Spacer in canister

Explorer · 10th September 2006, 22:44

Has anyone is RBW tried to put a PVC spacer in the cansiter below the sorb so you can use say 1/2 the amount of material when diving in the pool or so.

AD_ward9 · 10th September 2006, 23:51

Quote: (Originally Posted by Explorer)

Has anyone is RBW tried to put a PVC spacer in the cansiter below the sorb so you can use say 1/2 the amount of material when diving in the pool or so.

1. PVC is not a good material to use inside a breathing loop.
2. This is quite a hazardous thing to do. Surprising how many people can come a cropper in a pool.
3. Better to use a full scrubber and use it twice by sealing it well after your dive.
Alex

RonMicjan · 11th September 2006, 02:41

I keep some "pool" scrubber around for just such a thing. This would be used scrubber with an hour or two left on it that I dont want to take in open ocean diving. Pool diving is never deep and rarely strenuous so its a perfect match.

Gibbon · 11th September 2006, 04:57

Quote: (Originally Posted by AD_ward9)

1. PVC is not a good material to use inside a breathing loop.

Having experimented with PVC in the scrubber (and scrubbers in PVC) I agree, there are several issues with it.

1) WOB is increased beyond a reasonable level.
2) You can taste the PVC (and contaminants) in the loop which is not always a good thing.
3) The PVC becomes caustic and irratant unless well washed before reuse due to sorb in the seams.

If you want to really save on sorb you should look into green alternatives for the shallow pool stuff:

For a shallow morning dive we use:

His and hers options for a night dive:

His and hers deco munchies:

His and hers Marmite junkies: (lids must be removed for full flavour)

A personal favourite blend:

For those hoping to get lucky:

Please note that all products used must be O2 Cleaned and CE approved for use in dive equipment.

abowie · 11th September 2006, 06:07

Quote: (Originally Posted by Gibbon)

Having experimented with PVC in the scrubber (and scrubbers in PVC) I agree, there are several issues with it.

Silly sossidge!

AD_ward9 · 11th September 2006, 06:48

Quote: (Originally Posted by abowie)

Silly sossidge!

Just the point!

I received some private mail asking about this, so I will explain the issue:

Have you noticed that cling film (Food Wrap), says "Non PVC" on it nowadays?

The reason is the stabilisers and plasticizers in PVC gives off some "quite interesting" chemicals, including pyrethroids. One of them looks almost identical to a human female sex hormone. Synthetic pyrethroids are blamed for falling male sperm count.

The problem was first found in rigid clear PVC used for sample test tubes in a lab, so be wary of claims that very rigid PVC does not have the plasticizer. This problem is severe enough that Greenpeace are trying to have PVCs banned/limited. Have a look HERE for example. Some countries have already legislated against PVC. There is an international ban on PVC in childrens' toys.

When you dive with something, a lot of gas goes into the plastic. PVC is quite porous to gases. When you come back up, the gases come out, along with even more of the volatile organic compounds and hormone like compounds that you can smell when opening up a new box of PVC parts. You now breathe it in, for several hours at a time. Many times over.

I note a lot of home builds use PVC plumbing parts. Note, sewage plumbing parts, not drinking water plumbing parts. Best not to build rebreathers out of a toilet.

There are a fair number of other plastics that suffer this problem.

Cheers,
Alex

jakelost · 11th September 2006, 07:26

Im not 100 % sure but isnt the drinking water in half europe going thru
PVC pipes ??

Quote: (Originally Posted by AD_ward9)

Just the point!

I received some private mail asking about this, so I will explain the issue:

Have you noticed that cling film (Food Wrap), says "Non PVC" on it nowadays?

The reason is the stabilisers and plasticizers in PVC gives off some "quite interesting" chemicals, including pyrethroids. One of them looks almost identical to a human female sex hormone. Synthetic pyrethroids are blamed for falling male sperm count.

The problem was first found in rigid clear PVC used for sample test tubes in a lab, so be wary of claims that very rigid PVC does not have the plasticizer. This problem is severe enough that Greenpeace are trying to have PVCs banned/limited. Have a look HERE for example. Some countries have already legislated against PVC. There is an international ban on PVC in childrens' toys.

When you dive with something, a lot of gas goes into the plastic. PVC is quite porous to gases. When you come back up, the gases come out, along with even more of the volatile organic compounds and hormone like compounds that you can smell when opening up a new box of PVC parts. You now breathe it in, for several hours at a time. Many times over.

I note a lot of home builds use PVC plumbing parts. Note, sewage plumbing parts, not drinking water plumbing parts. Best not to build rebreathers out of a toilet.

There are a fair number of other plastics that suffer this problem.

