I wish Ken at Segway was still doing his thing…
I need a block of foam 8" x 8" x 12’ long.
Would prefer XPS but EPS works too.
Does anybody know where I can find something like this in California?
Ama for a boat?
EPS will be easier to glue and less likely to delam after glassing.
Geofoam rep in California:
Maybe they can hook you up with a drop of some kind. I like 1.5 PCF, some people like 2 PCF.
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Yes it’s an ama for an outrigger canoe.
Thanks for the info, I’ll contact them
There are at least three EPS companies in Arizona. A little further away, but easy freight into California. One of them is the originator of the former “White Hot”. Geo Foam America, Insul Foam and Universal Construction Foam. Consider the possibility of giving Marko a call. They sell all kinds of foam and make all kinds of foam products. If you were able to create a file or give them something to scan, they could cut an ama. If you go that rout; Get ahold of me and I will give you a cell#. They may have cut one for somebody else. In which case they may have a file that they can share.
Chrisp,
The suggestions above are good.
If you want to use 8” wide strips of 2” thick XPS housing insulation sheet, I would not use XPS insulation foam with less than 25 psi minimum compressive strength. DuPont and Owens-Corning both make sheet XPS insulation with this property (last time I checked it was about $30 for a 2” x 24” x 96” sheet).
For glueing 2” x 8” x 96” strips of XPS together, 3M 78 spray adhesive is likely to be much more effective than Gorilla Glue.
My guess is you have plenty of scrap XPS now that you could test the 3M 78 on. The XPS bodyboard I made for the grandkids 6 years ago from the cheap 15 psi XPS housing insulation and 3M 78 spray adhesive is still glued together — and I rode it at 185 lb 6 years ago. (I glued together three sheets of 1” thick XPS.). But don’t use less than 25 psi for your project.
For big canoe i would use 15kg/m3 eps core, no more, with an hand lam 6oz biax carbon between 4oz surfglass. I know a guy that build his long ocean canoe for fishing like that with succes.
Thanks for all of the responses!
JRandy, Geofoam needed a $1000 minimum. =(
OSS1, I will contact Marko…
Stoneburner, I do have XPS chunks laying around and will give the 3M a try. I don’t have any 3M 78 though, I will have to look for it. I have 77 and the permanent stuff (99?) but I suspect those might melt the foam? Hmmm
Lemat, thanks for the tips. I fully trust your expertise in glassing EPS. I put 15kg/m3 into a calculator and it came back as 1 pound per cubic foot. Does that sound correct? That’s pretty lightweight foam. I was assuming I should get 1.5 - 3 pound foam (24kg/m3 - 48kg/m3). Also, I have a bunch of 2mm cork and my vac pump… I was debating about putting cork on the top after glassing. For dent resistance and maybe traction since I’m sure I will stand on it at some point.
I saw that USBlanks does block cut SUP blanks. I contacted them to ask if they could cut me a block. Waiting to see what they say.
Another option is to buy a SUP blank, have them cut it in fourths lengthwise. I have a stringer already. I figure I could glue something up from that…
Just thinking out loud…
That minimum buy is no fun.
I like the idea of reaching out to Marko or someone making SUP’s.
We once got ahold of a 6" x 4 x 8’ sheet of 1 PCF EPS sold as roof insulation by a construction supply outfit (not a box store). It dented easier than 1.5 PCF but got us into 2 blanks without have to glue up for thickness when we were first starting out.
If you could stand it being in 2 pieces, I wonder if Greenlight would be an option (shipping might cost more than the foam but you could probably get some pre-shaping of the ama as part of the package)
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That’s not a bad idea.
I’m thinking about reaching out to some friends that work for large construction companies and see if they could get some…
My fingers are crossed that USBlanks or Marko can line me up.
They are both a few hours south of me and send shipments to my local blank shop bi-monthly
3M 77 will melt XPS/EPS foam. I suspect 90 will too.
78 is specifically formulated for XPS.
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Chrisp if i understand what you build, it’s lot of volume, hi density foam with light skin don’t work here, too much weight penalty and not enough skin stiffness. Look how are build race paddle.
