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Old 3rd August 2011, 04:25 AM   #11
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Yes, that Titebond III would be the stuff! Remember, you're getting your information from some joker in the internet, so test with some scrap pieces to be sure you like it.

Hint- Whenever I buy a bottle of wood glue, I write the date on the bottom using permanent marker. I just don't use it that fast and sometimes it can pretty old between projects. I don't know the shelf life, but at 2 years I usually buy another bottle.
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Old 3rd August 2011, 10:46 AM   #12
marce is offline marce  United Kingdom
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This stuff is also worth looking at, and will fill very small gaps.
Gorilla Glue
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Old 3rd August 2011, 11:15 AM   #13
AndrewT is offline AndrewT  Scotland
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I have repeatedly found that glueing to end grain of wood is not anywhere as strong as gluing to the the side face.
This applies even more when gluing MDF.
I don't know why. Could it be dust contamination?
Dowels or biscuit or similar do "add strength" but just as important "add shock resilience" to end grain joints.

I would never expect any glued end grain to end grain joint to be as stiff nor as strong as the parent material. A butt joint that includes one end grain face must similarly be limited in strength. Q.) why did someone invent and why do we see scarf joints?

Is it strong enough?
That is completely different and requires testing, probably destruction testing.
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Old 3rd August 2011, 11:53 AM   #14
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AndrewT,

Your observation on end grain is spot on...the problem is that the end grain of wood constitutes the openings of the channels which used to carry sap through the (living) wood. Glue spread on end grain tends to have the moisture drawn away prematurely through this pore structure interfering with proper curing. Most joinery techniques in woodworking (rabbets, biscuits, mortise & tenon, dovetails, etc) have as one of their objectives increasing the area of long grain to long grain glue surface which greatly increases joint strength. Of course with plywood the end of a panel is a mix of end grain and long grain which gives a better outcome than solid wood end grain.
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Old 4th August 2011, 01:33 AM   #15
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Much of the strength in butt joints in speaker cabinets comes from the fact that the joint is supported on more than one side. I have never seen a well-constructed speaker box made with butt joints fail. A closed box that basically just sits there its entire life doesn't need the sort of strength that a drawer does which is subjected to tensile and compressive forces on a regular basis. Save the dovetails for the drawers unless you are doing it for aesthetic reasons.

To answer the question about clamp pressure, a few years back one of the woodworking magazines did some testing to see if a joint could be starved of glue from too much clamping pressure. They found the exact opposite to be true which makes sense because glues joints are strongest when the film area is largest. Extreme clamping pressure pushes parts more closely together resulting in a larger contact surface area and more glue film.
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Old 4th August 2011, 02:37 AM   #16
jimbro is offline jimbro  United States
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I use pocket screws whenever I can. They are stronger than butt joints and no clamps are required. When there's no room I use biscuits but probably don't need to.
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Old 4th August 2011, 04:31 AM   #17
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I am surprised no has mentioned full cleats. Provided you have a brad nailer and at least a couple clamps you can build a box easier and stronger than anything mentioned so far and have no exposed fasteners except for the back panel.
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Old 4th August 2011, 11:04 AM   #18
jimbro is offline jimbro  United States
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Not sure what you mean by full cleats, Cal. Are you talking about glue blocks? Can you find a picture of one?
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Old 4th August 2011, 01:32 PM   #19
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Yes. They are installed on one panel first (fully glued) so there are no alignment concerns. You use clamps to hold the panels together nice and snug then fire your nails on the inside through the cleats. Quick, easy and strong like Ox. You can make it even easier by nailing through from the outside as the holes made by the nails are so small they don't need filling if you are going to veneer.
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Old 4th August 2011, 01:33 PM   #20
AndrewT is offline AndrewT  Scotland
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Much quicker than my screws method.
My last pair of speakers had over three hundred screws (yes, a box and half).
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