The last few months noticed a very thin trail of rusty water in the bilge. After much crawling around and with use of a mirror have at last located the source. It appears to be coming from a very small corrosion hole at the bottom of the metal pipe that leads into the large silencer cylinder (very near where there is a welded join. It looks like the corrosion has started from the outside of the pipe as opposed from inside out. The rest of the silencer is pristine. (Engine is a VP d4) Someone recommended I use a cold weld product called JB Weld to cover the area. I was unable to get hold of some, instead used Holt's exhaust gum repair paste to cover the offending area after rubbing down. Do you think this product will be adequate or should I use the JB weld instead. Also any idea why this small isolated patch of corrosion would have appeared? The unit is 2 1/2 yrs old. Thanks in anticipation.