Leak Sentinel Leak Detector

[diverdoug1]

I am having trouble following.
1. when the condensation happens, is it just in battery compartment?
2. when the condensation happens is it only when your going from outside to your cooler cabin?

The part if there are drops of water causing fogging when the camera gets very hot certainly can happen!

The case with the room with fans but no A/C is also a favorable case for fogging because the fans do not decrease the temp or humidity before closing the housing.

When you are opening quickly, it is long enough to completely change the interior air composition, so if done outside, this also would promote fogging.

Regardless of the use of dessicants and vacuums, I think prepping in a cold room will PROMOTE condensation, unless the housing is only opened in the cold/dry air, and all components are kept in the cold/dry air when out of the camera. If I am in a situation where I am not able to adhere to this, I keep my equipment on the outside camera table, or outside in a pelican box so that the housing and camera will stay warmer. Example would be you pull a beer mug out of the freezer and take it out by the pool, it does not take long to condenses and frost up

 

[Interceptor121]

1. I do not actually see any condensation this is really what pxxx me off. But if I look at few dew point calculators seems like it would condense so this is my best guess or I have to think the camera is absorbing moisture in some other way (OK I am happy to give up this idea if there is any reasonable alternative)
2. I have no idea. I had one case where the battery actually failed during the dive and the camera would switch off. That was the moment where I stopped going into the AC cabin

I think where the problem lies is that at the end of a day of shooting or when you need to change the battery you are quite keen to take the memory card and battery off and then seal the housing again.

If in theory the housing and the camera inside had time to cool down before being opened I guess there would not be issues. But is that moment of excitement of wanting to see the material that is the problem.

I have since bought an air gun to attach to the LPI I take this with me and blast the inside of the housing with it before closing. This seems to sort out all the issues as the compressed air is extremely dry (or I hope so?) never had any issues since.

Also I hate a cold cabin so that was another torture. I usually only keep the dehumidifier on and temperature of 26C

Out of all this experience I have now downloaded a spreadsheet to perform dew point calculation.

The question is do I get to become a complete sad fxxx if I take this with me on the boat?
SNAP - Touch Screen Weather Forecaster | Weather Forecaster | Weather Station | Oregon Scientific UK

LOL

 

[Akimbo]

Blowing compressed air inside the housing before closing the lid works for me. Low pressure from an HP source is very dry and a lot of dive boats have it available on their camera tables. You can also get an air nozzle that snaps into your BC hose. I have done that on liveaboards in the tropics and avoided fogging without using desiccant.

 

[Interceptor121]

Blowing compressed air inside the housing before closing the lid works for me. Low pressure from an HP source is very dry and a lot of dive boats have it available on their camera tables. You can also get an air nozzle that snaps into your BC hose. I have done that on liveaboards in the tropics and avoided fogging without using desiccant.

Yep I have bought an LPI nozzle.

 

[diverdoug1]

Make sure it is filtered air. I was on a Liveaboard earlier this year where the air nozzle was blowing non-filtered compressed air. It had little blips of water shooting out when it was humid. It was ok for knocking most of the water off your housing, but no good for shooting in your housing or shooting directly on electronics.

 

[Interceptor121]

I have had that experience too and ended up washing up the housing. Thankfully it was the outside. Since I only use an lpi connected to a tank

Have not found any way to determine the weight of a drop of water but if you go by traditional pharmacy standard there are 20 minim in 1ml of water. This means a single drop would be 0.05 grams in a drop. Air at 50% contains 0.02 grams of water if the air left in a housing is 1 liter.
Add one drop and you have effectively saturated the environment.
This also explains why compact cameras in small housing fog more than big housing of several liters capacity.
Say you have 4 liters left one drop equates to 0.05 grams air at 50% would be 0.08 grams total 0.13 grams over 0.16 required for saturation

I think I am now happy with all the various experiences reconciling to the theory thanks for that Doug, discussions pushes to investigate more and now I have a reason for fogging some preventive measures and an understanding of different housings, activities you do with the camera that may or may not lead to fogging. Question is do I take a weather station on my next liveaboard or just continue with LPI and compressed air? I think the 2nd!!!

 

[Akimbo]

Make sure it is filtered air. I was on a Liveaboard earlier this year where the air nozzle was blowing non-filtered compressed air...

Yeah, you want to make sure that the air comes off high pressure air banks and not from a low pressure compressor in the engine room or that drives a Haskell pump. A low pressure compressor will never produce air as dry as a high pressure.

 

[diverdoug1]

How are you guys using the nozzle to put the dry air in your housings? Do you open it a crack and pump the air in for a while and then shut quickly?

 

[Interceptor121]

I get my buddy to blast it whilst I am closing it. Another option is to fill a plastic bag but that really is only for gopro as other housing ate too big

 

[Akimbo]

How are you guys using the nozzle to put the dry air in your housings? Do you open it a crack and pump the air in for a while and then shut quickly?

I picked this trick up as an electronics tech on deep submersibles in the 1970s, except we used pure Nitrogen. It is an especially good procedure in large battery housings to displace Oxygen, but it worked great on video and electronics housings too.

For my housing, I start by opening the back up enough to get the nozzle to shoot air into the dome. Then I slowly pull the nozzle out as I close the back. There is no reason to rush the process. Probably the best way would be to put an 8-12" piece of ¼" Vinyl tubing on the nozzle. Then you could put the end in the dome and pull it out with the back closed except for the last ¼". That “would probably” do an even better job at displacing ambient moisture-laden air.

The reduced pressure at the camera tables on the Odyssey in Truk and the Turks and Caicos Explorer were set to 60-80 PSI — on the low side for an air nozzle. That is a lot lower than the ~140 PSI intermediate pressure on a second stage. I am more comfortable with the lower pressure because 130-150 PSI is more likely to blow an undetected piece of debris against the dome and scratch it… paranoid maybe.

I have an old second stage that I backed the IP off to 80 PSI in my shop. When diving locally I can usually leave the housing closed until I get back home, but humidity isn’t that bad in Northern California anyway.

I installed the Nauticam vacuum system with the sensor last year but still use the same method instead of Silica Gel packets. I didn't get any fogging before installing a vacuum system last May in Turks & Caicos.