Venting Hollow Paddleboards and Surfboards
Atmospheric venting of hollow surfboards or sup’s is critical. Without a functioning vent, your board will be vulnerable to structural failure due to (primarily) the expansion of air inside your board as the board heats up, which it inevitably does when out in the sun. The amount of pressure build up inside a board can increase to the extent that the board will actually pop! I know this to be true because it has happened to me. At first I wasn’t sure what the sound I had heard was, but as soon as I got to the launch site and looked at the deck of the board and how expanded and rounded up the deck was I knew exactly what had happened. The board didn’t actually explode but parts of the deck popped loose from the internal framework and the loud pop I had heard was the sound made by that structural failure. Oh man, did I feel horrible….I only had one board at the time, the surf was good and I needed this board!
I had installed two membrane (Goretex) vents and was confident that I had done the right thing. So what happened? The vents I had used were the Goretex membrane type. My comments are not about how “bad” the Goretex vents are, they are about the limitations of any membrane vent. Goretex vents will only transfer a certain amount of air through the membrane. The board I installed them in is a redwood board and what I hadn’t anticipated with the redwood skin on this board is just how fast the darker wood would heat up. So even with two Goretex vents in this board, the pressure built up to the point of failure….so, POW!! was the result.
The solution for me is that I now use mechanical vents which are simple screw in/screw out affairs….but you must remember to screw them in and take them out. Pretty simple but you can’t forget either operation. So is there a perfect solution to dealing with pressure build up in hollow boards? There may not be a perfect solution but there are options that should be considered beyond mechanical only or membrane only.
The current builds taking place in the CLEARWOOD shop may get both mechanical and membrane type vents so that even on a hot day in warm water I don’t have to worry about releasing pressure during my paddle outing. I have thought about this in the past but rejected the idea for reasons of keeping it simple. I’m now considering all options. I have heard that the newest membrane vents available from http://greenlightsurfsupply.com/leash-plugs-and-vents.aspx are better than the ones I used in my “exploding” board. I am not endorsing this product in any way, just putting some info out there for you to check out. I guess, at the end of the day, the one sure way to go is mechanical venting. As far as the the vented leash cup product, I’ve never been much of a fan of plastic leash cups in any form, vented or not….just my personal bias. I actually had a cheap plastic leash cup break on my first board and thankfully it happened at an uncrowded break with a sand beach. My current leash cup set up is one I make in my shop and I’ve had no failures. That’s with me and the board taking some serious abuse in some reasonably big (for me at least) 10′ surf. I’ll address shop made leash cups here soon and if anyone is interested in how they are made before I post the info you can get in touch with me directly through my website.
Here is a photo of the mechanical vents I like. The brass body threads into a wood block attached to the underside of deck, usually somewhere near the tail. The block is drilled through so that venting can occur. Some builders claim you need two vents in boards over ten feet in length but I’m not buying that argument for the mechanical vents. I can see using two vents if you are using membrane vents only, but then, I don’t think that’s a good idea.