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Clamp times
http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10123&t=36507		 Page 1 of 1
Author:  Irving [ Wed May 16, 2012 5:44 pm ]
Post subject:  Clamp times
How long do you leave work clamped together when using original titebond?

For: Scarf joints. Body blanks. Neck joints. Fingerboards.

I often go with 45 minutes and have not yet had a problem. I havn't done alot of set necks until now though.. I have heard some say that they leave their set necks clamped overnight. Others say 2 hours. I certainly don't feel quite at easy with only 45 min.

What do you think?
Author:  Chris Pile [ Wed May 16, 2012 6:43 pm ]
Post subject:  Re: Clamp times
Even though time was of the essence in my repair shop, I seldom took the clamps off before the 4 hour mark, and if possible - let it sit overnight.
Author:  alan stassforth [ Wed May 16, 2012 7:32 pm ]
Post subject:  Re: Clamp times
Since I'm not usually in a hurry, overnight.
Probably okay at 4 hours like CP said.
Titebond grabs pretty fast,
but it depends on what yer gluing.
How long does it take for the glue to dry in the middle of the fretboard for example?
Definitely an overnighter for me on that glue up.
I wouldn't rush a top cap glue up either,
or a lam neck, braces, bindings and well, just about anything else!
We rely entirely on glue to hold these things together,
so, don't rush it.
Build 2 at a time so ya can let one dry comletely.
My 2 cents.
Author:  Irving [ Wed May 16, 2012 7:53 pm ]
Post subject:  Re: Clamp times
Those are good thoughts. And it is better to be safe than sorry.

I'd like to carry out some sort of controlled experiment over this. Because I would like to know if there is in reality any difference between a scarf joint that was clamped for 30 minutes and one that sat overnight for example.

I wonder how much difference leaving something clamped overnight really does, or if it's overkill. It could well set your joints in a fantastic way, or maybe it's a waste.

There have been times where I have been clamping something together, realized something was wrong within moments, removed the clamps and had a very very hard time getting the wood apart. I tend to think that this stuff sets pretty dang quick.

One example from a professional environment that I know of for sure is that Warmoth leaves their body blanks clamped for 30 minutes and no more before removing the clamps and moving on. And I never saw or heard of problems there. Fretboards they leave clamped for 2 hours if I remember correctly.
Author:  theguitarwhisperer [ Wed May 16, 2012 8:55 pm ]
Post subject:  Re: Clamp times
I unclamp after 30 minutes. I've even carved braces after clamping for half an hour. I've never had any problems. I usually don't stress the joint for 24 hours though.

If you slather the glue on, it probably takes longer for the squeeze out to harden. I get a teeny bit of squeeze out.

If clamped tightly, there's only a very thin layer of glue in there.

The wood itself absorbs moisture and draws the water away from the glue molecules. so the glue under the fretboard polymerizes almost as fast.

One time I made a bolt on neck for an electric in roughly 4hours. Cut and glued the scarf, 15 minutes to cut, glue, and clamp, 30 minutes clamped, 15 minutes to route and install the truss rod plus spline, 5 minutes to glue the ears, clamped for 30 minutes, while the glue was setting I slotted and tapered the fretboard. 30 minutes to unclamp, plane the spline, sand the headstock face, glue and clamp the fretboard and head plate.
Half hour clamping. unclamped, 10 minutes to cut the headstock and trim the sides along the fretboard.
60 minutes to carve the neck. 10 minutes to install the dots on the fretboard and side, used CA. 10 minutes to radius the fretboard and sand it smooth. 45 minutes to install the frets, trim the ends, and bevel them.

I was rushing 'cuz I wanted to see how fast I could make one, no binding or anything.
Author:  Mike Dotson [ Wed May 16, 2012 10:38 pm ]
Post subject:  Re: Clamp times
45 minutes to an hour for stuff like body and neck blanks, overlays, top caps etc. that aren't going to be stressed.
On neck blanks and fingerboards I don't do anything else to them for a couple days to allow them to re-stabilize.
Stuff like acoustic bridges sit for at least 24 hours before any tension is put on them
Author:  Shaw [ Wed May 16, 2012 11:46 pm ]
Post subject:  Re: Clamp times
I always leave it overnight.
Author:  Mattia Valente [ Thu May 17, 2012 2:20 am ]
Post subject:  Re: Clamp times
Unstressed joints between 30 an 60 minutes, tend not to work them/stress them for 24 hours. Stressed joints for 2-4 hours or overnight.

