View Full Version : vent screw rubber ring on iS 121 WC 2010 breaking after 1-2 uses

12th July 2010, 01:21 AM
Hi All,

just a short notice of what happened to me: used my 2nd new iS 121 WC 2009 and saw that the rubber ring fell apart on 3rd use. Replaced it and saw that after 1 use with new ruber the rubber was fallig apart again. Since this is my second iS 121 WC in a couple of weeks and my first was exchanged due to tons of water "in" the board leaking out of the vent I would recommend all owners to check theirs for similar damage (and sb to look into this, I wouldn't expect the rubber ring to break/wear down so soon). I don't know why this is happening (I have 4 other boards, 3 sbs with no problems what so ever). <- no rant, just serious warning.

12th July 2010, 06:21 AM
Hello, Duracell,

You might care to have a look in the board at the "ledge" against which the O ring tightens. Sometimes this "ledge" can have material on it which cuts/erodes the O ring, leading to failure.

Similarly, have a look on the shoulder of the vent screw, to see if the shoulder has a rough edge on it, which can cause the same problem.

Hope this helps.

12th July 2010, 07:23 AM
See if you can find a composition (material) gasket, or use a couple of hole punches to
make your own composition gasket from some 0.032" gasket material.
The reason the "o" ring tears on your iSonic is probably as Windman suggests.
The surfaces the O'ring gets crushed between are not smooth or parallel.
Try using some soap on the threads and wet the soap and put a soap slurry on the
O' ring before installing it.
Also, the vent plug does not need to be real tight.
Just make contact with the O'ring and perhaps a little more.
The way the O'ring is used on vent plugs throughout the entire WS industry is
pretty much all wrong from a mechanical and seal engineering perspective.
O'rings are only supposed to be compressed approx. 15-20% of their overall
thickness, and the gland around them is supposed to be designed so the O'ring
can "move" in the direction required to effectively seal against both inside and
outside pressure or vacuum.
Crushing the O'ring traps it and completely defeats the normal design parameters.
A flat composition gasket (like on the oil pan plug in your car) will do a much better
job of sealing in the current design vent plugs.
Hope this helps,