I clean grass clippings from the underside of my 500-pound mower's deck with a sprayer I made from garden hose fittings. Not removing the clippings reduces the mower's efficiency and promotes rust, but it is difficult to reach under the deck or lift the front of the machine for cleaning. The sprayer alone does not have enough power to do the cleaning, but the whirling blades do. SAFETY RATING: This project has been awarded the grade of W by the League of Crackpot Scientists, which stands for "What could possibly go wrong?" STATEMENT OF LIABILITY: If you or anyone else is injured or any property is damaged during the construction or use of the device described herein, it is all your fault. To see my related Instructables, click on "unclesam" just below the title above or in the INFO box to the right. On the new page that appears, repeatedly click "NEXT" to see all of them.
Step 1: Tools and Materials
Adjustable wrench, combination pliers, screwdriver, sharp knife, drill and bits
Several feet of five-eighths inch garden hose
Lawn sprinkler nozzles or heads suitable for mounting securely onto a board
Metal fittings for five-eighths inch hose, and washers
Wood or plywood for frame or base
Sheet metal screws
Step 2: Layout
The shape and size of the sprayer base depends on the mower. My mower has three blades, and I wanted a sprinkler head below each of the blade hubs. My frame is a short length of two-by-four wood joined to the middle of a longer one using pocket screws. The spacings of the blade hubs were marked on the frame for locating the sprinkler heads.
Step 3: Assemble the Hardware
I chose low-profile sprayer heads, drilled two quarter-inch diameter holes in each, mounted them on the frame using large sheet metal screws. I then determined what hose fittings I would need to be able to supply the three heads from one inlet connection to my garden hose
Step 4: Connect the Hoses
The hose fittings were tightened in place and lengths of garden hose cut to run between them. Hose clamps are usually included with the fittings.
Step 5: Kinky!
A short run of hose did not conform to the required shape without kinking, so water could not flow through it.
Step 6: Ticketyboo
Adding angled fittings allows the short hose to be a straight run.
Step 7: Let Us Spray
First test of the sprayer. The Great Yellow Beast looks on, feigning disinterest.
Step 8: Blowing Chunks
The lower edge and blades of my mower deck are low enough to the ground, even in the highest position, that the machine must be elevated above the spray washer. I park the mower on a set of open-work metal loading ramps with the sprayer underneath. To be most effective, the cleaning should take place following each mowing, but most importantly immediately after mowing high and/or wet grass. With the water flowing and the blades spinning, the underside quickly gets a good wash, even though I use standard blades, not the optional high-lift blades. This method may not remove a thick longtime accretion of dried clippings from a mower deck, so they might need to be removed mechanically before the spray cleaner is put to use for the first time. Running the blades again after the sprayer is shut off blows any remaining water from the underside of the deck.