Peter Rooke adapts a water pump for the Baker Monitor VJ — Part 2 of 4
Baker Monitor VJ
This is the second in a four part series on Peter Rooke's restoration of a 1-1/4 HP Baker Monitor VJ. Read part 1 for the beginning of the restoration, and part 3 and part 4 for the rest of the restoration.
A water pump was needed to complete this restoration. The style of pump needed was not generally available in the U.K., so the plan was to use a regular hand pump and adapt it to work with the Monitor. Surprisingly, a pump similar in style to the original was on eBay, made in the U.K. under the Climax brand name and manufactured by Thomas and Son (Worcester) Ltd. This is believed to be the only type of pump made in the U.K. in the “American” style.
A badly-rusted pump was expected, and when it was delivered, did not disappoint. At least the body was intact.
As the pump was stripped down, all the nuts and bolts were wire brushed and soaked in penetrating fluid. This had no effect; the nuts refused to move and a couple of the bolts were sheared. The rest of the nuts had to be sawn off but even then it was not possible to punch out some of the bolts and they had to be drilled out.
It proved easy to remove the pump rod connector from the flat piston bar, but the pump rod itself had to be sawn off before it was drilled out of the connecting piece. The threads were cleaned using a small steel pick, then a tap.
Once the pump head was removed the full extent of the rust damage to the pump rod was visible.
The pump rod was soaked in penetrating fluid around the top gland fitting, but neither the fitting nor the rod would move.
The pump rod was then sawn off 2 inches above the bronze gland and also just below the bottom cast iron tube. A hub puller was then used to apply constant pressure to the pump rod to see if it would move. Nothing happened over two days, and it appeared nothing would.
The decision was made to saw through the bronze gland fitting as close to the cast iron as possible. In any event, the gland fitting would need some restoration: the pump rod had worn the hole to an oval shape, so the hole would need sleeving.
Even sawing off the bronze gland bushing did not help free the pump rod; it had to be drilled out to remove it. The remaining part of the gland nut was then mounted in the 4-jaw chuck to bore it out before the sleeve was fitted with a 0.750-inch hole for the pump rod. This sleeve was 0.375-inch longer than the threads to compensate for the piece of it sawn off in the cast iron top plate. After brazing the sleeve in place, a short length of 0.750-inch-diameter steel was glued into it to provide a temporary mandrel. This enabled the sawn part of the fitting to be turned true before sliding a further piece of bronze onto the sleeve. This was brazed in place then the mandrel was refitted after the heat destroyed the glue. This piece was turned to the diameter of the threads before carefully setting up a threading cutter to the old threads. The new piece was then screw cut to match the original.
It was still a challenge to remove the remains of the pump rod from the top plate. The cast iron tube broke off after trying to remove it with a wrench, but eventually the remains of the pump rod were pushed out and attention was turned to cleaning out both sets of threads in the top plate. It was a laborious exercise with a pick and miniature cutting wheel in a Dremel to get the first couple of threads clear. Any surplus was then ground away from the fitting until lines were showing through revealing the thread. Normally the remains of metal in the thread would peel away at this stage, but the rust acted like glue and the remainder was removed using a thread tap. The bottom gland fitting was cleaned up to remove the majority of rust from the outside before boring out the inside of the top part where the thread had broken off.
A piece of cast iron was then prepared by first turning to size to fit the bored hole, leaving a shoulder the diameter of the gland fitting. A thread was cut to match the thread in the top plate, and the inside was beveled to help compress the gland packing. Cast iron was used for the repair to match the original part; cast iron does not rust as badly as steel in this sort of wet environment. The threads were cut a little larger to compensate for the damage caused by rust to the thread in its seat.
After beveling the ends of both the original piece and the repair piece, they were welded together using a stick welder with cast iron rods. All that remained was to tidy up the weld with the grinder.
The main body of the pump was then examined and clearly the internal rust had to be removed. Before tackling this, the drain tap had to be removed. The corners of the hexagon around it were rounded so some care was necessary to avoid destroying it completely. None of my wrenches fit the hexagon exactly, so a slot to match the distance between two flat sides of the hexagon was cut in some 0.1875-inch thick steel. The sides of this slot were tightly clamped to the tap hexagon using locking pliers and the tap unscrewed, moving the “spanner” as necessary.
To gauge the state of the bore in the pump the rust had to be cleaned out first. A search of the shelves revealed a 3-inch-diameter flap wheel; the shank of it was pinned to an extension rod made to fit an electric hand drill. Wearing a mask as protection against the dust created, the flap wheel was used to clean up the bore and remove the surface layer of rust. There was some deep pitting in the cylinder walls, and after cleaning the bore measured a little larger than 3 inches.
From an engineering perspective the 3-inch bore in the pump should be machined true or a steel sleeve should be fitted. This would have been difficult to do using the modest machinery available, so this was left to see how the pump would work; it would not have to draw water from deep down.
A new pump rod was made from 0.750-inch-diameter steel, with a 0.750-by-10-UNC thread at one end and 3/8-NPT thread at the other for the short length of pipe to connect to the pump piston. Originally, a new piston was to be made oversize to fit the eventual bore of the pump. However, a standard 3-inch piston was found at a ridiculously cheap price so this was ordered to “try it and see.”
Before fitting the piston plunger, however, some further work was needed on the pump. The flanges where the various parts bolted together needed some work. The remains of any sealant and loose rust were scraped off and the holes were cleaned out for the securing bolts. Given their size, the parts could not be mounted on any machinery to be cleaned up so other methods were used.
To rough clean them, a disc grinder was carefully used to remove the worst of the peaks and troughs. After the first clean up, a piece of flat metal was coated in engineer’s blue and rubbed over the flange. The high spots were then ground away and the marking was repeated. When the blue covered most of the flange, a coarse file was used to finish off and leave a true flat surface.
