How long should a housing hold a vacuum?

[Akimbo]

I can pump up my Nauticam housing the night before and and go dive the entire day on it without it losing its vacuum.

Same here. I helped a friend with a Nauticam housing find a slow vacuum leak. We traded vacuum port caps and it fixed it.

 

[macado]

Sounds like a vacuum test in a bath tub (without the camera) might be in order.

Yup. That is my next step. It is just taking forever for it to "fail." which I guess is a good thing I'm on 4 hours right now and it's still holding a negative/vacuum. If it stops tonight I'll re-do the test and put it in my rinse tank (sans camera) overnight.

 

[Compressor]

Apologizes for the stupid question but I'm still fairly new to mid-range camera housings. I've always used crappy point and shoots and never bothered with a vacuum port but I recently purchased a Sony A400 with an Ikelite 200DLM/A Underwater Housing and DLM 6" Dome Port.

I installed a Vivid Leak Sentinel V5 in this housing. I noticed unfortunately that my camera seems to be losing vacuum after about ~3-4 hours. I cleaned the main o-ring seal and dome port o-ring but it seems the issue is still persisting. I noticed this and opted not to dive with the camera so now I'm trying to troubleshoot a bit more. I've timed it a couple times but it seems to lose part of the vacuum after 3-4 hours. When I left it overnight there was still a minor vacuum in the housing

My procedure has been to pump a vacuum until the sensor turns green and then I've been doing 3-4 additional pumps after that to ensure a good vacuum. This morning I woke up and checked the vacuum again and it's alternating between red/green so it seems to be slowly losing vacuum.

I assume this is not safe to dive or is a 4 hour vacuum sufficient? I've obviously got a leak somewhere it seems. I really don't feel like flooding my new camera. This also seemed to happen on a dive last winter but thankfully the camera didn't flood (I was in a cave and couldnt really quickly ascend).

I'm going to order a new o-ring face seal and o-ring for the dome port but if that doesnt work I assume I should send the housing in for service? Are there any other less obvious things I should check or tips/tricks?

The housing is less than year old. I've maybe got 15-20 dives with it (mostly in caves and one or two salt water dives) .

A sealed housing should not loose it's vacuum. Otherwise it's leaking.
I don't have your housing but an Ikelite. I create a vacuum, leaving the pump on. If after 30 min there is no change in the negative pressure generated, I take the pump out and go diving.. Even after a day of diving, I cannot peel the back off unless I release the vacuum with the pump reattached and reversing the the negative pressure.

Hope this helps.

 

[Compressor]

I agree with @Akimbo. Anomalies need to be investigated. They may lead you to avoid a more serious problem.

 

[Nemrod]

I too can pump my Nauticam NA6400 down the evening before and dive all the next day and it is still green when I get back. If you are pulling the vacuum and the temperature is stable and as you say, you are adding a few pumps past green, well, you have a leak is my guess.

N

 

[njdiverjoe]

I recently pumped my Nauticam down and it stayed green for 2 and a half days before I opened the housing up.

 

[jmark18]

My Aqutica has held it's vacuum for as long as a week. I only open it to change batteries. There seems to be a new vacuum circuit as a CR 2023 battery will last almost a week while flashing it's green is good light every 5 seconds.

 

[ATJ]

If the temperature isn't changing, there should be no change in the internal pressure of the housing unless you have a leak.

I also have an Ikelite housing with the non-electronic vacuum system. If I do any maintenance on my housing (like clean or replace a control) I use the vacuum system and leave it for at least a day before checking back. If I did the maintenance correctly, the pressure doesn't change at all.

 

[msteurer]

agree with others - the housing should hold the vacuum for many hours - at least 12-24h. Otherwise you have some slow leak (check for stuff like hair etc).

 

[macado]

Thanks; this was an old thread but I'm not sure if I ever updated it. I cleaned the o-rings for the 20th time, reseated the vacuum port and finally got it to hold a vacuum almost indefinitely (at least 24 hours). I'm guessing cat hair or the fitting was not completely torqued down where the vivid leak sensor was installed.

The other thing I was doing was not pumping enough of a vacuum so the sensor was right on the edge. I know make sure I do another 5 or 6 vacuum pumps after it turns green.