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me again with a concrete casting question.
So I have made a cast from a petrol tank (motorcycle) by covering the original with plaster bandage, added casting plaster, small lengths of wood. I then added two bits of wood lengthways, spaced apart, and screwed some ply between them. This was so I could cut the mould along the gap in the centre, made easier by using a bit of hosepipe as a spine as I used the plaster.
I now have (subject to a bit more work) a mould that can be taken apart, or put back together.
Obviously it's slightly bigger than the shape inside the mould. I will address this by adding a planned thickness of clay to the mould inside, then use heavy polythene inside the mould.
I plan to use this to cast a concrete block that's the shape to fit inside the fibreglass tank that is the source of the mould.
I'm worried that the weight of the concrete in the mould will distort the mould despite me trying to add reinforcement.
My plan is to use a "really useful" plastic storage box and possibly use some 2" polystyrene sheet to take up some slack, maybe some 2x2 timber offcuts, and place the plaster mould in the box. I was going to then use kiln dried sand to try to flow into any voids so the whole thing can be supported as much as possible.
Then I will hand pack the concrete tamping it as I go
Think this would work?
thx
So I have made a cast from a petrol tank (motorcycle) by covering the original with plaster bandage, added casting plaster, small lengths of wood. I then added two bits of wood lengthways, spaced apart, and screwed some ply between them. This was so I could cut the mould along the gap in the centre, made easier by using a bit of hosepipe as a spine as I used the plaster.
I now have (subject to a bit more work) a mould that can be taken apart, or put back together.
Obviously it's slightly bigger than the shape inside the mould. I will address this by adding a planned thickness of clay to the mould inside, then use heavy polythene inside the mould.
I plan to use this to cast a concrete block that's the shape to fit inside the fibreglass tank that is the source of the mould.
I'm worried that the weight of the concrete in the mould will distort the mould despite me trying to add reinforcement.
My plan is to use a "really useful" plastic storage box and possibly use some 2" polystyrene sheet to take up some slack, maybe some 2x2 timber offcuts, and place the plaster mould in the box. I was going to then use kiln dried sand to try to flow into any voids so the whole thing can be supported as much as possible.
Then I will hand pack the concrete tamping it as I go
Think this would work?
thx
