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Craftsmen's Corner / vacuum pump questions...
« on: March 17, 2025, 10:01:00 PM »
I made a vacuum chamber out of small trash can, a couple scraps of lexan, and piece of flat silicone rubber (pictures below). I want to use it to de-gas poured urethane that I plan to use to make some Hobie turbo fins (pictures to follow...).
Today, I tested it out, using a vacuum pump that I borrowed from the local O'Reilly auto parts store (18 CFM, as I recall). It worked fine, except that oil got sucked into the hoses, which was a mess to clean up. Actually, the pump itself was very oily before I started, so I think there might have been some problem with it.
I'm considering buying a cheap vacuum pump, and would prefer that it be oil-free, both to prevent the oily mess I had today, and so that I can run it indoors. The oil-free pumps seem to be expensive and not as powerful. This one is suspiciously cheap (several of the oily kind are in this same price-range):
https://www.amazon.com/Vacuum-Oil-Free-Oilless-Diaphragm-Silencer/dp/B0D9BPC79V/
However, online it says that an airflow of 8 CFM is needed, and you need to be able to pull 29 inches of mercury (https://www.smooth-on.com/support/faq/111/) and I'm sure that oilless pump won't do either. So, maybe I'll have to go with an oily pump.
Any thoughts on a cheapo pump that might work?
Today, I tested it out, using a vacuum pump that I borrowed from the local O'Reilly auto parts store (18 CFM, as I recall). It worked fine, except that oil got sucked into the hoses, which was a mess to clean up. Actually, the pump itself was very oily before I started, so I think there might have been some problem with it.
I'm considering buying a cheap vacuum pump, and would prefer that it be oil-free, both to prevent the oily mess I had today, and so that I can run it indoors. The oil-free pumps seem to be expensive and not as powerful. This one is suspiciously cheap (several of the oily kind are in this same price-range):
https://www.amazon.com/Vacuum-Oil-Free-Oilless-Diaphragm-Silencer/dp/B0D9BPC79V/
However, online it says that an airflow of 8 CFM is needed, and you need to be able to pull 29 inches of mercury (https://www.smooth-on.com/support/faq/111/) and I'm sure that oilless pump won't do either. So, maybe I'll have to go with an oily pump.
Any thoughts on a cheapo pump that might work?