...

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tim...
http://www.mcknightguitars.com

Tim, i have joined 3 LS redwood tops, all using HHG, when I cut out the top pattern, I always try to break the cutoffs at the joint, and it always breaks away or next but never ON.

Strange

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Lance@LuthiersForum.com

I built the littleredwood guitar I took to healdsburg totally with Hide glue. No problems on it at all...yet at least.

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John Mayes
http://www.mayesluthier.com

If you can pull a strip of glue out of the joint, however thin the strip, the
joint is not tight. Did you clamp the redwood any differently? Joint it any
differently? Were these four tops done last; or first (i.e., might the glue have
been in different condition)? Were these tops freshly jointed? It just may
(despite the odds) be a coincidence that this happened to the redwood tops.
But probably they had some different treatment.Howard Klepper38694.1288888889

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

Tim
Did you get the joint closed before the glue cooled? That sure does make a difference, and if the LMI worked well, (no cooling problem there) then perhaps during this cold weather you are having cooling problems.

Come on I want a definitive answer to this one. Someone out there take a master grade close grain redwood top, joint it, cut it into pieces cross grain and try different glues to join it. Then test it to distruction. There must be a public spirited (rich) luthier out there.

I have a good reason for wanting a definitive answer as I just got my first redwood top and I don't want to mess it up! It's one of Hank Mauel' stunning bits of wood (via Russell) It's going on to a redwood/rippled mahogany OM, for a classic Lowden combination.

Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

Years ago I wrote this little piece for FRETS.COM in which I tested Titebond
and hide glue for heat resistance. By chance, I used redwood:

http://www.frets.com/FRETSPages/Luthier/Data/Materials/GlueT est/gluetest.html

Sorry, but you'll have to paste the link into your browser window and then
remove the extraneous spaces between "T" and "e" and between "/" and
"gluetest" - I can't seem to get the Forum Code to work - is the link too
long for this format?Brock Poling38694.4891319444

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Cheers,

Frank Ford

FRETS.COM
HomeShopTech
FRETS.NET

Thanks, Frank. here's a clickable link.

Glue Test

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______________________________
Jonathan Kendall, Siloam Springs AR

Hi Frank -
To creat a clickable link, click the blue globe with the chain link over it, 4th button from the above left, Then (FIRST) type the name of your link, i.e. GLUE TEST, then click OK, then paste your hyper link into the box, and click OK, once more.

Hope this helps.

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Lance@LuthiersForum.com

Let me try that method....click at your own risk...very freaky pic link

Mystery Link

seriously them are some red pupils..

_________________
John Mayes
http://www.mayesluthier.com

Is that after shooting Nitro?

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Lance@LuthiersForum.com

Thanks for the replies fellas.

Howard: All tops were baked in an oven for 180*F for one hour and then stabilized for 30 days prior to joining. Then the joints (on all of the tops) were jointed within minutes of each other. Each top was candled and jointed again if it showed ANY light. All the tops were glued within a two day window in a 72*F, 38% RH environmentally controlled room. The hide glue was fresh, meticulessly maintained at 145*F and the same glue was used on all tops.

John: The joints were clamped immediately, in a press (see picture below) so the glue did not gel or get cold.


"If you can pull a strip of glue out of the joint, however thin the strip, the joint is not tight." I respectfully disagree with your statement Howard. There is a minute glue line in every joint and if there isn't then the clamp pressure was too great and the joint will then be starved and weak.

The first indication that there was a problem was when I scraped the hard glue off the following day. There were a couple of thin strips of seam that was exposed as I scraped. I want to emphasize that this was an extremely fine line in the .001" or less width. NOT a gaping cavity as in a poor joint or bowed joint fit up. After the joit was scraped I flexed the joint and that is when it failed.

Frank: I read your article years ago and learned a great deal from your testing. Your footwork has saved me, and I am sure many others,countless hours of R&D. I don't think that we (luthiers) ever THANK YOU enough for all of your great technical articles on your site. You are the epitimy of what we should all strive for and that is being a luthier who is willing to share their knowledge and experince, gained through years of OJT, freely and unselfishly with others . You, unwittingly, have helped me to mature and grow as a luthier in the craft that I love and for your help I am eternally grateful. THANK YOU again!

