Building lathe/mill in cast of concrete?

Hi. This topic is not much to do with lathes and mills, but it will work the same, because I started to build a 3/4 size snooker table, the " slate" bed was formed from 3 sections, using 3x2 outer frame and the base was 3/4 thick formwork ply, which is waterproof, and each side is varnished, as you only need one former, altering the "pockets" with poly foam, the fixings were Ramset expandable fixings, screwed these to the side frames, but filled the inside with a melted candle to stop the concrete from intruding on to the threads. The inside was layered with strong chicken wire, tied to the bolts with tie wire, (its too thin to weld). and then filled with a strong concrete mix, ie more cement than normal concrete.

I vibrated this with a large industrial Ramset drill, ( using a small workshop hammer drill is not big enough) using a block of wood drilled to take a bolt, made it loose enough to allow it to spin on the bolt, and locked the bolt in the chuck. BUT !!! DONT vibrate too much as the agregate will settle to the bottom and the base and the top and bottom will have only a weak slurry, which will crack, So I pushed the drill and block from below, hitting it it in 10-12 postitions for only a maximum of 10 seconds. You can make a vibrater probe out of plastic pipe fixed to the wooden block and sealed at the end, If you are careful you can hold the pipe from turning, but still vibrate enough the settle the concrete mix to the bottom without air bubbles and voids. As an after thought what if you use a watered down contact adhesive that will run down the inside of a Mill columb and then set, or won"t it go off ???.

Some of the cheap Chinese pool table had so called slate beds, but these were only concrete, coloured grey. and only 3/4 to 1" thick so were very fragile if handled wrongly.

Hope this is some help !!!

PS. its getting cold down here now. Although Autumn is a very pretty time of the year.

John Holloway.

Edited By Richard Parsons on 27/09/2011 11:00:46

Edited By John McNamara on 27/09/2011 15:40:51