Holding tank 40.5

[footerdog]

I am about to order a replacement tank from Triple M plastics for my Hunter 40.5. They sent me a picture but without pulling up the floorboards of my boat it does not look correct. The shape looks ok but should all of the lines be in a row? Should not the ones from the heads and to the vent enter in at the top and the pumpout be at the bottom? I replaced the lines when I bought her this past spring but I do not remember. Should I go with a single 1" vent line or two 3/4" lines with one clamshell vent facing forward and the other aft. I thought I read that here.

Thanks

 

[Rick D]

You will find that there is no room for top entry fittings. Be aware replacing the vent line (on mine) is a huge PITA. I was going to and then left it alone. Actually, it was larger than I thought. If you are up to it, at least smooth bore hose would be good, but then an upgrade in size would be in order. Maybe someone else has gone up to an inch; let's see.

 

[Rich Stidger]

Yup, like Rick D. sez, replacing the vent line is a PITA.

However, I did replace mine and I went up to a 1" line when I installed my new tank from Triple M. I had them provide a 1" threaded hole for the vent in the tank instead of the original smaller size.

You have to work the replacement through the electrical panel and you need a hose barb to threaded thru-hull where the fitting is a molded right angle. Clearance in this area is very small.

The picture below shows the new 1" vent in the original spot next to the aft shower sump outlet. Also shown is the right angle fitting that you need. Idealy you want a nps (straight) thread rather than a npt (tapered) thread. I don't remember if I was able to get the nps or if I just used a npt with lots of sealer.

 

[Rick D]

OK, so the fix is to get the 1" tank spec and, at worst, you can use a reducer to use the existing vent until you decide to dumpster dive to replace the whole thing properly as as Rich has, or bite the bullet and do it now.

PS: don't pay any attention to Peggy. She wants to do everything right ;-)))

 

[kebr]

That looks right. I'm glad that project is behind me. Everyone that has posted, 'if the tank hasn't been replaced, then replace it,' was right.

I used new pvc fittings and kept the existing hose. If you use standard pvc fittings, there is a special pvc adapter to marine hose that you will need. I think it went from 1 1/2" to 1 1/4" (you can see it on the end of the fittings on the old tank). I did not know about that adapter and it felt like I spent more time going back and forth to the store than I did on the project.

Good luck.

Ken

 

[Peggie Hall HeadMistress]

Hey Rick...

Phhhhhhhbbbbbttt!

 

[timvg]

You'll be amazed how much more your new tank will hold. Nothing like new plumbing

 

[footerdog]

Thanks for the help everyone, especially Peggie. I love wise asses'. The tank is the original and holds nothing, with just two of us onboard we are pumping out at the end of every weekend. Or it comes out the vent line. Gross!!! I will have Triple M spec 1" line, it will be a "fun" winter project. Can't be as bad as it was installing the new head lines. Hopefully the smells will go away with the new tank.

Thanks everyone
Frank Smith

 

[PrincessoftheLake]

I bought a new tank for my 1995 40.5 from Triple M back in 2007. They did a great job. Be aware the tank has a lifetime warranty. After two years my tank developed a small leak (I really do not believe it was a defect but was caused by the soon to be ex standing on the tank). Anyway, when I called to ask what I could do to repair the leak they insisted on sending me a brand new one. Once I got it I pulled out the old tank and sent it back. They even added extra bracing on top at my request and no charge.
You'll love it.

 

[Dennisail]

Is it possible without much hassle to temporarily bypass the holding tank so the waste goes right over the side?

 

[Rick D]

Yes

Is it possible without much hassle to temporarily bypass the holding tank so the waste goes right over the side?

For your passage, you will definitely want the option of overboard discharge. I'd be really surprised if your boat doesn't already have a Y valve on the aft head and maybe on the forward also. These were dealer-installed items, but I have not seen a California-commissioned one that did not. Your surveyor should have noted it.

 

[Peggie Hall HeadMistress]

Very easy..

Is it possible without much hassle to temporarily bypass the holding tank so the waste goes right over the side?

All you need is a vented loop and a y-valve in the toilet discharge line. Put the vented loop (don't forget the air valve for it!) immediately after the toilet as shown in the attached photo....down from it to the y-valve the provides a choice between going into the tank or directly overboard.

