My bilge stunk like an open sewer after I pulled the factory tank out. Must have been years worth of bilge crud and fish slime down there.

Here is the link to the custom tank mfg in New Jersey.

http://www.speedytanks.com/about/index.html

Carl

Holy Crap Kev:confused::confused:
Do you think it broke apart while getting jostled out or was it like that before. I cannot believe that hole did not let gas go all over the bildge

Willy....in the first picture of the hole, it shows it as it was before we stuck the crowbar in the hole and beat up on the tank. It was big enough for my pinky finger to fit in. The reason the tank did not just empty out was that there was foam covering the hole so that it would only seep out slowly into the foam. The foam at that end of the tank and below was gas soaked but at the forward end of the tank and along the sides it was dry. There were a couple of other spots that had some signs of corrosion (all on that end) but had not broken through yet.

Based on the the quotes I have so far for $700+ for a custom aluminum tank I am thinking a plastic tank that is a bit smaller doesn't sound so bad!

My old tank had two fist sized holes in it as well as a bunch of smaller ones. I couldn't believe it.

My coworker told me it is known as "poultice corrosion". Here is an excerpt from this site discussing it:

http://ammtiac.alionscience.com/pdf/...rialEASE31.pdf

Crevice Corrosion
Crevice corrosion occurs as a result of water or other liquids getting
trapped in localized stagnant areas creating an enclosed corrosive
environment. This commonly occurs under fasteners,
gaskets, washers and in joints or in other components with small
gaps. Crevice corrosion can also occur under debris built-up on
surfaces, sometimes referred to as “poultice corrosion.” Poultice
corrosion can be quite severe, due to a gradually increasing acidity
in the crevice area.
Several factors including crevice gap width, depth, and the
surface ratios of materials affect the severity or rate of crevice
corrosion. Tighter gaps, for example, have been known to
increase the rate of crevice corrosion of stainless steels in chloride
environments. The larger crevice depth and greater surface
area of metals will generally increase the rate of corrosion.
Materials typically susceptible to crevice corrosion include
aluminum alloys and stainless steels. Titanium alloys normally
have good resistance to crevice corrosion. However, they may
become susceptible in elevated temperature and acidic environments
containing chlorides. Copper alloys can also experience
crevice corrosion in seawater environments.
To protect against problems with crevice corrosion, systems
should be designed to minimize areas likely to trap moisture, other
liquids, or debris. For example, welded joints can be used instead
of fastened joints to eliminate a possible crevice. Where crevices
are unavoidable, metals with a greater resistance to crevice corrosion
in the intended environment should be selected. Avoid the use
of hydrophilic materials (strong affinity for water) in fastening
systems and gaskets. Crevice areas should be sealed to prevent the
ingress of water. Also, a regular cleaning schedule should be
implemented to remove any debris build up. Table 3 provides a
brief list of guidelines that can help minimize crevice corrosion.

Hi Whale,

I spent alot of time looking for a ready made plastic belly tank and didn't find any of them to be satisfactory. What I found was that the angle of the V20 deep V hull was about 22 degrees and all of the available ready made plastic belly tanks had a bottom angle of about 13 - 15 degrees. The ready made plastic belly tanks were Todd or Moeller. The angle of the tanks belly made it that the largest ready made tank that would fit below the floor was 29 gallons. All of the larger belly tanks would have the top of the tank above the floor. How I checked that was by getting the exact dimensions and angles of available replacement tanks and the exact dimensions and angles of the tank well in my V and did an installation simulation on my computer.

Schools suggestion about tank sealer is I think a good one. I called Por 15 about their sealer and found out that their sealer was ethanol proof. They guaranteed that if the tank was prepared properly internally (cleaning & etching) the sealer would permanently adhere to the inside of the tank and the tank would not be affected by ethanol. Por 15's website has full instructions as to how you clean, etch, and seal fuel tanks. The sealer is a tried and true process and has been used in antique car restoration for years. Where do you buy a new exact replacement gas tank for a 1910 Franklin?? Another company that puts out a similar product is KBS Coatings. The cost to fix holes in the aluminum tank and to clean, etch and seal it with sealer would be about $150.

Just my $.02

Geek

http://www.kbs-coatings.com/index.aspx?AFID=7
http://www.stoprust.net/Fuel-System-p-1-c-8.html

Whale, I had a plastic tank custom built in '04. Used the exact dimensions of the original tank as supplied by Florida Marine Tanks (who make or made aluminum tanks), which were 44" L x 31" W x 11" H (I left out the fractions). Sent them to Triple "M" Plastic Products in Maine, got a quote and had them build it. Here's a pic of it:
http://www.wellcraftv20.com/gallery/...d=P9240525_001

The tank, including a fuel gauge sending unit, was just under $500 not including shipping. I still have the drawings, if you want I can fax them to you, or try to e-mail them if I can figure out how to use my boss' scanner. ;)

That is PLASTIC? Wow, looks good! Besides my transom I can't think of any other item that I worry about more besides the gas tank. Either one could ruin your day.

These guys have one that will fit perfectly, but they won't sell it to you.

They only sell to boat manufacturers.

http://www.incaproducts.com/site/fue...atvbottom.aspx