Select to expand quoteKaiWei said..
These M12 X 1,5 screws from Amazon work perfectly as a replacement for my Flikka GoreTex vent: www.amazon.de/dp/B0DC9NG8V3?th=1
The get them here would be $40 pr.
I'm not convinced that these vents are bad. A normal vent screw won't work in the water either unless you leave it open lol.
If there would be systemic issues, we wouldn't be seeing these in so many boards still.
If you've got water in the board then you've got problems already.
I think the fact that these vents auto breath without needing to think about it will on average result in less pressure in the board so a better outcome.
The only thing to be aware of is to replace it if you've got water inside, otherwise replacing it is silly imo.
But they don't
salt makes them useless
the manufacturer of the vents produce a spec sheet that shows they should be not used like this.
so why install a $2 part that is not fit for purpose, into a $3500 item! Just wondering
Select to expand quoteptsf1111 said..>>If there would be systemic issues, we wouldn't be seeing these in so many boards still.
How many people check their valves to see if they are still working?
Most of the time you'll get away with it. There are a number of people here that get away with not undoing their bungs.
I replaced the bottoms on two boards that had delamned, both with gortex vents.
The construction was solid, the sandwich hadn't cleanly left the foam, the foam had split 1cm to 2cm down, with traces of resin in the foam still stuck to the sandwich.
Both boards were a fairly light colour.
So I think there are a lot more problems, that aren't registered as a vent cause.
The thing is with a bung, most of the time you know what it's doing, with a vent you don't. So if you know the bung really needs to be undone you do it. With a vent do you just trust it?
Select to expand quotedecrepit said.. There are a number of people here that get away with not undoing their bungs.
Most of the crew I sail with don't touch our bungs. Never a problem and we're in QLD. Except once. A large portion of deck. That was due to no resin sticking to the blank. Unless sitting in the sun for a while ,stored in a van , on roof racks or in a plane , I leave mine alone. We don't leave our boards roasting in the sun. We pull our boards out , rig up , go sailing and pack up. This seems to be fine.I believe boards puff up more if there is water inside. Constantly screwing the bung in and out is asking for trouble. Sand will flog out the O,ring and seat. Unless you can keep it anally clean , which you can't at the beach. If you look carefully , the seat of the O,ring will look bad with bits of sand squashed into the plastic ripping groves into the O,ring. Have a close look at your O,ring. 
If you're an unscrewer , I'd highly recommend replacing the O,ring every dozen times. And make sure the seat is in good condition. I would guess most people don't touch their bungs. There seems to be possible issues both ways and also venting bungs. In the old days we never had vents and I'd never seen a board explode . Every second person had a windsurfer and stored them on roof racks. The sun must have been different then when smoking was healthy.
in the old days, boards were made from closed cell foam and didn't have vents.
Ah closed cell foam, what a joy!!!!!!!
Select to expand quoteImax1 said..decrepit said.. There are a number of people here that get away with not undoing their bungs.
Most of the crew I sail with don't touch our bungs.
Why do all major board manufactures install bungs and always deliver them with the bungs removed and why do they all recommend that the bung is removed between sessions?
It's a 2 minute task before and after a session which ensures that board is not subject to undue internal pressure while in transit by car, truck or air and in storage at home.
Select to expand quoteJohn340 said..Imax1 said..decrepit said.. There are a number of people here that get away with not undoing their bungs.
Most of the crew I sail with don't touch our bungs.
Why do all major board manufactures install bungs and always deliver them with the bungs removed and why do they all recommend that the bung is removed between sessions?
It's a 2 minute task before and after a session which ensures that board is not subject to undue internal pressure while in transit by car, truck or air and in storage at home.
It's a safety for them. It's obviously better to remove the bung. But it's not their problem if you forget to put the bung back in or if the o ring is stuffed or got sand on it and leaks.
It's a safety for them to stick in a gore thing that is used outside its design specs... but might work just long enough and after a year who knows who cares. That's my issue.
If your paying 3.5 to 4k for a board and the manufacturer suggests you regularly undo the bung to release pressure then whats the big deal.
Ive always done it, guys I sail with dont bother. Its a personal thing but to me if it saves you big bucks and as John stated takes a minute or two then whats the biggie!! I also carry a small pack of O rings, sand will trash an O ring real quick.
I see many real delam (skin lift off foam) with what's call closed cell foam with single skin over, pu foam (surfboard foam) and XPS ( a winner for delam nightmare foam), nowadays black board fashion help a lot form massive delam! With eps core it's like Decrepit say, foam separate 1 or 2 cm inside, because of texture skin stick well to foam. With good quality, but denser, eps less risk. Never see bic techno, 20 to 25kg/m3 molded eps, delam like that, but they are in heavier side.
Loving the MOz wisdom on this subject. Bought an early Alien second hand in Dec. The ad didn't mention repairs and I'd already driven a million miles to pick it up by the time I saw. One rail job that looks super professional and a delam repair between the back straps. The delam repair has deck grip over it so not sure of the extent/quality, but it's supposed to have been done by the same repairer as the rail. The seller specifically told me that he had used the board heaps (it looks pretty well cared for aside from the repairs) but had never touched or replaced the gore vent after several seasons.
I haven't had it wet yet due to injury. I bought some Shapers replacement Gore vents but haven't installed.
