If you look at a manufacturer's data sheet it will often give a rating for brass or copper corrosion. Mystik JT-6 number 2 is better in that regard than number 1. 73, Jerry, K0CQ On 3/28/2010 6:28 AM, Mike Hyder --N4NT-- wrote: > On second thought, I may not use the Tri-flo stuff. I WILL, however, > use a synthetic grease. > > Mike >