XPS Stringless Dow Chemical (Blue Surfboard Foam)

A few years ago I had a couple oif truck loads of XPS Dow (Blue) and made 100’s of blanks. Since I have a down sized and in a smaller shop my storage unit host a fair amount of billets. Well I had my first XPS order in 2 years? So I gave in to make one. Since I have been gettting custom deck rockers of all my models life is so good. Today I realized how much work is involed with making an XPS board from a square billet. Before when I had a crew of employees it was easy. Just thought I would share the process if anyone cares?

 

Phase 1

 






Glassing schedule:

4 + 6 Deck

4 + 6 Bottom

Projected weight under 5 pounds

Here’s some more pics:

You can see where I cut the billet down. I use the scrapes for various things.





Cool … I was the distributor for Dow for a few years and like you made hundreds of those blanks.  Essentially the exact same way we did it.  Brings me back … thanks

thanks for the pics Mr.Ding...

i hooked up the wire you sent me to my hotwire. it glows nice and red. i'm looking forward to doing some cutting.

Agree…This weekend I am starting my first EPS board this way. Thanks to your pics, I know I am on the right track.

If you get your deck profile right the rest is easy!

I almost freehanded the deck on a piece of masonite. It looks ugly but it works. My bandsaw is at home so I used my jig saw to cut of the rocker profile. (Pretty hacker style) however its does help to remove all unwanted material so you get closer to the shape. The hot wire speeds up the process. I use to cut two blanks from one billet and bend the rocker into the blank and glue in the stringer to fix it in place. However since this is a stringerless I just plowed a whole billet. The waist material I can make sanding blocks and various gizmos.

 

Hi Michael -

That answers the 'Is it OK to hotwire XPS' question.

Ian (Lavarat) turned me on to a carpet seam roller with teeth to prep the finished blank.  What do you think?

 

Thanks for posting those picts. Where do you get the XPS? I glued up 1"
sheets from Lows but hate the glueJoint. thanks

what’s the going rate on a blank and machine cut of the stuff?

the last board I made wound up too small for me…got too agressive with the tweaks off the last board and want to make another.

 

Some guys dock it like you are avocating however I leave it at 60 grit sand finish and no screening. I have made over a couple hundred this way. Its the shear factor more than degassing. I normally use stringers however this customer wanted stringless.

So if you make it thick, and the thing doesnt flex, you wouldnt have shear, right?

The board is 2" thick?

hey surfding sorry a bit of topic but you seem to know your stuff with xps.

 i am planning an other xps board i have a few 2 inch sheets that i want to cut to my rocker outline and glue together to make the blank. do you think that i could get away with no stringer if i was to use epoxy to glue the center few peices kind of as a "glue" stinger maybe even add some glass to the center one?

board will be a little longer than i would think you could get away with no stringer  was planing a 7' 4 fun board with light glass 4 bottom 6 top with patch

do you think i will be asking for trouble ie  snapped board?

cheers for imput

antony

is this the foam that has to have little holes in the glass ?

 

2 inches thick ?  how big is the surfer ?

 

The surfer is 135 pounds and really fit and in his late 20’s.

125 or less = 1 3/4

135 = 2

145 = 2 1/8

155 = 2 3/16

165 = 2 1/4

175= 2 3125

185 = 2 3/8

195 = 2 1/2

205 = 2 5/8

Fittness and talent need to be factored in as well.

 

I have made a few 100 and never put docking holes in them however there are people who do with good results.

I leave them with a 60 grit sand finish and it works out fine. Since the foam is Hydrophobic (Hates Water) docking after glassing does make sense. John Mellor shows a tool Ideal for this.

Anthony if you do a epoxy impact cloth glue up between sheets the joint line along the rail will be hard to shape.

 

Javier over at XTR docks after glassing, or at least he used to.  The last time I saw him do it he was using some heated contraption that pierces the lamination with needle-sized holes spaced about 1" apart and reaching just far enough to get into the foam.  He calls them “thermovents”.  

From there you just ignore them - the blank doesn’t seem to absorb any water through those vents.  When we did get delams it was always at the rails - which were unvented; and even that would only happen when we allowed the board to get hot by violating Javier’s simple instructions for board care.    I had one board for 3 years with no problems until one of my kids took it to the beach for the day without using my board bag.  We had some words over that one.  

Javier is one of the best at glassing XPS he glassed one of my shapes for one of my customers about 5 years ago. The customer is still riding it today. For in house glassing my method of 60 grit finish before glassing is pretty easy. You don’t want to leave a XPS board in full sun or in a hot car. Common Sense is apreciated when caring for this type of surfcraft.

John I’m going to make other one and want to try that Gismo. Where can I get one. I was going to run a heating coil through it.