The most active shaper on the Oregon Coast who shapes a ton of EPS uses the Leash plug vents that Greenlight sells with good results. Off course his boards are not Wood Composite. Straight EPS glassed with Epoxy. The Cadillac Vent is the Goretex vent made by Casica Tech. If you do any kind of EPS/Epoxy or Composite construction; a vent is an insurance policy. Funny though, I have never seen a Surftech or Boardworks with a vent…
with exact molded to shape blanks like surftech (and others) vents is less needed. With low volume surfboards vents is less needed too. In fact with well build and cared board vents are not necessary but it can improve lifetime of board that experiment temperature change frequently (guys that have to let it in car…) and it reduce inconspicuous water suck.
i use gorevent screw in some build but they are expensive here and i have breakage from plug set on top of deck crown in front of front foot. Greenlight vented leash plug is a nice thing for me but can’t find it here so i have to build my own version that’s why i search information about wich kind of goretex fabric use.
Lemat , I bought a large piece of gore Tex fabric from a supplier. I make my own parts and a small piece of the fabric for the vent. And a small rubber gasket. Speedneedle gave me the idea. I just modified the design to work for me. I place then in the front third of the board just ahead of front foot so probably not the best location. I can post some pics of the build if people are interested. They work ok but are a good bit of effort.
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Ok thanks, i will look at it better at my local fabric store next time… Front third is a good location for venting but for my build i have to inserted it in my springer wich creat a hard point in lenghtwise flex of board, in front of front foot it’s a failure point when guys air drop take off or aerial flat landed. So i would like vent in plug wich is not so good for venting but is safer for strength. I use 1.5 lb good quality EPS block so venting is just a plus.
If I’m right you are from France. You can get Goretex valves in Europe from there, its about 8,50€ per screw:
Please check that you buy the ones with high airflow…
To add: in my experience, there seems to be a difference between EPS brands in terms of how permeable the foam is to water. I could be wrong, so I won’t mention the brand, but there is a 2lb, very popular brand that seemed to be to be like a sponge, allowing air and water to travel between cells readily. That, and the fact that every time I used it I or someone else broke boxes out (even using “slow” RR hardener to set the boxes), despite lining boxes with cloth, scoring the inside of the box for better adhesion, etc… It’s very possible that was my fault, and that there are steps I didn’t know to add, as far as the breaking boxes issue. I know of a few local shapers who use this EPS without this issue being notorious on their boards, so surely there is something they do differently from what I did, and there was something missing from my construction.
That said, Marko 2lb foam has not had those issues for me, and it seems to be genuinely “closed cell” based on what I saw when I stripped down this board:
https://www.instagram.com/p/BygUgy5gcCM/
If you look at the 5th photo in the series, you can see a water stain in the tail area of the bottom. It was a delam that occurred (1) because there was a leak in the box, there, (2) the owner leaves his boards in his car in both hot weather and cold with the windows up (in scorching Summer), (3) I spackled the board before sanding and lamming.
I did put a vent in that board, because I knew #2 above is a norm for the owner, despite that it was only maybe 32-34L. I was putting vents in all my boards made for me from Marko because my volume is up around 42-52L on any given board. I now think, based on what I saw when I stripped the board in the Instagram post that the vent probably wasn’t doing anything.
Why: when I stripped the board and began working on the blank again, the water stain turned out to be purely on the surface. What seemed to happen with the delam: the water followed the spackle, through the surface of the blank, allowing the lam to separate from the board everywhere it was wet. But just below that skin/surface, the foam was virgin white.
I may still put vents in on Marko in the future because even if they do nothing they’re also not hurting anything if installed well. In fact, on that stripped board, I just left the vent in on the grom board I made from the blank, no harm no foul, maybe some benefit, maybe not.
I have sold and shaped too many Marko blanks to count. I Spackle. It is my experience that I am only attempting to fill the voids and spaces between beads. The Spackle will also fill any scratches due to the shaping process. After 24 hr. dry time I fine screen the whole blank, leaving the voids filled and the flat surfaces of the EPS beads exsposed. The exsposed beads bond to the Epoxy/fiberglass cloth. I guess the experts would call that a mechanical bond. I would think that a layer of Spackle that covers the bead faces would yes be prone to delam. I don’t vent and have yet to have a delam. When I lived on Maui I repaired many, many EPS/Epoxy boards. Surftech, BoardWorks, Focus etc. none of them were vented and I rarely saw a delam. When I did it was minor and due to the fact that surf schools and shops would rent them with open dings. It gets pretty hot on Maui. And Maui was the Sun demi god. I believe it has more to do with methods than materials.
Please don’t respond to posts of mine any more. You have some useful stuff to impart, but when you reply to me it’s always with some kind of dumb, passive-aggressive bullshit, now that you know how I regard you.
That’s not going to change. Your minor insights aren’t valuable enough to me to make-up for your unwanted attention being focused on me.
I have no control over what you do. I’m just asking you to stop replying to me, ever, because personally the upsides are far outweighed by the annoyance of you aiming your malfunction at me.
My opinion’s not going to change. You are who you are. Just please reply to others. When I like your posts, I’ll still click “like.” That will never mean my opinion’s changed. Please just ignore me. I like using this site. If you can’t ignore me, I’ll leave. If you refuse, just say so, plainly, and I’ll leave.
