Gas and Oil Home Heating Furnaces - Oil from old tank

Hi, been a while since Ive posted. I replaced my indoor oil tank this spring with an outdoor one. Im to the point of removing the old one from the cellar. I know that its not good to put old oil from the old tank into the new tank. Ive been draining the old oil from the bottom outlet, not sucking it out the top. The oil is not as clear as new oil but its still red if not a bit murky. I know theres sludge in the tank and I figure it will eventually clog the line and not let me drain any more. Can I use this oil in my new tank? Its quite a bit, maybe ten gallons. I hate to waste it. Second question, whats the deal with cutting this old tank up to get it out. Can I use a sawzall to cut it up without blowing myself up? I want to cut a section out so I can remove the sludge with a scoop. Should I put some water in it before I cut it open? Is it safe to do this? Thanks.

You might be able to get away with the oil, I'm sure someone else will chime in with a better answer.

As far as cutting the tank, once most of the oil is pumped out, stand the tank on end and cut away. A sawzall is what I've used. Oil is a flammable liquid, not combustible like gasoline. The flash point of the oil is too high for sparks to be an issue.

For 10 gallons you're going to contaminate your new tank?
Don't even think about it. Most of the tanks I replace have 50+ gallons in them & it all gets scrapped. If you transfer any of that old oil you are simply seeding your new tank with bacteria which produces sludge.

A reciprocating saw is fine for cutting up the old tank. Wear eye & ear protection. You will need it. Once you cut it in half lengthwise, it's easy to remove the sludge. Do not use any water.

If you have not done so already, completely remove the old fill & vent pipes then patch the wall. If this is not possible for some reason, cut them off flush with the wall, pack paper or rags in the ends & fill the outside part with concrete. This will prevent anyone from attempting to fill a tank which is no longer there & creating a mega-mess in the basement.

Great, thanks for the advice. I'll have to call and find out where to dispose of the old oil. The fill tube for the old tank was removed right after the new tank was installed. I'll have to pick up a few spare blades for the saw. I think Im gonna need them.

Oil is a flammable liquid, not combustible like gasoline. The flash point of the oil is too high for sparks to be an issue.

Just a quick correction on terms. Oil is the combustible liquid as it has a flash point 100 degrees or more. Gasoline is flammable as it's flash point is less than 100 degrees.

Thanks for catching that Grady.

Carbuff: Once you get the tank cleaned out, you can take it to a scrap yard & get a few bucks for it.

HankHill: Hope you'll bail me out when I goof.