The correct material for making a diaphragm for the OMC Pressure Tanks

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  • seakaye12
    seakaye12

    US Member - 2 Years
    Replies: 493
    Topics: 116
    #6392

    Yes; I know that the diaphragms are sold by various suppliers (OMC #305715 and #302563…..Plastic Button/Metal Button) but most likely they will not be available for much longer and I would like to get a handle on what the material is so I can make my own.

    Can anyone provide a source for the bulk diaphragm material for the OMC pressure tanks? Or…..can someone tell me exactly what the material is called? Nitrile Rubber? And the appropriate thickness etc.

    Thanks!

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    ede

    US Member - 2 Years
    Replies: 135
    Topics: 3
    #53392

    As long as there is a demand, the part will be available

    frankr
    frankr

    US Member - 1 Year
    Replies: 4812
    Topics: 48
    #53393

    Nitrile rubber. Also known as Buna-N. Or if you want to get highly technical https://en.wikipedia.org/wiki/Nitrile_rubber

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    wedgie


    Replies: 975
    Topics: 94
    #53394

    I believe it is called Buna n nitrile. Someone here has used some rubber gloves to make diaphragms. I’ll see if I can find the posting.

    seakaye12
    seakaye12

    US Member - 2 Years
    Replies: 493
    Topics: 116
    #53396

    quote Wedgie:

    I believe it is called Buna n nitrile. Someone here has used some rubber gloves to make diaphragms. I’ll see if I can find the posting.

    Yes; I read that just before posting here. Here’s the post:
    viewtopic.php?f=2&t=10388&p=54523&hilit=nitrile#p54523

    Can anyone tell me what thickness the Nitrile is that OMC uses in their diaphragm? I just found this one source that might have what we need if I can narrow down the thicknes:

    http://www.warco.com/pdf/WARCO-BILTRITE … atalog.pdf

    Around pages 13-14 there are various Nitrile products that should work?

    Mumbles
    Mumbles

    Canada Member - 2 Years
    Replies: 4385
    Topics: 431
    #53401

    The BuRP tank diaphragms I have mike out at 0.030" which is thicker than the fuel pump material. A few years back TT posted it or the pump material in 36 or 48 inch wide rolls and I believe McMaster or Grainger was the source. The diaphragms also have a woven reinforcing in them.

    A piece of fuel pump diaphragm material measured out at 13 thou.


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    wedgie


    Replies: 975
    Topics: 94
    #53413

    Here’s the post I was referring to 😉

    viewtopic.php?f=13&t=3556

    seakaye12
    seakaye12

    US Member - 2 Years
    Replies: 493
    Topics: 116
    #53424
    quote Wedgie:

    Here’s the post I was referring to 😉

    viewtopic.php?f=13&t=3556

    http://www.ebay.com/itm/One-pair-North- … SwpDdVJ-~8


    That seller is still offering them; $1.79 plus shipping. Although as Mumbles states….that material may work for fuel pumps but a thicker re-inforced material would be required for the tank diaphragms.

    So; the search goes on. I might stop by my local Grainger and; armed with the thickness (0.030") ask if they have something suitable.

    Does anyone know if the diaphragms included in the kits that Laings or Vintageoutboards sells are genuine OMC….or something a bit different?

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    wedgie


    Replies: 975
    Topics: 94
    #53450

    The diaphragm I have from Vintageoutboards mics out at .035, and the dried out original one it is set to replace is around .027 or so. The new one looks pretty good though I doubt it is OEM. Maybe one day I’ll get around to installing it. Perhaps when my order of 2 line fuel hose arrives in the spring 😎

    seakaye12
    seakaye12

    US Member - 2 Years
    Replies: 493
    Topics: 116
    #53659

    Well….I placed my order thru Grainger today. Their part Number #1DPZ3. A 12" square of the Buna-N/Nitrile rubber sells for $4.24….shipped to a store for free. I figure I can make as many as 12 diaphragms from that 12 x 12 sheet ….so it’s worth a try.

    They sell a variety of Nitrile materials…..they differ in hardness. elongation , and various other factors. I’m hoping that the one I picked will work ok.

    We’ll see.

    https://www.grainger.com/product/E-JAMES-Rubber-1DPZ3

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    billw

    US Member - 2 Years
    Replies: 1115
    Topics: 38
    #53668

    Nice detective work….I am going to order a piece, too, just to see what it looks like…….

    Long live American manufacturing!

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