Udo van Dongen

I use a few drops of silicon oil which is sold as 'seal saver' and rub it in with my fingers.

 
I (used to, because it quit working by itself some months ago) have a Hugycheck with its permanent monitoring and I think it is a good idea. Pressing buttons during the dive etc... may cause a leak (it did to me) even after being perfectly watertight on the surface. If I were to get a vacuum system I would get one with constant monitoring and, please, a reliable one...

 
The Hugycheck indeed isn't flawless! When i put my housing under a vacuum the green LED blinks and keeps on blinking, also overnight or longer. Last week i was using my housing in Spain and almost every day after a day of diving i discovered some tiny drops inside the housing. I emailed the manufacterer about it, and (as usual) they said it's most likely that the drops of water fell from my hair or that they are originated from the wet outer edges from where tiny drops spash in when you take the 2 halfs from the housing apart. But later that week i discovered that after a day of diving my camera body was wet too! Especially around the AF-ON button there is a rim around the button on the camera and with a balloon air blower i could blow out salt water. Fortunately my camera body still works fine, because it's weather sealed (advantage of a pro-body?). More accurate examination of the housing showed that the AF-ON button was having a slight leak. I put my housing under a vacuum without a camera and via the port i could see a small drop of water on the inside of the AF-ON button (the housing was still wet on the outside from the rinsing); no doubt about it, a leak. The Hugycheck always indicated that the vacuum is still present. Apparently a few drops of water in the housing do not cause a detectable pressure increase, which makes sense to me because the pressure increase is indeed minimal. BTW, an overnight green blinking Hugycheck was still green blinking the next morning, so based on hugycheck my housing was always perfect.
 
Anyway, Pascal from Hugyfot was so kind to send me a few new buttons, O-rings, spacers and some extra strong replacement springs which they sell for tech dive photographers who want to take photos up to 150 metres depth. My personal belief is that stronger springs put slightly more pressure on the O-rings, which will make them close better. Pascal denied it would make any difference, but i feel a little more confident about it this way. Fingers crossed the next trip! My housing is now almost fully equipped with extra strong springs except for two buttons (he didn't send enough springs...)
 
cheers, Udo