[martinw]

I actually have no problem with the repeat posts. As time passes, we look back at what we said earlier and may have a different take on things.

Anyway, let's discuss vibration. I thinking about bolting this to a table for making my own vibrating table.

Dear Zumba,

I mentioned RC countertops in post #587, and a book on the subject by
Fu-Tung Cheng. The author said that bolting serious vibrators to the outside of the formwork might destroy the whole shebang unless the form-work was pretty strong. My guess, and it may well be entirely wrong, is that powerful external vibration may create much greater forces on the formwork than the forces needed to contain a static mix.

I have only done a few pours with RC, used hand-held sanders to the outside of the mould, poked wooden sticks to begin with, banged the outside of the mould with a rubber-headed mallet, and put a sander in a plastic bag on top of the mix (messy). I have also applied vacuum, but not with the purpose of drawing off excess liquid .

IMHO, powerful external vibration will do a good job, together with internal vibration....but watch out for the dynamic forces on the formwork.

These were points made by the author, a better man than me.

Best wishes

Martin