Some reinforced rubber purchased for the restoration of a deep well pump some years ago was found to be ideal not only for gaskets but also for the flap valve at the base of the pump. The rubber was 0.125-inch thick and reinforced internally. Two pieces were cut for the flanges and holes were punched to secure bolts.
The threads on the drain tap were well worn; once the rust was removed from its hole and the thread was re-cut, it was a loose fit. To repair the threads, the tap was mounted on the lathe and the old threads were removed with light cuts, taking off a further 0.0625-inch (0.125-inch of the diameter). A 0.375-NPT thread was cut on a piece of brass before drilling it out to fit over the old threads on the tap. This was then brazed on to the tap; when it was cool, surplus brazes were cleaned with a file.
The spout of the pump had a void where any tap would have been. Rust had run riot so the tap mounting faces were cleaned and the remains of the tap plate mounting screws were filed off. The holes for these screws were drilled out and the 0.250-inch by 20-UNC threads re-cut.
The spout was mounted on the mill, holding the flange in a vice. It wasn’t an ideal set up, but care was taken to make only light cuts to avoid moving the spout. The seat for the valve itself was also machined flat.
An old brass gate valve was adapted to form a tap for this pump. The threaded section of the valve was sawn off and soldered into a hole cut in a new plate made from two pieces of brass sheet sandwiched and soldered together.
In place of the wheel on the valve, a cross bar was made as a handle. The core of the handle was some 0.625-inch brass rod 0.70 inches long. This was drilled through 0.3125-inch before files were used to square the hole to fit over the stem of the tap. Two 1.125-inch lengths of 0.375-inch round brass were cut then brazed to the core piece with the handle then being filed to shape.
The internals of the old valve were sawn and filed to fit inside the spout with a brass plate made to support a rubber tap washer. After the dried-out gland packing was replaced, the new tap was operational.
The original base plate for this pump was a substantial piece of cast iron weighing nearly as much as the pump itself. Using this would limit the mobility of the pump and make it difficult to mount the pump for a mobile display. It was therefore discarded and a piece of 0.250-inch steel plate was cut to fit the bottom flange. In the center of this plate a short section of 1.250-inch threaded pipe was welded as the connection point for the water inlet pipe. To support the pump and provide clearance for the water feed pipe, a 6-inch length of steel pipe was cut and welded to this new base plate, with four 0.50-inch thick bolts welded to it to provide mounting studs for the base plate.
The flap valve would be fitted to the top of this new base plate. Another piece of the rubber gasket was cut, then four holes were punched for the mounting studs. The center of the gasket was cut to leave a flap to seal against the end of the inlet pipe. The center of this flap was then drilled with a hole so that a brass bolt would pass through to a disc of cast iron that would act as a weight to help close the valve.
The new piston plunger arrived complete with washer and 0.4375-inch pivot pin, so a similar hole was drilled in some 1-inch hexagonal steel after shaping one end by thinning it to 0.50-inch so it would fit between the ears of the valve. The other end of the hexagonal bar was drilled then threaded 3/8-inch NPT to fit the end of the pump rod.
Now that the gaskets and valve were ready, it was time to test the pump to see if the new piston plunger was large enough. The pump was assembled and some water was poured in to prime the pump and by the time the final nuts and bolts had been tightened the leather washer had swelled to create a satisfactory fit in the bore. Pumping the handle, water gushed from the spout which meant that no further remedial work was required to tidy the bore of the pump.
Now that the pump worked, and needed no machining, it could be painted. The body of the pump had already been treated with a stiff rotary wire brush that had removed the rust. It was then given two coats of zinc paint. The paint used has very high zinc content and is sold by weight rather than volume!
After giving the base coat time to cure, a few coats of black paint were applied.
The flat rod above the pump rod rattled around in its guide, and to prevent this rubbing its paint off, some soft plastic was cut and glued inside the guide for the rod to bear against.
As the final assembly of the pump was finished, some 0.250-inch square gland packing was wrapped around the pump rod. When the bronze packing nut was tightened, it compressed around the pump rod. The cones cut in the gland nuts ensured the packing was pushed around the body of the piston rod; this was lubricated to keep the packing effective.
The original clamp to hold the engine against the pump had sufficient clearance for a normal pump arrangement, with the pump mounting plate close to the ground. A short length of metal pipe under the pump was used to cover the water supply pipe. This caught the frame of the cart so the mounting had to be adjusted to allow a fit. It was necessary to mount the pump to the engine and cart to make it easier to move as one unit. This would also reduce the risk of damaging the pump when transporting such a heavy, oddly-shaped object.
To solve this problem, any arrangement would have to be temporary and not have any long-term effect on original parts of the engine or the reproduction cart. With this in mind, another clamp was made by cutting two pieces of 0.250-inch angle iron. It would be held in front of the original clamp on 0.50-inch-long spacer washers cut from 0.875-inch diameter steel.
The two pieces of angle iron were shaped to fit around the pump, welded together and drilled for the securing bolts.
The original bolts were too short to fit so replacement fittings were needed. Given the length required, it would not be possible to slide all the new bolts into position; they would catch on parts of the engine. To get around this, 7-inch-long threaded studs were made from 0.375-inch diameter steel with nuts to be used at each end.
A shift rod moves the eccentric so the pump gears can move in or out of engagement and it had been badly bent in its travels. The judicious use of the vice restored it to normal contours.
To fit the pump to the engine it was lifted off the ground onto some 2-inch-thick wood. This gives clearance to wheel the cart around with the engine and pump. Once the cart is in position at a show, wood or stone can be slid underneath to give a solid footing at the pump base.