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Twin Pipe (loop) Snorkel (DIY)

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artiz

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Following on from REVAN's project (much thank's Ron) I have now managed to construct a Mark 2 of Ron Smith’s excellent loop snorkel with a few modifications to please myself. The most important being the addition of a more conventional snorkel mouthpiece.

PART 1
I therefore used an old but suitable donor (IST) snorkel which already had a detachable silicone mouthpiece…

ist snorkel.jpg
donor mouthpiece.jpg

I cut the fitting off with a jigsaw and sanded down (manually) with sand paper wrapped around an old piece of 15mm copper pipe until the shape matched my 16mm pipe precisely. I then wrapped masking tape around the pipe and drilled 2 x 11mm holes carefully… finishing off the breathing hole with a soldering iron and then ruffed up the bonding surfaces with sandpaper.

mp fix.jpg

The average bore or inner diameter of the 5 snorkels I own worked out to be about 22mm so the pipe I chose was spot on (by luck & REVAN's (10mm ID) guidance rather than judgement) and was (£3.73) - 16mm OD x 11mm ID from ebay uk.
mp hole.jpg
I assumed the bonding together of these 2 parts was going to be the weak part of my upgrade but didn’t really want to spend loads of money on top quality bonding agents etc... so tried using only the glues/bond which I already had. Firstly I super glued the mouth piece mount directly to the pipe. I then filled/gunned a bead of black Sikaflex-EBT all the way around the outside join, smoothed and then left for 24 hours. This just didn’t look or feel secure/good enough so I found, ordered and applied some black sugru which is a malleable silicone putty, (£8.50 for 3x5g) and clearly made for the job....

These initial results speak for themselves... whether/how long it lasts is another story/post?

mp 2.jpg
mp1.jpg
mp full.jpg

full pipe mp angle.jpg

Some important points to note so far are:
  1. The angle of the actual fitting (exactly where on the pipe) is critical later on but must come from individual choice & comfort and based on a bit of research and test? (more in part 2)
  2. The natural bend, flexibility and bore of your pipe are critical!
  3. The holes drilled in the pipe should probably exceed 20-22mm or the size of both diameters of your chosen pipe or you risk restricting airflow.

More later in PART2 when finished.
 
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Great work! The only thing I am worried about is the diameter. Having a small one allows you to evacuate the water well. A big one is nice to get lots of air though, but it will be hard to evacuate the water.
 
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Would be interested to see how this turns out, everytime I dive my throat dries out from breathing in the salt air and sometimes makes me want to gag. Perhaps this may solve that if it's easier to clear.


Sent from my iPhone using Tapatalk 2
 
Great work! The only thing I am worried about is the diameter. Having a small one allows you to evacuate the water well. A big one is nice to get lots of air though, but it will be hard to evacuate the water.
There's plenty of room for adjustment regarding airflow/purge to suit personal requirements Gab. For instance when you drill your 2 holes through your pipe they could set your preferred airflow/purge diameter... by not joining or widening those 2 holes, whatever size inner diameter you choose (9.5mm recommended by Ron) may actually help to keep the water in the pipe rather than filling up your mouthpiece too? You could always start with 2x9.5mm-2x10mm-2x11mm drill pieces, widening in steps to suit personal preference/comfort. I chose a wider inner bore (22mm, 2x11mm) because I'm used to/prefer an older style, wider bore snorkel. I also couldn't find a UK pipe maker selling Ron's Tygon in black... I didn't really like the clear pipe? Also the Tygon pipe seemed a bit too stiff, plastic and less flexible than the silicone pipe I luckily chose?
The most important aspect for me now will be if I can mount this snorkel so that the bend or pipe curve helps to pull the snorkel mouthpiece out of my mouth and down conveniently under my neck/chest when I release my bite?
Part 2 coming shortly...
 
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Great Job!!

Looks like I got some work to do.

Let us know how it works in the water.