I'm prob just asking for speculation, but do you think it's likely the vent has contributed to the previous delam in some way? Maybe ingress following the rail ding that couldn't get out through the old vent? I'm guessing delam wouldn't normally be common in a Severne?
Would you recommend I still replace the vent with one of the new Shapers or is that too high risk? Do they just screw in with a little silicon grease or do they need to be epoxied?
The board feels light and seems sound. I hope it's not a mess in there from the vent... 
needsalt - replace it with a Moz retro fit ! ......... and read the spec sheet for these Gore-tex vents .
From what I`ve gathered from peoples comments is that the Gore-tex vents stop venting out pressure rather than the water ingress and It`s the quality of board construction that determines delam happening or not , or when .
If you are worried with gore vent, replace with a screw system and only think navigation.
If you are worried with gore vent, replace with a screw system and only think navigation.
Needsalt, as seen above there is no reason to replace a Gotetex vent UNLESS the board has had water inside which is the case in yours so you have to fit a traditional vent now.
I see a reason. tell me if the membrane is intact in your vents. With certainty..
I have now four Severne-boards, one of the first Fox included. I have just changed the valves to "Gore m12x1,5 PMF 100585".
I?m also a bit worried about the gortex valves and salt infiltration. The valve is a plastic screw so I suppose that the cylinder in the board is also made of plastic.
But what happens if I replace the valve with a metalic screw with m12x15 dimension?
Gore recommend a torque of only 0,7 Nm, so I guess I can damage the plastic cylinder in the boards with a metalic screw.
What is your opinion?
John
Select to expand quoteMark _australia said..
I see a reason. tell me if the membrane is intact in your vents. With certainty..
I think I'm more concerned about that than failed venting...
Wish MOz would do some kind of annual repair trip to the east coast. Or just clone himself... 
Select to expand quoteasturcon said..
I have now four Severne-boards, one of the first Fox included. I have just changed the valves to "Gore m12x1,5 PMF 100585".
I?m also a bit worried about the gortex valves and salt infiltration. The valve is a plastic screw so I suppose that the cylinder in the board is also made of plastic.
But what happens if I replace the valve with a metalic screw with m12x15 dimension?
Gore recommend a torque of only 0,7 Nm, so I guess I can damage the plastic cylinder in the boards with a metalic screw.
What is your opinion?
John
I think this low torq is more to avoid screw breaking.
Select to expand quotelemat said..
I think this low torq is more to avoid screw breaking.
yes it's a crazy design, the head will snap off at the drop of a hat.
Yes you can stick metal in. The insert into the board is actually beefier than the metal manual vent has.
Nic buy me the ticket I'll come over
What about a pressure vent?!
Yes it's too big at 3/4" BSP thread and you would need to clean sand from around the pressure o ring.
I have seen a vent body machined from PVC (for extremely corrosive chemicals that eat into stainless 316). Reduce size to M12 thread.
It has to be a better solution to current gortex vents 
For NZ we don't have the intense heat of WA summer to bother.
Select to expand quote515 said..
What about a pressure vent?!
Yes it's too big at 3/4" BSP thread and you would need to clean sand from around the pressure o ring.
I have seen a vent body machined from PVC (for extremely corrosive chemicals that eat into stainless 316). Reduce size to M12 thread.
It has to be a better solution to current gortex vents
For NZ we don't have the intense heat of WA summer to bother.
Good idea , however the minimum 3 psi is way too much.
Thanks Imax, appreciate your reply.
So what pressure do you think is appropriate?
With most higher pressure valves, they have specific springs for pressure range.
This set up would depend on how much the spring is compressed and at low pressure it becomes harder to re seat the o ring.
The lowest pressure one of my customers want is 0.15bar - a fleas fart! My supplier has recently changed from imperial (PSI) to metric (bar)
The above, you could reverse the cap head to the top and use a weaker spring.
515 - it will not work , if the valve is venting on the beach then it will be getting sand blasted and the fine grit will get in and stuff it .
I have put together a simple CAD file for an emergency basic vent screw. I have 3D printed a few up to test on Mark_Oz test rig.
The slot to tighten is M6 fin washer size. If anyone wants details or the .stl file just let me know, but otherwise I will report back after a bit of testing.
^ I used the Goretex tech drawing (thanks @DWF).
- thread as per drawing and DIN961.
- printed at 103% to give a nice snug fit.
- used PETG at 100% infill for test screws. PETG will breakdown if left exposed to UV for long periods so I will paint the surface with UV blocker - outdoor spray paint. The screw is only intended as a temporary measure. (Alternatively printing in ASA will deal with the UV issues).
I've had two boards explode, one had a screw which let water in cos of the crap screw design with an o ring. Then exploded on the beach. Board two broke cos I didn't get all the water out before repairing it and the goretex didn't breathe water. 
. All my boards are goretex plugs and I have no problem.
Select to expand quoteMark _australia said..
But they don't
salt makes them useless
the manufacturer of the vents produce a spec sheet that shows they should be not used like this.
so why install a $2 part that is not fit for purpose, into a $3500 item! Just wondering
True, the biggest killer of goretex clothing is sweat, it blocks the pores and wears out the membrane. It's really tricky to wash a vent plug really well. I would guess they would stop air coming out before they let water in
