Integral Fuel Tank Leaking
Integral Fuel Tank Leaking
Hi, I have a 60' ferro auxiliary ketch by William Bollard, Sydney which carries a total of 500 gals of diesel in 7 bunkers in the bilges. When last slipped we discovered a weeping of diesel from the heel of the keel and emptied all of the tanks, removed and re-applied the barrier coat after a thorough detergent wash down and drying out of the external bilge areas and left the tanks empty. Anybody have any info on possible detrimental effects of diesel working its way through a hull in that manner? I have not as yet examined the fuel tanks for where the internal barrier coat has broken down (huge, huge job) or trolled for ideas on how to repair the leak(s).
Frank Killick....viewpoint@talent.com.au
Hi Frank, I don't think you will want to hear this.....anyone who is worth his salt in ferro-cement boat design will be fully aware of one of the first important rules...do not create internal tanks for fuel. A ferro-cement tank will hold water, and even if it springs a leak it is easily repairable. The plaster mix of a ferro-cement hull will absorb carbon fuels and especially diesel fuel. And if the plaster mix is not absolutely spot on, diesel will break it down. I have never seen a painted seal work yet, on integral tanks. You can almost always tell if a ferroboat has integral fuel tanks when she is out of the water....stand well back and you will see a discoloured area of the hull where they are grinning through. You will need to thoroughly drain through all areas of the tanks and keel a water based solvent/detergent, and then run through a cement grout mix until thoroughly sealed with set grout. Then fit mild steel fuel tanks inside them, Regards,
Colin Brookes...colb@xtra.co.nz
Thanks a lot for the info Colin -- I had feared as much. Currently I'm in the process of fitting a temporary 30 gallon stainless tank just to get us going again and will have to leave the replacement main tanks job for sometime in the future. As far as the actual main tanks installation is concerned, would the way to go be to glue timber battens/cradles to the bilges and bunker sides and wedge/bolt the new against tanks to these? Thanks again, it's a great forum Colin I'm glad I stumbled across it and I've a few ferro yachtie friends who'll know doubt be sending down the odd quezzy or two.
Frank Killick...viewpoint@talent.com.au
Hi Frank, yes you could ...but you might find it easier to place some pieces of hard foam packing under and then spray setting foam around the outside until it is set in nicely. You missed my bit in the last post about mild steel tanks for diesel. You should not use stainless steel either for diesel or you will be heading in to another series of problems. Regards and best of luck..
Colin Brookes...colb@xtra.co.nz
