maybe its shaper friendly for a machine but compared to a good poly it literally shapes like sh!t. the blank was 4 inchs thick, rocker was all wrong and need a shapers barrel to do it. i can shape a bennet with a 40 dollar planer no tearouts. eps also is far easier to shape and you can make your own blanks for a 1/10 of the cost
From a do it yourself perpective XPS can be a hard road to travel. From a production stand point even harder.
It’s a tricky foam to work with. For all practical reasoning a well rockered PU Blank with a light formula that is well poured is the most user friendly foam there is.
On any given day PU is my foam of choice.
I do the XPS from time to time still . I got into it in the first place because we had no Foam for a while in California after the Clark Shut down. The PU that was being imported was poorly poured (not enough chemicals in the molds cause of shrinkage). The PU available was so bad I started making EPS and XPS blanks. I learned how to work with alternate foam options at this time Late 2005. We had delam problems and tear out in the beginning. However we learned how to finish shaping it before laminating. I never got the plugs blown out for: Leash Plugs, Futures or FCS? Made many with only two delams. One was fine screened and the other one was left in the back of a shelled truck in the hot sun in the middle of summer all day for three straight days.The shaper who turned me on to it was also a very good glasser. He would finish the material to 40 grit and never passed 60 grit. Also if you wait 24 hour between top and bottom lams before advancing. For production xps is in not practical. However I have a few XPS boards that are still being ridden today that are going on five years. The original attraction was the memory the foam had. Were PU would lose it’s life after a few months the xps would still be lively. For this reason we learned how to work with it. Plus it’s HYDROPHOBIC.
In the end it was a flash in the pan. Soon after the EPS/XPS craze “PU” flooded California once again and it was cheap and in your face. We had ICE 9, KING MAC, SAFARI, PETRA TECH, ECHO TECH, BENNETT, SURFBLANKS, WALKER, BLAIR, EXCELL, ESIKMO, US BLANKS, TEXCELL. Did I miss anyone?
From CLARK and a small production from WALKER pre December 5, 2005 we jumped to 12 suppliers of PU Blanks plus there were other foreign companies wanting in the US market. Well having said that XPS died. Your right Paul PU is user friendy the easiest foam to shape so it’s popularity is well deserved.
Kind regards,
Surfding
I prefer surfing XPS now but that wasn't my initial feeling. For me I had to surf a while solely on XPS before I clicked with it, then I found my old PU sticks felt kinda dull, and unresponsive when I went back to them. Try dropping a couple of inches (scale the thickness/width down to match) when going from a PU outline to XPS to get a similar feel, XPS pushes back more. I turn my handsaw on its edge and run it at diagonals up and down the board, pretty diamond scores, no delams, I like to tint too.
The foam doesn't absorb water but dings soon become delams so I still fix quickly. Had similar problems with plugs so used wood inserts but... I prefer glass-ons. I used white, 7cm by 220cm wall insulating XPS, no manufacturer marks. But... I've only shaped nine and none are as good looking as what I've seen Paul post before so take what I say with a pinch of salt.
[quote="$1"]
For me I had to surf a while solely on XPS before I clicked with it, then I found my old PU sticks felt kinda dull, and unresponsive when I went back to them.
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That's interesting. I'm in the process of building my first board out of XPS. The thing I noticed was the twanginess of the XPS. When you bend a sheet of XPS, it just snaps back into its original position. PU doesn't seem to have the same flex return, which is probably translating to the dead feeling you observed. I think wood is the same way. A few years ago, I build 6’2 x 20” x 3” chambered balsa board. After riding it for a few months, and then switching back to my PU/PE shortboard I felt the same deadness.
My other observation was that If you bend XPS a little too far, then all hell breaks loose. I remember reading a post by someone (GL I think) that suggested to never bend XPS sheets to create the rocker. You are essentially pre loading the foam, which means it has less distance to bend before the big snap happens.
The main reason I tried some Xps blanks was that I wanted a board that didint pressure ding after one surf, I have found that the xps we can get here ( think its chinese) shapes ok but is a slower process than Pu, you have to run the planer real slow otherwise it will tear and or melt. So not ideal for handshaping which is one of the reasons I have gone away from using it. Delamination has not been a problem yet, scoured the decks with a wax comb previously to glassing which seems to help adhesion.
I have found the board itself really responsive and “Twangy” as described, its quite a dynamic feeling which im sure has its merits but for me so far I think they are too light for the majority of the waves I surf. The extra buoyancy and less weight means the board is much more effected by any surface chop or bumps on the face. I have found it less than ideal for surfing these kind of waves, especially on the backhand where weight plays a role in controlling the board( burying the rail) to slow yourself down and turn.
I am definitely erring on the side of Pu for ease of shaping and performance, also Xps comes with extra cost, more for the blanks and glassing materials and more labour.
nocean I have a XPS buid in the works with a combination core material. I’m going to post the entire build in one post to avoid any train wrecks that I might create.
I like PU as well however its so awesome to explore.