Connor
 
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PART 2

I left the silicone putty to cure for 48 hours and bought some fluorescent water proof tape and attached it to the pipe to where it would hold the pipes together at the top and again further down... but not so far down that it would interfere with any working adjustments.

complete1.jpg


I then attached the snorkel to my (occhio) mask with just one old silicone snorkel loop at the back... too tight and it will restrict your inner diameter - too loose and it will prevent working adjustments. Simple is best perhaps?

snorkel loop fix.jpg


The open or cut out style straps allow a range of attachment points which can in turn allow continual/futher adjustment whilst snorkel and mask are fitted. I have found that by sliding the pipes up or down the old snorkel loop that this adjustment determines how much bend or curve of the pipe actually pulls the mouthpiece automatically out of my mouth. Notice that the snorkel has now 'flipped over' making the position of the exits of the 2 pipes curling downwards or backwards... this point is also important regarding where you have attached your mouthpiece fixing/mount (from your donor snorkel) on the pipe.

on head.jpg

full pipe mp angle.jpg


Mine (above) seems slightly too high so I would recommend a little lower for comfort sake but again not too low or you may compromise the highly desirable advantage of this snorkels unique ability to 'pop out' of your mouth & lay down under your chin when you release your bite or indeed slip into unconsciousness.
You can also adjust the mask strap higher or lower on the back of your head to determine where the pipes are positioned when on the surface. Also not forgetting that you don't have to cut the length of your pipe until you have 'field tested' for your own personal requirements/conditions?
I have tested underwater now and the purge/airflow seem perfect in the bath;)... I will test in my local pool soon but it maybe sometime before I can test in the field.
There really are many advantages to this type of DIY snorkel so I hope my efforts here can help others to find/build their own 'perfect' snorkel?

Overall costs will vary but no more than £10 and perhaps even as low as £3-£4 for just the pipe... depends on what bits you already have laying around of course.
 
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Part 3

I did a few tests in a local 5 Meter pool and liked everything about this snorkel, especially being able to 'allow' the mouthpiece to pop out of my mouth and sit under my chin when I released my bite... as well as the airflow feeling correct for me.

twin pipe snorkel 0.jpg twin pipe snorkel 1.jpg twin pipe snorkel 2.jpg twin pipe snorkel 3.jpg

Purging/clearing was a different matter though... it was difficult to get that last dribble of water out which echoed irritatingly up through the pipe with a whistle and a rattle. This is exactly what has annoyed me for years with a lot of my older, wider barrelled snorkels... which in turn had me wasting money on snorkels with purge valves... with varying degrees of success, but never spot-on.
My old IST donor snorkel (above) was probably the best of these so I have now added this donor snorkels one-way purge valve which I cut to shape again using my jigsaw and then followed the procedures above using super glue and sugru to secure the purge valve to the bottom of my twin pipe snorkel.

twin pipe snorkel purge valve.jpg twin pipe snorkel purge valve 2.jpg twin pipe snorkel purge valve 3.jpg

Back to the pool today and the difference the addition of the purge valve makes is quite remarkable. Purging is as clean and clear as it gets... I only drilled one 11mm hole for the exit out through the purge valve.
It is now possibly the quietest snorkel I have ever used... the exit of the twin pipes are also streamlined to the back of your head and don't flap around... going down or coming back up!

After allowing my mouthpiece to automatically pop out as I drop below... I can now rise (slowly or quickly) to the surface continuing to look down whilst putting my mouthpiece in on the way up if I so choose... purging just as I reach the surface and in turn immediately ready to take in air through the snorkel... and still continue to track targets below... all this and even more quietly than before!

Works for me!
 
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Why would it be hard to purge? Is it a function of cross section and smaller tubes would solve the problem? Or is it a function of the twin tube format? Something else? I hate purge valves with a passion so that is not a option for me, better a bit of gurgle.
 
Why would it be hard to purge? Is it a function of cross section and smaller tubes would solve the problem? Or is it a function of the twin tube format? Something else? I hate purge valves with a passion so that is not a option for me, better a bit of gurgle.

It's not at all hard to purge Connor, it actually feels easier, sorry to mislead... I wanted a snorkel that made as little noise as practicable and even better still... as clear of any water residue as possible... my two personal irritations with snorkels.
I certainly think versions built with thinner pipe and no valves (9.5mmID) could/will be entirely possible or even perhaps better... depending on your own personal sub-aqua requirements and preferences. Adding a purge valve was just a further step regarding my own personal requirements/aims.

There's more than a few reasons why I now think the twin pipe snorkel/format is significantly better for spearfishing;
  • hydrodynamics/no flapping snorkel
  • easier to clear/purge
  • quieter
  • using the doubled-up pipe bend helps pull your mouthpiece out... if required/safety
  • looks/feels specialised
  • wearable/convenient loop
  • recycles old snorkels
  • DIY
  • cheap as chips
 
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Is there a small "lip" inside the mouthpiece holder where the tubes enter? Could that be catching some water? If there is a lip, can you smooth it with some sugru or similar?
 
