XPS/Glassing/delamination

Hi Guys, i want to start to glass my XPS core but i really dont know how to solve the delamination problem! May be some of you guys could give me some good advices!?

Is it enough to scratch the blank with an (20-60 grit paper) before glassing or should i add more resin?

i have no experience glassing XPS…

check out this link though…

http://www2.swaylocks.com/forums/some-sways-inspireds-boys-and-my-greenroom-resin-experience

After my own experimentation and study it seems one is best off not using XPS, or dealing w/the gassing.

I did “post holes” (Made a tool to poke 3/32" holes about 1/2" deep, every 1/2" by putting 120 nails in a sheet of heavy corrugated paper board, curving it on a curved wood frame, and had at it.) I also did scoring by setting six razor blades about 1/2" apart, in some foam w/friction tape, and running it, a half inch deep, all over the board. In the end both those methods did not prevent the gassing from forming bubbles.

I did not go as far as, which was suggested by a couple guys who claim to have success with it, drilling tiny holes on a half inch grid.

I’ve toyed w/the idea as recently as a couple days ago when I saw a pickup drive by with some sheets of 8’x2’x3"… Nice and cheap, and, considering the foam itself is water proof, you could just keep a close eye on the board and make a tiny hole anytime you start to see a bubble.

But, the biggest drag was the large bubbles that “popped” up during lamination… I guess I could have hung around longer, but I didn’t feel like investing more hours baby setting any longer…

Got a good deal last winter on 2# eps $50.00 8’x11"x8" - made two boards (Granted I added some left overs from other foam to make my 10’7"x4.5" thick… and had enough left to make my latest 7’5" x3.5 thick… Stoked!!!

In the end, as it was put to me, by more than one concerned party here… “Use EPS.”

I bagged an epoxy laminate over an XPS blank and put in a vented leash plug for insurance.

the board is bomb proof…I’ve dropped it, banged it and I do horrible things to it with my knees.

it does not, however, get exposed to high temperatures…caveat.

My worst xps delam was in the underside 12" of the nose, pretty much a huge bubble. I think it was my second board, pretty sure. Yep. Stupid. Dont use brrown frown tint in yer epoxy, unless you keep it in the dark like a gimp. chocolate brown is a no no fer me with xps from now on, metrafact I dont think I wanna use it ever again except I might give it one more try, there are some ‘buoyancy billets’ available nearby…8’ x 24"x12"…it would defnitley be my last try, though, unless I had some epiphanany with a solid chunk of this bastard foam. I’ll say the same as any thread here will tell you: sand it rough as hell and STOP. Don’t try to make it baby butt smooth. And I’d suggest tint some light color at any point in glassing, or join the dissapointed

ohhh ohhh ohh, i see Epoxy/XPS isnt a very good combination! Iam not sure if i should try to glass the Blank! My first try was a disaster! A lot of big bubbles in the bottom! I thought it has something to do with my skills!

Love it! Hundreds of XPS boards made from 2005 to 2008. From making the blank to a finish product. Gassing comes from the stringer normaly, When you put the stringer together use cabasil in your epoxy. Sand both sides of the blank surfaces before gluing and clamping. The foam becomes slick from hotwire cutting. Never leave the foam smooth. I always leave it finished with 60 grit before glassing. I don’t do the docking holes however they do work.

XPS is Hydrophobic so the key is only to get a shell around the blank for durablity.

The best combination was when I made a XPS parabolic with a 1.8 pound EPS core vacuumed bagged 3 years ago. I may make another one here shortly. The down side of XPS is leaving them in a hot car as they will bubble.

I had 2 failures during the time I was really involed with the XPS craze just after the Clark Closure. No big deal just fixed them and the surfers kept surfing them.

  1. Milling XPS is tricky as it has a low melting point. It's better to just shape them by hand. There so easy to shape out and I love the way the rails do what you want. I found the foam very forgiving hand wise. However for CNC all your setting (Feed Rate and Spindle Speed) have to be just perfect.
  2. PU is the most friendy for production and top end surfers love the way it has dampening qualities.
  3. XPS is very responsive however comming off floaters and airs is hard on the ankles.
  4. Dow chemical or Corning will not invest in the surf industry therefore XPS will never be delevoped to it's true potenial.
  5. Can you image Marko using there molds with XPS? They would kill it,
  6. Inovation is needed!
I have 5 billets of Blue XPS left from the 225 that I had. You can get 2 Blanks per billet. That leaves me with 10 more boards to build however theres no hurry. People are not willing to pay what they are worth plus you do have risk of miss handling.

Thx for these comment! Its really helpfull!

But my first try glassing was without stringer! Are you working just with vacumm? I glass the blank normaly by hand!

Have you got an idea concerning painting the blank? Is it also possible?

99% IS ALL HAND ONE 1 WAS BY VACUUM.

PAINTING IS NO PROBLEM HOWEVER PEOPLE LIKE THEM WHEN THEY ARE BLUE.

STRINGER LESS? YOU MUST HAVE SOFT WAVES? THEY WILL SNAP!

MINE HAVE BEEN SURFED IN INDO AND NORTH SHORE. SOME SNAPED WITH A STRINGER.

