Oil options for rough pumps

[Mark Rowley]

Bruce, for you to imply that I haven't changed pump oil in 17 years is comical at best and is strikingly similar to something one would see on facebook, sad. I contend you received a bad batch or there is a hardware issue. It's not bad advice. Tons of folks here have run HVAC pump oil without issue and your one report is the only documented outlier.

Mark Rowley

[Victor Gonzalez]

220 BRL = 52 USD per liter....

No way...

I think you forgot how high your country taxation is.

1L of cheap HVAC on mercadolivre.com.br is R$40,00.

[Mark Rowley]

I will say this....if what you say is true, then my roughing pumps should be able to pull 5mTorr or below in my system if I opted for lab quality oil. But for a fusor, I dont see the immediate need for such a high performing roughing pump. Seems like a waste of money since the secondary will easily drop it below a mTorr. It's not benefitting the cash strapped rookie to constantly push for the pricey gold standard. It's common sense frugality and not to be confused with cutting corners.

Mark Rowley

[Richard Hull]

Just a point, I used regular HVAC oil in my 5CFM Yellow Jacket (bought the pump used), and it regularly could hit 8 microns on fusor II. I cannot say that I experimented with forepump oils, however.

All my oils for both direct drive and belt drive pumps were common oils recommended and commonly used in those pumps and all the oils were under $30 per gallon. All of my pumps have done well with the common oils, and I just will not use a pump that pumps above 12 microns at the head, regardless of pump or oil.

Richard Hull