UniSeals

[Time2Go]

Hi Friends,
Planning on a installing a new holding tank
and plan on using UniSeals instead of traditional thru tank fittings.
All fitting will be on the top of the tank.
1 vent
1 input from head
2 outputs via dip tubes (deck pump out & macerator to thru hull)
What has been your experience with UniSeals? Good Bad Ugly
I also plan on mounting the macerator below the tank so it would have
to draw the waste up the dip tube and then down and out.
It would be more simple to put an outlet on the bottom of the tank
but have herd horror stories if there is a malfunction. Comments and any
advice greatly appreciated
Cheers
Neil

[rslifkin]

I've got Uniseals in the top of the tank for all of the fittings on my holding tank. I put the current tank in ~3 years ago and haven't had any issues. The dip tube pumpout is my preference, as it avoids hoses that are full of waste and could dump the tank into the bilge if something fails.

[peghall]

Uniseals are essentially rubber grommets. So 'twould be a good idea to order the Uniseals on the phone instead of online, to make sure you drill the right size holes for the outside diameter and buy the right size Uniseal to fit. They're very helpful folks. Phone number is on their website. UNISEAL

It's also a good idea to follow ALL the instructions if you don't want any leaks....starting with, make sure none of your hoses pull to one side.

Why does the macerator pump have to be mounted below the tank? Jabsco macerator pumps can lift up to 4'.

--Peggie


(Why does this forum software have to turn double spaces between paragraphs into 4 spaces? It's really a pain to have to edit every post to shorten it.)

[Time2Go]

Hi Peggy and RS
Thanx for the info
The pump will either be below the tank or offset sideways
a bit but still way lower than the top of the tank
Due to space limitations
The tank is above the waterline so am not sure
if a vented loop is needed to connect the macerator
to the thru hull
Adding a tank to a mid 70’s boat which was built
with no holding tanks just direct out
Cheers
Neil

[peghall]

You shouldn't need a vented loop if the tank is entirely above the waterline.

If you haven't ordered the tank yet, you could also eliminate the macerator pump by putting the overboard discharge thru-hull IN (NOT at) the bottom of the tank. However the fitting would have to be a spinwelded hose fitting...Uniseal is not recommended for use at OR in the bottom of a tank. a proper thread-barb hose fitting wrapped in plenty of Teflon tape shouldn't leak.


If you haven't already bought or ordered a tank, Ronco Plastics is your best source. They make TOP quality thick-walled (50% thicker than most other mfrs) water and waste tanks for a very reasonable price and have more than 400 shapes and sizes, over 100 of which are non-rectangular, and they install fittings--including diptubes--in the sizes and locations specified by the customer when they make the tank. There are retailers who sell Ronco tanks, but Ronco sells direct for a much lower price...and they're great to work with.



--Peggie

[ranger58sb]

Originally Posted by Time2Go

Hi Friends,
Planning on a installing a new holding tank
and plan on using UniSeals instead of traditional thru tank fittings.
All fitting will be on the top of the tank.

No experience with Uniseals...

Because I was able to buy our replacement tank from Ronco (see Peggie's note) with all the correct fittings already installed... top of tank, with diptubes... where I wanted them.

The spinweld fittings can be either inside (in case of clearance issues) or outside the tank, they'll supply the diptube... Bob's Your Uncle.

-Chris

[malbert73]

Ronco is great. My solution is to have the exit at bottom of tank (makes complete emptying much more likely than a dip tube) but I used PVC pipe and fittings to create an external standpipe up to top of tank which then connects to the hose. So standing sewage is only in tank or PVC pipe.