WITHOUT ONE?

UNLESS YOU GLASS IT HEAVY THEN WHAT’S THE POINT?

THE LIGHTNESS AND THE SPRING IS THE ATTRACTION.

hey ding. i still have a blue xps flat blank sitting there waiting for a deck skin and rails. maybe i should finish it

Everyone tells me that, if you use XPS you need not a stringer! I have seen some guys in the dominican republik @ the north shore! It works 100%

here are some examples!

http://www.youtube.com/watch?v=R4xM9EhfK0U&feature=related (Surfersteve.com)

also BUFO Boards! The build the boards without stringer! http://www.bufo-boards.com/home/start/index.php

I will glass the board with 160g/m2 layers! Its about 5,5 OZ per Layer! 2 Layers on the Bottom and 3 on the deck!

to the delam probs! I have deciced to use an vented leash plug, but here in Germany its hard to get this nice tool;)

i thought these plug is a fine solution!

http://stores.greenlightsurfsupply.com/Detail.bok?no=172

Vented leash plug is a smart idea! I’d be worried about damaging the goretex with that design though. You could check out PeteC’s vents.

Karl

A vented leash plug is not going to achieve anything in an XPS board except vent the area immediately at the base of the plug. For a vent to work, the air/pressure must be able to travel through the foam (as it does in low-density EPS) to the plug. There is no such travel in XPS.

so i have no idea how to solve the prob! I think i will try the surfersteve-method!

surfersteve.com

"

One more alternative is to use 2lb./cubic foot (25psi - pounds per square inch) extruded polystyrene foam (XPS) - Dow Square Edge, or “blue board”. Please try to keep and open mind, and disregard much of the information you might have read online etc., about this foam. The delamination problems which have caused some builders to stop using this foam can be solved by following the directions below. A very good board can be made with this foam if you will simply build the board a little differently. This foam does not have the water absorption problem that expanded polystyrene has. Extruded polystyrene is stronger (pound for pound) than polyurethane, or expanded polystyrene (most surfboard polyurethane is about 3lb/cu.ft.). If you build with this foam using conventional methods, you are much more likely to have delamination problems.
Please allow me to insist you do the following:

  1. Use an epoxy glue joint/s (in place of a stringer/s) - one is o.k., two is better.
  2. Finish the blank by sanding lightly with #20, leaving hundreds scratches and small pits.
  3. Add about 5% more resin to the laminate after dragging the excess resin out of the cloth.
The extra resin will fill in all the pits and scratches left on the rough blank. I realize it is hard to scratch and tear the foam of a blank you worked so hard to perfect, but do not skip this step. The pits and scratches greatly increase the bond, and with the glue joint/s, will minimize the delamination problem to a level equal to other foams. As with all boards, but especially XPS, avoid exposing an XPS board to a car interior on a hot day with the windows rolled up. This foam is available in sheets 8' x 4' x 3" and 8' x 2' x 4" thickness maximum, so you may have to glue (epoxy) two sheets together. It is possible to make two good boards out of one 8' x 4' x 3" sheet, if you bend the foam as in the paragraph below. XPS was available in 2006 for $46 for a 8'x4'x3" sheet. "

I think if you follow those directions and install one of Greelight’s vented leash plugs, you’re going to be golden!

I have a billet of XPS left and I’m contemplating a compsand stinger and an assymmetrical “open face sandwhich” style.

Bamboo skins on XPS and you’ve got some serious durability and a great rider.

fwiw - ive just made my first xps board, and the only issue with delam so far - haven’t sanded it yet as it is baking - is along the ply stringer. The rest of the board is rock hard, and way stronger than the 2lb EPS blanks I’ve been using, with less cloth.

In the UK it is pink, so I’ve added pigment to the lam, but the next one will just have glue line stringer, and clear lam.

I’m also wondering if you glassed it in falling temps it would stop the outgassing during lam. Then you could drill out the leash plug, and leave it out until its done cooking…I glassed mine in the morning, and temp. went up all day, so surely led to the small bubbles along the stringer.

It is a really nice foam to shape, and while I did tear mine by planing too fast on the bottom, the deck side is almost the same as PU…I like it, and it’s cheap!

Is XPS really cheap? In germany ist expensive. EPS is about 30% cheaper!

I have payed for 2 blocks 125x60x12 (cm) 34 €

The **Blue xps **is from Dow Chemical - The Pink is from Corning

Most of the of gassing comes along the stringer. You must sand both sides before gluing and clamping in the stringer.

The reason you leave the foam slightly rough (hairy) is to prevent shearing which is the biggest factor rather than delam.

Vent Plugs are for Hollow Boards and 1.0 - 2.0 pound EPS. For XPS it’s pretty silly as there has no benifit whatsoever.

yeah dont vent xps. air doesnt travel through it. venting is a waste of 40$ . i think adding a skin to the deck may be beneficial due to reducing point load compression damage. this would reduce delaming a great deal and increase overall board strength

i think adding a skin to the deck may be beneficial due to reducing point load compression damage. this would reduce delaming a great deal and increase overall board strength

That a very intelligent thing to say!