Air pump vane material

I'm repairing a older air pump that used vanes (hard to say repair as the vanes and vane holder are missing completely). From suggestions I've found some MoS2 impregnated Micarta as a vane material but I thought I'd ask here as it seems that a lot of vacuum pumps use a carbon (graphite?) vane. The vanes I will be using won't get moving fast and the originals were just polished cold rolled steel with decent lifespan so I'm thinking that I might find some salvaged vacuum pump vanes for use. Thoughts?

Years ago I repaired some low pressure vane type compressors. The vanes were canvas reinforced phenolic (Bakelite). The suitability of the MoS2 vanes will depend on what the reinforcement material is. Canvas would be ideal.

Illinoyance said:

Years ago I repaired some low pressure vane type compressors. The vanes were canvas reinforced phenolic (Bakelite). The suitability of the MoS2 vanes will depend on what the reinforcement material is. Canvas would be ideal.

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AKA Tufnol style vanes normally need some kinda lube though. That with dust and crap in the air tends to cause em to gum up in time if the pump sits too long.

Carbon vanes are strictly oil free and work great in that environment. Any contamination though and its a problem and you need pump output filtration to catch the dust.

Steel vanes normally need lube also,

Key thing material aside is getting the clearances correct Vanes get hot quick and expand and you have to have enough length for them to do so with out locking everything up. See if you can find some pump rebuild manuals on line that use your vane material choice then set the end play based on thoes. Its a common step in rebuilding any vane pump.

adama said:

Carbon vanes are strictly oil free and work great in that environment. Any contamination though and its a problem and you need pump output filtration to catch the dust.

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FWIW, we build obsolete engines and some of them use a vacuum pump with carbon vanes; it's driven by a stub shaft off the bottom of the oil pump. They run submerged in engine oil for years.

jack vines

I was using a small Gast vacuum pump to bleed brakes with. I got too much brake fluid in the collection jar and it got into the pump. It totally and instantly trashed the vanes (carbon). I was amazed at what a new set cost from Gast so I made some out of phenolic. They have held up well.

I use phenolic for vacuum pumps and similar vanes. However the quality of canvas reinforced phenolic varies considerably and I find that most of the current stuff is of poor quality, is prone to de-lamination and machines poorly. I think it has to do with density as my old stock is slightly heavier for same size piece. As well, though I am not sure if this is an indication, the old stock is of darker colour than what I bought recently.

I can't find any phenolic with MoS2 for retail sale, but there is this Garolite CE - cotton reinforced phenolic with graphite. McMaster-Carr I think it'll do about as well.

Wlodek said:

I think it has to do with density as my old stock is slightly heavier for same size piece. As well, though I am not sure if this is an indication, the old stock is of darker colour than what I bought recently.

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If is available in different grades, also some grades have wear reducing fillers added too, finding those is probably the harder bit and probably for certain not off the shelf local any more.