I can only speak for me. And I do make “normal” eps boards with 2#. Actually, I believe it is 1.7 to be exact. Those boards I do not vent. I have dabbled in spackle in the past but use only epoxy resin and cabosil now. Less chance of any incompatibility and possible problems.
The real issue I have is on my composite boards with 1# core. I make my own blanks out of big blocks so I am aware of how tenuous the bond between beads is even deep in the block. Greg used to check foam quality by flicking an edge. I know I am using the flimsiest core material at this weight. I wish I could get 1# fused blanks but alas, none exist. I talked to US Blanks. Not any desire to do anything that light.
I live in the PNW, cold and wet. If I take a board from the back of my truck and go surfing, the temp might change very little in winter. Water year round is 50-55 usually. Often colder, seldom warmer. Air in summer can get to 80’s so now about 30 degree drop on hitting the water. Hell, it shrinks my balls so fast I hope the board isn’t aching like I am. In winter air temps 30-50 are normal. That is a temp. change of a different color. So I can see that with the added air volume of my 1# core, plus a less than desirable bead bond, I am forced to seriously reconsider some means of allowing pressure to vent in either direction.
And then there is the nagging doubt about my hubris to think I can conjure these magic craft and protect them with a tiny piece of cloth in a fixture I dreamed up myself. Good enough for me. But I have been trepidatious about selling these boards and having one blow apart on a customer. I need a bullet proof breather vent that looks good, light weight, bonds well with epoxy, easy to service if necessary. Anybody know of one?
eps surfboard molded blank are more expensive than pu ones in France. way more too expensive for eps, on other hand industrial " good" quality locally made eps bloc are easy to find at good price.
All eps foam suck more or less water when they are pressurised in a close surfboard skin, open the skin (ding) and the core suck. i find that feet of surfer, acts like a foot pump too. i believe vented core help a bit…hot box cured boards too.
Spackle is right but after many years building and repairing eps surfboards i like more stay with epoxy cabosil microballon mix.
Darker color is a killer for delam.
Did you see my post #45, about GORETEX Valves… ?
Your skin is thin and you’re too self important. Don’t assume everything is about you… I’ll respond as I see fit.
Surf dude, saw that valve. Looks very similar to the one Speedneedle used to modify to make his. I will post a pic of one I made. Very flush with deck, no drag.
You are deeply, irreparably mentally ill. I get what you don’t: this is your family’s fault, not really yours, but the effect is the same. This forum would be much better off without you. I’m leaving, at least til at some point I read again and hopefully you are dead or just gone, but I’m not important. What is: more expert people than you don’t use this site because you do. You harm all with your dumb, dysfunctional, bipolar, continually toxic/overcompensating cycle of bullshit.
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I think it is as GLoehr stated in the early pages of this thread and as Johnny restated; less than 2lb. EPS which also stated; No foam supplier cares to invest time and money in doing anything that lite. Marko used to state that their SUP blanks were 1.5, but I don’t think so. I would probably vent an SUP primarily because so many of them are used inland where air temps are quite a bit warmer than coastal climes.
Funny, I never paid much attention to you before now. Other than the fact that you are long winded, I never gave you a second thought. You peaked my interest now though.
Yes, this is what i use when i vented, find them here for same price but i had trouble to fit them : at 1/3 front is a good place for venting but not good for my composit springer, near leash plug is too big and board is too thin to be set cleaninly so i want much vented leash plug like greenlight.
It never fails to amaze me how many people are still in denial if a hollow or EPS core board needs a vent just because they haven’t enountered a problem YET. It even further amazes me how much effort some will take to make a home-brew version that isn’t even close to the reliablity of the crappiest vents commericially available now. If you’ve spent about $200 USD on making a board, is $20 USD more (or even $12 AU) insurance with a vent worth it? The leak risk is very high with trying to mechanically clamp a piece of Gore-Tex material, and worse yet it is not even the same membrane as used in the screw-type vents. Just use a screw-vent and the insert designed for it, many are available and they are flush with the deck. If you think they compromise strength of stringered boards, use two (one on each side of the stringer).
As far as EPS goes, it’s not the beads but the air spaces between them. At a fixed board size, the higher the EPS density the smaller these air spaces are. From that we can say for a given board size, the higher the density the less reactive the core will be to relatively small external temperature / pressure changes. This also means that hollow cores are the most reactive of all. This “reactivity” is how fast the skin will heat up and then transmit this heat to the air spaces of the core. Conversely, if you cool down the skin the air spaces will shrink and the core volume will decrease. Thermal contraction like this is different than heating and it will draw water into any leak area. Thermal expansion heating is a cubic rate (3rd power) and can happen very quickly depending on skin temperature and sun exposure. There are many factors besides just N or S latitudes, and I’ve heard of problems at 45 degrees N during the summer (Maine USA) within less than 10 minutes. Air pressure changes will have similar effects, just ask the NZ people who drive thru the mountains all the time. One last point to remember is the area of the board which is heated will continuously get hotter if not vented. This is because the heat energy will continue to expand the air between the beads (along paths of least resistance) until it delams the glass which then provides more volume. To get the energy needed to do this work the heated surface must get hotter and the sun has no limit furnishing that.
Wisdom
all the best