galvanized steel in gas tank

[forestb]

I have a plastic gas tank that hangs under my bed. The bottom of the tank is bowing upwords in the center but not around the edges. I want to put a pole inside to give it back it's original structure. What I was thinking of doing is putting a galvanized steel tubing inside the tank and coating it with the sealer that you use to line the inside of the tank. I can not find the reason I have this problem. It is vented and when I take off the cap it does not change and it does not get squeezed from the sides.

[Blue666(2)]

Have you checked the tank when it's full of gas? If the tank bottom flattens out as the weight of fuel increases, then you are still getting full volume. If the bow remains after you have fully filled, you have lost some volume to the bow area. Is the volume loss enough to be of real concern?

Inserting a prop to keep the tank in the original shape presents other problems like interference with the fuel sending unit, sharp edges that could cut the plastic tank from inside or just coming loose & causing problems.

[forestb]

It does not flatten out when the tank is full. It probably has a 3 inch depth/height at the center. The tank is so large that it does not hurt its capacity that much but it bugs me to know that it is there. I have tried pushing down on the bottom from inside the tank and I could not get it to flatten out that way. Maybe I just need to get over it and leave it be.

[PGSigns]

It will not ever flatten out. I have seen a couple tanks do this and it seems it is from the plastic aging and the reaction to the fuel over time. Happened with a couple of the cheap racecar tanks.
Jimmy

[forestb]

Originally Posted by PGSigns

It will not ever flatten out. I have seen a couple tanks do this and it seems it is from the plastic aging and the reaction to the fuel over time. Happened with a couple of the cheap racecar tanks.
Jimmy

Do you think I should be concerned with the over all structural integrity of the tank. It is a Jazz fuel cell and it is being supported by two straps going front to back and 2 going side to side. It is not at all brittle or dried out.

[Blue666(2)]

The plastic tanks on lots of new cars just have two straps.

[PGSigns]

We had one crack in a mud truck in the 80's but other than that I have not seen on split. We used RCI fuel tanks in all the cars I have had or built because I liked the sizes they offered and I always ran there belts.
Jimmy