Using a kit that comes complete with instructions, any homeowner can now put in an underground lawn sprinkling system in less than one day - thus permanently eliminating the need for dragging wet garden hoses and sprinklers over the lawn several times a week.

Produced by Mobile International, Inc. (16291 West 14 Mile Road, Birmingham, Mich. 48009) the kit comes in two sizes - the Spra-rite 1200 and the 1400. The first will cover up to 4,000 square feet. Each kit contains 100 feet of flexible polyethylene pipe that can be buried underground and can be cut with a pair of garden shears, as well as an assortment of special snap-on connector fittings that permit the installer to join the pipe without tools; the pipe is simply pushed into the connector and the cap then tightened by hand.

The 4000 kit, which costs $66.95, has two large rotary pop-up heads that will cover a cirlce 50 feet in diameter. The 1200 kit comes with smaller heads that still cover a circle 20 feet in diameter. Half-circle and quarter-circle nozzles are also included.

The system is designed to be completely assembled on top of the ground so that the heads can be moved around for optimun coverage. When the layout is finalized the pipe is buried by simply slitting the sob with a spade, then pushing the pipe into the split. The heads are recessed to make them flush with the grass Plastic Patch

A new fiberglass patching material that can be used to repair wood, metal and fiberglass surfaces can be applied without separater resins or other adhesives which must be brushed on separately. Called Duro Ultrapatch, and manufactured by Woodhill Chemical Sales Corp., 18731 Cranwood Parkway, Cleveland, Ohio 44128, the fiberglass cures on exposure to sunlight after it has been applied. Ideal for repairing cracked window sills and exterior trim, as well as rusted auto bodies, garden tractors, toys, boats and metal furniture, the patch measures 6 by 8 inches and will cure in about one hour on a sunny day when temperatures are about 75 degrees (longer when temperatures are lower). Once dry and hard it can be sanded and painted. Combination Drill

Combining the function of a powerful electric drill with that of an electric percussion hammer Black & Decker's new NO. 7928 convertible drill enables the home handyperson to use the one tool for drilling in concrete and brick, as well as in metal, wood or plastic. As a hammer-drill, it drills much faster in masonry than would be the case when using an ordinary drill with a carbide-tipped bit, yet it can be switched from one action to another with a simple shifting mechanism. It comes in two models: a 33/88 - inch, single speed mode ($30); and a half-inch, two - speed commercial duty model ($60). Both models are double insulated. Multipurpose Hammer

Molded of a tough, yet resilient plastic, the one-piece softuff Hammers are like small sledge hammers with many uses. Available in various sizes, from 1 1/2 to 3 pounds, and with either a standard heard or a slimline head, these hammers have a "soft" but firm face that makes them ideal for banging out dents, for hamering pieces of wood or plastic together when assembling furniture, for driving loose wheels back on toys and yard equipment, for tapping panels into place and for a multitude of other uses where heavy blows are required without danger of damaging the surface in the way that a metal hammer would.

An unusual feature of these hammers, which vary from about $10 to $15 in price, is that all have "dead blow" heads - that is, when a heavy blow is struck they don't bounce back the way a normal hammer would. This not only eliminates the possibility of chipping, it also insures that a maximum of impact or striking force will be delivered with each blow. Softuff Hammers are made by the Compo-Cast Division of C.E.S., Inc. 222 N. Olney St., Indianapolis, Ind. 46218.