I've used Ospho a good bit in my shop, but not on my boat much. It's basically phoshoric acid, which can accomplish the same thing as Ospho if you can find it for sale by the gallon. If you could get your ballast bone-dry, it might work, but it should probably be regarded as a patch, not a fix. It won't reduce the volume of the existing rust. If you're planning on flooding the ballast with Ospho and leaving it wet, then you might get accelerated blistering. Of course, it's been wet for all these years, so that's probably accelerated blistering too. Other than that, it shouldn't hurt fiberglass. Digging it out and replacing with lead is your best fix, but I understand that's a LOT of work... how much was Bob asking for new 17s, again? Best BG -- Brian Gilbert Marine Media Author, Fix It and Sail (423)876-9990 3404 Hartford Drive Chattanooga, TN 37415 www.sailingsmall.com on 1/19/06 6:28 PM, montgomery_boats-request@mailman.xmission.com at montgomery_boats-request@mailman.xmission.com wrote:

Anyone familiar with a product called Ospho? It is a chemical to retard and nuetralize rust. Someone suggested it to me with respect to my problem with the steel ballast in my keel being wet. It is drying out, but now that air is in there it is obviously going to rust. The suggestion was to inject the Ospho into the area and let it coat the steel punchings. Ospho apparently has about the consistency of water as far as how it flows. This sounds like a do-able idea except I have no-idea what the effect (if any) on the fiberglass would be. Honestly, unles someone tells me that they have seen this done, I'd probably shy away from it. So far I haven't been able to get in touch with the company that makes it to ask them how the product would react with the glass. I'll have to try earlier in the day on Friday when I'm off.