Cheers,
Alex

decoweenie · 11th September 2006, 07:54

Quote: (Originally Posted by Gibbon)

Having experimented with PVC in the scrubber (and scrubbers in PVC) I agree, there are several issues with it...

How old is your Meg unit ?

I am just curious from the conditions of the clear scrubber canister and AL housing shown in the pictures...

Gibbon · 11th September 2006, 08:16

Quote: (Originally Posted by decoweenie)

How old is your Meg unit ?

I am just curious from the conditions of the clear scrubber canister and AL housing shown in the pictures...

6 months, what are you curious about in particular?

We live in very high humidity, you would be amazed at how quickly things rot here.

Note to self, must wipe white stains off canister before taking photos

decoweenie · 11th September 2006, 08:38

Quote: (Originally Posted by Gibbon)

6 months, what are you curious about in particular?

I used to have a clear scrubber canister for the CK, never had a chance to use it before sold away. However, a lot of people said that it would react with the sorb and look nasty in no time. So just wondering how true that is...

Also, a lot of comments were made to me in the past about AL corrosion in saltwater environment of the Meg housing. So I want to keep an eye on that as well...

Quote:

Note to self, must wipe white stains off canister before taking photos

Are people getting jumpy lately on RBW or what ?

10th September 2006, 22:44	#1 (permalink)
Explorer I will teach you a..... Current Rebreather/s: Evolution Megalodon Other Rebreather/s: Join Date: Sep 2005 Location: Alberta, Canada Posts: 784	Spacer in canister Has anyone is RBW tried to put a PVC spacer in the cansiter below the sorb so you can use say 1/2 the amount of material when diving in the pool or so. __________________ KONA COFFEE
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10th September 2006, 23:51	#2 (permalink)
AD_ward9 RBW Member Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Jun 2005 Location: Scotland Posts: 2,011	Re: Spacer in canister Quote: (Originally Posted by Explorer) Has anyone is RBW tried to put a PVC spacer in the cansiter below the sorb so you can use say 1/2 the amount of material when diving in the pool or so. 1. PVC is not a good material to use inside a breathing loop. 2. This is quite a hazardous thing to do. Surprising how many people can come a cropper in a pool. 3. Better to use a full scrubber and use it twice by sealing it well after your dive. Alex
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11th September 2006, 02:41	#3 (permalink)
RonMicjan Cap Ron scourge of the NW Current Rebreather/s: Megalodon Dolphin Home Build Other Rebreather/s: Sport Kiss Classic Kiss Dolphin Home Build Join Date: Feb 2005 Location: Cape Disapointment, The Graveyard of the Pacific Posts: 1,120	Re: Spacer in canister I keep some "pool" scrubber around for just such a thing. This would be used scrubber with an hour or two left on it that I dont want to take in open ocean diving. Pool diving is never deep and rarely strenuous so its a perfect match. __________________ Marine rescue, towing and salvage. Interfering with natural selection since 1983. www.tmishop.com Diving bits etc. www.seatowpdx.com The Summer Job
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11th September 2006, 04:57	#4 (permalink)
Gibbon Southern Monkey Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Aug 2005 Location: East Devon Posts: 224	Re: Spacer in canister Quote: (Originally Posted by AD_ward9) 1. PVC is not a good material to use inside a breathing loop. Having experimented with PVC in the scrubber (and scrubbers in PVC) I agree, there are several issues with it. 1) WOB is increased beyond a reasonable level. 2) You can taste the PVC (and contaminants) in the loop which is not always a good thing. 3) The PVC becomes caustic and irratant unless well washed before reuse due to sorb in the seams. If you want to really save on sorb you should look into green alternatives for the shallow pool stuff: For a shallow morning dive we use: His and hers options for a night dive: His and hers deco munchies: His and hers Marmite junkies: (lids must be removed for full flavour) A personal favourite blend: For those hoping to get lucky: Please note that all products used must be O2 Cleaned and CE approved for use in dive equipment.
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11th September 2006, 06:07	#5 (permalink)
abowie Fighting Girl Current Rebreather/s: Sport Kiss Other Rebreather/s: Join Date: May 2005 Location: Land of Oz Posts: 574	Re: Spacer in canister Quote: (Originally Posted by Gibbon) Having experimented with PVC in the scrubber (and scrubbers in PVC) I agree, there are several issues with it. Silly sossidge! __________________ Andrew Bowie Rebreather-friendly Buddy
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11th September 2006, 06:48	#6 (permalink)
AD_ward9 RBW Member Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Jun 2005 Location: Scotland Posts: 2,011	Re: Spacer in canister Quote: (Originally Posted by abowie) Silly sossidge! Just the point! I received some private mail asking about this, so I will explain the issue: Have you noticed that cling film (Food Wrap), says "Non PVC" on it nowadays? The reason is the stabilisers and plasticizers in PVC gives off some "quite interesting" chemicals, including pyrethroids. One of them looks almost identical to a human female sex hormone. Synthetic pyrethroids are blamed for falling male sperm count. The problem was first found in rigid clear PVC used for sample test tubes in a lab, so be wary of claims that very rigid PVC does not have the plasticizer. This problem is severe enough that Greenpeace are trying to have PVCs banned/limited. Have a look HERE for example. Some countries have already legislated against PVC. There is an international ban on PVC in childrens' toys. When you dive with something, a lot of gas goes into the plastic. PVC is quite porous to gases. When you come back up, the gases come out, along with even more of the volatile organic compounds and hormone like compounds that you can smell when opening up a new box of PVC parts. You now breathe it in, for several hours at a time. Many times over. I note a lot of home builds use PVC plumbing parts. Note, sewage plumbing parts, not drinking water plumbing parts. Best not to build rebreathers out of a toilet. There are a fair number of other plastics that suffer this problem. Cheers, Alex Last edited by AD_ward9 : 11th September 2006 at 06:52. Reason: Putting in the link.
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11th September 2006, 07:26	#7 (permalink)
jakelost New Member Current Rebreather/s: Sport Kiss Other SCR Other Rebreather/s: Other SCR Join Date: Feb 2006 Location: Sweden Posts: 27	Re: Spacer in canister Im not 100 % sure but isnt the drinking water in half europe going thru PVC pipes ?? Quote: (Originally Posted by AD_ward9) Just the point! I received some private mail asking about this, so I will explain the issue: Have you noticed that cling film (Food Wrap), says "Non PVC" on it nowadays? The reason is the stabilisers and plasticizers in PVC gives off some "quite interesting" chemicals, including pyrethroids. One of them looks almost identical to a human female sex hormone. Synthetic pyrethroids are blamed for falling male sperm count. The problem was first found in rigid clear PVC used for sample test tubes in a lab, so be wary of claims that very rigid PVC does not have the plasticizer. This problem is severe enough that Greenpeace are trying to have PVCs banned/limited. Have a look HERE for example. Some countries have already legislated against PVC. There is an international ban on PVC in childrens' toys. When you dive with something, a lot of gas goes into the plastic. PVC is quite porous to gases. When you come back up, the gases come out, along with even more of the volatile organic compounds and hormone like compounds that you can smell when opening up a new box of PVC parts. You now breathe it in, for several hours at a time. Many times over. I note a lot of home builds use PVC plumbing parts. Note, sewage plumbing parts, not drinking water plumbing parts. Best not to build rebreathers out of a toilet. There are a fair number of other plastics that suffer this problem. Cheers, Alex
(Online)

