bertram31.com

I was hoping some one may come in who has some experience with polyproperlene diesel fuel tanks here , I have a US built Bertram 33 which needs a new fuel tank, found a whole lot of sticky tar like substance on the bottom of my tank , which some say looks like resin .not keen to put in another glass tank and the poly is a much cheaper option , and recommended by a number of installers , alternative it would have to be aluminin tank .

any help would be appreciated

Syd

Syd,

The problem with a HDPE tank will be volume. Rotocast HDPE tanks are seamless and would hold the diesel chemically, but would have no baffles. A large tank, much over 50 gallons, requires baffles.

The only way to add baffles to a rotocast tank would be to cut the top off, weld in baffles, and weld back the top. Expansion and contraction of the fuel and, independantly, the expansion and contraction of the HDPE, would break a weld. Not a matter of IF, but WHEN...

If your tank has not been subjected to ethanol laced fuel it's probably OK and the substance at the bottom is likely old gasoline residues and varnish.

I'd get some more opinions locally and even closer inspect and have tested the residue before changing out the tank...

Br,

Patrick

Pat: Has anyone explored the option of using 3 or 4 of the rotocast tanks in tandem? Just a thought. If it could be plumbed properly it might avoid the baffle problem.

Rawleigh-

I briefly looked into using poly tanks in my B31. To get any kind of capacity, you'd need 4, they wouldn't fit right because you couldn't get the right shape, and the plumbing (fill, venting, pick-ups), grounding, sending unit issues are numerous. I just put a new 225 gallon aluminum tank in my B31--looks great. I'll try to post some pics.

John

Once again I am over complicating simplicity!!

If that 33 is a diesel, I wouldn't change it. Was it ever a gasser that used Ethanol? If not, no way is the residue resin. You can have it flushed out if it makes you feel better. A lot cheaper and better than an aluminum one.

New tanks are available complete with baffles I just saw and ad in one of my boating mags. The only problem with Poly is they will stink. They let gasoline and diesel smell out. If the tank compartment is not connect to the salon then on big deal I guess. But stink will come right through the plastic.

My understanding is that they can be built with baffles, but each shape is a custom mold. They aren't easy to one-off like aluminum--all adds to cost.

sorry guys it was ATL. They make the Bladder tanks. Their new add shows tanks like Bertrams and other odd shaped tanks; complete with baffles. Not HDPE.

Why does it need a tank? Just curious. Mine was a gasser, switched to deisel and just cleaned the tank with a prof. tank cleaner. My glass tank seems to be good. Red all the way to the bottom..... some coffee grains in the filter bowls about once every 10 12 months or so. did the switch in 2006 .

I just ran across the ad for polypropylene fuel tanks.
The company is from New Zealand. They will be at IBEX in October
www.herculestanks.com With baffles by the way.