Home |
Search |
Today's Posts |
|
Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
Posted to rec.crafts.metalworking
|
|||
|
|||
Metal Compatability in Water.
I need to make a reciprocating water pump as :-
http://good-times.webshots.com/photo...ost=good-times for a small marine engine. Casting and machining one is out of the question, so it is piece one together. Steel tube outer casing with brass inner sleeve and using silver steel rod for the piston. Question : Would the brass sleeve and the silver steel rod be compatible materials, corrosionally speaking, if left in contact with fresh (not salt) water together for any length of time? Thanking you in advance. Regards, DJC. |
#2
Posted to rec.crafts.metalworking
|
|||
|
|||
Metal Compatability in Water.
"D.J.Carter" wrote in message ... I need to make a reciprocating water pump as :- http://good-times.webshots.com/photo...ost=good-times for a small marine engine. Casting and machining one is out of the question, so it is piece one together. Steel tube outer casing with brass inner sleeve and using silver steel rod for the piston. Question : Would the brass sleeve and the silver steel rod be compatible materials, corrosionally speaking, if left in contact with fresh (not salt) water together for any length of time? Thanking you in advance. Regards, DJC. (For the American readers, "silver steel" is oil-hardening tool steel.) I can't comment on the galvanic corrosion relationship, but silver steel is only slightly corrosion resistant, all by itself. -- Ed Huntress |
#3
Posted to rec.crafts.metalworking
|
|||
|
|||
Metal Compatability in Water.
On Tue, 4 May 2010 14:21:23 -0700 (PDT), "D.J.Carter"
wrote: I need to make a reciprocating water pump as :- http://good-times.webshots.com/photo...ost=good-times for a small marine engine. Casting and machining one is out of the question, so it is piece one together. Steel tube outer casing with brass inner sleeve and using silver steel rod for the piston. Question : Would the brass sleeve and the silver steel rod be compatible materials, corrosionally speaking, if left in contact with fresh (not salt) water together for any length of time? Thanking you in advance. Regards, DJC. Use stainless for the piston. Marine grade. |
#4
Posted to rec.crafts.metalworking
|
|||
|
|||
Metal Compatability in Water.
D.J.Carter wrote:
I need to make a reciprocating water pump as :- http://good-times.webshots.com/photo...ost=good-times for a small marine engine. Casting and machining one is out of the question, so it is piece one together. Steel tube outer casing with brass inner sleeve and using silver steel rod for the piston. Question : Would the brass sleeve and the silver steel rod be compatible materials, corrosionally speaking, if left in contact with fresh (not salt) water together for any length of time? Thanking you in advance. Regards, DJC. Bronze would be a better choice if you can get it. Brass will wear fast and the silver steel will rust regardless of what water it's in. Will this be pumping hot water or is it the intake pump pulling in cold water? -- Steve W. (\___/) (='.'=) (")_(") |
#5
Posted to rec.crafts.metalworking
|
|||
|
|||
Metal Compatability in Water.
Thank you, Ed.
I wasn't too sure on the corrosion resistance of silver steel. A bit less resistant than I thought. Thank you, Brian. Marine grade stainless it is for the piston. Thank you, Steve. Bronze it is for the sleeve The pump is for drawing cold water up and pushing it through cylinder jacket and water cooled exhaust . It will be mounted on the cylinder similar to this one. http://good-times.webshots.com/photo...ost=good-times Thank you very much, gentlemen. Much appreciated. Regards, Dave Carter. |
#6
Posted to rec.crafts.metalworking
|
|||
|
|||
Metal Compatability in Water.
On May 5, 2:38*pm, "D.J.Carter" wrote:
* *Thank you, Ed. * * * * *I wasn't too sure on the corrosion resistance of silver steel. A bit less resistant than I thought. * Thank you, Brian. * * * * Marine grade stainless it is for the piston. * Thank you, Steve. * * * * Bronze it is for the sleeve * *The pump is for drawing cold water up and pushing it through cylinder jacket and water cooled exhaust . It will be mounted on the cylinder similar to this one. http://good-times.webshots.com/photo...3FbliXM?vhost=.... * Thank you very much, gentlemen. Much appreciated. Regards, * * Dave Carter. If it's not a model, use a centrifugal pump, ala car water pump. You'll have a lot fewer problems. Can't see your pics here, so have to guess from your application description. It's a high-flow, low- pressure application, centrifugal is the way to go. Stan |
#7
Posted to rec.crafts.metalworking
|
|||
|
|||
Metal Compatability in Water.
On 6 May, 17:22, wrote:
er. If it's not a model, use a centrifugal pump, ala car water pump. You'll have a lot fewer problems. *Can't see your pics here, so have to guess from your application description. *It's a high-flow, low- pressure application, centrifugal is the way to go. Hello Stan, Sorry for the delay in replying. The engine needs a reciprocating pump because of the water cooled exhaust system. The water pump has to be timed to pulse water through the system between crankshaft tdc and bdc, irrespective of crankshaft rotation. (The engine is two cycle and reversible). An adjustable amount of water is squirted into a chamber (attached to the exhaust port) on the power stroke, and is vapourised by the heat energy of the exiting gasses, thus cooling and quietening them. After the initial blast of gasses out of the port, and before the piston covers the port on the compression stroke, there is a negative pressure wave going back into the cylinder. If a rotary pump were used, then any water still entering the chamber at this point could be sucked back into the cylinder with disasterous consequencies. The bore and stroke of the pump is 7/8" and 1/2" respectively, so quite a low flow rate at 600rpm. The engine is of 1911-14 vintage and will be for show purposes only. Regards, Dave Carter. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
ISD 2560P chip pin-out compatability | Electronics | |||
Replacement Wiring compatability | Home Repair | |||
Camcorder 8mm playback Compatability? | Electronics Repair | |||
Compatability Issue | Metalworking | |||
Bus compatability | Electronics Repair |