Head system rebuild

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Oct 15, 2009
18
Ohlson 38 Sloop Marion, MA
After sailing our new-to-us boat this year, I think I have found some issues with the head system (smell).

The previous owner never used the holding tank he had made for the boat. he used the WAG bag instead. Now if I could get the wife to use them too, we wouldn't have a smell from the head system. Head is a baby blake (kick ass head btw!)

Here is a diagram of the head. Right away I notice a problem with the hose from the valve to the holding tank going uphill (exagerated in the drawing). I would think, to me anyway, it should be level or downhill into the tank. The vent goes straight up and out the side of the boat through a fuel tank vent, pointed aft. Also the pump out hose, at the bottom of the tank, will fill to the level of the tank, possibly contrilbuting to the problem. (I know the photograph doesn't have a hose from the head to the valve, it was still being worked on)





What I am thinking of doing is:
* move the valve up, level or higher than the tank.
* new hose from valve to tank input
* new hose from head to valve
* soft couple a section of pvc from the tank output to above the tank; hose from pvc to pumput (or just new hose)
* add another (2nd) vent line (through hull?? fuel vent again?)
* switching to trident 102 or poly-x hose

Comments, suggestions?

Thanks

Paul
 
May 6, 2004
916
Hunter 37C Seattle
Paul i think your diverter valve is in wrong spot, it should be before the loop, so you pump into tank without going up and over the loop. I also like the system where everything goes to the tank and the overboard discharge is from a tee in the deck discharge hose. if you put a marcerator in after the tank, then you can go down to 1" hose after the marcerator and 1" vented loop between macerator and thru hull.
 
Oct 15, 2009
18
Ohlson 38 Sloop Marion, MA
look a bit closer, the diverter is before the loop, which is for the overboard dump. the other side of the valve goes directly to the tank without a loop.

Also remember in the photograph above, the head to valve hose is missing! Look at the diagram
 
Dec 2, 1997
8,915
- - LIttle Rock
I think you're on the right track with your planned mods...

* move the valve up, level or higher than the tank.

I think that's a great idea! And I would put the loop ahead of the y-valve, so you only have to pump the toilet long enough to push bowl contents over the top of it...then gravity can get it the rest of the way. That solves a lot of problems...and your toilet is certainly capable of pushing bowl contents over the top of a loop at least 4' above the bowl in the dry mode. And btw...if you haven't priced a Baby Blake lately, I think you'd better be sitting down when you do...'cuz at the current rate of exhange it's about $5700!!! http://www.mailspeedmarine.com/toil...-taylors/baby-blake-deluxe-toilet948403.bhtml

* new hose from valve to tank input
* new hose from head to valve

If you've confirmed that those hoses are permeated. Or, if they're so old that they've become hard and brittle.

* soft couple a section of pvc from the tank output to above the tank; hose from pvc to pumput (or just new hose)

You can just run a piece of hard PVC from the tank discharge to the top of the pump, then switch to hose for the rest of the run.

* add another (2nd) vent line (through hull?? fuel vent again?)

We prob'ly need to talk about that a bit...where to put it...diameter...etc. If you want to send me a PM or better yet an email (just click on my name above my photo here), we can pick a day and time to get together on the phone.

* switching to trident 102 or poly-x hose

Go with Trident 101... or 102 if you just have to have white...101 is about $2/ft cheaper from the online store here. There's never been a single reported odor permeation failure of either one...so I don't see any need to pay extra for the Shields.
 
Oct 15, 2009
18
Ohlson 38 Sloop Marion, MA
* move the valve up, level or higher than the tank.

I think that's a great idea! And I would put the loop ahead of the y-valve, so you only have to pump the toilet long enough to push bowl contents over the top of it...then gravity can get it the rest of the way. That solves a lot of problems...and your toilet is certainly capable of pushing bowl contents over the top of a loop at least 4' above the bowl in the dry mode. And btw...if you haven't priced a Baby Blake lately, I think you'd better be sitting down when you do...'cuz at the current rate of exhange it's about $5700!!! http://www.mailspeedmarine.com/toil...-taylors/baby-blake-deluxe-toilet948403.bhtml

* new hose from valve to tank input
* new hose from head to valve

If you've confirmed that those hoses are permeated. Or, if they're so old that they've become hard and brittle.

* soft couple a section of pvc from the tank output to above the tank; hose from pvc to pumput (or just new hose)

You can just run a piece of hard PVC from the tank discharge to the top of the pump, then switch to hose for the rest of the run.

* add another (2nd) vent line (through hull?? fuel vent again?)

We prob'ly need to talk about that a bit...where to put it...diameter...etc. If you want to send me a PM or better yet an email (just click on my name above my photo here), we can pick a day and time to get together on the phone.

* switching to trident 102 or poly-x hose

Go with Trident 101... or 102 if you just have to have white...101 is about $2/ft cheaper from the online store here. There's never been a single reported odor permeation failure of either one...so I don't see any need to pay extra for the Shields.
Yup, well aware of the Blakes value! Even have an entire spare baby blake system the previous owner removed (still in good condition). Even the spare seal kit is $300 alone! On a side note, the previous owner put a Taylor propane cooker in (also about $5-6k) and I have a spare cooker too!

back on topic :)

So you want the loop before the valve, so it will go by the valve going into the tank, or overboard. Right now the loop is only used when being dumped overboard. Not sure what it gains me, but isn't hard to do, so it is pretty much moot.

On the hose replacement. I figure, I got a $6000 head, whats $50 in hoses :) If I take a hose out, it ain't going back in!

