Converting Fiberglass (fuel) tank to Holding Tank?

[first230sl]

Hey there. We have a 58YF which has three fuel tanks as well as a livewell (the latter in the lazarrette).

We don't use the livewell at all, and could live with only two fuel tanks instead of three - but we need more holding tank space (I am sure a number of jokes come to mind right now).

Anyway - I am consideriong converting either the livewell or the mid fuel tank to a holding tank. Does anyone have experience with this? Will fiberglass eventually become permeated with the holding tank smell (which would be a real problem in a mid-ship keel tank)? Is there something I should be doing to the fibergalss before the conversion to make it impermeable to odors?

I am kind of leaning toward using the livewell - although it is a lot smaller than the fuel tank, it is likely big enough. Also, if I do end up with an odor issue in the future, the livewell can be removed from the boat whereas the mid fuel tank cannot (since it is integral with the hull).

Please let me know if you have done this before - and to what result.

Best regards - Murray

 

[yachtsmanbill]

Hey Murray...
My 1974 58TC came with no holding tank at all! There is however a 185 aux fuel oil tank in the front that I converted with great success. Also, out board of the port engine is another 100+ gallon tank that can be used for the head, fuel or water.
That 185 gallon tank lasts me almost all summer, and some guys here think I am full of renderings too LOL! ws

 

[drburke]

Careful there, Bill. If you get the plumbing wrong, you'll foul your Racors!

Nice shots of the mini-GLHR in the Racor crud thread--I am envious!

DAN

 

[yachtsmanbill]

Hey Dan!
Human feces I can deal with... as an ex plumber, but that fuel crud is really bad! Read the new "gas" thred!
BTW... we may still try to limp out to the beach in a week or two. C'mon along!! ws

 

[first230sl]

Yes - the 58YF also came without holding tanks. I do have two that were added recently - but both are woefully small (10 - 15 gallons) and have to be emptied frequently - even with a vacuflush. I don't have a port-side tank as you do - but I do have foward, mid and aft fuel tanks.

Did you do anything to the fibergalss before converting the forward tank? No odor problems? How long ago was the conversion done?

The livewell in the lazarrette looks like a good option to me. I think it would be over 50 gallons.

Thanks so much Bill.

Hey Murray...
My 1974 58TC came with no holding tank at all! There is however a 185 aux fuel oil tank in the front that I converted with great success. Also, out board of the port engine is another 100+ gallon tank that can be used for the head, fuel or water.
That 185 gallon tank lasts me almost all summer, and some guys here think I am full of renderings too LOL! ws

 

[yachtsmanbill]

That aux forward fuel tank was barely used, and was 100 percent empty when I opened it up. I "de-plumbed" the fuel stuff (Dburke!) and then made the penetration. I have 2 Atlantes Freedom heads and Raritan specs "two vents of 1-1/2" port and starboard". Thats for a cross flow of air for anearobic action. Never even caught a whiff off odiferousness in its second year! I NEVER add chemical treatment either.
This boat was used primarily offshore and had direct O'board discharge heads. With that said, I plumbed in a deck pumpout fitting and a diaphragm pump with a LOCKED Y valve for future south american adventures. The OEM tank is more than ample for odor permeation as far as I am concerned. This seems to be De' Riguer for current apps as well. Thats a 185 gallon tank BTW !
I think youd be in for trouble pumping 50 feet to the lazarette without a booster pump IMHO.
This is before during and after the install....
PM me with your email if you need another 100 or so pics of the job from inception to flush!! ws

 

[first230sl]

Looks like a nice clean job you did. Thanks so much for the pics.

BTW - the run to the lazarette will not be an issue as this holding tank will be meant to serve only the vacuflush in the aftmost head. It is a short run.

Best regards - Murray

 

[34Hatt]

I converted my fiberglass water tank to a holding tank 6 years ago No problem at all works great much better then plastic which will hold the smell after time. I do flush my out at the end of the season real well with some bleach.

 

[SKYCHENEY]

The 53 has a very long hose run from the master head up to the bow holding tank. My GM pushed that sewage just fine as does the new Atlantes.

