Scratchbuild a Rectangular Wooden Water Tank for Outdoors


This water tank is based on the V&T's double spout water tank that stood at Carson City, Nevada between 1887 and c.1950. It has been modified in several ways. For a scale drawing of the original see Narrow Gauge & Short Line Gazette, March, 1981. The original tank had diverging ends to fit between two diverging tracks. Mine has been made rectangular to allow more freeedom in placement on the railroad. Also I have downsized it slightly for narrow gauge use and to make it easier to use dimensional lumber for its "framework". Lastly the original had board & batten siding. I have opted for straight board siding to better conform to my own Port Orford Coast Railroad's practices.

This structure has been designed for outdoor use. Thus its construction is very robust without, hopefully, compromising its prototype character and looks. Internal construction is essentially a simple box made up from #2 cedar. The box while relatively simple is the heart of the structure. Care used in keeping it absolutely square and countersinking any screws or nails used in its construction is the key to a good looking model.

Basic measurements as used by me are: Total length of box 17", width 6", height 7 1/2". End and side walls are made from 2x8 cedar. The sidewalls could be made from 1x material but 2x works perfectly for the ends as you'll see later. The entire box was set upon a 1x6x17 piece of cedar for a floor which increased the height of the box to 8 1/4". Usually I enclose the floor up inside the box but I needed just a bit of additional height to the box for proper proportion. Note that the end blocks have the top corners cut off at a simple 45 degree angle.

Legs are 5 1/2" in length and are made from 1/2" square cedar that I ripped to size on the table saw. Bracing is 1/8" x 5/16" cedar. The bottom of the floor was ringed with 1/2" square stock and the upper ends of the legs were milled to sit half inside the ring and half on top of the ring for better strength and to give an "inset" look. Everything was secured with Siliconised Acrylic Adhesive Caulk and deck screws for the main body and 18 ga. brads with a nail gun for the legs and bracing.

Three roof rafters were next cut from 2x8 cedar to a 45 degree angle and then cut across their bottoms to conform to the width of the box. One was placed at the middle and the other two butted up against the box ends. This leaves a gap between the rafters and the tank end that needs to be filled as in the photo. I cut two 45 degree pieces, set them in place on the ends and marked the angle from roof peak to end and cut a the front angle on thebandsaw. This is a little tricky but if you have trouble here you can always just frame it with stripwood. It should be strong enough. I also applied the first coat of grey primer at this time and added a prepainted upper door with white trim secured with the adhesive caulk.

Siding is 1/8" x 1/2" cedar boards ripped on the tablesaw and prepainted before installation. One advantage of solid block framework is that the siding is automatically square if put on straight and the board thickness can be heavier than the prototype for more robustness since it doesn't show. Cut all siding boards to length for one side/end at a time and place them on tank body for fit beginning in the center. I also applied an upper trim board which was painted white. You may have to rip down the end boards to fit. Remove the siding boards keeping them in proper installation order and prepaint on both sides.

Draw a centerline vertically on the tank box and spread an even coating of adhesive caulk or your own adhesive preference. Press your prepainted siding boards onto the tank side in order. You can make small adjustments for about 10 minutes or so depending on humidity because the caulk dries slowly and doesn't fully cure for many hours. Let cure for a couple hours and then repeat for the other three sides.

Two Hartford 1:20.3 resin spout kits were used, one on each end. If you are scaling this down for another scale then use appropriate spouts. In the prototype two separate round water tanks were enclosed within this one enclosure. Each had its own spout of course to service two adjacent tracks. Only one pulley was used from the kit(s) on each side and the chain after being secured to the spout was fed through a hole drilled into the tank end and secured inside with a brad. As usual everything wa prepainted. You can get fancy by making it operating by securing the chain end to a spring or a weight inside the tank. I opted for permanence because of wind and wildlife outdoors here. The spout comes with instructions so I won't go into any more detail on that. A water gauge was cut and painted white. After drying marks were made on its front with a soft dark pencil and oversprayed with a flat clear spray. The marks will eventually fade but they do likewise on the real thing and it's easy to re-do them.

The subroof was fitted next, made from 1/8" MDO plywood. Begin by cutting the two long side pieces leaving enough extra for about 1/2" overhang on both ends and the side. Temporarily screw in place using deck screws in pre-drilled holes. Next cut and fit the two end pieces and carefully fit them between the overhanging sides and allow for the desired overhang at the bottom. Make as close a fit as possible and screw in place temporarily. With a sharp pencil draw a line inside the side roof sections conforming to the angle and surface of the end sections. Remove the side sections and cut along the line(s) being sure to cut them flush with the end sections. and screw them back on to check fit. Use a rasp file or sander to conform the roof sections. Any small gaps can be filled with caulk and will be covered with the final roofing material.

Remove the subroof sections for painting. It is advisable to keep the sections in order in case of any slight variation in size because of fine tuning the fit. Prepaint the sections on both sides giving special attention to the edges. When dry apply a liberal amount of adhesive to the understructure and fit and screw the sections on. Additionally I used my brad gun to further secure the roof at crutical places. Note: If access is desired then just use screws to secure the roof. You will have to make provision within the final roofing used or peel up the final roofing to gain access to the screws.

You may choose any kind of roofing for your water tank. The prototype was shingled but rolled roofing or even metal would look good depending on era and your own preferences. I opted for shingles. A very nice plastic shingle material in several styles is available from Precision Scale. I don't know how well it will hold up outdoors but it looks good and seems fairly durable when painted.

I make my own shingles as those in the photo above from 20# roofing felt cut into 1" strips and slotted every 3/8" to represent individual shingles. The strips are cut the full width of the rolled goods,36" and then cut into 12" strips for slotting. I save time by bundling the 12" strips into stacks of 25 or 30 secured with a good quality masking tape to facilitate removal and slot them on the bandsaw. Be warned however that this is very hard on the blade. It gums up quickly and is very difficult to clean. I use an old chisel to remove gunk by gently holding it against the side of the running blade. The blade is not of much use for other things after this but it's a lot easier than cutting by hand.

I prepaint the shingle strips with various flat earth tones to get just the color I want with spray paints. Krylon's "Camouflage" paints are excellent for this. The strips are then further cut into average 6" strips for application to the roof. Begin by drawing guidelines every 3/8" down the roof. Work with one line at a time, bottom to top by applying adhesive and pressing the shingles into place following the guide lines. For each course apply two beads of adhesive, one on the top part of the preceding row and the other just above it. Use a small putty knife to spread the adhesive evenly and apply the shingles. Be sure and glue down well. While the shingles and adhesive caulk do well outdoors, loose ends will curl up in the rain perhaps giving a more rustic look than wanted.

Cut some smaller 1/2" strips of roofing felt for the roof peak and along the sides where the roof sections meet also prepainted. Cut the strips into 1" lengths and pre-fold longitudinally at the center. Apply these one at a time to the seams where the roof sections join from bottom to top. Overlap each by about a 1/2" as you work your way up. For the cap you want to start on both ends and meet in the middle. Cut the final middle piece to about 1/2" length and fasten ontop of the last two cap pieces.

Voila! The finished tank

Good Luck! Any problems or questions? Just ask Bob McCown. Heehee!

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