okay, I found the zinc rods and I can supply the material for making the ROP easy. If there are those of you who want the following, contact me with a PM and I will send you the stuff. Don't know what to charge but should be fairly reasonable. You need a 2 inch zinc round bar, a two inch copper tube and some surgical tubing to put it together for your correct length. I saw that the ones on ebay are going for $46. Whew, that is a bit steep. GS