Scepter Military Water Can Hand Pump Conversion: A DIY Overlanding Field Craft Guide
Why a Hand Pump Converts a Scepter Water Can Into a Field Faucet
This DIY hand pump conversion using the common 5 gal / 20L Scepter Military Water Can is a highly practical mod for overlanding, road trips, weekend camping, and home emergency water planning. Credit for the original concept goes to a post I first encountered on NorthWestOverlandSociety.org around 2009. That domain has since been deactivated, but the idea deserves its original acknowledgment.
Anyone who has spent time in the field without plumbing hookups knows the difference a flowing water source makes at a primitive campsite. Wild rivers and streams are not personal sinks, and treating them as one is poor etiquette. A simple hand pump faucet mounted to a military grade water can changes how comfortably and efficiently you live at a basecamp.
If there are two questions asked most often at overland events when this setup is in use, they are: "Where did you get that?" and "How did you do that?" This article answers both.
The pump integrated in this tutorial is a marine grade boating product that allows one-handed operation to dispense water with each stroke via a plunger style mechanism. The model used here is a Fynspray Ultra Galley Pump (P/N WS67), priced around $90 to $120 USD online at the time of writing.
Materials and Components List
- 5 gal / 20L Scepter Military Water Can, or equivalent clone
- Fynspray Ultra Galley Pump, P/N WS67
- 3" x 4" x 1/8" thick food grade sheet gasket or non-toxic closed cell foam
- 16" x 5/8" OD / 1/2" ID food grade silicone tubing
Tools Required
- Hand drill (or drill press if available)
- 1 3/8" diameter hole saw
- Utility knife
- Pencil, Sharpie, or other marking implement
- Scotch-Brite General Purpose Hand Pad or 150 to 220 grit sandpaper
Safety note: Use proper safety glasses when operating any tools. Be planned and deliberate when handling cutting tools, particularly the utility knife.
Step-by-Step Conversion Instructions
Step 1. Unscrew the main cap from the water can and unfasten the cap retaining collar. You will be cutting off this retaining collar and also removing the spout cap and its smaller retaining collar.
Step 2. With your utility knife, score the material of the retaining cap collar where it meets the cap.
Step 3. Bend at the score line until the retaining collar separates from the cap.
Step 4. Use your utility knife to clean up any excess material. Use the Scotch-Brite pad to smooth rough edges as needed.
Step 5. Score around the base of the spout where it meets the cap until you cut through, then carefully work your way around the base to remove the spout entirely.
Step 6. Use the 1 3/8" hole saw with a hand drill to cut and enlarge the necessary hole in the main cap to allow the pump neck to fit through. A finer toothed hole saw is easier to control with a hand drill. Use a wood block behind the cap to back it up when drilling, and position the pilot drill bit as close to the center of the main cap as possible rather than centering on the old spout hole. This ensures the pump base has maximum contact with the main cap surface. A drill press is preferable if available. Clean up rough edges with the Scotch-Brite pad or sandpaper.
Step 7. This step was not in the original tutorial but improves the final result. A 1/8" thick gasket between the pump base and the top of the main cap creates a better seat. Because the main cap has a slight curve and the pump base is flat, the gasket compensates for the gap and provides a tighter fit. Closed cell foam or even neoprene is preferable as it is more compressible and seals more effectively than rigid gasket material.
Step 8. Trace around the base of the pump on the gasket material using your marking implement. Remove and cut along the traced line to create the gasket pad.
Step 9. Cut your food grade silicone tubing to approximately 16". This length allows the tubing to fit over the bottom of the pump neck nipple and reach the bottom of the water can.
Step 10. Unscrew the nylon nut-washer from the threaded pump neck. Insert the pump neck through the cap opening and re-thread the nylon nut-washer finger tight only. Thread the main cap back onto the water can and rotate the pump base to its ideal orientation. Once satisfied with the position, unscrew the cap again and tighten the nylon nut-washer firmly so it will not move.
Step 11. Rinse the complete assembly in clean hot water to remove any debris or dust. Use dish soap for a thorough clean and rinse again. Screw the main cap and pump assembly back onto the water can. The conversion is complete. For a finished result, run a bead of silicone caulk around the base of the pump where it meets the cap. Not required, but it seals the joint cleanly.
Note: The faucet rotates within the pump base. Keep it rotated inward when transporting and deploy it outward when in use.
Field Notes and Tips for Long-Term Use
This setup has been in active field use for well over a decade. A few observations worth noting for long-term reliability:
- The Scepter cap thread is the same on both the 5 gal and 2.5 gal versions, so this conversion works on either size. On the 2.5 gal can, the silicone intake tube may need to be shortened slightly or allowed to curve along the bottom.
- If the pump stops pushing water out the faucet and begins pushing it back down the intake tube, the pump is losing internal pressure. Contact the manufacturer for a replacement valve kit before assuming an assembly error.
- As an alternative to the closed cell foam gasket, food-safe silicone caulk applied around the pump stem and base creates a permanent, waterproof seal and is easier to source at a hardware store.
- Running the hole saw in reverse is an effective technique for preventing it from walking across the cap surface if you do not have access to a drill press.
This is one of the most useful campsite amenities you can build in under an hour. Running water at a primitive camp changes how comfortably and efficiently you operate in the field. Build one and it will outlast most of the other gear in your kit.
