Weeping O rings

[mtb]

I'll get a big bag of mixed O rings to take back with me. The local chandleries are a bit hit and miss with stuff that you actually need rather than want.

have you looked on simply bearings web site ?

 

[colind3782]

have you looked on simply bearings web site ?

I have lots of rings now but thanks.

 

[Heckler]

Silicone grease

Silicone grease goes hard when cold and sticks, Vaseline is better.
S

 

[johnalison]

I hope that you have more luck that I had when trying to replace an O ring. We were in Cowes and a trip round the "chandlers" failed to reveal one who had even heard of such a thing.

 

[cryan]

I was always taught as a cadet at sea to lubricate all o-rings with vasseline before fitting. O-rings, gaskets, joints etc should be lubricated unless the manual says not to. I have never been on a ship that does not carry a tub of vasseline in the Engineroom specifically for the purpose of lubricating o-rings.
O-rings are usually one hit wonders though. Once disturbed they become stretched so its better to just replace them.

Companies such as Dow Corning supply O-Rung dressing in spray form but the general consensus seems to be to avoid these as they cause the o-ring to swell and fail quicker?

 

[cryan]

I should add that the likes of Screwfix can supply assorted o- ring kits for quite cheap. Or Cromwell Tools etc will supply you with o-ring material to make your own.

 

[Plevier]

I bought a mixed box when Aldi were doing them. The quality was so bad with surface defects and mould line flash that there was no chance they would seal, I took them back.
i would check carefully for the same with cheap boxes from ebay etc.

 

[Bilgediver]

The O rings on my logwheel transducer were letting seawater past them as a slow weep. I seem to have stopped the leak by applying a liberal dollop of Vaseline to the O rings but I'm sure there must be a more suitable sealant? The sealant must be non-setting as the logwheel takes taken out regularly for cleaning.

Any recommendations apart from replacing the O rings?

What can be done is to fold ptfe tape and wind on a couple of turns in the bottom of the groove....

 

[ZigZaging]

I was unable to find any in Bastia before we left, they were quite large about 27mm ID for the smaller of the two as I remember. I've emailed Airmar for the sizes and they offered to supply a kit For 37euros containing 4 X O rings the wheel and spindle.

(Paddle wheel kit Valve ST600 610 Part No 33-250-02 Amount 33.75)

I replied asking for the sizes again - we'll see.

If they do answer I'll post here.

 

[colind3782]

This is the set that I bought and they seem ok.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItemVersion&item=360988728141&view=all&tid=573913293023

 

[ghostlymoron]

O-rings shouldn't need any sealant to make them leak free provided they are the right size they rely on compression between the two surfaces. They are prone to damage when inserting and a bit of vaseline or other grease makes this a lot less likely.