Fuel tank inspection

[PiratePast40]

As part of a rebuild, pulled the 22 gallon steel fuel tank out of the bow compartment of my 18' Fiberform runabout. During hand sanding of the rusty spots, noticed that some of the pits seem rather deep. Am assuming that if it passes a 5 pound, 5 minute pressure test, then it should be ok but wondering about the pitting. I have no reason to suspect there are any leaks but it does look as though there have been previous weld repairs on this tank (2-1" patches). I certainly don't want to be throwing away money on a new tank if it's not necessary but wonder how to tell the tank thickness and get a warm fuzzy feeling that it's in good shape. Any ideas?

Thanks

 

[Mark42]

Re: Fuel tank inspection

If you want to keep the boat, buy a new plastic tank. The steel tank will just continue to rust.

 

[PiratePast40]

Re: Fuel tank inspection

I was thinking the same thing in the back of my mind but wanted some outside opinions. It's just one more thing to buy. I've allready got about $2000 (and plenty of time chewing fiberglass dust) into this $500 boat. I'll take the tank to a local shop to see what they say.

If it's a perceived problem then I really don't have much choice than to do it right.

 

[PiratePast40]

Re: Fuel tank inspection

Mark,
You're absolutely right, now that I think about it, the metal will continue to erode and no new metal will magically grow back. I'm spending the money to do it right so why take the chance of ruining all the new foam, stringers, deck, and carpet with an old tankt that's allready been weld repaired once in it's life?

The next question is about grounding a poly tank. The metal tank has a ground wire going to the fill neck and then on to the battery and transom plate. The fill fitting is non-metalic so not sure what a ground wire is really doing for me. I'll go ahead and run the grounds "as found" but it doesn't really make sense to me. Any ideas as to how and why to ground a non metalic tank and fill fitting?

 

[bowman316]

Re: Fuel tank inspection

don't feel bad about putting $2,000 into a $500 boat, I bought my runabout for $1000 and paid $2100 for a new transom, and $800 for new gears in the lower unit. And with all of the other minor repairs, i prob have at least $4,000 in that boat.

But now I know it is a solid boat, with no major problems.

About to spend another 200 or so the get the impeller replaced. I could do it my self, but don't want to risk messing something up.

 

[Mark42]

Re: Fuel tank inspection

A poly tank itself does not need a ground, but the fuel sender attached to it will. Also any of the metal fittings, such as fill plate and vent attached to the hull will need grounding, even though "isolated" from the tank by rubber hose. I just went through this process installing a poly tank in my boat. A green jacketed 14 gauge wire should be run to all metal fittings and then to a ground. That eliminates the buildup of static electricity that can cause sparks and explosion. Don't forget double clamps on the fuel fill connections. Being that you are replacing a tank, the grounding and clamps may already be in place.

If the boat takes a standard tank, you can shop around for best price, but if it takes a special or non-standard tank things can be more difficult.

I ended up buying my tank from these people, they had good prices on non-standard tanks: oceanlinkinc.com

 

[PiratePast40]

Re: Fuel tank inspection

Thanks for the information on grounding. It just wasn't making much sense to ground non-metalic components. I've been looking at a few sites and my tank is pretty close to a standard size so they're available at a reasonable price.