A Vacuum pump is a handy device to have in your workshop if you're interested in tinkering with boats. Above is a picture of a vacuum pump that I put together.

I picked up an industrial sewing machine for $50. Mainly because I was interested in the 1/2 horse motor. I was given an automotive air conditioner compressor. I removed the sewing machine head and mounted the compressor on the machine table. Had some pulleys made up to gear the compressor so it ran 500 to 700 rpm. Fitted a vacuum guage and hey presto one really good vacuum pump.

The most expensive part was the pulleys an their machining  at around $120.

All up the vacuum pump cost me less than $200Aus. Check out my page on Carbon Boards and Components to see some of the things it can help you make.