Honestly, unless I have something I really want to do with the clamps, I leave them on overnight.
Author:  John Coloccia [ Thu May 17, 2012 9:23 am ]
Post subject:  Re: Clamp times
I set a timer for about 15 minutes. When it goes off, I take care of the squeeze out (it's slightly gummy at this points and will come right off with a glue chisel instead of smearing it around or scraping it off later). Then I set the timer for another 30 minutes. Fact is that I have enough other things going on all day in the shop that I rarely get to it before a couple of hours is up anyway. The main point of the timer is for the squeeze out to make my life easy (credit to Cumpiano for showing me that) and then to vaguely remind me that I was working on something else so I don't forget about it.

Then I unclamp and work. If it was a chair seat, I'd probably wait overnight before sitting on it, but I've never had an issue on a guitar.

If it's a stressed joint, like drop top I make, then I'm using Titebond Extend (because Hugh says it creeps the least) and it will stay clamped overnight because the joint becomes stressed the instant I release the clamps.
Author:  Quine [ Thu May 17, 2012 1:15 pm ]
Post subject:  Re: Clamp times
It depends on the joint for me. Small woods like braces and plate joints are fine after 45min. For larger wood or large area joints I go a couple hours. I think the Tightbond bottle says only 30min
Mostly the extra time lets the squeeze out harden up. Nothing worse than going to clean up a glue joint and fouling up a tool with gummy glue.
Author:  John A [ Thu May 17, 2012 1:35 pm ]
Post subject:  Re: Clamp times
....... I go this from someone's site - not sure who - Wells maybe - not sure who it was....
Author:  Chris Ensor [ Thu May 17, 2012 3:00 pm ]
Post subject:  Re: Clamp times
John A wrote:
....... I go this from someone's site - not sure who - Wells maybe - not sure who it was....


Oh Oh I know!. I posted that on the forum after I took Sergei de Jonge's class a few years back. User discretion is advised.
Author:  John A [ Thu May 17, 2012 6:54 pm ]
Post subject:  Re: Clamp times
and I thank you for it - as I have used it several times during my periods of impatience.
Author:  Chris Ensor [ Thu May 17, 2012 9:48 pm ]
Post subject:  Re: Clamp times
John A wrote:
and I thank you for it - as I have used it several times during my periods of impatience.


You are more than welcome. I reference it often as well.
Author:  John Coloccia [ Fri May 18, 2012 9:13 pm ]
Post subject:  Re: Clamp times
I have to admit that I'm a bit confused about those clamp times. For example, the braces, which is a stressed joint, is only clamped for a 1/2 hour, but the neck heel is clamped for 2. Did he give any indication what the reasoning behind the clamping times is? It just seems kind of random to me. It would be nice to understand what his reasoning is.
Author:  theguitarwhisperer [ Fri May 18, 2012 10:28 pm ]
Post subject:  Re: Clamp times
I don't know what his reasoning is, but my reasoning is what the bottle directions say.
I've even glued up a multilam body blank, unclamped it after half an hour, and immediately started routing and shaping.
I recently did that with a 5 piece strat body.
Author:  Dan Greene [ Sun Jun 03, 2012 6:13 pm ]
Post subject:  Re: Clamp times
Last year, I toured the Gibson factory in Memphis, where they build all of the archtops and semi-hollow bodies. If memory serves me, the tour guide said they clamp for 2 hours. I believe we were at the station where they glue up the back and sides, in particular, when she mentioned clamping time. Just a bit of trivia. May be of some use... if you want to build like they do at the Gibson factory.

That's what I recall, anyway. That tour was a bit of an overwhelming blur to a young luthier.
Author:  theguitarwhisperer [ Sun Jun 03, 2012 7:44 pm ]
Post subject:  Re: Clamp times
When I toured the Gibson factory the only clamp time I remember is the neck glues. They used white glue and clamped them for 45 minutes.
Author:  Chris Ensor [ Mon Jun 04, 2012 9:40 pm ]
Post subject:  Re: Clamp times
John Coloccia wrote:
I have to admit that I'm a bit confused about those clamp times. For example, the braces, which is a stressed joint, is only clamped for a 1/2 hour, but the neck heel is clamped for 2. Did he give any indication what the reasoning behind the clamping times is? It just seems kind of random to me. It would be nice to understand what his reasoning is.


Sergei's clamp times are based on a couple of things, surface area and number of layers. For instance, he usually uses multiple laminates for the heel. These times are what a master luthier uses in his particular shop environment and should be taken with a certain amount of discretion. While I was at his course, I saw him do some things that I have tried to duplicate and have failed over and over.
Author:  alan stassforth [ Mon Jun 04, 2012 11:13 pm ]
Post subject:  Re: Clamp times
So, why hurry?
Let the the glue dry completely.
The edges will be dry,
but what about the inside?
Author:  sttelnoj [ Mon Jul 16, 2012 7:40 am ]
Post subject:  Re: Clamp times
Hours not minutes. I've notived that under dense ebony headstock caps, that even after several hours, when cutting the truss rod access that the glue under there is still very wet.
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