Actually defender has a decent buy on the 101 and 102 hoses at the moment ($7.81/ft) as well http://www.defender.com/product.jsp?path=-1|51|106370|315126&id=336246 .

On the bottom of the tank, is a cpvc (grey, I assume it is cpvc) 1.5" barb 90 going up, with 1.5 hose going to the deck pump out. How can I connect pcv to the barb connector (which is why I was thinking of a soft couple connection)? I guess I could just use the hose instead of pvc. In my mind (could be wrong), logically, I think the solid pcv would have the best chance of being smell free longer than hose.

The vent is (I believe) 5/8, going straight up (couple feet) to the highest point on the hull, then 90'ed out the side of the boat, using a fuel vent pointed aft. I have a hard time imagining this would give the tank enough ventilation. TRUST ME I HATE the idea of drilling another hole in the hull!! This was the first season after the boat was fully awlgripped! The thought of a drill on the hull sends a chill down my spine!

I think the only real variable is the venting.

Personally, I think the BEST solution is using the PETT WAG bag. This is what the previous owner used to liine the head, use it, tie it, bag it, toss it. Done! But the wife won't hear of using it! Oh well.
 
Oct 15, 2009
18
Ohlson 38 Sloop Marion, MA
Here are some more pics of the system if it helps.

You can see how the output of the valve goes uphill.

I think I have the system design, the only question is the vent







 
Dec 2, 1997
8,915
- - LIttle Rock
If the black hose in the next to bottom photo is your vent, the horizontal loop needs to go. Ideally the vent should be at least 1" ID, straight as an arrow, horizontal--or at least a rise shallower than 45 degrees and no more than 3' long. But your tank location makes that impossible. Since you don't want to put another hole in the boat, that rules out a second vent to create some cross ventilation (which might not be the answer anyway)...so about the best you can do is straighten out the line and replace the thru-hull with a bulkhead fitting and clamshell cover. But it would be helpful if you could increase the diameter.

Keep a close eye on the welds in your tank...'cuz urine is socorrosive that, on average, a metal--ANY metal, even 316 stainless--waste tank will start to leak at a seam or fitting within 2-5 years and turn into a colander in about 10 years. Since yours have never been used and since your season is short, you should be able to maximize the tank lifespan if you're religious about rinsing it out very thoroughly before you store it each winter. Or...convert it to water holding while you still can and replace it with a good quality plastic tank.
 
Oct 15, 2009
18
Ohlson 38 Sloop Marion, MA
If I do replace the vent line and thru-hull with a clamshell cover.. which way should the open end of the clamshell go - forward or aft? The boat is on a mooring, so it will usually point into the wind.

I had the same thoughts about the holding tank being stainless steel. The boat is a 1968, there was no holding tank originally. The previous owner had the tank custom made to fit into the cabinet. Not sure if I could find a plastic tank to fit in there. Are there suppliers that can custom make plastic holding tanks?

How about this for thinking outside the box.. could the inside of the tank be coated with one of those fuel tank sealer coatings? Or would the tank contents/chemicals be too much for it as well? this is one company that sells this product http://www.kbs-coatings.com/Gold-Standard-Tank-Sealer_p_7-30.html

Not to make the system more complicated. Can I 'Y' off the tank output and put a valve by the throughhull so I can dump the tank overboard? I can directly dump the head overboard, it would be nice to dump the tank overboard (of course when legal to do so)
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
Paul, while Peggy may have different thoughts about this, when I moved up to a 1.25 vent hose, I used a regular thru-hull mushroom fitting. But, as she sumizes, is that plastic-hose-turned-black your vent? Mine goes downhill (to the original thru-hull hole) and exits half way between the waterline and toerail, so water backing up into the tank is not a concern. The size of it, and not having a clamshell, allows a hose to be stuck in and flush the vent. Since blocked vents are so often discussed here, I think this was a good idea. It works as planned so far.
 
Oct 15, 2009
18
Ohlson 38 Sloop Marion, MA
Paul, while Peggy may have different thoughts about this, when I moved up to a 1.25 vent hose, I used a regular thru-hull mushroom fitting. But, as she sumizes, is that plastic-hose-turned-black your vent? Mine goes downhill (to the original thru-hull hole) and exits half way between the waterline and toerail, so water backing up into the tank is not a concern. The size of it, and not having a clamshell, allows a hose to be stuck in and flush the vent. Since blocked vents are so often discussed here, I think this was a good idea. It works as planned so far.
Yes that black hose is the vent line. Straight up from the tank, the bends,out through a fuel tank vent, pointed aft.
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
Okay. In the next to last picture the vent hose droops down. Your "straight up from the tank" makes it look and sound like it does not come off the top- like it should? In the bottom picture we can't tell which hose is the vent line, but I'm assuming it's one of those two. In either case, it must get back up to the top of the tank to a vent fitting? WAY to much hose, Paul. Can you come off the top of the tank and take it horizontally as Peggy said, over to exit the hull? That IS the holding tank in those pictures, isn't it?

By the way, unless you prefer the neatness-look, usually you'd want to orient the doubled hose clamps so the screw of one is opposite the other.
 
Oct 15, 2009
18
Ohlson 38 Sloop Marion, MA
The vent hose comes off the top part of the tank, horizontally, like the input hose you see in the second picture.

I didn't engineer the system, just trying to make it work better. If I had it my way, we wouldn't be using the tank at all. I think the PO had it right, line the head with the wag bags and toss it when you get ashore. Worked for him for 20 years he owned it!

I know it is best to put a new fitting through the hull to vent it. I just can't get myself to drill through a brand new $20,000 awlgrip paint job. It may be the best thing to do for the holding tank, but I might have to wait to drill a new vent line.
 
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