I have started the auxiliary tank installation in my '93 Seafarer. For anyone that is interested I will update this post with any parts and problems for future reference. So far this is working out very well.
Objective - Install an auxiliary tank so that I can run the new engine (Yammy 225 4 stroke) on fresh fuel from a new tank and lines, allowing more time to get rid of the nasty fuel in the old tank (and probably getting rid of the old tank).
WARNING - Never, ever (ever) run fuel from an old tank into a new motor. I am told that the ethanol found in much of today’s fuel will loosen up the lacquer build up in an old tank and pretty quickly gunk up the filters in the new motor, and there are several filters to include the separator and the injectors. IMHO, not worth the headache given the intent of buying a new motor.
Parts (about $430 so far):
- 58 gal poly tank - Moeller 032558 - Boatbandit - $260 and about $40 shipping with other parts
Gas fill - 316 SS - Whitecap 6123C - Boatbandit - $23. Looks similar to the Perko part that GW used but is cast stainless and less $$. In case it matters to you, the word "Gas" and screw holes are in different locations from the OEM part (the Perko 0520DPGCHR is what GW used, but has a metal cap instead of the black plastic cap).
Gas vent - Perko 0509DP4CHR - Boatbandit - $30. A bit pricey but is exactly the same as the vent that GW used.
Spring to go around the vent hose to stop kinks - McMaster-Carr part number 9637K17 (pack of 5)
3/8" A1 rated fuel supply hose - Qty = 14' - Great Lakes Skipper - $45
Brass fitting for fuel supply - Straight w 1/4" MIP threaded & 3/8" ID barb - Lowes
#10 SS oval screws for fill plate - Qty = 3
SS clamps for 3/8" hose - Qty = 4 - Lowes (hopefully marine grade-ish )
SS clamps for 5/8" hose - Qty = 4 - Lowes
SS clamps for 1.5" hose - Qty = 4 - Lowes
5200 caulk - Walmart (small tube since this stuff gels once a tube is opened)
The tank measures 44.0" l x 21.5" w x 15.75" d which fits nicely in the aux tank compartment that measures 55.25" l x 26.0" w x 21.0" d. The lip around the compartment opening is further restricted to a width of 23.5" but that is still not a problem given the dimensions of the tank that I chose. The main effort was that I had to remove the shelf at the aft part of the compartment. I suspect this shelf was intended to support the water tank if so equipped. My Sawzall tool tackled this nicely.
I used 5200 and a couple of screws to hold two 48" PT 2x6's in place that support the tank bottom as well as to lift the tank 1.5" so it does not interfere with the angled part of the compartment (presumably the boat's bottom). Also the 2x6s provide a place for mounting 2x2 blocks fore and aft of the tank to stop it from moving.
I positioned the tank about 10" back from the front wall so that the fill and vent connections could be made without kinking, while also keeping them at the high point under normal conditions.
The boat already had a 1.5" fill hose and 5/8" vent hose from this compartment to the area where the existing fill and vent are located. Another example of awesome GW forethought given it would have been very tricky routing these in the tight spaces.
The hole for the new fill was drilled next to the existing fill using a drill hole saw. It was set to 1 7/8" diameter for the Whitecap 6123C hardware that I used and was fastened into place using 5200 and the 3 #10 SS screws
Similarly, a hole was drilled in the side for the vent hole, but caution is needed to make sure the hole is drilled far enough forward so that the new vent hose will not interfere with the new fill hose. The vent hose needs room to be routed up then back down in an inverted "J" so water can never enter. Care is also needed not to loop the vent hose in such a way that fuel can ever collect at a low point as this too will cause future problems. GW installed a hose spring on the original vent hose to stop it from collapsing. Definitely needed given the cramped space. If I were to do it again, I would try using the next smaller diameter spring in the McMaster-Carr catalog because I suspect it would work a bit better, but the one noted above did just fine but let the hose collapse just a bit more than I had hoped, but certainly not to the point of obstruction (the main thing trying to avoid).
I put PT 2x4's on each side and one across the top in between the related grooves as the final means for holding the tank in place. It is important not to over restrict the tank as it needs to be able to flex.