We are using 2" enclosures with blank, 2-hole and 4-hole end caps. We’ve tested them and they work great underwater, however, after a month of sitting on my desk, I noticed that on at least three of the end caps, the o-rings had degraded to an extent they would fail underwater.
My question is, am I doing something wrong? We used the supplied silicon grease and have not exposed the o-rings to any chemicals (as far as I am aware). Would o-rings be expected to perish so quickly - should they be removed from the end caps if not being used - is exposure to daylight an issue (through a window in an office).
Any tips much appreciated - thanks!
Hi @jamie_mac, welcome to the forum
The o-rings are technically consumables, but they definitely aren’t expected to lose their effectiveness after just a month of storage, and they shouldn’t need to be removed while the vehicle is not actively in use.
That said, many plastic and rubber materials are degraded by extended exposure to high temperatures and UV, so that does seem a plausible reason for the issue you’ve run into. That also seems to be a common failure mode for o-rings generally.
I’ve asked internally and will confirm, but it’s likely worth at least covering the vehicle (especially if you’re using an acrylic enclosure) when it’s expected to be exposed to long periods of daylight (be that in storage, or in transport in a car or boat on the way to an operation site).
Hi @EliotBR Thanks for your your response. I took the device to our marine technicians and they seemed to think it was unlikely that exposure to daylight through triple glazed windows (we are right next to a stormy beach) would be the cause of this. The only thing I can think of is that perhaps indirect mist from cleaning fluid used to regularly clean the lab could have caused a reaction? Otherwise I’m pretty stumped. Pic of the degradation attached.
Fair enough, although untreated glass does not block all types of UV light, so it may not be possible to completely rule out this option, especially if there’s frequent extended direct sunlight exposure through the window.
Hmm, maybe? You could do some testing and directly spray an o-ring with some of the cleaning fluid a few times to see if it degrades over a short period of time.
Either way, both of your currently hypothesised causes can be mitigated by covering the device when it’s not actively in use, which may also help to protect the electronics and other components (from dust, cleaning chemicals, sunlight, etc)
There may also be issues if the o-rings are generally kept exposed to air, especially if your lab is actively de-humidified.
If you aren’t already it could be worth keeping the enclosure tube on while not working on the device, which should also reduce the amount of o-ring cleaning and re-lubrication required when re-installing the tube.
Hi @EliotBR - thanks for the thoughts. I’ll replace the -o-rings and follow that guidance - hopefully that will solve the issue. Cheers.