Polyethylene tank for diesel

aj1976 · #1 03-12-2010, 04:25 AM

Hello all, I just bought an '85 Sceptre powered by a volvo 165 diesel engine. After pulling the 100 gal aluminum fuel tank, I discovered that it was pitted and holed. I'm going to have it replaced and was wondering how a plastic polyethylene tank would work out in lieu of having another aluminum tank made. Having an aluminum tank made in hawaii will cost upwards of $1000. From what i've read, poly is non corrosive, very durable, and about half the cost (or less) of aluminum. Sounds too good to be true. With the diesel engine, I don't need to go as big as 100 gallons. I would need at least 60 gallons but can go as high as 90 gallons with the new tank. I just haven't heard of anyone using poly tanks for diesel applications. Is there a reason for that? thanks in advance. The new tank would be mounted underneath the deck where the old tank sat.

aj1976 · #2 03-12-2010, 04:53 AM

Almost forgot, here she is. She's in pretty good shape but just need to tie up some loose ends here and there and get her ready for summer.

Islandtrader · #3 03-12-2010, 10:12 AM

Quote:

.... and get her ready for summer.

I thought you guys had SUMMER all year round

cdavisdb · #4 03-12-2010, 11:12 AM

Looks like a fabulous rig.

I don't know how bad the pitting/holes were in yours, but if they were small and on the outside, you have another alternative, fixing the old tank.

I had similar problems when I pulled a gas tank 13 years after installation, lots of deep pits and a couple of holes that showed up after we sand blasted it. All the damage was from corrosion on the outside of the tank. We filled the holes and pits with epoxy/cabosil and put one layer of glass cloth/epoxy on the entire tank. Sold the boat 8 years later with no further problems. Note: I never inspected it again, so don't know if any problems were beginning to develop.

Blue_Heron · #5 03-12-2010, 02:18 PM

I agree with Connor. I have an older action craft with a leaky tank. My plan for repair is pretty much as Connor described. Did this with a corroded tank in my Seasquirt about 15 years ago and it held up fine for as long as I used the boat. I also plan to laminate the aluminum tanks for my 25 Seafari before reinstalling them. They don't leak yet, but they do have some corrosion on the bottoms that I want to keep from deteriorating further.
Dave

MasterBaiter · #6 03-12-2010, 02:23 PM

Before alcohol there was a 2 step coating I have used for fuel tanks. The first step was an etching then after drying you put the coating in and let dry. It seals holes and rust.

The reason I siad "before alcohol" is I don't know if there is any affect with the new fuels.

aj1976 · #7 03-13-2010, 02:23 AM

thanks for the replies everyone. I would definitely rather repair then replace the tank. It seems I am having trouble finding a platic tank that would fit as the tank I have right now is only 10 inches in height not including the pickups which only add another 2 inches. Here are some pics of the tank. Can it be repaired? Thanks again.

Fr. Frank · #8 03-12-2010, 07:55 AM

The polyethylene will work fine. I have a Ford truck with a factory poly tank. Make sure the tank is well fixed in place.