I'm sure that explains it. I'm curious as to just what is sweated out. I ran more patch-out through the bore and left it 30 mins and folloewd with a dry patch and it has come out completely clean. However, I ran 5 more copper cream (mild abrasive by Montana X-treme) and they started out black and have got progressively cleaner. Given wipe-out's reputation on copper, my guess is that its the carbon that is not coming out completely. Only more experiments will tell, but for now all my bores are as clean as they are ever likely to be so I will have to wait a while to find out.