replacement washers for fuel/water bottles?

[MicheleK]

Where can one buy rubber washers to replace perished ones in Melbourne?

I have found round washers for my Trangia burner by going to the Bearing Wholesalers in Bayswater where they are 68 cents (compared to $4 for genuine Trangia ones in Bogong Equipment), but they don't sell the square sided ones for my Sigg fuel bottles. They didn't know where i could find those. I know they are probably on ebay etc but i like to be able to walk into a physical shop and have the old ones measured precisely rather than buy something sight unseen which might not fit.

Any ideas? Tried Clark Rubber so far, no luck. Sigg probably does sell replacements, so i will resort to that if i can't find cheaper ones.

[Moondog55]

SIGG haven't sold fuel bottles for over a decade so spare washers may not be available from them but I just checked my last remaining SIGG fuel bottle and it has a standard flat washer. Photo??

[MicheleK]

Here's a photo and rough dimensions using calipers.

Attachments

[north-north-west]

I would have thought an appropriately sized O ring would work just as well.

[Moondog55]

It's what I would call a flat washer and like NNW I see no reason why an appropriate polymer "O" ring wouldn't work

[Gadgetgeek]

Any auto parts/farm supply store should be able to help. From memory (and google) you want Neoprene or Butyl rings, for ethanol. Found this handy chart
http://mykin.com/rubber-chemical-resistance-chart-3

[Warin]

O rings are sized on
the inside diameter and
the thickness

You may get more accurate measurements/estimates from the caps rather than the worn seals.

A look on ebay for an O ring 27 2.5 got a silicon one - 10 off for <$5.

I have a box of Adli ones - closest is 26.5 3.55 mm might be more common.

[MicheleK]

Thankyou! I did wonder if i could just use an O ring instead but wasn't sure.

[sambar358]

Standard rubber O-rings are not suitable for fuel bottles as the fuel can/will dissolve them quite quickly. These are fine for drinking bottles but for fuel use fuel-tolerant Nitrile O-rings which will be available from retail outlets that sell automotive products....SuperCheap Auto, Autobarn, Repco, Burson etc. Cheers

s358

[Gadgetgeek]

Nitrile isn't stable long term with ethanol. For white gas nitrile or polyurethane.

[MicheleK]

There are quite a few websites that suggest nitrile washers are OK with methylated spirits/denatured ethanol:

https://www.applerubber.com/chemical-co ... ity-guide/
https://www.allorings.com/o-ring-compatibility

Gadgetgeek, when you say "nitrile isn't stable long term with ethanol", what do you mean by "long-term"? The original washers in my fuel bottles lasted 10-15 years, so i'd be happy replacing them in that time frame.

[Gadgetgeek]

I'm just going off the site I found. I have no reason to doubt your experience, or your research. Could be that there is a difference in opinion or one person's "questionable" is another's "fair" or even "no worries" due to conditions, or even testing methods. Having not tested this myself, and not knowing what any of the orings I've used were actually made of, I can't speak with much overall authority. Just internet authority.

I've not noticed ethanol doing much that was odd to nitrile gloves, maybe weakening them a bit, but not doing the same things that happen to latex gloves with some chemicals.

I would suspect that the best move is to get an oring, soak it in the fuel for a few weeks and see if its breaking down or getting stiff. If it seems unchanged you'd be good to go.

[MicheleK]

Ah, I see. OK, I will do the experiment and report back. I have learnt a bit in this exercise already, thankyou to everyone who responded.