From: Richard B. Emerson <pavilion_at_pinefields.com>
Date: Wed May 30 2007 - 06:30:58 PDT

As Star Trek's Dr. McCoy said to Capt. Kirk, "He's dead, Jim."  Our fuel tank is certainly heading for flat-line country due to rust, including a large mound at the very bottom of one sidewall (now that would be fun if it opened up!).  The problem has been how to replace it without a) boogering up the interior, and b) having a plumber's nightmare tying multiple (sub-)tanks together. 

Over the weekend a friend came up with a solution that seems very promising: cut the old tank apart and remove it piecemeal (no surprises there), make up two tanks 3' 3" long (the original tank is 6' 6" long) and following the original tank's shape (narrow and deep at the aft end, wide and shallow forward - all differences are on the order of a few inches), install the aft tank, install the forward tank, and weld the tanks together in place (see below for details on the welding phase).  Without removing any floors or cabin sole, there is about 3" clearance above the existing tank.  It appears that, at most, the floors, and maybe some of the sole, might have to be removed, as opposed to removing the inboard end of the galley cabinetry (which is never going to be made really "as before" short of museum grade restoration).  There seems to be no issue of not having enough room in the cabin to move the tank(s) forward and sliding them aft into place, as would be the case with a single six foot long tank (just isn't room for that).  Air vent, fuel filler and pickup routing remains as before, with the exception of adding what ever might be needed to vent air between the two sub-tanks. 

The welding phase... there is a single point of contact between the sub-tanks: the forward end of the aft tank and the aft end of the forward tank.  A spigot (size driven by at least the diameter of the fuel filler) would be welded, during tank fabrication, onto one bulkhead and a hole, to receive the spigot, would be made in the corresponding bulkhead of the other tank.  An alignment plate, welded to one tank and extending under the other tank (but not welded, as it'll be inaccessible when the tanks are in place), will help set the tanks up initially.  Using access ports, the spigot would be welded to the other tank and then reinforcing plates added to the tank tops.  Air venting between the sub-tanks can either be via external hoses or an additional spigot.  As an added bonus, this approach puts a large baffle in the middle of the [two] tank[s] and requires large access ports, all of which is very desirable. 

Has any Baba 35 owner done anything similar?  I'm obviously also interested in comments regarding issues involved in welding aluminum, particularly inside a boat.  The goal is to wind up with only two signs the tank was replaced, a shiny aluminum tank in the bilge and (only facing reality) a bill in my hand.  Added fillers, transfer valves, day tanks, etc. all would not meet these criteria. 

Cheers,
Rick

P.S.  I read the recent Practical Sailor article on fuel tanks, which was really little more than a rehash of tank basics, printed in many sources.  I hoped for more and better... 
----------------------------------------------------------- Baba Panda and Tashiba Owners Mailing List -- For more info, please check out the FAQ... http://www.ballreich.net/hypermail/baba-l/faq.html Received on Wed May 30 06:31:04 2007