Custom holding tank

[Colin]

I would like to increase the capacity of the holding tank on my Hunter 335. I cannot find one that exaclty fits my requirements so I am considering making one out of 316 stailess steel. I have the reourses to do a professional job of this project. Are there any problem with using stainless for such a purpose other than the additional weight?

 

[Peter]

Problem

Colin, I recommend NOT using a metal even 316 stainless holding tank, and I believe Peggy will say the same. Urine is a highly corrosive material and will likely eat through the welds in 5- 10 yrs. The additional weight is not the problem. I believe that this area has been discussed quite a bit in the archives, have a look.

 

[Peggie Hall/Head Mistress]

Peter is right...any metal is a bad choice

Check the Ronco Plastics catalog (link below). Surely there's one among their more than 400 shapes and sizes that will fit the space.And it's a tank that fits the space, not an exact match for your existing tank, that you want to look for. Since there is no top or bottom until the fittings go in, and you get to specify where they go, the drawing can be oriented in any direction...even standing on an edge if necessary, as long as the sides are well supported.If you can't find on there, the only other viable choice is a welded plastic tank.

 

[Fred Ficarra]

Shop for a rubber, collapsible tank.

We have been using one of those collapsible rubber tanks since the 80's. The size (when full) might be a problem for some apps but it is a choice that lets you stick a tank almost anywhere and then let the installation compartment dictate the final shape, keeping in mind that the compartment must be able to survive the loads, if any and have no sharp edges. Ours works under the v berth on our 34 so it is held by frp.

 

[Ken]

Stainless Holding Tank

I had a new Stainless holding tank built on aPearson 35 I used to have.Lasted less than 2 years, waste ate right thru it. Wouldn't do it again!!Use Plastic!

 

[Colin]

Thanks a bunch!

Was all set to make a stainless tank.....real glad I asked you guys first. Think I will look into the welded plastic option. Thanks a bunch!

 

[Peggie Hall/Head Mistress]

It's a rare bag that doesn't stink

Not necessarily inside the boat--although there's plenty of potential for that too--but out the vent. Reason: bladder tanks are designed to hug the contents, expanding and contracting with the volume...therefore no air space to keep the content aerobic. And when organic matter turns anaerobic ("septic"), it stinks!