cobalt

I cast magnesium for 30 years so it gets in your blood.

I would be interested in knowing if they are now aluminum or not. If the sliver one weighs about 30% more than we will know.

Thx.

NC TRACKRAT

Was over at a friend's shop in GSO a couple of weeks ago. He had just installed a new fan housing on a 964 and said that they're all coming in out of AL now.

cobalt

How did he verify it was Aluminum? They could use the same tooling for aluminum or magnesium but to change a material would require a part number revision.

99310666703 still comes up as a valid part number. I have heard many parts are coming from classic division without previously supplied coatings or painted. Would be interesting to know for sure.

willus

I weighed my old, presumably but not guaranteed, original fan housing at 1954 grams, while my new one received this year measured a similar 1893 grams.

Given the (low) quality appearance of the casting and machining, this seems like a believable part-to-part variation for two pieces in the same metal.

cobalt

I agree with you. The material looks to be magnesium as well. I would have expected the fan to weigh closer to 2700 grams or more if it was made from aluminum. This is a concern. It would appear that parts are being supplied without protection. Being magnesium this will not fare well once put into use.

I recommend media blasting and painting or clear coating this before installing. Unless this part was preserved in some way it will need a cleaning prior to painting. Some form of media blasting followed by coating within an hour or so of the cleaning is the recommended approach.

Ideally a chemical conversion like Dow 7 should be performed prior to painting but that would be too involved.

willus

I don't have a media blasting setup, so that is a bit of an obstacle. What's next best? Self-etching primer?

I do have a shop nearby that does Dow 7. If I went that route, would you still recommend media blasting first? After the Dow 7, is a primer recommended or does the Dow 7 act as the primer?

cobalt

If they do the Dow 7 they should prep it for you.

A good primer followed by paint would work best