Kind regards,
Surfding
Hey jesus.
I also have a couple of pieces of XPS that I’ve shaped into convex pads for sanding concaves… Personally, that’s all it’s good for…
I built a few boards with it in the 80’s and they de -lammed, even after doing all the dimple and groove patterns on the surface…Don’t even think of leaving the board in a hot car…
If reduced water infiltration is the main reason for choosing XPS… There are stronger, better suited materials out there…
Those who haven’t had problems with XPS must be doing something wrong.
[quote="$1"] There are stronger,, better suited materials out there... [/quote]
Cost/cubic inch ... Price Tag? Density? e.g.?
"Those who haven't had problems with XPS must be doing something wrong."
LOST SURFBOARDS has made 1000's of XTR's which are really XPS!
Making some today in fact.
Hope I keep doing it wrong!
Kind regards,
surfding
Where are you buying your XPS?
If we can take it for granted the stuff is closed cell, then we can agree that there is no point in putting a vent in an xps board. If we believe that , then how can we believe that xps can ‘outgas’? Trapped blowing agents can magically travel through xps foam, but air cant? Whatever. For now i believe it is shear failure, and maybe by using the foam inside a core where there is less shear movement closer to the center of mass this issue can be resolved. The bond between the glass and foam is torn under stress, the air space expands with temperature change and delams form, i think thats all there is to it. I am not a hitech board scientist. Locally i can order a blank for 80 bucks plus shipping, or buy shit one poind eps or xps sheets. For this one i spent 75 bucks on corecell and 15 for the xps, so no cheaper…but its fun. Current sandwich board pic. What could POSSIBLY go wrong? I’ll let you know when it falls apart…might take a while.
Some good points. Adhesion is about bonding surface/penetration “area” and the shear strength of the surface bonded. A scattering of pits and holes 0.25"-0.5" apart do little to significantly increase bonding surface area and/or resin penetration.
I suppose some gas could be released after crushing a few cells. How would that be any different from crushing other “closed-cell” foams (e.g. divinycell)? Crushing is related to compressive strength/density of the foam.
I came up with a similar concept to your skin idea. But your skin looks like a lot of work.
Right now I am playing with Dow High-Load 40 and 60 (2.2-2.3 lb/cf). Big difference over Home Depot pink. I paid $25 per 2’ x 8’ sheet. No shipping charge, just throw it in my car with seats down.
Too cold to glass now unless I do it in the living room. So this will be a warm-weather project for 2011. Besides the longer I wait, I usually come up with new/better ideas after continued pondering.
Good point, cells crushing. I’d have to agree with you, gas could be released when the foam is damaged like a piece of fruit dropped on the floor. so heel dents and dings would lead to failure as well. Based on previous build and real life riding and abuse, my other corecell board is extremely tough, so dings are not an issue. I only make a few boards a year so i have no stock in xps, im just having fun and on the quest to make the best surfboard ive ever made, which is an endless pursuit that has me trying all komds of foolish things. A heavy skin is durable and doesnt add too much weight. At 33 I will not become in my lifetime a lip bashing, aerial maneuver kind of surfer, so i dont care about a five pound board.
I would probably be playing with EPS if I could find a cheap local source. But there is a local construction contractor that carries Dow High Load for occasional jobs. Easy to get and relatively cheap to experiment with. I don’t like paying $100 for a commercial blank, and as much in shipping, when I am experimenting with shapes and construction techniques.
I’m sure the corecell works great – no mock intended.
I’m just playing and experimenting. Have no idea if my skin concept will work to avoid XPS delam issues – I think it will – plus retain low water-logging properties. I enjoy shaping and glassing and like solving problems with the materials available for use. And I like cheap but effective solutions.
BTW light, cheap and available don’t have to be mutually exclusive.
Are you using a stringer in your skin boards?
no stringer. i used to go on month long trips to mex and costa, now im a weekend warrior who makes it to a few points amd coves in ri, and sometimes a couple beach breaks at cape cod, may go down obx for a trip this winter, used to live and work down there. Went wherever i felt like before a kid. in other words my boards if they see steep walls they arent monsters; generally riding forgiving point breaks nowadays. no stringer, no buckling yet.
No… I was doing something wrong.
By using the wrong material for windsurf boards that took a major pounding from jumps and violently switching foot stances…
I considered not posting my feelings on this xps thread and probably should have went with my gut…
.Let me leave it now by just saying…“It’s not for me”
It's unlikely that I would have commented about this post.
But then, there wouldn't have been as much interactive discussion either.
If something doesn't work, try something different or change your approach. I think a cost effective and durable board can still be made with XPS -- even for your purposes.
If it's workin for ya, keep doin it.
Im using My Xps as an additional foam for stringers/Rails at the moment, heres a stringerless board im doing with a Xps center, mainly to widen the blank as much as anything:)
what glue are you using to build the blank?
Hi afoaf, Have been using gorilla polyurethane glue, I find it sands really well if you make sure its clamped or taped nice and tight, I spackle any small holes before finish sanding…