The oil tank is made very similar to the water tank; a steel outer tank and a PVC inner tank. After making the inner tank of PVC it was learned that polypropylene is the correct choice of material for oil tanks so if or when the PVC tank fails it'll be replaced by a polypropylene tank. Polypropylene sheets and welding rods are available from McMaster-Carr.
The oil tank side is very similar to the side of the water tank except only 9 1/2" front-to-back. The front of the tank is inside of the cab. The back edge of the cab side is riveted to the front of the oil tank side. The last rivets are not shown on the side drawing above; that detail will be covered on the Cab page.
The back of the oil tank is identical to the back of the water tank except it is 1/4" wider than the water tank. The back panel is identical to the water tank front and back panels.
The oil tank front is identical to the back except that a hole is cut for routing wiring in the middle and the bottom part is raised 9/16" to match the raised frame bars.
The top of the oil tank was made of 16 gauge steel. Short vertical reinforcing strips of 1/8" X 1/2" HRS were riveted one to each side and two to the front and two to the back to help support the top. The top is tack welded to these strips similar to what was done on the outer water tank.
The sheet metal was obtained cut to size from a local shop:
Front and back: 9 1/2" X 14 1/2" 18 gauge
Sides: 9 1/2" X 12" 18 gauge
Top: 15 3/8" X 12" 16 gauge (had cut slightly oversize and the filed to exact fit.
This photo shows inside of the finished tank with those support strips. The hole for the input port was cut with a hole 2" hole saw as described later.
The outside of the tank with considerable surface rust. Note that the bead has been applied to the back and part of the sides. The bead will be finished after the cab sides are attached.
The inner PVC Oil Tank is shown above. The overall outside dimensions are 5 3/4" high 15" wide and 8 7/8" front-to-back. The inside dimensions are 5 1/4" X 14 1/2" X 8 3/8" giving a capacity of about 2.7 gallons. The 1/4" thick PVC sheets were cut to the following dimensions:
Top & Bottom : 8 7/8" X 15"
Sides: 8 3/8" X 5 1/4"
Front & Back: 5 1/4" X 15"
The the sides and bottom were plastic welded on both the inside and outside just like the water tank. At this point the top is attached with four small sheet metal screws and a bead of caulk run applied along the seam to give a temporary seal. The plan is to open the tank after a couple months and check for deterioration. If everything is OK the top will be welded on. If there is a problem at that time a replacement tank of polypropylene will be fabricated.
The fill port is 1 1/2" PVC pipe glued to a 2" hole sawed in the top. The PVC tank was placed inside the outer tank and the 2" hole was sawed through both tanks at the same time. A piece of coupling was glued to the lower end of the fill pipe and the outside turned to the exact diameter of the hole similar to what was done on the water tank.
This photo shows the under side of the tank. The output port is a 3/4" PVC pipe to 1/2" NPT female adapter. The hole through the tank was made with a 1" hole saw. A piece of PVC pipe was glued inside the adapter to strengthen it and the end was then turned down to the exact diameter of the hole for a length of 1/4" matching the thickness of the tank bottom. The adapter was glued into the bottom and then welded. The output port is midway between the frame side and the outside frame channel. The fittings are a 1/2" to 1/4" bushing, 1/4" nipple , 1/4" angle valve and 1/4" coolant type quick connect. The fitting just in front of the output port is the bottom of a 3/8" tube compression to 1/4" NPT pipe fitting threaded through a 1/4" NPT hole tapped in the bottom of the tank. A piece of 3/8" copper tube in the upper compression end of the fittings serves as a vent/over flow. The top of the tube is about 1/16' below the bottom of the tank top.
Shortly after the tank was finished it was knocked off the workbench. The output port PVC fitting broke off just below the tank bottom. The is a reminder that PVC is somewhat brittle. The fitting was repaired by plastic welding --- worked really neat!
Photo above shows the finished PVC tank in position on top of the battery. The tank is held in position by the steel outer tank.
The 1/4" thick PVC sheets were purchased with the intent of gluing them together. A thinner sheet could be used since they are welded rather than glued. I'll probably use 3/16" thick sheets on the next tank.
This photo shows the steel outer tank in position. Once the cab side has been attached to the tank a fastener to hold the tank-cab combination in place will be designed ----- probably a couple studs down though the cab floor.
Another view of the outer tank showing that vertical part of the electrical compartment no longer sticks up like a sore thumb.
The cab is next .......