Maybe Hank will chime in but I have noticed a vast range of properties within the redwood species. Some are super tight grained while other are wide, some are light weight while others are heavy, some are stiff across grain while others are as limp as wet cardboard. These tops were the heavy and stiff variety. Now that I have had a chance to look at them more closely there seems to be a sheen to this group of tops and almost a slight waxy feel to them. Maybe this could be the culprit??? Who knows. They (the redwood tops) are all joined successfully now with LMI white. I actually broke a top (joined with LMI white) in the middle of one of the plates while I was playing Arnold Swartz-who-ever.

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tim...
http://www.mcknightguitars.com

[Q]"If you can pull a strip of glue out of the joint, however thin the strip, the
joint is not tight." I respectfully disagree with your statement Howard. There
is a minute glue line in every joint and if there isn't then the clamp pressure
was too great and the joint will then be starved and weak. [Q]

We'll have to agree to disagree on this. I think the starved joint from
overclamping with any glue but epoxy is a myth. The amount of glue that
needs to remain in a good joint is less than the minimum that would cohere
as a strip of material pulled from the joint. Or so I believe.

_________________
Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

I agree with howard on this one, glue bonds at the molecular level and you simply need enough to create a bond for both sides, I have yet to have a joint with proper squeeze out fail at all..

Tim one question...

How long was the time between when you fitted the tops and glued them up, also did you plane or sand them??

I ask for a couple of reasons...

1. You want to glue up a freshly joined top ASAP, otherwise the wood will oxidize and you'll lose penetration in the joint.

2. On redwood especially a planed joint will give you a much better join than sanding will. If I have to sand, I religously blow out the joint before gluing...

Other than that I would change my HHG out...

Cheers

-Paul-

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-Paul-

Patriot Guitars

I've made a couple of starved joints, so it is possible. Embarrasing, too....

I've noticed that redwood can act as if it's waxy. I've found that I have to allow any sort of glue to dry completely when I'm joining redwood if it's to be reliable.

Back in WW II the Forset Products Lab did some experiments on gluing for the aircraft industry. One thing they found was that parts that were planed glued much better than ones that were sanded to thickness. Another was that freshly worked joints(within 15 minutes) ended up stronger than ones that were shaped and allowed to sit around.

The thing is that when you remove wood from the srface you are breaking chemical bonds. This leaves some 'loose ends' on the surface that are looking for something to latch onto. Eventually they will grab something out of the air and become inactive. If you present the surface with some glue before that happens you will get a stronger bond.

I read about this reasoning in an article on fibergalss layups. They called the loose ends the 'surface energy' of the material (sounds kinda new age, but what the heck). They said that one good test of surface energy was to sprinkle a little water on it. If the water beads up the surface energy is low, but if it spreads out the energy is high and you're good to glue.

Perhaps redwood just reacts quicker chemically and tends to have low surface energy?     

[QUOTE=Sprockett] How long was the time between when you fitted the tops and glued them up, also did you plane or sand them??-Paul-[/QUOTE]

I prepared the joint on my jointer. I never sand the edges. There may have been a couple of hours between the time they were jointed and the time they were glued so I suppose they could have oxidized.

After the joint failed I ran them through the jointer and glued them (within minutes) with LMI white glue so this makes a bit more sense. I wish I would have glued them with Hide glue again to rule out the glue as a factor.

Howard: Please don't take my comments personal and I agree that it's OK to disagree ;)

Al: Thank you for your comments about some redwood being waxy. Makes me feel better that I am not off my rocker, again. I have some sets from Hank that are much drier and don't have the slight waxiness that Don's sets have. [this is no way a reflection of one person's wood being superior or inferior].

Thanks again for all of your suggestions and help...

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tim...
http://www.mcknightguitars.com

What if you treated the Redwood just as you would do with a back that is a hardwood that is more resinous such as Cocobolo in which it is common to wipe the wood with acetone or DA to remove any oily or waxy resin that would keep the glue from penetrating?

When in doubt if it feels oily or waxy, a solvent such as DA or acetone would help...

