Bond Strength: A Video is Worth a Thousand Words (and Tells Us Much More Than a Lab Test)

We have a lab at Cathedral Stone, and we’re proud of the testing we do in that lab. We test for salts; we test compression and bending tensile strength. We do a lot of compatibility testing. Some of our tests have been ongoing for 4 or more years!

We’re always being asked about bond strength with our Jahn Mortars. The questions typically reference ASTM or AASHTO standards. We understand that the industry has been trained to use these standards. But we always struggle to stress to architects and engineers that these standards are specifically written for mortars with bonding agents. Jahn Mortars do not use bonding agents; it is our opinion that bonding agents are, and have always been, a mistake.

We often get photographs from training sessions where students stack bricks onto a repair to “test” the bond strength. We love these photos. We love them so much that we decided to do our own build-out “stacking test.” They’re fun to watch, but they also do so much more than a lab test in illustrating the initial bond strength and potential full-cure bond strength.

Here’s our video:

And Dennis Rude, CSP’s resident stonecutter and founder, did his own “testing” on our new Self-Cure Mortars, which, again, speaks volumes about the bond strength of Jahn Mortars.

Here’s that video:

Let us know if you have any questions, and let me know if you need some lab results as well — we have those too.