Clamp Time For Glue

[dpb]

OBTW, I'm an engineer, too, albeit a fairly useless for this stuff one...NucE/Physics (Nuc Science)... :)

--

[Larry Blanchard]

I usually take stuff out of the clamps after 30-60 minutes. But I wait several hours, preferably overnight, before I stress the joint with further operations. So far I've had no problems.

[David Merrill]

You might find something in this document. Look particularly starting around page 130.

had searched FPL for 'pva' and 'clamp time' from this page Merrill

[Leon]

From what I have read and witnessed, clamps are use for the sole purpose to hold things together while the glue dries, you could use masking tape. Typically wood glues, PVA are quite strong after 1 hour, strong enough that clamps should not be needed any longer. In the old days when I used WeldWood mix with water glue I left the clamps on over night. For the not "quite right fit" I suspect leaving work in clamps over night may have some additional benefit "if" the joint starts to separate after 1 hour as you remove the clamps. But if the joint holds immediately it should continue to hold. Then again it does no harm to leave the clamps on over night.

[mac davis]

I sort of follow the directions on the glue (Titebond) Clamp for 45 minutes, (I usually do something else for an hour or so), and don't subject to stress for 24 hours..

This is in part because of confidence in the glue, but mostly because I don't have THAT many clamps...

[PDQ]

In news: [e-mail], Tom Watson dropped this bit of wisdom:

Haven't hear the word "fero-cement" used in 60 years. Last time I did = it was a fellow who worked in iron that was building himself a boat = (vessel?) out of concrete.

I asked him why concrete and he replied "Because they said it couldn't = be done".

I don't know who "they" was but that sucker actually floated and was = about as agile as one of those cars that could go on land or sea.

What's to say, I know he later built one out of iron plate that was a = bit faster.

P D Q

[Han]

"PDQ" wrote in news:gvufi8$rdj$ [e-mail]:

Reminds me of the mythbusters boat made of newspaper and water (actually thay made a mold, wetted newspaper to fold into themold, then froze the whole thing. It planed with the huge MF Evinrude on it. Of course it didn't last all that long, but the episode was quite interesting.

[Robatoy]

batteries recharged. They have a station for that on Manitoulin Island.

tend to think more in terms of long helix, dreadlocks, interwoven springs, or old fashioned telephone cords. I don't 'see' the crystalline structures as most of those glues are gummy and a bitch to shear(sand). I can see crystalline structures in hide glue, because that shit gets all cracky and brittle over time. When in doubt, use epoxy. Uncle Lew has made me see things his way. I have never had a WEST joint fail, and I have glued up some pretty goofy dissimilar material joints.

I now use Weldbond for justaboot everything.

WEST

[Robatoy]

Please don't go talking Mozzies. A close friend of mine (best man #2 when I married Angela), eats, sleeps, dreams, Mosquitos. If he finds out there is a thread about those birds, he'll show up and we'll never be able to get rid of him... His aunt worked on them in Mississauga, ON. 2 Merlins and some birch/spruce/glue. Wicked crazy plane.

[diggerop]

be of interest

[Andrew Barss]

: Reminds me of the mythbusters boat made of newspaper and water (actually : thay made a mold, wetted newspaper to fold into themold, then froze the : whole thing. It planed with the huge MF Evinrude on it. Of course it : didn't last all that long, but the episode was quite interesting.

See:

and Project Habakkuk. Fascinating story.

-- Andy Barss

[Phisherman]

the glued piece until the following day. I think the 30 minute clamp time stated on the bottle is too short. Allowing the joint to slowly cure undisturbed will give better results, I suspect.

[Robert Bonomi]

Most of what you're looking for is available from specific glue manufacturers if you ask them.

Having done a little digging in years past, I can summarize (from memory), but don't have hard facts/details to hand.

"Fully cured" time for most commonly used wood-glues is on the order of 24-48 hours, or longer.

After the glue has set up enough to provide a reasonable 'hold', there is very minimal benefit in keeping the pressure on.

There are _minor_ benefits from keeping the clamping pressure on for somewhat longer than the manufacturer-recommended period.

Take the manufacturer recommended clamp time, and do something like triple it, and you're probably out in the 4-5th decimal place for the share of ultimate strength you're giving up -- i.e., around .00005 of the 'leave it clamped for the full curing period' strength. As this is well past the 'stronger than the wood itself' point, that small fraction contributes

-nothing- to the overall project, and you can proceed significantly faster.

Robert Bonomi [e-mail]