Wohoo, Dyna Bolted (5x12mm) the Pier on today and man is it solid..
When this pier was out Leyburn I had a couple of washers as packers under each dyno bolt hole as the base had warped from welding the Gussets on, These washes never really made the Pier sit real solid, even tho all was tight, there was a fine vibration & a ringing sound when hit with something solid, like a 4x2 !
As seen in Pics 1) & 2), I decided to Diamond grind the Pier's concrete base into a hollow with approx 3mm sagittal depth so that only the circumference of the steel pier base would be in contact with the 'crete ! This took about 5-6 times to get just right so the pier sat firm without any movement when sideway pressure in two directions was applied by hand to the top of the pier.
I also decided to cut out a '2mm perspex gasket' to fit between the steel and 'crete for Two Reasons :
A) to create better contact - as this perspex can squash under load, I found this out by testing in the Vise to see if it would crack under load - simulating the force of being tightened in situ with the dynobolts, which it didNot, but the vice instead left indentations on it - good stuff !
B) To create a barrier for the painted surface from being scratched which would expose bare steel,, & also from moisture coming in contact with the steel base, especially during them multi day rain events where ground and 'crete slabs etc just keep sucking up moisture until waterlogged, so to speak.
I have also applied 3 beaded rings of silicon under the perspex, plus around & on each dyno bolt hole as the bolts were placed and subsequently tighten very tightly
I have hit the pier with a 4x2 and it just gives this 'short dead sound' now, no vibration and definitely no ringing
