Classic AquaSport
Aquasport Mechanicals - things that need a wrench, screwdriver or multimeter => Fuel tanks and anything about fuel systems => Topic started by: CThomps on May 20, 2010, 01:13:47 PM
-
Installing a new fuel tank on my '85 200 Aquasport next thursday.
The old tank is already removed and I have the new tank and hoses.
The strapping from the origianl tank was unuseable
What is my best option for strapping down the new tank?
Aluminum straps? Where can I get those?
Band it? That's stainless but I can run it through clear tubing.
Stainless steel hose clamps? I can get those really long at a local supply store. I can double them up if necessary and run them through clear tubing. But will the clamps slowly unscrew or will the hold permanently? The clamps would be the easiest option.
Nylon straps? I don't like that idea much.
Thanks in advance.
-
http://www.yachtsurvey.com/fueltank.htm (http://www.yachtsurvey.com/fueltank.htm)
-
JJ as usual gives great advice. David Pascoe is a nationally-renowned marine surveyor, based in So-Fla.
His discussion on any subject is worth note.
-
The only thing that article said about straps was to make sure they don't cause crevice corrosion. That's understood.
Anyone else? I'm leaning hard on the super long hose clamps.
-
Anyone else? I'm leaning hard on the super long hose clamps.
FWIW,
I made aluminum brackets for mine but my mounting situation is slightly different than yours.
-
I'm with Bob, I'd use aluminum straps with neoprene beneath. Go to the metal yard and buy some strips....about 40 cents a pound.
-
But how would the straps attach to themselves if using aluminum strap? I think i'm jsut having trouble visualizing this.
With the stainless hose clamps I was thinking i'd run two of them side by side through clear plastic water tubing with the top of the tubing cut out where the clamp would fasten on top of the tank. That way there would be no metal on metal contact and no water holding materials used at all.
-
The only thing that article said about straps was to make sure they don't cause crevice corrosion. That's understood.
Anyone else? I'm leaning hard on the super long hose clamps.
What I got is that if you do it his way it doesn't need straps.
The 5200 is so strong and will create so much suction that you not need any other method of securement. Don't worry that ballooning of the tank will break the seal. The weight of the fuel in the tank will pretty much hold the tank in place.
-
CThomps,
The straps are just that, straps across the top to hold the tank down, in place. Not necessary to join to itself, sorry you misunderstood. You could run three across, (2 inches each in width or so ) screwed solidly to the vertical coffin sides, a few inches below the top of the tank. MAKE SURE to use a minimum quarter inch thick neoprene strip between the strap and the tank, as a chafe-guard, and corrosion guard, if choosing this method.
Or, you could go with Pancoe's recommendation. He's no dummy. Only thing I'd throw in, would add some wooden/nylon stops, hold-downs, chamfered on the top to fit to the tank, and placed strategically every foot or so to hold the tank in place, from the top. Have a dozen or so of them made and pre-drilled; Bed the tank per his method, and set the stops/hold-downs as applicable. Make sure that you take into account the height of these stops, when finally bedding down the cockpit sole.
One final note, DO NOT use treated lumber anywhere near aluminum. The copper napthamate interacts with the aluminum as a catalyst, and corrodes/destroys the aluminum. No question that the aluminum boat manufacturers in the 80's and 90's wished they had this hindsight, as their transoms back then were made of treated pine.
Your idea of the long stainless hose clamps? Its just that, its a hose-clamp, and its Chinese-stainless. It's stainless barely. Set in the hoses as you suggest, will hold water, and will rust out quickly.
Post to us your thoughts/decisions.
Tx.
-
I followed the advice of that article on my tank install. I disagree with using stainless fittings. They will still react with each other and cause corrosion. aluminum fittings would be best. Brass would be the next choice. You can see how in installed my fuel tank here:
http://classicaquasport.com/smf/index.php?topic=4460.0
I used aluminum straps that are insulated from the tank with clear tubing.
-
Now there you go....nice work!
-
Just MHO when I installed my new tank in my 86 AS I followed David Pascoe advice 100% but I also used giant plastic ties to hold it in place while the 5200 dried,my leak was caused by the stainless strap from the factory.
-
ANYTHING that traps just a little bit of water will cause crevice corrosion. Same reason you can get a little rust stain on a hatch hinge around the screws. Check back under that clear tubing in a couple of years.
-
Good thinking/input from the board. CThomps, you posed the question.....what have you decided?
-
I've been so busy with work i've about run out of time. If Industrail Marine Supply has aluminum strapping i'll go with that.
If I run the SS hose clamps they will be run through the clear water pipe and the pipes will be open ended. So they wouldn't hold water so the hose clamps won't rust. At the top of the tank where the clamp will attach I can cut the top out of the clear hose so that there is still a buffer. The original straps were band-it type SS straps
and they lasted 25 years. They would have lasted longer but foam strips placed in between the strap and the tank had worn out. I can't imagine clear plastic tubing will wear out.
Where the tank rests is typical of other 20' aquasports. It sits in thin fiberglass craddle. There are two sets of holes equa-distant apart through which the straps can be run. Because of the fiberglass craddle I don't think glue plastic strips to it is an option.
I could always run nylon ratchet straps through the tubes. The tank is 60" (ish) in diameter. I fear the ratchet itself my be bulky at the top of the tank. But I could possibly move it to the side.
FOAM: I'm planning on using a small amount of foam in several spots just to act as a cushion. Closed cell foam is obviously the way to go. In using foam is there anything else I should be weary of?
Thanks for everyone's input by the way.
-
Do not use ANY foam. Even closed cell will allow water to wick between the tank and the foam. I used closed dell foam on a tank in another boat and it corroded where the foam was BAD. Remember it's ok if water gets on the tank. It just has to have a way for air to get to it so it will be able to dry out. So anything that holds water trapped against the tank will cause crevice corrosion. The vinyl tubes I used under my straps is slit open lengthwise to allow any water that get in the tube with the strap to get out. There is no perfect tank install since there has to be some trade offs.. Do you really need your tank to last 30 years?