by Andy Wade » Tue Dec 26, 2006 12:55 pm
DavidLeeds wrote:It is a terrific picture. Would be great to be up there!
Interesting point Andy. I wonder if it is possible to apply plaster out there (or even in zero gravity) and would it take?
I'm willing to go up there and test this for you, where do I sign?
Actually when I think about it, gravity is essential for what I call trowel and handboard work, where you pick up a lump of mixed plaster from the mixing bath and centre it up on the handboard so that you can take small amounts and plaster them on to the wall. Gravity is definitely helpful and should you tip the handboard too far the plaster will slide off on to the floor. (been there - done that
)
Actually sticking it on to the wall would be similar as the technique is to tip the trowel at an angle, and just before it slides off the face of the trowel, you push it against the wall. The timing is important here! Once it is on the wall hydrostatic suction keeps it there as long as the weight of the lump of plaster does not exceed the suction, (a rough wall surface increases the mechanical 'key') and you leave it and add another bit until eventually it's all on the wall, then you would 'trowel it up' to smooth the face a bit, waiting as the plaster slowly sets chemically (about 90 minutes from mixing to finishing) and trowelling occasionally to smooth the plaster a bit more each time. I reckon that this part would work in space.The final smoothing off is done with water splashed on to the face of the plaster (this would be interesting in space
) The problems in zero or limited gravity would probably be getting it from the mixing bath to the handboard and from the handboard to the trowel and then to the wall.
Very interesting, I'd never considered that. Excellent question. I can't believe I'm talking shop during the Christmas holidays...
[quote="DavidLeeds"]It is a terrific picture. Would be great to be up there! :)
Interesting point Andy. I wonder if it is possible to apply plaster out there (or even in zero gravity) and would it take?[/quote]
I'm willing to go up there and test this for you, where do I sign? :lol:
Actually when I think about it, gravity is essential for what I call trowel and handboard work, where you pick up a lump of mixed plaster from the mixing bath and centre it up on the handboard so that you can take small amounts and plaster them on to the wall. Gravity is definitely helpful and should you tip the handboard too far the plaster will slide off on to the floor. (been there - done that :lol: )
Actually sticking it on to the wall would be similar as the technique is to tip the trowel at an angle, and just before it slides off the face of the trowel, you push it against the wall. The timing is important here! Once it is on the wall hydrostatic suction keeps it there as long as the weight of the lump of plaster does not exceed the suction, (a rough wall surface increases the mechanical 'key') and you leave it and add another bit until eventually it's all on the wall, then you would 'trowel it up' to smooth the face a bit, waiting as the plaster slowly sets chemically (about 90 minutes from mixing to finishing) and trowelling occasionally to smooth the plaster a bit more each time. I reckon that this part would work in space.The final smoothing off is done with water splashed on to the face of the plaster (this would be interesting in space :lol: ) The problems in zero or limited gravity would probably be getting it from the mixing bath to the handboard and from the handboard to the trowel and then to the wall.
Very interesting, I'd never considered that. Excellent question. I can't believe I'm talking shop during the Christmas holidays... :lol: