glue hassle

[devonwoody]

Making a new box yesterday (with mitred corners and an internal platform, the pen tidy) I have found a glue problem, this has been on my mind in the past.

Using Titebond 3, I glued the corners and the dado (for platform) and noted that all corners were nice and tight so did not put on clamps but relied on the masking tape to hold the pieces in place until glue had set.
Checked that joints were tight a few minutes later and was satisfied, but when I returned 3 hours later three corners have opened slightly.
This I assume is because when the glue sets hard it has an energy that can force open the joints ( a kind of expansion).

So it looks in the future that clamps holding tops and bottoms of boxes are a necessity

 

[Waka]

Or you could use Titebond 1.

 

[aldel]

I think a possible explanation is that the wood absorbs some of the moisture in the glue and thus swells a little whilst the outside face of the wood remains dry. The very slight bowing or movement forces the joint apart, the glue hardens and then prevents the wood from moving back when it has dried.
Clamping will prevent movement.

Aldel

 

[gardenshed]

Instructions on the Titebond 3 says use clamps for 30mins minimum .

 

[Harbo]

I've used Titebond III on some mitre jointed boxes recently with no problems - wood was mahogany.
Just clamped them fairly gently with a belt clamp for about 30mins then left them over night.

Rod

 

[Digit]

I think you'll find it's moisture John. I've had the same problem when clamping was difficult so now I use hide glue as it seems to set before the moisture can affect it. Alternatively I use box lock joints, as on a pair of bracket clocks I've been nagged into making at the moment!

Roy.

 

[joiner_sim]

Any joints that are only glued together with nothing else holding it, should be clamped and left under pressure until at least the recommended time on the glue tub. I find that in the winter the glue takes even longer than recommended to set. Generally though anything that I glue together, such as joints are left clamped up for 24hours before messing about with it again.

I use cascamite sometimes too and find this take a little longer than white glue to set, but it is definatley stronger than white glue is after being left for 3/4hours. We can spindle mould casements and panels, etc.... alot sooner than we could if we used white glue.

 

[devonwoody]

Perhaps its the dampness and condition of stored timber, because I have been getting away with masking tape, strapping up mitred boxes until now.

 

[Digit]

Why this time and not before then John? Did the glue take longer to cure this time perhaps?
The fact that the corners curled outwards suggests that the glue is the culprit.

Roy.

 

[Derek Willis.]

John,
Buy yourself one or two of the four corner band cramps from Screfix Direct, they are very cheap and do a grand job, I use them all of the time for this type of thing, then no problem.
Derek.