Can anyone suggest the correct material to use when fabricating new piston rings? Ex. Monson RR #3 at the Maine Narrow Gauge needs a set. She has ten inch cylinders. We have a supplier who will supply to us at no/low cost "Ductile extruded cast iron" known as DURABAR #s 65-45-12, 80-55-06, 100-70-02 or we have a choice of regular cast iron ASTM A-48 class 40 or ASTM A-48 class 30. I don't know which one to go with! Good advice would be much appreiciated.

psnh@mediaone.net

> Can anyone suggest the correct material to
> use when fabricating new piston rings? Ex.
> Monson RR #3 at the Maine Narrow Gauge needs
> a set. She has ten inch cylinders. We have a
> supplier who will supply to us at no/low
> cost "Ductile extruded cast iron"
> known as DURABAR #s 65-45-12, 80-55-06,
> 100-70-02 or we have a choice of regular
> cast iron ASTM A-48 class 40 or ASTM A-48
> class 30. I don't know which one to go with!
> Good advice would be much appreiciated.

Class 30 grey iron is a good choice. Be sure and get centrigufula cast with fine grain structure. it machines up very nicely and has no "blowholes" or other imperfections that can haunt you.

Let me offer a different thinking on this piston ring question. The standard practice was to use a cast iron ring and a bronze ring in combination (unless you have the one piece ring configuration). TVRM got away from this some 11 years ago and have ran bronze T-type sectional rings in the 4501 and 610 quite successfully. We use two type of alloys. One is a CDA937 and the other is a CDA932 (I hope I remember that correctly). The harder bronze is actually more porous and acts as the "oil" ring like the cast iron ring. The softer bronze is the sealing ring. The thought here was the use materials that were "softer" than the cylinder liners. We've got ten years of service on our 610 now and we've seen little in the way of wear on the cylinders with absolutely no scoring.

aw90h@cs.com

Your locomotive is a nice, simple and easy low pressure saturated hog right? If memory serves....and you don't do a lot of fast mainline operation.

Any of the options will do OK for you. Mark Ray's bronze is great too. Extra Extra Heavy iron pipe end cutoffs can be bought at scrap dealers for a couple bucks and several rings peeled off. Cast iron plate can be sawed out and machined to fit. I made a ring for my air pump's nasty groovy cylinder bore from a cast iron water pump housing.

Best of luck and don't sweat this one too much.

Dave


irondave@bellsouth.net

Many thanks to all who responded to my question about material for piston rings. It is good to know that you guys are out there and willing to help.


psnh@mediaone.net