Picture Drip… crack?
- Thread starter Rodders67
- Start date
After some research… apparently common on BMW castings.
“ They're what are called 'cold shuts'. When casting something and the molten metal is flowing, it cools slightly at the front of the flow. When flow from another direction meets up with it the two 'cold' edges create a slight surface imperfection. Plastic does the same and with some plastics you can actually see a slight difference in the colour where the 'cold shut' happens.”—E39GIRL (Bimmerforum)
“ They're what are called 'cold shuts'. When casting something and the molten metal is flowing, it cools slightly at the front of the flow. When flow from another direction meets up with it the two 'cold' edges create a slight surface imperfection. Plastic does the same and with some plastics you can actually see a slight difference in the colour where the 'cold shut' happens.”—E39GIRL (Bimmerforum)
Nice one @Rodders67 , nailed it, I was a toolmaker by trade and built moulds where cold shuts were unavoidable. Unlikely to be the source of your drip though, that is unless the casting has been subject to some abuse in its life. Sorry and all that...
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