15kg/m3 is 1lb foam max you should use is 20kg/m3 (1.25lb). Sandwich where you need most of stiffness (cockpit) multiaxial glass carbon for all skin.
Look this project:
Crisp,
I believe some canoe skins have used sheet cork between (over and under) fiberglass skins.
This cork sandwich construction might make a good durable skin for your outrigger.
A little XPS prep work with a Wartenberg pin roller after sanding with 100 grit should significantly improve bonding. Pre-seal the prepped XPS with a thin coat of epoxy (then sand smooth with 150 grit) before laminating the skins. You can pick up a 7-wheel Wartenberg pin roller for about $15-$20 on eBay (get the neurological tool not the erotic toy).
This is what Wartenberg pinwheel roller perforations look like:
The 7-row Wartenberg rollers (22 pins/wheel) I have make 44 perforations per square inch. Pinwheel diameter, pin-tip to pin-tip, is 1.125" (28.6 mm). Roller width is 1" (25.4 mm), pin-tip to pin-tip. Pin length is approx. 5-6 mm. Perforation hole diameter at the foam surface is approx. 1 mm. Space between perforation holes is approx. 4-5 mm.
Stoneburner, thanks for the tip on the glue. I’m *hoping to get a block of EPS and not have to glue up a bunch of pieces but, if I do, I will give the 78 a shot.
Also, thanks for the tips on glassing XPS. That roller is perfect! I remember years ago Lavarat mentioned something about using a roller like this for XPS.
Lemat, that is a COOL project!
My project is like JRandy posted below your comment. The main hull of my canoe is wood. I only need a piece of foam for the ama/outrigger. See the arrow in JRandy’s post. I will try to post pics of my canoe to give you all an idea…
JRandy, thanks for the pic! That’s exactly what I need.
So, USBlanks got back to me. They have 1.5lb EPS foam that is 16” wide and over 12’ long and they are sending a shipment to my local blank shop 05/06.
***btw, anybody on the central coast that is remotely interested in building surfboards, boats, ding repair needs to go check out “The Craft” in Morro Bay. Good knowledgeable people. I cannot say enough good things about Nick. Seriously, go check them out ***
So, I am tentatively excited about getting a solid block from USBlanks. I asked if they’d cut it in half so I can add a stringer at home. I’m going to go talk to Nick at The Craft today and see how much this will run me.
I kinda wish I hadn’t sold my hotwire 
The way they used the hotwire to shape the foam in Lemat’s link is sweet!
I am building the “Wa’apa” from Gary Dierking’s book.
These pics are from the first day I could put it together and it actually kinda looked like a canoe. I have done a lot of little things since then.
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It is built in 8’ sections that bolt together.
You can do 2 8’ sections or 3.
I am currently only building 2 but may add the 3rd (middle section) later.
The goal is to have something that can be paddled and/or sailed. Beach launchable, un swampable for exploding our coast, fishing, diving, surfing, camping, etc.
I have used epoxy to bond cork sheet to a scrap of XPS, then laminated FG cloth over it. Appeared to be very solid/tough.
Another thought for adding cork/FG skin to EPS/XPS might be to use 3M 78 to bond cork sheet directly to your shaped foam, then laminate FG to the bonded cork sheet.
Try a test a panel first…
Cork is impact absorbing.
“Cork cells have a unique 14 sided polyhedron structure that can be compressed to 15% of their normal volume and then regain most or all of its size and shape slowly. This compression capacity combined with a very slow rebound allows cork to act as a very effective energy dampener, thus its popular use in flooring and noise proofing.”
Sounds like USBlanks is gonna be the go.
Stoked!
I’m going to try to see if I can find someone near me with a hotwire I could borrow.
I think I can do most of the shaping with a hotwire which would be more precise and a lot cleaner.
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Yes Chrisp for eps/xps hot wire tools are a good for faster and cleaner work. You probably not really need a stringer for this kind of build. Thanks to the shape, with couple layers of fiber and resin it will be strong enough.
Stone Burner i use a lot of cork sandwich nowadays. Discover more and more how it can be use effectively. On scuffed xps i use glass and epoxy to glue cork, it work. I bet you can use pu glue instead, also with glass between.
Carbon/glass cork sandwich is durable, light and strong.
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