Is there a small "lip" inside the mouthpiece holder where the tubes enter? Could that be catching some water? If there is a lip, can you smooth it with some sugru or similar?

It's definitely a good idea to make sure all interior fittings are as smooth as possible but there is always the possibility of not getting it perfect I suppose. The water residue I initially had before fitting the purge valve may have had more to do with my increased inner diameter of 11mm... the valve clearly sorted that problem out for me... so a thinner diameter pipe could also be the answer? Your snorkel donor parts will also have their part to play of course... just a bit of trial & error?
 
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Just some thought that popped into my head now. It should be possible to model an ideal connector for such a double tube snorkel in a 3-d modeling program and then use a 3-D printer to get a clean and perfect connector. You would then only need to add your personal mouthpiece + the two tubes to finish it off.
 
Yep, which is what we'd talked about in the original thread. A 3d printed connector for both tubes so they become one tube at the top would be nice too.
 
Just some thought that popped into my head now. It should be possible to model an ideal connector for such a double tube snorkel in a 3-d modeling program and then use a 3-D printer to get a clean and perfect connector. You would then only need to add your personal mouthpiece + the two tubes to finish it off.
Yep, which is what we'd talked about in the original thread. A 3d printed connector for both tubes so they become one tube at the top would be nice too.

Try Sketchup... its a free to try 3D modelling software which quite a few 3D printing companies recommend. I did give it a try but it all seemed a bit too expensive (and time consuming) still... compared to using a donor snorkel that is.

Still a great idea of course if someone would give it a go... would be nice to keep it in the public domain too?
 
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So I gave Sketchup a go and it's a bit easier than I expected.... you can also download 2 Sketchup files to get you started at the bottom of this post and Sketchup is here... if interested!

mpiece with barbs.jpg mpiece dimensions.jpg


 

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  • sketchup - pipe connector with barbs.zip
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Here's my hacked-together example:

3 parts: scuba mouthpiece, tubing, Sugru

1 tool: exacto knife

ImageUploadedByTapatalk1387330016.209331.jpg


ImageUploadedByTapatalk1387330038.144212.jpg


ImageUploadedByTapatalk1387330061.122445.jpg


ImageUploadedByTapatalk1387330081.617067.jpg


ImageUploadedByTapatalk1387330099.264341.jpg


No idea how it'll hold up.

The tubing is still a bit long and I haven't trimmed it yet. A bit more breathing resistance than I'm used to with my LBS.

I had the damn pipe fitting for several months and couldn't be bothered to spend the time and make the mess with a dremel. This assembly took :15 mins
 
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Excellent, I like your long bite mouthpiece... for a few pennies and 15 minutes toil you've got another/spare snorkel.
What did you think of Sugru Apneaddict... I have had a few pool practice runs with mine and seems to be holding up well... nothing like the sea to really test it though?

I'm currently addicted to Google Sketchup?

total build sml.png
 
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Excellent, I like your long bite mouthpiece... for a few pennies and 15 minutes toil you've got another/spare snorkel.
What did you think of Sugru Apneaddict... I have had a few pool practice runs with mine and seems to be holding up well... nothing like the sea to really test it though?

I'm currently addicted to Google Sketchup?

View attachment 37458

So you have tested your design?
 
So you have tested your design?

You mean my 3D Sketchup 'design' Gab... no not complete yet... it does take some work/time to get your model 'solid' for 3D printing... seems to be a chasm of difference between 'looking OK' and 'ready for printing'... amazing free (not for commercial use) software though.
I will put my model file up for download when/if finished.
 
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complete MP.jpg


Having completed my 3D model above it's now ready for 3D printing. I went for as small as possible. It has been designed to take the 11mm inner diameter hose which I got from ebay. However the inner diameter of the mouthpiece hose attachment is 10mm as recommended by Ron Smith. The measurements (20mm x 33mm to fit 19mm x 32mm) where the detachable silicone mouthpiece fits onto are taken from my old snorkel which appears to be the most common fitting size... but please make your own checks/measurements first. (helpful site here)
You can simply upload the .dae file (below) to your chosen 3D printers... I got an initial quote from iMaterialise for about £25 delivered... so it's worth shopping around.
Probably best to wait until I get mine for testing of course... but any comments regarding progress will be much appreciated.
 

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