Which furnace oil tank?

[westcoast]

Well, I am just taking ideas and information from everyone here on this site about building my evaporator from a furnace oil tank. I went out today to grab the tank and noticed another one further back in the shop... but it's not the same size. I thought they were all uniform, but no! So, tank #1 is 25 inches wide by 5 feet long... tank #2 is 23 inches wide by 6 feet long. Basic math tells me tank 2 has a larger surface area, but could there be a problem with the tank being longer? Both look in pretty good condition so thought I would ask before cutting... Thanks from the west side!

[lpakiz]

Keep in mind that factory made pans come in even sizes like 24,30, 36 inch width. Same for length.
For a 2 foot wide pan, your outside width dimension of the arch should be 26 or 26 1/8. Now if you plan to make pans and never sell or buy one, any dimension is OK.
Also keep in mind that you may want fire brick and insulation board in the firebox area, so your inside dimension of the firebox will need to be narrower than the outside.

[Bernie/MA]

Some of the older tanks were made of 14 gauge (thinner) steel. Look at the tag to make sure it's made of 12 gauge. I made a rig for a 2x4 pan. I left the last foot plus one end of the tank for the stack. Works good. I also have some CI radiator sections for grates.

[westcoast]

Went with the 5 foot tank, the extra couple inches may come in handy for the firebox. Bernie, you said you had CI radiator sections for grates... what is a CI radiator section? Are you sitting the pan on them so they diffuse the heat better? I see some people have problems with the heat not spreading evenly, is this your solution? Thanks for any tips, nobody around my area to compare notes or ideas with....

[Super Sapper]

CI is cast iron. using grates to keep the wood off the bottom helps with air flow to the fire. You can also use angle iron positioned like this V to hold the ashes to insulate the metal and keep it form sagging and burning up. I used unistut and it has held up for 2 years now and looks as good as the day I put it in. As far as the heat goes, try to make a ramp starting about 24 inches from the front to within a couple inches of the bottom of your pan. This will force the heat up to the pan. Someone with more experience with this type of evaporator could probably help yor more but I would think a straight wall up to a couple inches from the bottom of the pan should work well. Remember to leave room for insulation as it helps your boil a lot.

[Bernie/MA]

Sorry about taking so long. I don't come here so often this time of year. These are/were steam radiators out of a house remodel. The sections can be popped apart leaving 2" thick x 4to6" x 30" pieces.

[optionguru]

Hunt around on here you'll find a bunch of these oil tank evaporators. Mine has been getting upgraded each year, last year I put an adjustable air entry/ ash clean out under the metal grate in the fire box to allow the air to come up through the fire. This helped my boil rate quite a bit. I also used a bunch of steam table pans thinking it would make a "poor mans" flue pan. Got about 8 gallons an hour consistently. Not bad but I'm making more tweaks this year to shoot for 10gph. Feel free to ask any questions.

[westcoast]

Thanks for the replies and ideas. I have cut the top off my tank, got the back of the firebox cut to fit, and cut some angle iron for the firebox grate. Looking around for an old firebox door, then will cut out the fire door and lower door for ash cleanout/ air inlet. One question I can think of now is, what to use to insulate the flue area? I figure I'll use fire bricks in the actual firebox itself, but I see others talking about insulations blankets. Not too sure what that is! Oh, and I haven't cut the chimney yet, am I right in thinking it would be a 6 inch, not 4? And the longer the chimney (within reason) the more draft I should get from the fire. Optionguru, 8 gallons an hour is more than I was hoping for, I would gladly take half that amount in my first attempt! Thanks again... I'm sure I will have more questions in the not too far future.

[OCHTO]

I bought the vogelzang kit for making a wood stove out of a 55gal barrel. It has a door and the smoke stack collar. It was less than $25 but shipping might be a detriment to you. Easy to install and perfect size for my oil tank evaporator. I cut ash cleanout/ air intake door in under the firebox door. Mine works great. I have pictures in one of my previous posts.