Category: Research & Testing

We did another test, this time using a sample of the non-creep crossed linked construction grade wood glue.

This time, we took pieces of CLS timber, one was left as is (looking it age of about 5 years) and the other piece was planed to remove that “dirty” layer.

After drying and curing overnight with the clamps on, we then tried to pull them apart. It was rather hard to do!!

We ended up putting it in the vice and using the strength of the lever principal, managed to snap the joint apart. It was quite hard to do, bearing in mind that the joint was at the end of the timber grain, which is the weakest point.

The “Dirty” old piece:

It was very noticeable to how the wood grain splits across the rings in the timber, pulling a large chunk still stuck to the other piece. Notice how wide the rings were, not so many of them.

The “Clean” planed piece:

This one was definitely harder to break, and only splitting a thinner layer of wood. Then we noticed the closeness the timber grain lines were and it is much more heavily pack together. This was a much stronger piece of timber!

 

Conclusions:

The glue was very strong and there was no signs of the glue itself failing. It was also very nice to see the glue working just as well on older grey wood as well as fresh timber.

Another quick piece of testing done!!

This morning, we went back to our test pieces after having 24 hours to set and cure.

The first one under the spotlight is the dry wood:

The rubber piece peeled off cleanly leaving behind the solid glue on the wood. It was quite hard to pull it off. The glue was well stuck on the wood.

the cement board didn’t budge and just snaped at the joint.

Tried to use mini crowbar to force the piece off but kept breaking.

The Steel was very well held and it took quite an effort to drive the crowbar in at an edge.

It finally came off but only by splitting a layer wood fibre completely off the timber. The glue was well and truly stuck on the metal.

 

Now for the second test piece, the wet one:

 

The rubber piece came off fairly easily and the glue was still stuck to the rubber and not the wood itself.

The cement board came off also fairly easily with the crowbar and only had some splitting of wood fibres. We didn’t try bending the end up!!

The steel was easier, just like the other two pieces, and again, only having a little bits of split wood fibre.

 

Conclusions:

Withstanding the difficulty of having two identical timber pieces with the same surfaces, it does seems to indicate that gluing onto dry surfaces is much better than wet ones, which of course is always going to be the case.

But at the end of the day, we were attacking these test pieces with far more force and pressure, including the wet test case and in reality, the strength of the bond should be perfectly fine for our purposes. Also, we have to remember that we won’t be working in totally dripping conditions and most likely will be dry or only slightly damp when we are building our house!!

 

That was one very interesting little quick test – grin!!