What is this black gook?

[jagilbert]

I was going to remove the grate and plate to inspect the impellers, but it looks like the previous owner sealed the plate with some kind of caulk. Is this normal? Can you tell anything about the condition of the impeller from this photo?



Thanks,
Jeff

 

[crisso]

No.It is not normal.On the strakes.Scrape a little back and see if there is some stress cracks.No other reason for the caulking to be there..Just have a look