To fill up with oil....??

paulraymaekers · 3rd August 2006, 17:04

Quote: (Originally Posted by jradomski)

On handsets that I have filled with oil I have used a strip of neoprene across the back, this has worked well (but made it more difficult to fill) and I haven never had any oozing (nor any bubbles afterward) since I started doing this..

hello all, once you put a compressable X in the housing and fill it up with oil, again the housing will take up all the pressure from outside, as the compressable thing inside allows the housing to deform and the inside will stay at 1 atmosphere: so in this case filling up with oil to make the unit more pressure-resistant is not working!

regards
paul

DrJM · 3rd August 2006, 17:13

Quote: (Originally Posted by jradomski)

On handsets that I have filled with oil I have used a strip of neoprene across the back, this has worked well (but made it more difficult to fill) and I haven never had any oozing (nor any bubbles afterward) since I started doing this..

The Primary display (or used as a HUD) of my old Mk15.5 used to be originally factory filled with oil (liquid parafin) and a small buble of air was left in.

No prob playing at -186m in 13 celc deg, but had trouble at 0m in 35 deg in the boot of my car

leaking ...

I guess you need to fill your handset (Boris, Meg, etc ) at nearly the same temp of the water and leave a tiny bubble for the rise of temp due the activity of the circuit board, leds etc ...

Just my 2 centimes d'euros !

Jerome

paulraymaekers · 3rd August 2006, 17:58

well, I'm not shure that it is always needed to fill up with oil.
I think a well designed housing must resist easaly 20 bar

(the rEvodream housing crashed at 55 bar during pressure testing:-)

regards
paul

***jradomski*** · 3rd August 2006, 18:04

Quote: (Originally Posted by paulraymaekers)

hello all, once you put a compressable X in the housing and fill it up with oil, again the housing will take up all the pressure from outside, as the compressable thing inside allows the housing to deform and the inside will stay at 1 atmosphere: so in this case filling up with oil to make the unit more pressure-resistant is not working!

regards
paul

not really true, the idea is to have enough to take up the expansion due to heat but still allow the incompressibility characteristics of the oil to do its job.. sure the case may deform slightly but its not the same as an air filled case where deformations can be quite large.. What were are trying to accomplished is a limited deformation range..

What I do is figure out the volume of the liquid necessary (Just fill the case and mesure how much liquid you used) without any "buffer" and cut a strip with a volume about 5% of this, this allows for small variations of liquid expansion without sacrificing the properties we are looking for..
I'll fill the unit with the oil on the cooler end of the expected temperature range to prevent introducing an air bubble, and at "normal" temperatures the neoprene is already partially compressed..

spottydog · 6th August 2006, 10:24

I've seen a plb housing filled with oil with a flexible plastic tube about 2 feet long bonded to the housing containing the antenna, and also being oil filled.

Seems to do away with any expansion problems cracking handsets.

Squidgy rubber handsets anyone?

3rd August 2006, 17:04	#11 (permalink)
paulraymaekers rEvo's daddy Current Rebreather/s: rEvo Other CCR Home Build Other Rebreather/s: rEvo Other CCR Home Build Join Date: May 2005 Location: belgium Posts: 1,432	Re: To fill up with oil....?? Quote: (Originally Posted by jradomski) On handsets that I have filled with oil I have used a strip of neoprene across the back, this has worked well (but made it more difficult to fill) and I haven never had any oozing (nor any bubbles afterward) since I started doing this.. hello all, once you put a compressable X in the housing and fill it up with oil, again the housing will take up all the pressure from outside, as the compressable thing inside allows the housing to deform and the inside will stay at 1 atmosphere: so in this case filling up with oil to make the unit more pressure-resistant is not working! regards paul __________________ www.rEvo-rebreathers.com .... the earth is flat, Elvis is alive, and radial scrubbers give longer dwell time than axials...
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3rd August 2006, 17:13	#12 (permalink)
DrJM Deep Cave Explorer Current Rebreather/s: Ouroboros Other Rebreather/s: MK 15.X Join Date: May 2005 Location: France Posts: 340	Re: To fill up with oil....?? Quote: (Originally Posted by jradomski) On handsets that I have filled with oil I have used a strip of neoprene across the back, this has worked well (but made it more difficult to fill) and I haven never had any oozing (nor any bubbles afterward) since I started doing this.. The Primary display (or used as a HUD) of my old Mk15.5 used to be originally factory filled with oil (liquid parafin) and a small buble of air was left in. No prob playing at -186m in 13 celc deg, but had trouble at 0m in 35 deg in the boot of my car leaking ... I guess you need to fill your handset (Boris, Meg, etc ) at nearly the same temp of the water and leave a tiny bubble for the rise of temp due the activity of the circuit board, leds etc ... Just my 2 centimes d'euros ! Jerome __________________ www.snoopyloop.com Deep Cave Exploration
(Online)

3rd August 2006, 17:58	#13 (permalink)
paulraymaekers rEvo's daddy Current Rebreather/s: rEvo Other CCR Home Build Other Rebreather/s: rEvo Other CCR Home Build Join Date: May 2005 Location: belgium Posts: 1,432	Re: To fill up with oil....?? well, I'm not shure that it is always needed to fill up with oil. I think a well designed housing must resist easaly 20 bar (the rEvodream housing crashed at 55 bar during pressure testing:-) regards paul __________________ www.rEvo-rebreathers.com .... the earth is flat, Elvis is alive, and radial scrubbers give longer dwell time than axials...
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3rd August 2006, 18:04	#14 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Home Build Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Home Build Join Date: Mar 2005 Location: "Da" Bronx Posts: 2,871	Re: To fill up with oil....?? Quote: (Originally Posted by paulraymaekers) hello all, once you put a compressable X in the housing and fill it up with oil, again the housing will take up all the pressure from outside, as the compressable thing inside allows the housing to deform and the inside will stay at 1 atmosphere: so in this case filling up with oil to make the unit more pressure-resistant is not working! regards paul not really true, the idea is to have enough to take up the expansion due to heat but still allow the incompressibility characteristics of the oil to do its job.. sure the case may deform slightly but its not the same as an air filled case where deformations can be quite large.. What were are trying to accomplished is a limited deformation range.. What I do is figure out the volume of the liquid necessary (Just fill the case and mesure how much liquid you used) without any "buffer" and cut a strip with a volume about 5% of this, this allows for small variations of liquid expansion without sacrificing the properties we are looking for.. I'll fill the unit with the oil on the cooler end of the expected temperature range to prevent introducing an air bubble, and at "normal" temperatures the neoprene is already partially compressed.. __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated. Last edited by jradomski : 3rd August 2006 at 18:07.
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6th August 2006, 10:24	#15 (permalink)
spottydog New Member Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Jan 2006 Location: Sydney Posts: 23	Re: To fill up with oil....?? I've seen a plb housing filled with oil with a flexible plastic tube about 2 feet long bonded to the housing containing the antenna, and also being oil filled. Seems to do away with any expansion problems cracking handsets. Squidgy rubber handsets anyone?
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