 

[REBrueckner]

Contrary to popular belief, early 1970's 48's came equipped with "holding tanks" that were not plumbed. I'll bet 58's did too!!!

They were provided by Hatt in anticipation of no discharge rules pending, but were NOT plumbed. And they were used by owners for other applications, like fuel. I found out when a sistership to my 1972, also a 1972, had the "holding tank" plumbed for fuel...I discovered my tank was still unplumbed....So I called Hatteras and got the above information....I plumbed that tank almost exactly as Bill's photo's...all PVC connections, no metal, so no corrosion.

 

[captddis]

The only concern I can see is the egg crate baffles that the fuel tanks have, seens to me a lot of material would get stuck in the baffles. Many holding tanks have been converted to fuel though.

 

[yachtsmanbill]

After some serious considerations as far as the actual plumbing was to be routed, I took a hole saw for the flanges, then drilled and tapped directly into the tank (over 1/2" thick!) and ran a nice solid bead of RTV to seal it all up. The tank is a bit uneven for the flange so the RTV took care of that. Also put a good dollyp of RTV on the bolts and cleaned up the excess when done. So far so good.
I am surprised the 58YFs dont have the longitudinal port side tanks... all the 58 TCs do... ws

 

[yachtsmanbill]

The only concern I can see is the egg crate baffles that the fuel tanks have, seens to me a lot of material would get stuck in the baffles. Many holding tanks have been converted to fuel though.

That aux tank forward had solid baffles with good sized scuppers at all the strategic points. In the one pic posted, theres a 1-1/2" npt cap that allows for a decent look inside with a small mirror.
Dave, can you elaborate on the fuel tank baffles in the "no gas thred"? I really wanna get these tanks clean, and only do it ONCE!! ws

 

[first230sl]

Contrary to popular belief, early 1970's 48's came equipped with "holding tanks" that were not plumbed. I'll bet 58's did too!!!

In the 58YF I know of 3 fuel tanks (forward and mid keel tanks plus a platform mounted tank in the lazarette) plus two water tanks (one against the transom in the lazarette plus another one mounted under the starboard-most bunk in the mid stateroom).

I will be in shock if there is a tank I have not yet encountered - unless it is disguised by being a continuation of the mid or fwd keel tank. But I will look - and be most surprised and appreciative if I find one.

Is your port-side tank platform mounted, or integral with the hull? I will go take a look on the outboard side of my port engine. The hull area is covered with plywood for walking on and I don't think there is more than a couple inches underneath - but hey - it is worth a try.

Have any other 58YF owners found such a tank?

Take care - Murrary

 

[yachtsmanbill]

Just about the entire bottom is tankage on the 58TC... From front to back are as follows:
185 G waste /aux fuel tank
185 G potable water tank
460 G fuel tank
465 G fuel tank
175 gallon water tank against transom
PLUS the port side wing tank that runs the length of the ER minus the Gen platform and stab drives. The starboard side is a void.
This kinda shows the wing tank... ws

 

[first230sl]

Thanks so much for all the info and the picks. Looking at the way your tanks looks, I am quite sure it is not there on the 58YF. I've crawled around the various bits of the boat many hours on end and would have seen it if it was that apparent. But I will look again just to be sure.

One thing I can do is possibly get my fiberglass guy to build one in there or in the forward bilge behind the bow thruster tunnel (this time for the forward head).

Take care - Murray

 

[bigbill]

my 58yf 1972 has a holding tank under the hatch in the v berth, forward of the bulkhead that devides the genny room from the forward compartment, and a smaller one outboard of the stbd engine. bigbill

 

[first230sl]

Interesting. I know for certain I do not have the forward one you describe - and will check for the stbd one. Mind you - mine is a 1971 - maybe they only started doing this in 1972.

Take care -

my 58yf 1972 has a holding tank under the hatch in the v berth, forward of the bulkhead that devides the genny room from the forward compartment, and a smaller one outboard of the stbd engine. bigbill

 

[Dustoff44]

What is the hull number? My 1971 58 YF hull #58YF323 has both holding tanks