11th September 2006, 07:54	#8 (permalink)
decoweenie Crash Test Dummy Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Feb 2005 Location: Cairo Posts: 5,487	Re: Spacer in canister Quote: (Originally Posted by Gibbon) Having experimented with PVC in the scrubber (and scrubbers in PVC) I agree, there are several issues with it... How old is your Meg unit ? I am just curious from the conditions of the clear scrubber canister and AL housing shown in the pictures... __________________ "...after a while you get bored offering advice to a bull that like to keep butting the fence with its head rather than walking through the open gate..." - Rebreather World PM
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11th September 2006, 08:16	#9 (permalink)
Gibbon Southern Monkey Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Aug 2005 Location: East Devon Posts: 224	Re: Spacer in canister Quote: (Originally Posted by decoweenie) How old is your Meg unit ? I am just curious from the conditions of the clear scrubber canister and AL housing shown in the pictures... 6 months, what are you curious about in particular? We live in very high humidity, you would be amazed at how quickly things rot here. Note to self, must wipe white stains off canister before taking photos
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11th September 2006, 08:38	#10 (permalink)
decoweenie Crash Test Dummy Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Feb 2005 Location: Cairo Posts: 5,487	Re: Spacer in canister Quote: (Originally Posted by Gibbon) 6 months, what are you curious about in particular? I used to have a clear scrubber canister for the CK, never had a chance to use it before sold away. However, a lot of people said that it would react with the sorb and look nasty in no time. So just wondering how true that is... Also, a lot of comments were made to me in the past about AL corrosion in saltwater environment of the Meg housing. So I want to keep an eye on that as well... Quote: Note to self, must wipe white stains off canister before taking photos Are people getting jumpy lately on RBW or what ? __________________ "...after a while you get bored offering advice to a bull that like to keep butting the fence with its head rather than walking through the open gate..." - Rebreather World PM
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