A Lanham company called Cemcom Inc. has developed an unusual cement compound that is being used to make molds to form aircraft parts, such as wing flaps, helicopter blades and body parts.

Composite airplane parts, made of graphite, fiberglass and other materials and molded in Cemcom's "cementitious composite," are being used increasingly because of their exceptional strength and light weight. Composite parts also are used in the Stealth aircraft, being developed by the U.S. Air Force to escape detection by radar.

The molds, or tools, used to make these composite parts play a crucial role in the lengthy part-building process -- and that's where Cemcom comes in.

The three-year-old company began selling its product in January and hopes to capture 8 percent of a $500-million-a-year tool-making industry by 1986. Sales are now about $75,000 a month for a product that cost $4 million to develop, says Jake Bauer, Cemcom president and cofounder. Tool-making costs are high, however, and Cemcom is breaking into the market slowly.

Bauer, half scientist, half executive, says his new product "is just the beginning."

Bauer's interest in the properties of cement led him to start a ferro-cement boat-building company in the 1970s. Bauer began researching the scientific literature on cement and "discovered there wasn't much. . . . The tech base for cement was 10 generations old." Bauer decided to conduct his own experiments.

"I thought the reason cement was under-researched was that everyone in the field thought that cement was something you built bridges, streets and sidewalks out of. No one thought to use cement as a substitute" for plastics and other materials, Bauer said.

In 1980, he received $70,000 in funding from Boeing Vertol Co. of Philadelphia for a feasibility study on the use of a cement material for aircraft-part tools.

To provide the financial base for continued experimentation, Bauer and partner Howard Leith founded Cemcom in late 1981 as a research and development partnership of about 30 investors, most of whom were from the Washington area. The partnership contracted with Cemcom to perform research, with Cemcom retaining the option to buy back any product that was developed.

A little more than two years after the company was formed and $4 million later, Cemcom came upon its first marketable formula.

As aircraft manufacturers began to increase their use of composite materials, a need arose for a cheap and easy-to-use tool that had the other properties required, such as strength, vacuum integrity and heat resistance. A cement composite seemed to answer the need.

Tools now used in the aircraft industry are made mostly from electroplated nickel or graphite-epoxy compounds. Both have drawbacks. Nickel tools are expensive and may take 30 days or longer to make. Cemcom tools can be made in about two weeks, Bauer says.

Unlike graphite-epoxy tools, Cemcom tools can be cast at low temperatures, do not shrink as much as graphite-epoxy and can be made with considerably less labor. The life-cycle of cement tools is known to be much greater than graphite-epoxy.

Reactions by industry to Cemcom's tools have varied. Some aerospace engineers complained that the tools they initially received from Cemcom were poorly made and they doubted whether they would have an application for such a product.

Bob Fort, an engineer with Boeing Vertol, said composite parts sometimes stick to the molds. Fort said he has decided not to use Cemcom tools in production.

Other engineers were impressed with Cemcom. Howard Horner, a tooling engineer at Rockwell International in Tulsa, said that when he ran into problems making a complex part, "I was forced into using Cemcom tools and found they were successful. There was nothing else to use in that application."

Bauer plans to raise $3 million this month from private investors and is considering a public offering in a couple of years, he says.

Until last month, Cemcom's only customers were military aerospace contractors. But the company recently received a $200,000 order from General Motors Corp. for prototype tooling for GM's Saturn auto model.

Cemcom also is developing a ceramic-cement device to re-form used titanium jet engine parts for Pratt & Whitney. And a cement compound friction material for auto brakes is being developed with Abex Corp.