XPS or XTR or whatever??

I have a question about XPS or XTR or whatever You would like to call extruded polystyrene foam.

How come some people like http://www.pointblanks.com/ are still in business, well their website is still up anyway while so many people here are saying this type of construction is “A dead horse”.

Have they worked out a way to manufacture with this technology that others have not?

Has any one here owned a Pointblank surfboard with extruded foam?

If so how was it ? Did it last? Did it delaminate?

What’s the scoop?

I’ve up to date only just made one board out of this stuff but haven’t had time to finish it yet. (only done with the glassing) but I still have a few blanks left in my backyard.

Do You think It’s worth shaping and glassing them?

I can only get blanks here in Sweden if I ship them in from UK (expensive).

Can get EPS blanks here but I’ve had really bad experience with this material from my sailboarding days. Waterabsorption problems

Well any way all ideas/suggestions welcome

/Erik

hey eric…

i checked out that website, i couldnt find out how long theyve been building them…i read under there technology link ,they spent a year testing different foams resins and so on …

that would be a logical thing to do ,to find some direction …

im not trying to be negative or bag them in any way…

but , once you start producing boards and put them in the market place ,any number of things can happen to different people , i noticed they say keep the board out of heat , fine but what happens if you have no choice???

considering many regulars to this site have put the foam to the same type of tests ,then got excited how it performed in test panels ,only to be disapointed with its long term durability when made into a surfboard and have a wider variety of tests to undergo…

i say this coz at one stage i to beleived xps was the holy grail of foam ,ive since found out others were using it over a decade before me ,thats now at least 25 years minimum its tried to be applied to surfboards and no one has conquered it yet ,everyone has been through the same dramas,it takes a few years before the boards get fully tested and all the customer feedback comes in , even tho they all look so promising in the first 6 months …

i see youve had problems with eps , but appart from water absorbtion, it ends up being a way more durable foam long term ,has better peel strength and works alot better with epoxy coz eps has memory…

you just have to watch your dings…like you watch your temperature or oil gauge in your car…you wouldnt drive your car with no oil would you???just like you wouldnt surf an eps board with a hole in it…

ive been building boards for over 20 years now and have used all foams in the last 15 , to date only my eps boards have stood the test of time ,and i mean real everyday use,not just built and shelved somewhere…

eps will tolerate way more heat ,than either xps or p/u as long as its vented,wont go brown when wet and decay with age or pressure ding…

but it does suck water ,so keep an eye on dings and itll last a lifetime…

regards

BERT

ErikG, there are different types of XPS foam. XTR is an epoxy pro product. They worked around the gassing/foam shear issues using thermovents, which are small holes through the glass, allowing the gas to escape.

I’ve only seen 1 patagonia board and I didn’t see any problems with it.

HDX uses some XPS white, XPS blue, and eps 1.5 lb . To date, we haven’t had any delam issues, including the board that I intentionally tried to mess up. That board was ridden pretty hard, left in a black board bag locked in a car, exposed to direct sunlight with temperatures exceeding 110 degrees.

yep thats fine jeff , all make sense , clever as well to solve the gasing problems …

last issue to solve is , the peel strength , xtr has the worst peel strength of all the foams, and once the board gets hammered under foot ,just the shear stress alone is enough to break the foam resin bond …

the soloution i came up with for that ,was blade cuts at about 6mm deep at 15mm intervals on a 45 degree angle both ways…it actually held the glass in place , the only down side , when the board got hot you would get a print through of the groove pattern ,which was permanent even after it cooled ,where each resin filled groove was ,it was sunk …the foam swelled but couldnt swell on the solid resin parts…when the foam swelled the board was hot ,so the resin would reach its heat distortion temperature (hdt)and change shape permanently…

im wondering if a combination of grooves and thermovents would do the job???

the foam may not swell if the vents let out the gas ,which means even if the resin does get hot enough to reach hdt theres no pressure on it to conform to a new shape…

regards

BERT

also the comments about the board in the car , i also did that and had no problems with new boards,but once theve had a bit of use they cant tolerate that sort of treatment as well…

I have to agree with Bert. I’ve not seen the XPS we all have dreamed of. Fortunatly EPS is pretty good stuff and the water intake through dings is no worse these days than a lightweight urethane.

hey greg ,did ya get that email?

i been on the honeycomb trail down here,found 2 companies who do core…i gave one guy today all the stats on what i need ,cell size,density,chemical make up,and overall size…waiting now ,hope he has something …

my location makes it harder to view samples ,as soon as i see it i will know if i can use it or not…i want to give nida a ring , but the time difference is a real pain…and i want to exhaust all possibilities down here…

question for ya greg???

have you used a product called core cell???

they make some pretty grand claims…

is just a white divinycell? or is it better?

regards

BERT

Bert,

We have used Corecel in the Hatteras shop. It’s nice and it seemed similar to Divinycel but white. Well, off white. I seem to remember that it cut better and was perhaps a bit harder per density. A bit stiffer too but that was a while ago and I’m having trouble remembering the exact stuff. The stiffness was maybe approaching Klegecel or Termanto but not that brittle.

We’ve also used Rohacel in Hatteras and FL which is VERY white and VERY expensive. $120 for a 1/4 inch sheet. Also we’ve tried Lasta-foam which is inexpensive and yellow which worked nice. They have a new R7100 which is a fine celled urethane that I liked the looks of and I’ve got to get some. It’s whiter and doesn’t look as resin hungry as a lot of cores. Available in 4# density and up.

And then there’s Airex which is more flexible. Used Airex on decks because it bends without breaking. You can also thermoform it easy. Airex also has a new R82 core that looks awesome. Nice and white, small cell size and … expensive as hell. Oh my God!!! And I thought Rohacel was expensive! This seems to be made for government contracts only. I got a 4"x4" sample that I’ll bet I can auction for the rest of my daughters college education.

I’ve also seen but not used Stephan Foam which is a urethane which looked reasonable. We’ve used Coremat 1 mil for some decks which comes out nice and we are looking into Spherecore which sounds really nice in a 1.5 mil. Nidacore also has a Coremat type product that comes1 mil but it is perforated so i didn’t like the cosmetics as much.

actually the urethane is not a bad option, i used to get this stuff from midget at surfblanks years ago , he was blowing real high density tdi then cutting it into any thickness you wanted down to 4.5mm …

but i stopped buying blanks from him coz i went full eps epoxy, and getting the high density sheets from over 4000 kms away was a drama by themselves ,but previously in the containers was no drama…

and your right about price on some stuff …

imagine the boards we could build if some of this stuff was realisticly priced…

thats one of the major reasons more crew arent stepping up to the next level of contruction…alot of financial pain just to learn…

regards

BERT