looking to buy a used 150 gal tank w/tool box.
it's got 70 gal of off-road diesel still inside.

will sell the off-road diesel to a farmer. but some dye will stay in the tank. how long does it take to clear the dye?

or shall I just pass?

 

If you empty the tank entirely, add five gallons of onroad fuel and slosh it around and empty it all the way again the dye will disappear.
You could also get a receipt form the guy you brought the tank from saying it was used for offroad and some dye could remain. Hopefully most law enforcement would be understanding.

 

thanks.. so the dye can be flushed from the tank fairly easy..

I'm not going to.... but how long does the dye take to disappear if someone runs off-road diesel?

 

It takes about 3-5 tanks to flush it out. Of course it all depends on how low you dare run down each tank.

 

Put 5 gallons of umo in and it will turn black!
Won't hurt anything.

Tom

 

Or tell them it has transmission fluid in it If they do not actually test it they will not know.
I got a 55 gallon drum that had about 1 1/2 gallons of red dye fuel in it. I put 1 gallon into my 75gal aux. tank which has about 50 gallons right now and you can barely tell it is there.

I put the other 1/2 gallon into my ready heater.

 

Won't work
If your fuel is anything other than clear to yellow/green they will test it for the markers added to the red dye.
Same goes for ATF

 

I'd take my chances and burn it. Then fill it with 5-10 gals and burn that. Maybe even burn several small batches of fuel through it after emptying the farm fuel.
Then as Infidel said the rest of the fuel you put in it should look clean.
I feel at least for me that I would be safe.
I've never seen troopers or anyone else dipping tanks in my area.
Don't get me wrong..I'm not condoning the purchasing and burning of farm fuel for over the road but you might as well use it since it's there.