Formula 233 fuel tank questions

Shepman

Newbie
Oct 4, 2019
3
0
52
Mountain View
Name
Mark
Boat
Bahia Mar
Bloody Deckers I have a survivor 1974 Formula 233 Fisherman long deck boat in pretty much stock condition. It has twin 165 Mercs with Alpha 1 sterndrives. I bought it out of a storage lot. It's history is unclear as the previous owner had passed away. It's now at the mechanics getting a full service on the motors and out drives. I haven't even had it in the water yet but am excited as I've seen plenty of the Australian videos on youtube showing these boats in action. I live in northern California where ocean conditions can be challenging. The original fuel tank has been removed, a new one is going to be fabricated and installed with all new fuel lines, filler and vent hoses. The tank was foamed in and is obviously wet and trash. That will come out leaving a bigger cavity. I'm hoping to maximize this space with a slightly bigger tank. Here's my question; what is the best way to install the new tank? I've heard various solutions, coal tar it, put rubber gym mats down below, weld tabs to the top that bolt into the stringers, etc... As this is now in progress I need to finalize the plan and move forward. Looking forward to hearing your suggestions. Thanks!
Formula 233.jpg
 

MATTANZA

old man of the sea, in training.
Aug 23, 2004
5,694
3,315
Cali the state of confusion, the state of shock
Name
RICK
Boat
Boston Whaler 25' Outrage "MATTANZA II", 34' Radovcich "AMY ANNE" {when it needs to be fixed}
get a moeller plastic tank , if you can find one that fits right. i'm getting ready to take the tanks out of my whaler{maybe}. they're the original aluminum tanks, fomed in, from 1981. they don't leak. i have to remove my console , so i'm going to pull up my decks , and check my tanks. if they're bad , i'll go plastic . easier to install , lighter weight, and the won't corrode .
 

Shepman

Newbie
Oct 4, 2019
3
0
52
Mountain View
Name
Mark
Boat
Bahia Mar
Thanks for the reply. I looked at plastic tanks but could not find one that fit my dimensions. I came across a 60 gallon tank but that is smaller than the stock 85 gallon. I definatley want all the fuel I can get. I have someone who will make the stainless tank, I'm just trying to figure out the best way to install it when the foam is removed.
 

Day0ne

I Should Upgrade My Account
Dec 24, 2004
1,033
493
74
Texas
Name
David
Boat
233 Formula Shadowdancer
Great hull, love my '67. You should be able to get over 100 gal in there.
 

alex88

Member
May 15, 2006
908
174
40
Oakland
Name
Alex
Boat
2003 Robalo R235
All of the above, epoxy the tank, 5200 strips of neoprene rubber on the bottom for wear protection and air gap so no water can sit against tank and tabs to hold it in place.

My 2003 Robalo factory tank is like this except for being coated and I can’t see a bit of pitting anywhere, just a good even oxide layer
 

sickcat

Silverback
Aug 5, 2003
3,513
1,549
64
LA
Name
Kerry
Boat
Yellow spot
Why stainless?

I thought for a minute about stainless for my new tanks but IMO you really don't gain much except a little extra weight. The welds with stainless would be the corrosion concern. I'm going aluminum, stripped and coal tar epoxy.