Marking a 55 gallon barrel?

[Kevin McG]

I want to mark a plastic 55 gallon barrel in 10 gallon increments starting from the bottom. How much are the increments in inches?

I think I am brain farting

 

[Kevin McG]

Nevermind figured it out

barrel is 33.5 inches high / 11 for 5 gallon increments. So it would be 6.09 inches per 10 gallons

 

[denvig]

What diameter is it?

 

[Kevin McG]

What diameter is it?

22.5 inches

 

[Pat H.]

I basically did the same thing you just described Kevin, it wasn't accurate for some reason. So I filled it with a 5 gl bucket, marking it at each fill. Ends up my "55 gallon" barrel is more like 65 gallons Who woulda thunk it!

 

[smcnally]

Yeah...a 55gal drum isn't filled to the top when "full" the reason you have the inconsistancy (sp?) in markings is because on the metal drumbs they have those ridges ever so often. On the plastic ones they bow out and the back in.

 

[Kevin McG]

I basically did the same thing you just described Kevin, it wasn't accurate for some reason. So I filled it with a 5 gl bucket, marking it at each fill. Ends up my "55 gallon" barrel is more like 65 gallons Who woulda thunk it!

Interesting... how high from the floor about is your 55 gallon mark?

 

[denvig]

(pi) 3.141592653589 times the radius 11.25? squared, will give you the area in square inches. That times one inch will give you the cubic inches of water in one inch high. = 397.607820199 Cu. In.
One gal. = 230.999767086152 Cu. Inches 10 Gal. Would be 2309.9976708 Cu. Inches or 5.809 inches high for 10 gal. So a barrel 33.5? high would hold 57.669134 gal.
I think thats right

 

[smcnally]

(pi) 3.141592653589 times the radius 11.25? squared, will give you the area in square inches. That times one inch will give you the cubic inches of water in one inch high. = 397.607820199 Cu. In.
One gal. = 230.999767086152 Cu. Inches 10 Gal. Would be 2309.9976708 Cu. Inches or 5.809 inches high for 10 gal. So a barrel 33.5? high would hold 57.669134 gal.
I think thats right

But if it changes dimensions (as they do with ridges and bowing), then all that cool math is now no good.

 

[denvig]

I know

 

[Pat H.]

Interesting... how high from the floor about is your 55 gallon mark?

I didn't mark the 55 gl spot because I never fill it past 50. My 50 gl mark is at 27.5". The problem with trying to figure it out mathematically is that these plastic barrels change diameter at the top and bottom(at least mine does) and seem to bow in the middle. It's a PITA but IMO the best way is to measure it out with a known volume container and mark it as you go. HTH