Kittyhawk
Established Member
This may be well known but it's a new one to me.
In my aircraftery I finish the aeroplane models in Britax Teak Oil which I buy in 500ml tins. Usually they get 5 - 6 coats depending on timber density and each coat uses about 10ml. So theoretically I should open and close the tin 50 times. In reality by the time the tin is half full the remaining teak oil has gone thick and gluggy and unusable. Since the tin is only open for the couple of seconds it takes to scoop out a spoonful of oil I assume the problem is caused by the air volume increasing in the tin and not solvent evaporation.
A chap I know is a supplier of various clear finishes to cabinet makers and they take the product in 20 litre drums so I asked him how do they stop the oil or varnish from going off in the drum? 'They put rocks in it,' he said. I dutifully laughed at his little joke and asked again, but how to they do it, really? 'I told yer,' he said. 'They put rocks in it.'
So the penny dropped. Put some sort of ballast in the tin to raise the oil level which in turn displaces the air. I tried it on my just emptied latest tin of Teak oil and got to use almost the entire contents without problems. Obviously an amount if teak oil was trapped among the pebbles but the loss was far less than having half a tin becoming unusable. The instructions on the tin of teak oil is to give it a good shake before use and I saw that the pebbles were causing a big of damage to the tin - the pebbles being a bit pointy in places. So the current plan for the next tin is to pinch some of my grandson's marbles and try them out.
In my aircraftery I finish the aeroplane models in Britax Teak Oil which I buy in 500ml tins. Usually they get 5 - 6 coats depending on timber density and each coat uses about 10ml. So theoretically I should open and close the tin 50 times. In reality by the time the tin is half full the remaining teak oil has gone thick and gluggy and unusable. Since the tin is only open for the couple of seconds it takes to scoop out a spoonful of oil I assume the problem is caused by the air volume increasing in the tin and not solvent evaporation.
A chap I know is a supplier of various clear finishes to cabinet makers and they take the product in 20 litre drums so I asked him how do they stop the oil or varnish from going off in the drum? 'They put rocks in it,' he said. I dutifully laughed at his little joke and asked again, but how to they do it, really? 'I told yer,' he said. 'They put rocks in it.'
So the penny dropped. Put some sort of ballast in the tin to raise the oil level which in turn displaces the air. I tried it on my just emptied latest tin of Teak oil and got to use almost the entire contents without problems. Obviously an amount if teak oil was trapped among the pebbles but the loss was far less than having half a tin becoming unusable. The instructions on the tin of teak oil is to give it a good shake before use and I saw that the pebbles were causing a big of damage to the tin - the pebbles being a bit pointy in places. So the current plan for the next tin is to pinch some of my grandson's marbles and try them out.
