I took the grinding wheels off my grinder and fixed a sleeve on one end of the shaft with a big pinch bolt then screwed it to the frame of the table which held my moulds . The spped of RPM and the slight unballance of the pinch bolt made a fantastic vibrator table .
If you want to make a big rustic trough planter for herbs make the outer skin using 3/4 ( 19 mm construction ply of similar use screws and battons on the outer faces of the box frame ( no top & no bottom paint it with veg cooking oil a couple of times on th internal faces and then put a big block of polyestyrene expanded foan in the middle evenly spaced so the gap inbetween will form the walls about 3 inches thick ( 75 mm ) . Set this on a sleet of builders plastic and make you concrete usinfg a 6 mm ( 1/4 pea grit or gravel mix a bucket of dry peat into the mix work it in well and pour it into the mould when done after making it ever so slightly sloppy , push several pointed round greased sticks down into the polystyrene block so you get drainage holes and leave to cure for 14 days .then unscrew the mould sides and gently turn the trough on its back or onto some battons .
If you want some sort of personalization of it all add a wired on object to the outer walls is plastic letters or a motiff in relief so long as it does not reduce the wall thickness too much or router a design into the wall before assembly .. Remember that numbers need to be a certain way round for them to be the right way round on the finished item .( been there done it and failed
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Best thickness for the base is about the same as the walls or very slightly thicker You can add a water proofer to the mix if you don't want the pots to hold water in the walls during winter and end up with the frost cracking them .If you do this forget about using wash liquid or a plasterciser like FEBMIX as they counteract each other .
Pour some petrol on the polystyrene to dissolve it and leave for another 14 days for the concrete to get a reasonable strength . the end product should be failry pourous and have slight colour and a decent rustic weathered texture
One big long coffin sized trough I made had a hollow wooden boxform in the centre covered in 2 inch thick expanded polystyerene sheeting which had rounded corners for greater strength of the finished item .
I was able to unscrew this inner box and used a spade to ease the polystyrene foam off the concrete . after 28 days of curing .
Ii gently hose pipe washed the remainder of the marks off after scraping of the worst of the remains .
Topic: Thus could all end very badly (Read 7235 times)