Don't forget the intake intake vented loop..note in the photo where it's installed and how it's tucked neatly into the "pocket" created by the discharge loop.

If you also want to dump the tank at sea, spec TWO discharge ports in the tank...this eliminates a y-valve. If you have at least 5" clearance above the tank, put all fittings on the top, with pickup tubes inside the tank on the discharges.

Maybe we oughta talk before you order anything...'cuz you seem to be just a WEE bit confused about the fittings locations, and I'm not crazy about burying a holding tank under the cabin sole. Send me an email (EMAIL plz?? NOT a PM) if you'd like some help.

 

[Dennisail]

Thanks heaps guys. The reason I am confused about the fittings is that I am on the other side of the Pacific compared to where my boat is so its hard to take a look.

I have had the pleasure of sailing it when I was there last month and wont be back until Feb. The surveyor noted "head discharges to holding tank only". So I presume this boat does not have the Y valve. Since I plan on a pacific cruise I will try to limit the use of the holding tank. When the time comes I will be sure to be in contact with you guys. So thanks!

I see many questions regarding the holding tanks on this forum. Are they a known area of problems? Also my 40.5 does not have a forward head. It has a genset there and tool room, which suits us fine.

 

[Rick D]

Well, that's pretty amazing, given that boat. If you can reach the prior owner, ask him. Regardless, it's not going to be too hard to install a Y valve and through hull. I'll show you mine when the time comes. It's pretty sanitary.

Yea, holding tanks are a problem at this age if they are original. His may not be. Check with him for info. The selling broker can help with contact. I replaced mine. There is an outfit on the east coast US who does them on a custom basis. If you get the overboard installed, you won't need a new tank for a long time even if it is original, given your destination.

 

[Dennisail]

This is what I got from the original owner.

Regarding the holding tank, it is original but as I mentioned at the sea trial, I would usually flush with fresh water vs. salt so I think there shouldn't be a problem with corrosion and I would also use holding tank chemicals which help break solids down and also limit corrosion. There is no Y-valve, think using a Y-valve in the States is illegal. Tank discharge at sea is via the macerator pump (orig pump was newly replaced last year) which discharges through a thru-hull fitting. Tank discharge in the marina is through a deck fitting via a dockside sewage pump.

Will I need an extra through hull fitting with this setup?

 

[Rick D]

Overboard Discharge

Yes, you will need a through hull. You can get a short-haul to install it after you put in the rest of the hoses and Y valve. When you get into the states, contact me and I'll show you mine since it isn't an obvious installation. I wouldn't worry about the holding tank now. You won't be using it much once you get out of the US until you get back to AU. It IS legal to use overboard discharge along the west coast, just not within 3 miles of the coast and Y valves are legal as well.

 

[bustedrudder]

40.5 Holding Tank job DONE!

Wow that was a chore.
Always replace the hoses. We were stunned how permeated the old ones were. Replaced the mascerator and rebuilt the old one as a spare. I was amazed the old one worked at all with half of the impeller blades missing and a wad of tampon around the cutter blade!
Rebuilt one head replaced the other.
Be sure to use the old hose to pull the new one through (I cable tied them together). The hose to the takeout on deck and the vent are REALLY hard to get to but it is possible. You will need an offset driver to get at the clamps at the deck.
New tank from triple M fit great! While the old tank was not leaking (yet) the PVC fittings were no longer glued together and the PO had duct taped them! Note the odor eater next to it as if it would help. If you still have an aluminum tank be aware that the pump out suction tube inside our tank had corroded which explained the copious air in the mascerator outflow and pump outs were slow.
Installed a SCAD tank monitor. We definitely love our poo level indicator!
Not a cheap project, but very necessary!
We can have friends on-board again without the shame of hose permeation

 

[Rick D]

Re: 40.5 Holding Tank job DONE!

Welcome to the 40.5 holding tank replacement owners' association (40.5HTROA). You will now hold your head up high, nose twitching with the sweet smell of... nothing.

 

[bustedrudder]

Thanks Rick!
It feels/smells great to be in the club... of which you are commodore!

 

[PrincessoftheLake]

Thanks Rick!
It feels/smells great to be in the club... of which you are commodore!

Yes, welcome to the club! Nice job, it looks great.