Search a few supply sites like Foam EZ, Surf Source etc for the Casica Goretex Vent. Should be a pic or two on those sites. Probably the same. I have never used a vent on a board so don't know for sure.
That which can be assorted without evidence was read in an illegal magazine.
Because guessing sucks,
I just went and busted out a thumbscrew and my digital calipers.
Measuring the thickness of the threaded portion including the threads it is exactly 3/8"
Measuring the thickness of the threaded portion NOT including the threads it is exactly 5/16"
Setting my calipers to exactly 1/4", I count exactly 5 threads,
so I would say it is a 3/8" 20 teeth per inch thread, and it is certainly not a metric thread
1/2" = 12.7mm.
Perhaps it could be tapped for the Casica/amphenol m12 1.5 gortex vent, but I dont feel 40ml per minute is enough to deal with rapid temperature changes, though of course is better than a perfect seal.
I might look into modifying a casica threaded portion and tapping it for the 3/8-20 thread size and making it thumb screwable. as some added safety.
One thing I like about a non venting thumbscrew is if I open it and no air comes in or out, it means one of two things, either there has been no temperature difference since the vent was closed, or the hull integrity has been compromised.
Guessing does suck-- and I appreciate this research and precision, thank you.
Of course in my haste to resolve this, I ordered a plug from Chinook Sailing this morning-- looks identical to the r62-5150 mentioned above but I guess we'll see. Either way we now have the invaluable measurements!
I know the Vents ben used and provided for my first 6'8", were flanged, and the plug without the thumbscrew would sit about 3/16 above the surrounding deck.
When I made my first HWS after the one I made in Ben's workshop, Fiberglass supplydotcom had the flush mounting/ non flanged thumbscrew receptacles, and I ordered 10 pairs of them, then.
The thumb grab portion is still raised, and if one sands down the top of the flush mounted plug during the shaping process, then there is an even larger gap between the thumbscrew and the receptacle in the board.
Ideally I'd want the thumb portions touching the deck at the same time the O ring is compressed enough, instead of raised 0.5mm or more above.
I like to mount the vents as far towards the nose as possible to assist draining should water get inside. The vent plugs themselves are like a giant hairy wart on the nose of a supermodel, but oh well.
The pics of the thumbscrews above, one of them I shortened the threaded portion as it was for a thin nosed board. One of them also spent a year or more in the dirt in Baja, and I found it on a subsequent trip camped in the same spot..
It's good to have extras.
3/8-20 is an uncommon thread pitch, compared to 3/8-16. It made me go back and recount the threads and take a better picture.
Which makes it less likely I'll acquire an amphenol connector and try and rethread it for 3/8-20 and get the O ring to seal properly in existing plug.
I don't mind the Brass insert with 1/4-20 internal threads that I installed in the tail of my latest hws, for cross ventilation, nearly as much.
I think I'd design some sort of flush mount for the goretex amphenol vent, with some thumbscrew design added, if I were to make another HWS, but I have no such plans to do so.
The Amphenol takes a 16mm hex and needs a 17mm or larger hole to be recessed and allow the head to sit flush or lower. The thumbscrew receptacle on Bens' and my boards, would not accept this.
So I'm going to stop thinking about attempting to get a goretex vent into the existing thumbscrew receptacle.
Ignore the O-rings in the center photo, they are from/for the O ring on my transmission dipstick tube and are 3/4" outer diameter, and were inside the digital caliper's case.
Just for your information, I'm using Goretex Polyvent "High Airflow" which allow for 4000ml/min or 40l/min Airflow. I got them from a company in Europe at about 8$ each.
This link refers to a official goretex brochure, so they should be availlabe in the US too.
https://www.distrelec.de/Web/Downloads/_t/ds/WLGore_ScrewIn_Vents_eng_td... the vent I use is the first on the third page...
By now I installed them in three board and they never failed, but my experience is limited, the oldest board is 3 years and is not used more than 25 days, because I'am a vacation only surfer. I used homemade screw vents before which I forget to close two times before entering the water... :(