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

[seakaye12]

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!

[ede]

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

[frankr]

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

[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.

[seakaye12]

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]

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.

---

Attachments:

[wedgie]

Here’s the post I was referring to 😉

viewtopic.php?f=13&t=3556

[seakaye12]

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?

[wedgie]

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]

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

[Author]

Posts