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ScubaLawyer
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Magnahelic question

Sat May 02, 2020 1:47 pm

Is there an optimum inside diameter for the tubing going from the magnahelic to your reg for proper readings? Or does it make any difference? My new magnahelic didn't come with tubing so looking to do it correctly. Mark
"The diver who collects specimens of underwater life has fun and becomes a keen underwater observer. .. seek slow-moving or attached organisms such as corals, starfish, or shelled creatures." (Golden Guide to Scuba Diving, 1968) :D

tbone1004
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Re: Magnahelic question

Sat May 02, 2020 2:28 pm

doesn't really matter. We are pulling a negligible amount of vacuum, so it won't really change anything. The key is making sure that it is stiff enough to not collapse when you suck on it, and IMO you actually want to go as small as possible to get the most accurate readings due to the gas volume in the hose itself.

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antique diver
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Re: Magnahelic question

Sat May 02, 2020 2:35 pm

ScubaLawyer wrote:
Sat May 02, 2020 1:47 pm
Is there an optimum inside diameter for the tubing going from the magnahelic to your reg for proper readings? Or does it make any difference? My new magnahelic didn't come with tubing so looking to do it correctly. Mark
If a hose barb fitting came with it you could just use something that fits it. Other than that I agree with tbone.
The older I get the better I was.

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ScubaLawyer
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Re: Magnahelic question

Sat May 02, 2020 5:22 pm

Thanks for the feedback guys! Always like to ask before I leap. Actually, I learned that about an hour after I got married for the first time. :)
"The diver who collects specimens of underwater life has fun and becomes a keen underwater observer. .. seek slow-moving or attached organisms such as corals, starfish, or shelled creatures." (Golden Guide to Scuba Diving, 1968) :D

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Nemrod
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Re: Magnahelic question

Mon May 04, 2020 10:39 pm

I use 1/4 OD clear tubing or Tygon. Maybe I better go measure it but that sounds right.

James

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ScubaLawyer
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Re: Magnahelic question

Wed May 13, 2020 4:49 pm

I received many suggestions on how to connect my Magnahelic vacuum line to a double hose mouthpiece so I can check cracking effort as I rebuild/tune my regs.

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Hated to destroy a good mouthpiece but I found this old original USD one in my bin-o-parts that is as stiff as a board and would not be comfortable to use on a reg so I decided to sacrifice it to the cause.

I'm sure I'm not the first person to do it this way but thought I'd share. When in use I would have a wagon wheel and valve in the exhaust side of the mouthpiece.

First, took a Dremmel to the insignia to flatten the area:

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After a little hand sanding I had a nice flat surface:

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I drilled a hole and screwed in an air nipple resulting in a vacuum line to my Magnahelic. The nipple is nice and tight so I don't anticipate any leaks. Guess I could put some neoprene cement or superglue around the base but don't think it is necessary.

The whole project took about 10 minutes so now I gotta find something else to do. :)

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"The diver who collects specimens of underwater life has fun and becomes a keen underwater observer. .. seek slow-moving or attached organisms such as corals, starfish, or shelled creatures." (Golden Guide to Scuba Diving, 1968) :D

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rhwestfall
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Re: Magnahelic question

Wed May 13, 2020 7:21 pm

now I need to make one....
Bob

No Longer Awaiting my Kraken.....

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Herman
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Re: Magnahelic question

Thu May 14, 2020 6:21 am

I did the same thing to a straight mouth piece for mine.
Herman

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TeamDoug2015
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Re: Magnahelic question

Fri May 15, 2020 2:31 am

Brilliant. Now I have another project for my shut-in time.

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ScubaLawyer
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Re: Magnahelic question

Sat Jun 13, 2020 7:16 pm

Did the same thing for my single hose regs. I used a snorkel mouthpiece that was curved so the vacuum line had room to move away from the reg. I then used a 1/4" aquarium nipple, drilled a hole, and superglued the thing into place. Works great.

Image
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"The diver who collects specimens of underwater life has fun and becomes a keen underwater observer. .. seek slow-moving or attached organisms such as corals, starfish, or shelled creatures." (Golden Guide to Scuba Diving, 1968) :D

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antique diver
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Re: Magnahelic question

Sat Jun 13, 2020 11:51 pm

Good idea, and better than the typical commercially made type for ease of use.
The older I get the better I was.

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rhwestfall
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Re: Magnahelic question

Tue Jun 16, 2020 7:31 am

and a second project has been put on the "to do" list....
Bob

No Longer Awaiting my Kraken.....

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