Lubrication free condensing?

[Lopez Mike]

I've often thought that you could run a pump like that with either a slight interference fit with Delrin or Teflon or a flexible lip and the same materials like a bike air pump. It would make for a good vacuum at fairly low speeds. And easy to experiment with as the only thing you would be risking would be the piston.

I've often thought that a diaphragm pump would work. I had an old truck that had a fuel pump with a vacuum pump as half of the pump for the windshield wipers. I have no idea what vacuum it achieved. The diaphragm would probably wear out and crack.

[barts]

There was an article in steamboating magazine many years ago about using dual car mechanical fuel pumps as an air pump... seemed to work just fine.

- Bart

[fredrosse]

"I wonder if wildly overheating a Teflon frying pan would do this"

Of course the safety implications here with very common cookware applications, and certianly many hundreds of incidences of neglectful cooking are obvious. Once I heated up some pizza in my oven, intending to eat it right away, but got distracted, and ended up with the pizza in the oven at 550F for three days! At least I got to see how much carbon there is in pizza!

Anyway, with teflon cookware left to overheat on a stovetop, if it were toxic I would think we would hear about this on the news all the time. Does anyone know about this with more than my uneducated conjecture?

[barts]

"I wonder if wildly overheating a Teflon frying pan would do this"

Of course the safety implications here with very common cookware applications, and certianly many hundreds of incidences of neglectful cooking are obvious. Once I heated up some pizza in my oven, intending to eat it right away, but got distracted, and ended up with the pizza in the oven at 550F for three days! At least I got to see how much carbon there is in pizza!

Anyway, with teflon cookware left to overheat on a stovetop, if it were toxic I would think we would hear about this on the news all the time. Does anyone know about this with more than my uneducated conjecture?

http://www.goodhousekeeping.com/cooking ... ety-facts/

Definitely will take out your pet birds.... your mileage may vary .

- Bart

[RGSP]

"I wonder if wildly overheating a Teflon frying pan would do this"

Of course the safety implications here with very common cookware applications, and certianly many hundreds of incidences of neglectful cooking are obvious. Once I heated up some pizza in my oven, intending to eat it right away, but got distracted, and ended up with the pizza in the oven at 550F for three days! At least I got to see how much carbon there is in pizza!

Anyway, with teflon cookware left to overheat on a stovetop, if it were toxic I would think we would hear about this on the news all the time. Does anyone know about this with more than my uneducated conjecture?

Fred, pure aluminium (or aluminum if you prefer) melts at about 660C, and cooking pan alloys rather less, while Teflon is only mildly nasty at high temperatures up to about 690C. I think that's your answer. It may also explain why cast iron pots are never Teflon coated in my experience, although it may be that they'll take viteous enamel, which can be almost as non-stick as Teflon but much more durable.

[barts]

[
Fred, pure aluminium (or aluminum if you prefer) melts at about 660C, and cooking pan alloys rather less, while Teflon is only mildly nasty at high temperatures up to about 690C. I think that's your answer. It may also explain why cast iron pots are never Teflon coated in my experience, although it may be that they'll take viteous enamel, which can be almost as non-stick as Teflon but much more durable.

Teflon is not recommended for use over 550F.

"When Teflon® AF resins are decomposed in air at temperatures
from 360 to 450°C (680 to 842°F), products observed are
HF from reaction of COF2 with moist air, COF2, CO, and
hexafluoroacetone (HFA). The amount of HFA evolved upon
complete decomposition at 500°C (932°F) is up to 100–
200 mg/g of sample"

https://www.chemours.com/Teflon_Industr ... H75334.pdf

- Bart

[Kelly Anderson]

The guy at the Oly Brewery was Al Giles and my dad made the rings for the brewery compressor. I believe, however, that he used ordinary cast iron rings on his boat, the Crest, but used Teflon for packings and had very good service. I will check on that the next time I look the engine over. It's out of the boat in Olympia.

Al Giles wrote that article. It was in one of the first issues of Steamboat News. He was using carbon filled Teflon for piston rings. I used that material for several years in Reciproca before Green Velvet PB&J came available. It worked well enough for piston rings, but the slide valve running with water lubrication only was another story, even though it was balanced. The seat came out looking quite similar to that photo.

There was an article in steamboating magazine many years ago about using dual car mechanical fuel pumps as an air pump... seemed to work just fine.

That was Ike Harter, writing for Live Steam back in the Seventies.

[Lopez Mike]

Al wasn't afraid to experiment. He and my dad worked in the same small shipyard in Olympia, Washington in WW2 building 300' wooden tugs with steam power. Al was a carpenter and my dad's job was to assemble the partially knocked down triple expansion engines, get them running and take some indicator diagrams during sea trials to tweak the valve settings. I think they turned out five of them. As far as I know all of them got blown up in minesweep duty in the South Pacific.

Al got the steam bug from that exposure. Bought that old whale boat hull that he worked up into the Crest and made one practical design after another work for him. And wrote clear articles about it.

He told me once that working maintenance at the brewery was where he learned that there was a right way and a wrong way to use a pipe wrench as a hammer. Hmm.

He met his match with a three cylinder Disney uniflow. Never did get it to reverse reliably. Nailed a fee docks hard. Once with me along as deck hand. Ended up with an I.C. engine in Echo, his big boat. Are you listening, Bart? (grin)

[barts]

He met his match with a three cylinder Disney uniflow. Never did get it to reverse reliably. Nailed a fee docks hard. Once with me along as deck hand. Ended up with an I.C. engine in Echo, his big boat. Are you listening, Bart? (grin)

Yup... you'll note that with a Kitchen rudder, the engine continues running forward, and the rudder acts just like a jet engine thrust reverser to stop the boat and start moving backwards. There are accounts of boats so equipped stopping in one and a half boat lengths from full speed ahead. There's a reason we're going with that plan.

Reversing reliably requires auxiliary vacuum and a valve that gives one 70% cut-off or so.

These rudder also make leaving a mooring really easy... put the rudder in neutral, start the engine and get it hot. Then go forward, let go the mooring line and move the rudder to reverse position to pull back from the mooring.

- Bart
.

[PeteThePen1]

Hi Folks

Many thanks for all your posts. I have learned a lot and am now much more suspicious of the cookware in our kitchen!

I think the answer for me is to build the system with a mind to recover the oil and set the oiler to its lowest setting.

Now all I need to do is see how I can get it all to fit in the available space.

Regards


Pete