Change of storage tank use - diesel to gasoline

C

Castaway

New member
Perhaps someone here will have had some experience with this.

I have a fuel storage tank, with a capacity of 125 gallons. Until now, it has been used to store diesel fuel. I want to use it for gasoline. In its past life, the tank sat at a construction site where it was used to refuel an excavator. It would get refilled from a tank truck. Where it is now, it will remain stationary. It will be refilled from a fuel barge.

The tank has about half an inch of diesel covering the bottom, to that means there's probably a couple of gallons I'll have to get rid of by perhaps tipping the tank to it runs to one spot where I can siphon it out. The tank has a mounted hand pump, and all the fuel the pump can reach has been removed.

My question is, once the tank is essentially dry, can I simply fill it with gasoline, or must (should) I endeavor to clean out the tank to remove any diesel residue? The tank has one of those large cartridge-type fuel filters on the hose, and I can still see diesel in the plastic cylinder. I'll dump that and insert a new filter.

I have read that a diesel tank can be washed out with water and TSP (tri-sodium phosphate), but then getting the interior to dry can be a problem, although I understand that denatured alcohol can help. Should I go that route, or will I just create work for myself and open the door to unforeseen problems associated with putting water and cleanser in a tank designed to hold fuel?
 
One point--diesel filters and gasoline are often not complatable. I would replace the filter, with a specific Gas filter.

Will you keep it full? Will you have E 10 or E 15 fuel? Is there any rust in the bottom of the tanK--how about algae? I suspect that a few pints of clean diesel in 125 gallons of fuel will not do any harm--assuming that the fuel is well filtered before going into the boat tank.
 
Hello,
When I was younger I hauled gas and diesel in a 8000 gallon aluminum tanker. After hauling diesel we were always told to load the first gasoline very slowly into the tanker as it was said it could become a very volatile situation to dump gas full force after hauling diesel into an empty tanker. I don't know if it had to to with the aluminum or not. Just an FYI
D.D.
 
It is okay to run gas through a diesel filter but, not the other way around. Gas will break down the glue used in most diesel filters. Not sure why they don't make them all multi-fuel. As for the remaining diesel I would most likely add 5 gallons of gas to it and then drain that before changing the filter. If you have rust and sediment in the tank, give it a day to settle before pulling any fuel out. The new filter should catch any solids on the move after that. Take these suggestions how you like, I'm no expert. Just a lot of years on the farm.
 
On more than one occasion I have had to empty out diesel from a cars gas tank to put in gasoline. We never worried about completely draining the tank. We simply got as much out as we could by siphoning it out, then filled it back up with gasoline. The car might have smoked a little for the first tank full. But after that it was fine.
 
I had a Racor diesel filter plug up yesterday when I was filtering gas through it. (I also had thought that you could run gas thru a diesel filter). Learned the hard way, when some mechanic put a gas filter on my diesel RV and it started rapidly loosing power. Racor differentates between the gas and diesel filters.
 
Thank you gentlemen for your replies and suggestions.

C-Brats are sure a learned and helpful group, even when it comes to someone like me, who is simply an aspiring C-Brat. Sadly, I was not able to get off our island to attend the CBGT in Nanaimo this past weekend. I sure hope it'll he held again next year and that my family will turn up in our own C-Dory. It sounds like it was a wonderful event, despite the desert heat.

thataway, thanks for the tip about gas-specific filter. The gas will be E zero. Here in British Columbia, gas with ethanol is available only at Mohawk stations, which sell E 10. I understand the government of B.C. intends to require all gas sold in the province to be E 5 sometime in 2010. It's hard to get a good look, but I suspect there's a small amount of rust on the bottom of the tank, but I don't think algae is a problem. The tank won't be kept full. It will probably get down to about 1/3 full before being refilled. Do you think a fuel stabilizer should be employed?

dave d, I'll keep in mid what you said about volatile situations. I would prefer not to be the one who has an accident that starts a forest fire here.

ramos, I think you have confirmed for me thataway's suggestion about obtaining a fuel-specific filter. I'll make sure that I ask for that.

gljjr, thanks for your input too. Sounds like I need not worry about a little bit of diesel being mixed in with 125 gallons of gasoline. It should be pretty diluted.
 
It depends on the turn over of the fuel--but I would suggest that you either use Stabil or Pri G as a stabalizer if the fuel sits more than a few weeks.
 
Thanks thataway. Until I get my C-Dory, and am taking it out every day, I expect the tank to be topped up on a cycle of about every 60-90 days.
 
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