Out of date building sand???

[Munroast]

Not 100%?? I do that but with tubes in as well, it's to reduce tyre pressures for competition use and snow to increases the footprint area without increasing tyre width, but I leave some air in hence the tubes so the tyres don't push off the rims. Never noticed any difference when pumped back up with fresh air.

the other great benifit of doing this is the extra flex in the tryes allows the tread to clear itself of snow better. But what a difference lowering them to 20psi if struggling in snow or mud.

 

[frutbunn]

the other great benifit of doing this is the extra flex in the tryes allows the tread to clear itself of snow better. But what a difference lowering them to 20psi if struggling in snow or mud.

I used to run mine at 12psi for competition use and heavy snow (where I worked had the highest road in England!), hence the tubes. The tyres I used were self cleaning anyway, though at lower pressures this worked even better but it was best not to stand within 40' of the back of the vehicle.

 

[Scarlet Pimpernel]

I thought it was to do with certain grit sizes being washed out, but then it could be rubbish@

NO, it'll still be sand. Finer sand, maybe, but still sand.

 

[Nige F]

I think you will find it's when the waves come back in.



Andy

Time and tide waits for no man

 

[Nige F]

It might be because it can get contaminated with things

Things left by animals.

 

[^woody^]

Things left by animals.

Dinosaur bones?

 

[Mottie]

Cat ****!

 

[Keithmac]

Mould is probably biggest problem?.

 

[teaboyjim]

Mould is probably biggest problem?.

There could be lichen that grows in it if it's just left

 

[jeds]

Technically, sand is a range of particles which fit within a grading envelope for different uses. A trowel full is put into the top tray of a stack of sieves of descending size. Each tray catches a proportion of the sand. There's a min and max for each particles size - the quantity caught in each tray has to fit into the min/max envelope. Sand gets finer and finer over time but beyond a certain fineness it stops being sand and becomes silt. I don't think this is going to happen in a plastic container though, so I reckon it'll be perfectly safe to build two courses of path edging with it.

 

[teaboyjim]

Technically, sand is a range of particles which fit within a grading envelope for different uses. A trowel full is put into the top tray of a stack of sieves of descending size. Each tray catches a proportion of the sand. There's a min and max for each particles size - the quantity caught in each tray has to fit into the min/max envelope. Sand gets finer and finer over time but beyond a certain fineness it stops being sand and becomes silt. I don't think this is going to happen in a plastic container though, so I reckon it'll be perfectly safe to build two courses of path edging with it.

So does that mean that sand theoretically could have a shelf life?

 

[jeds]

Not if it's still. To reduce in size it needs to be on the move, abrading against something. Somebody mentioned mould, which could be an issue. If you keep a dumpy bag for too long it can get a bit mouldy but skim a bit off the surface and it'll be fine underneath.

 

[oldbutnotdead]

Tyre inflation (specially on racing setups)- use dry air. Watetladen air changes expansion rate with temperature.

 

[teaboyjim]

So there is some truth in this as well?

 

[oldbutnotdead]

Yeah. Esp with steel rims, oxygen & water will cause corrosion of the steel & reduce the tyre pressure (a bit) as the oxygen combines with the iron to form rust. Water vapour has a greater effect- takes more energy to heat water than it does to heat the same mass of air so the pressure increase with temperature will be slower.EDIT The temperature increase due to applied force will be lower or slower with waterladen air.

None of these effects are significant in normal applications, only at the boundaries of motorsport performance & technical regs