machinable plastic for low temp use?

[mrPelagic]

I am designing a part that will live submerged in sea water, under the bow of a boat. It will be exposed to freezing water for relatively long periods of time (Alaska).

I need a machinable plastic, and I can't find much data for notch toughness of plastics at that temperature.

I was thinking delrin, uhmw, maybe polycarbonate. Does any one have any suggestions?

thanks

 

[patprimmer]

LDPE will be OK at around freezing point. If it is underwater, obviously it can't be below the freezing point of sea water.

I don't actually know the freezing point of sea water, but I am having a wild guess at about -5 deg C

Regards

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[ozchevy]

LDPE will be sucessful as patprimmer suggests.

The company I work for manufacture mooring bouys that are rotationally moulded and foam filled for such purposes.

Our client we manufacture these for are Australian Waterways, and many of our units are currently in the southern artic ocean.