Tim, you would have to try a lot harder if you wanted to to offend me. I
don't think you have it in you. I know the difference between
disagreement and personal insult. A lot of people who use the net are so
afraid of the latter that they avoid the former. I think that is too bad.

No one has said redwood is oily or waxy. It isn't. Al suggested that it
may act as if it were waxy. Redwood is chock full of chemicals and resins
that are not common in other woods (some of which are very similar to
synthetic pesticides, and are one of the reasons for redwood being
among the most toxic woods; this means avoid breathing the dust,
guys). Something in there may come to the surface and form some kind
of coat. I've never had problems gluing it, but it certainly is a possibility.

That and that you maybe should clamp harder.

_________________
Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

Also, if the top wood was bought already sized, the edges may have been waxed to retard moisture exchange. Of course, jointing should have taken care of that, but there may have been wax introduced.

Ron

_________________
OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

Tim....

One thing I would do is to get a good jointing planer like an old Stanley Bedrock or a Lie-Nelson, you will never get a superior joint using a power jointer, they leave little indentations in the joined pieces. I'm sure everyone has heard the story about the Sr Martin coming back to visit the factory and his surprise that they where using a jointer to join the tops, he basically made them stop and go back to doing it by hand.

I know I'll get feedback on this one, but a good quality hand plane simply can't be beat for getting a good joint, it's really not that hard to use with just a little practice. Of all the places on the guitar this is the one that I worry about the most, so for my money $250 for a good Lie-Nelson jointing planer was a good investment and man can it do the job!!!

I know some people on here use jointers, routers and other things but for me this is one place where the old ways are the best ways....

Ok let the firing begin ;)

-Paul-

_________________
-Paul-

Patriot Guitars

Paul

I will back you on this one. I use a hand jointing plane to join all my top and back plates. I don't have a power jointer. If the plane is setup proper and with a little practice it is fairly easy to achieve a perfect joint. I do plan on getting a power jointer when I have the money, but I will still be hand planing my joints for the top and back.

joshJosh H38695.4848958333

_________________
Josh House

Canadian Luthier Supply
http://www.canadianluthiersupply.com
https://www.facebook.com/canadianluthiersupply?ref=hl
House Guitars - Custom Built Acoustic Instruments.
http://www.houseguitars.com

Would the "baked in" or "carmelized" tannin repel the protein molecules in the hide glue?

LMI glue maybe wouldn't react the same way

Just tell Don to send larger, one piece tops next batch

I'd try it again with an "unbaked" top. Might not taste as good raw though...Terry Stowell38695.6016087963

I've power-jointed hundreds (and I do mean hundreds) of tops, and none, to my knowledge, have ever failed do to a bad seam.

Hand jointed does work very well too though.

The little indentations are only present if eithe your jointer is not set up right or your moving too fast.

_________________
John Mayes
http://www.mayesluthier.com

Hand or power...?

As usual, there are points on both sides, but I'm going to come down on the side of hand joining.

John Mayes: you're a better man than I am, or 'most any other joiner-setter-upper I've seen. Yes, I can get a good looking straight surface if I take it slowly enough, but I still worry about compression.

I've joined my own hundreds of tops using my good old Record 04 smoother. That includes things like harp soundboards, with six or more pieces, tops and bottoms for hammered dulcimers, and several sizes of fiddles up to 'cellos. The only problems I've ever had were either from trying to get away with something that I knew I shouldn't, or a starved joint from overheating or overclamping hide glue. The fact is that there is no better surface than a freshly hand planed one, period. It's not hard to learn to join by hand, and with practice it can be quick and reliable. Why would you want to do anything else? ;)   

[QUOTE=Colin S] Come on I want a definitive answer to this one. Someone out there take a master grade close grain redwood top, joint it, cut it into pieces cross grain and try different glues to join it. Then test it to distruction. There must be a public spirited (rich) luthier out there.

I have a good reason for wanting a definitive answer as I just got my first redwood top and I don't want to mess it up! It's one of Hank Mauel' stunning bits of wood (via Russell) It's going on to a redwood/rippled mahogany OM, for a classic Lowden combination.

Colin[/QUOTE]


I'll pony up a sacrificial top to the first luthier who wants to do the test, document the procedures/results and report back in a format that Lance can archive for the good of future top-gluer-uppers

Hank