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+-- Thread: Clamping (/showthread.php?tid=7369861)
Clamping - Gregor1 - 07-11-2022
30 years ago when I was doing a little wood working, we always let our glued projects sit over night. Old habits die hard. Doesn't matter if it's glued up at 4 am, or 4 pm, "It Absolutely, Positively, has to be there, OVERNIGHT " Of course back then, I would work on projects a few hours after work, and on weekends some. Now I am in my garage at 3 am until 6 pm, every day. I don't have all that many clamps. Having 10 or 12 of them tied up for a day is a pain. Once something is glued up and clamped, is there any advantage to letting it sit over 4 or 5 hours? Can I take the clamps off, and just let the glued piece sit over night with todays glues? Titebond III Ultimate.
Thanks Greg
RE: Clamping - Tankwood - 07-11-2022
For sure as long as no stress is placed on it , allow a little time with the clamps 30minutes is safe
and your good to unclamp with TB glue.. bottle I think states 30minutes
Still allow 24hrs to fully set b4 any stress.. easy enough
Peace
RE: Clamping - Bill Tindall - 07-11-2022
(07-11-2022, 04:27 PM)Tankwood Wrote: For sure as long as no stress is placed on it , allow a little time with the clamps 30minutes is safe
and your good to unclamp with TB glue.. bottle I think states 30minutes
Still allow 24hrs to fully set b4 any stress.. easy enough
Peace
The problem is knowing if there is any stress. To avoid my stress I leave panels in clamps for an hour. If pressed I will plane a panel after one hour. If the squeeze out has become rubbery I assume the glue in the joint is largely dry.
Case pieces with mortise and tenon and dovetail joints are left clamped overnight. These joints can have glue in gaps that will take much longer to dry than a panel joint where the excess glue is squished out.
3AM really!?!
Keep in mind that set time depends on temperature and most of all the moisture content of the wood. I was told by a contact at Franklin (company that makes Titebond) that lumber at 12% could take a couple of days to fully cure. Glue set time is one of the reasons furniture factories require lumber to be at 7% moisture.
RE: Clamping - museumguy - 07-12-2022
Boy do I feel better now. I've always let my pieces dry overnight.
RE: Clamping - Bob Vaughan - 07-12-2022
(07-12-2022, 06:42 PM)museumguy Wrote: Boy do I feel better now. I've always let my pieces dry overnight.
Two terms mean different things.
Set: 30 minutes to a few hours. The joint is set and won't pull apart.
Cure: usually 24 hours @ 70º or better to achieve maximum strength and hardness.
Panel glue-ups should be clamped for 24 hours to reduce the risk of a shrunken joint months later. Web frames, mortise and tenon joints, and most other structural joints are not usually at risk of a shrunken glue line.
RE: Clamping - toolmiser - 07-12-2022
Way back in the seventies when I was in High School, we used elmer's white glue. I doubt anything was in clamps more than an hour because there were many classes that needed them. I never saw a joint fail.
Now many years later, I always let the glue cure overnight before working it. I've tried and failed a couple times doing less.
RE: Clamping - Gregor1 - 07-13-2022
Bottom line. I need more clamps.
RE: Clamping - jcclark - 07-13-2022
I never let my glue ups stay clamped for more than 30 to 60 minutes.
But I do let them dry a few days before finish sanding because if any
moisture is in the wood from the glue and you sand joints flat they
will come back to haunt you later when the moisture finally dries and shrinks the wood.
I have seen this problem a lot on table tops, the joints will mismatch a little later,
sometimes 6 months or longer.
RE: Clamping - sweensdv2 - 07-13-2022
(07-13-2022, 04:31 AM)Gregor1 Wrote: Bottom line. I need more clamps.
Of course you do, that is always the universal truism.
RE: Clamping - CStan - 07-13-2022
My motto has always been "no late afternoon glue-ups." They're a first thing in the morning kind of thing for me. They're set aside and unclamped 24 hours later.