a friend of mine asked me to build a SUP for the lakes nearby.
She is 65 years old , 55 kg + a 2kg little dog ,and i think a light board would be the best not for the performance, but for simply carrying it around and getting it on the top of her car.
I am thinking of a 130-140 l volume board.
I have 20kg/cubicmeter eps foam (1.2 ppcf), 4 ounce and 6 ounce glass, some corecork nl 20, some uni carbon, and this 80 gm (2.8 ounce) hollow glas fiber that was on sale at the composite store.
Has someone used H-fiber? And what part of this mix would you built in a board?
I never used it, but I believe you need to use vacuum bagging to laminate this stuff.
Since it is hollow, it has the tendancy to float on the resin like kevlar.
It is especially good in compression. However, if you want a big and light board, I’d advice on using 10-15kg/m3 EPS with an HD foam skins (compsand). Especially in thick boards like SUPs and sailboards, you can save a lot of weight with this construction.
I agree with Hans, My strongest by weight are 1.6 EPS with corecell deck. With corecel, use lightweight skinz/ Cerex under, and a single 4 oz over. Must be vacuum bagged.
I used 10m of H glass. You can laminate it by hand it’s not really lighter than other fiberglass. I don’t find it speacilly “stronger” too. On 20kg EPS, 6+4 top and bottom + 6oz deck patch with exposed Cork give a good weight/durabilty ratio.
With strategically placed deck layers and a pad, you can go pretty light but the rest of the board will be fragile. Don’t forget a pad for the pooch. For flat water and a light rider you can skip the stringer too… maybe shape rail slots for stiffness and to help grab it.
You are right that light pays off when moving it around from garage to car, etc. In fact, I’ve built them heavier for durability and the handling thing became enough of an issue that it might have led to more dings! Strong guys can do it OK but women tend to drop them on rail, drop them on end, hit the racks on the way to the roof, etc. With the light ones it is a good idea to apply urethane ‘rail saver’ tape along the sides.
Hans, everysurfer, i think you are right, i should have started with lighter foam, but now i have this 5 cubicmeter eps monster in my garden and i am desperate to cut it into blanks. It is not easy to get a block longer than 2m here, and the last time i glued a sup blank together out of light (10 kg/m^3) eps i ended up with a lot of spackle and glue making it not exactly light. So this time i will stick to what i have. But thanks!
Lemat, the exposed cork as a deck pad? And 6+4 b/ 6+4+6 t without stringer?
Johnmellor, funny, the last board i made for Croatia was thought to be super durable, but carrying that thing over the rocks is a pain in the ass.(and i am used to carry weights, working construction) Thanks for your advice and the link,
Nice picture, this one illustrates my friends dream pretty well!
I just finish one for waves, 7’7" x 27" x 4", 20kg EPS composition springer, 2x6 bottom, 6xglass époxy foam + 2x6 top, Cork front pad. Final weight is good say the rider and board is really strong to the antique tumb test so 2x6 bottom and 2x6+6 deck patch could be a good and simple build over 20kg EPS. Of course can make better with compsand tech.
If you check the photo I posted you’ll see the dog wearing a flotation vest with a handle on the back. This can be a life saver for the dog. If the dog falls or jumps off, you can pick it up like a suitcase and put it back onboard.
Six ounce one layer both sides. One layer of four ounce over the six deck. Full deck EVA pad. Strong enough and still keeps the weight down to a moderate level. It’s for a lake not Jaws. All that other stuff is over kill and unneeded weight gain. Plus you don’t need a Vac Bag. I know all of the above techies will pooh-pooh that lay up but that is the current industry standard. Depending on your climate and temps consider a vent. I like the “Cassica Vent”. Lowel
No. It is the most popular and widely used vent for EPS, but I don’t believe it is fitted to a handle. Seems like a good idea though considering the positioning of most SUP handles. PM petec on this website for info. Lowel
I am no pro, but here is what I have found after building 6 SUP’s and also working in a retail shop that sells and demos boards:
For glassing, I have found that 2x 6oz bottom and deck with a 6oz deck patch and eva pad results in a decent strength to weight ratio. A little heavy for some, but I don’t like boards that are to light. After a full season of use I have no dents or dings and I was intentionally being hard on them (within reason) to test the limits. Also, this is over 1.5lb EPS.
With normal use, rails and the area of the deck where the user is standing seem to be the vulnerable areas. Rails because of droping while the board is being carried. and the deck from paddlers falling onto their knees and being heavy footed. I have seen and repaired dings on the flats of the bottom or deck, but these are typically due to some weird event and having 1,2,or 3 layers of glass would likely not change the result.
Also, consider the type of handle being installed. Strap handles can make a heavy board much easier to carry with more control and for flatwater use, are safe to install.
If it’s a “real Waves” sup, i don’t think that 1x 6oz only both side + deck patch is enough on 20kg eps. But way not. I post photos of the sup i make in my last post in photos thread. Boards is just under 7kg, it’s really easy to carry even for my small wife. I use the FCS handel with goretex nut.
It is not easy to get a block longer than 2m here, and the last time i glued a sup blank together out of light (10 kg/m^3) eps i ended up with a lot of spackle and glue making it not exactly light.
When using 10kg/m3 foam, you should use the compsand construction! No spackle should be used, wet out the cloth on a wetout table or directly on the skin, not on the blank, otherwise you’ll soak it with resin.
And only use a tiny bit of glue, just enough to hold the pieces together while shaping. There is no strength needed in the glue joins.
How heavy is a little heavy? I just fear, like johnmellor mentioned, that if it gets to uncomfortable weightwise for the lady the board is not going to be used.
Thanks for your advice and the link,