We have been getting a lot of requests for suggestions on how to seal the new aluminum mast from water ingress, and apologize for the delay of this much needed blog post. Before we dive in, I want to reiterate that leaving the mast open was a difficult decision, and that we agree with some of you when you tell me that a well-designed, premium product would have been sealed at the time of manufacturing. Again, the rationale for leaving the mast open included the following:
1. It’s really hard to achieve a long-lasting seal. Eventually, it seems that all sealed OEM aluminum masts eventually suffer from water ingress, and then it’s impossible to get it out. H20 is a very small molecule, and can find it’s way into pretty much anything, only to come out when you don’t want it to (in your car, on your carpet, wood floors). A truly long lasting seal would involve significant amounts of testing, expensive primers and adhesives, and a very tightly controlled application process. With the COVID-19 supply chain issues, we saw an opportunity to offer a domestically produced aluminum mast and did not want to miss the window testing seals.
2. Cost. Our goal with the aluminum mast was to offer the industry leading stiffness, strength, quality, and modularity of Project Cedrus at a price point similar to other aluminum masts. Because the mast is extruded in the USA, and it actually costs more to install the 4 helicoils than to extrude an entire mast in Asia, we we simply didn’t have the budget. Adding a proper seal would have easily added $50+ in costs due to materials and labor. I figured many of my clients would prefer to save that money, and potentially even enjoy the process of a little DIY sealing.
3. Customization and e-foils. Project Cedrus is the only mast, carbon or aluminum, which you can purchase at a desired length down to the inch. Having the masts sealed in bulk, only to cut them down and re-seal, would have likely doubled the cost. Furthermore, many clients are converting these aluminum masts to e-foils, and need access to the cavities for wire routing.
While there are certainly cases for sealing (mainly weight), we appreciate your understanding for our reasons not to seal the mast and want to offer the following options for those who’d like to seal themselves.
(Picture Credit: Alex Bramwell/Getty Images)
The displacement method: Our preferred method is simply cutting strips of pool noodles to fill the cavities of the mast, to displace water and reduce the volume (weight) which can enter the mast. This is quick, easy, cheaper, and less wasteful than other methods. Any closed-cell foam will work, and there are lots of options on McMaster-Carr if you want to try other shapes and sizes..
Ethan sealed his mast with JB Weld Marine
Liquid sealants and adhesives. The cleanest looking for sure, but also the most time-intensive solution, liquid/paste adhesive and sealants can be used to pot the end of the mast and prevent water ingress. Surface preparation of the aluminum is critical to a long-term bond, so be sure to wipe with Acetone or IPA (alcohol) before applying adhesives. Getting stuff to stick to anodized aluminum can be challenging, so we reccomend a more elastic adhesive, such as a urethane-based chemistry, to better tolerate the expansion and contraction of the aluminum due to thermal cycling (hot beaches, cold water). 3M 4000 UV is a great sealant for marine applications.
Josh @ The Foil Shop used Great Stuff
Spray foams. This was a method we tried during our prototyping phase. It’s quite messy, but quick and so far effective. This stuff expands A LOT, so be careful as it will come out the top and potentially run down the side of the mast. WEAR GLOVES, and wipe before it cures. To be honest we’re not a huge fan of this method, as it is pretty wasteful (you’ll only use 10% of the can) and super messy. But we want to share all options. The pond & stone version comes in a re-usable spray can and may have better performance in the marine envirnonemnt, but we cannot make any guarentees.
Have more ideas that did, or better yet, did NOT work? Let us know! We’ll update this accordingly, and appreciate the crowd-sourced method of finding the best solution. Good luck and have fun!