Rain water cistern to storage shed

[Case485Guy]

I have this old steel galvanized water cistern that I want to cut a door in and make small storage shed for our camp site at the ranch. I am going to use a cutoff wheel-4-12" grinder to cut the door. I think i can just make the first cut top to bottom, then bolt my hinges on and then cut rest of door out. Maybe brace the door with flatbar or small angle iron> and brace the outside door frame same way? Or be better to cut hole and build a frame to stand out from curvature and install a regular door? just need a walk in door, storage for tools and small stuff. ideas? Example of what I got.

 

[2458n]

Cutting the galvanized with a wheel would be better than using a torch. Be careful when welding on this metal. The gas given off will make you sick. I would install a metal door with the premade metal frame.

 

[Stimw]

Could the tank be more valueable as a tank? Maybe sell it for enough to buy a shed?
When you cut the hole the piece is probably not going to stay at the same radius. There are internal stresses that you release when cutting something like this.

 

[forgeblast]

Before you cut look up grain silo houses. They should give you some great ideas. Its just yours would be on a smaller scale.

 

[radioman]

Sounds like you have a plan - but I would just build a wooden frame inside and fill in pieces to fit the curve so its more professionally finished look.

 

[chim]

Sounds like a fun project. How about making up an 1-1/2" angle frame the size of the opening you want and fit to the radius of the tank wall. If you don't have someone who can bend angle for the top and bottom, maybe go with flatbar as a second choice. Predrill on 4" centers or so and put it against the tank. Run self-drilling screws through the holes to fasten the frame to the tank. Then take your cutter of choice and use the inside of the frame as a guide to cut the sheet metal. HOPEFULLY the frame will keep the tank round. Take the material you cut out, add some ribs and hinges to make it into a custom-fit door. Some caulking and you're done. Especially if you use angle for the top of the opening to shed the water outside the door.

A note of interest. I don't know what material that is, but the other Saturday I had the need to cut some sheet metal of about 16ga. For the first few cuts I used a sawzall and it worked OK but did catch and jump a few times. Then on a whim I tried my 18V DeWalt jig saw with a metal cutting blade. It did a terrific job. Cut like butter, easy to control and no bouncing.

 

[dave1949]

It could get pretty hot inside that tank with sun on it. I would make sure there is ventilation out the top and somewhere for air to enter near the bottom.

 

[davedj1]

I would do exactly what you plan. Then I would rivet some flat stock around the inside of the opening to give it a weather tight and more finished look. Then as advised above I would make some ventilation in it.
dave

 

[Case485Guy]

Thanks for the advice. This is an old, very old like 1950's era, the bottom has rusted through in spots. So i doubt resale would fetch much money. I had planned on cutting the bottom of the door starting about 6-8" above bottom for 2 reasons. I plan on putting about 2" of concrete in bottom and to help keep rattle snakes from accessing it so easy. So an inner lip for for the door to close against is really needed.
Ventilation I had not considered. Would one the "whirly" bird mounted on roof work? Is a bottom vent needed also?