Old lawnmowers may look and act worn out. But, unless there is major damage or an engine that is truly blown, then you still have a usable piece of equipment. Restoring an old lawnmower involves careful planning and attention to detail. Taking the lawnmower apart and cleaning it may seem like the tedious part, but if you do not take notes to help your memory then you will almost certainly never get the mower reassembled. A clean engine with new gaskets placed on a newly painted mower deck will give your machine a new lease on life.
Disassemble the mower completely with your socket set and screwdrivers. Keep the pieces together and write down the order in which they came off if you are unfamiliar with the reassembly process. Scrape away any loose paint or old gaskets with your putty knife.
Pour a quart of gasoline into a bucket. Dip a rag into the gas and wipe any grease off of the parts. Fill another bucket half full of water and add 1 tablespoon of liquid soap. Dip a clean rag into the soapy water and clean every part. Wipe the parts with a dry rag and set them aside.
Rub any painted pieces with sandpaper to remove the old paint. Take your time and remove all of the old paint. Clean these pieces with soapy water and dry them with a clean rag. Set the pieces aside, placing pieces that need to be repaired in a separate location.
Mix the hardening agent with the body filler as recommended by the manufacturer. Use your putty knife to fill in any holes in the metal. Coat each damaged section with a coat of filler and allow it to dry completely. Sand the hardened filler smooth and even with the surface of the surrounding metal. Wipe it clean with a dry rag.
Cover all of the openings on your engine pieces with painter's tape to keep them clean during the painting process. Spray primer onto all of the pieces you want to paint. Let the primer dry and add a second coat. Take your time and hold the spray can 12 to 15 inches from the metal to insure a smooth, even coat. Let the second coat of primer dry completely before continuing.
Apply 3 coats of spray paint over the primer. Use short bursts of paint while holding the can 12 to 15 inches from the surface. Let each coat dry completely before applying the next. Allow the last coat to dry for 24 hours before continuing with reassembly.
Reassemble the engine parts and attach them to the mower deck. Apply gasket maker to each surface that needs to be sealed. Let the paste cure for 10 minutes and attach the piece to its mate. Let the assembled engine set for 24 hours before completing the assembly of the mower. Attach the wheels and handle to the deck. Tighten each piece without over tightening. Use your notes if you cannot remember the placement of the pieces.
Work gloves and safety glasses are required when using hand tools. Using gas to clean oily parts is effective. But you must use caution to prevent contaminating the environment. Dispose of used gasoline and other chemicals in a legal and environmentally manner. Never dump gas or chemicals onto the ground.