Pour foam blank making?

General Discussion
1

Hey all. So i am wanting to make a polyurethane foam block that is 11 feet long, 30 inches wide and 4 inches thick. I am making a SUP x 4-8 blanks (Christmas presents?!). I am going to make a big rectanglular box that is these dimensions and buy a pour foam kit in 2lb density from uscomposites.com and make my own huge block of foam. From that, carve/shape my SUP blanks.

Im wanting to do this for savings using polyester resin and foam blanks.

Anyone else do this before? Is it very difficult? Anyone have any ideas as to what possible negative effects could happen?

Much thanks!

 

2

My suggestion is go out and buy a proper blank. If you try and pour your own you’ll need a steel reinforced box with clamps that can withstand tonnes of pressure. The foam needs this to attain the density thats needed for a surfboard blank. Free pouring foam will result in it expanding so much that the foam will have little to no structural integrity.
cheers
Rich
www.thirdshade.com

3

[quote="$1"]

Hey all. So i am wanting to make a polyurethane foam block that is 11 feet long, 30 inches wide and 4 inches thick. I am making a SUP x 4-8 blanks (Christmas presents?!). I am going to make a big rectanglular box that is these dimensions and buy a pour foam kit in 2lb density from uscomposites.com and make my own huge block of foam. From that, carve/shape my SUP blanks.

Im wanting to do this for savings using polyester resin and foam blanks.

Anyone else do this before? Is it very difficult? Anyone have any ideas as to what possible negative effects could happen?

Much thanks!

 

[/quote]

 

A bit like manufacturing your own petrol engine. Why bother??

4

Hi firefighterjay -

While I applaud the ambition, I agree that you'll likely be far happier with the results of a professionally manufactured blank.  Beleive me, you'll have your work cut out for you just shaping and glassing those!  Often the pour foam will turn out like a loaf of bread - complete with crust, irregularities and giant air holes in the interior.  It really does take a calculated volume, a closed mold and a specific formula to get anything close to good surfboard foam. 

If you are willing and live in Southern California, Segway Composites is a good bet for EPS blocks, paddleboard slabs, and machined blanks.  Polyurethane foam blanks are available elsewhere in paddleboard sizes but you won't have the selection. 

Maybe that's what led you to thinking about blowing your own?  Well it won't be cheap and once you calculate the mold cost, defect rate, and poor quality, it just won't be worth it. 

I don't mean to rain on the parade - I just know too many who have tried, including guys who have tried to use pour foam for the rails on their custom fiberglass knee spoons... a real mess to be sure.

 

5

Pour foam kits cost more that surfboard blanks from what I’ve seen working around boats.

6

First of all Firefighterjay if you make a blank in PU your blank dimensions are real tight.

11’ x 32" x 5 1/4" would give you more room to work with.

You being a Fireman have plenty of free time I’m sure.

However the material cost would kill your savings.

Making a surfboard in your backyard is doable and a fun experience.

Making a SUP is like building a small boat.

Plus you need light carbon paddles. (Heavy cheap paddles are worthless)

You can buy a SUP with a Paddle complete with fin cheaper than you can make it.

For a Christmas present it would be very time consuming and very expensive.

Even for a Fireman it’s not worth your time unless you have no wife & kids and the pets have died.

The mold to produce the blank will cost you some money and a lot of time.

Besides your SUP’s would be so heavy you would need a small crane to launch them into the water.

 

If you still want to build it yourself take this approach:

 

Buy a blank ready to shape (Don’t even bother cutting it)

Get your supplies at www.foamez.com

You can have them get you a 11’0"

I highly doubt that you have enough time to complete 4 paddle boards by Christmas.

However if your just over the top Mr. Craftsman then go for it!

Make sure you have the real estate large enough to build these size of boards?

Cost? Time? Weight? Space?

Pick and choose you battles carefully.

Kind regards,

surfding

 

 

 

7

Cut, ready to smooth, out the door.

A home grown blank would be the biggest mistake of your life, toxic and more pressure than you could ever imagine, your mold sides, tops, ends would be feet away from where you started.

8

Don't try it. It will be nothing but a huge mess. I've made blanks before but with no success and major hassle when all said and done. We made lightweight concrete forms, buried in the ground and parked a pick up on top for compression and still turned out  a major P.O.S.!!

Fugeddaboudit.

9

Let me be the first to encourage you in your endeavor.  Post up some pics of the process and track your costs.  This could be interesting

10

Thank you sir! I appreciate your comment. I will undertake this. I talked to uscomposites in regards to my exact desires of what I want to make. They said: "Yeah, itll work great. Theres many guys here that do that. THe foam expands 2-3 inches in height, so in your mold box just make sure the lid has a few air holes so no air pockets form and excess can drain out." He said you don't force the foam into a smaller area and make it more dense.

That also rings true to me with the physics of buyoancy. If a ship was entirely made of steel she would sink. More density does not equal more buyoance (relative density). I will bring this up to my physics teacher (thank god in Pre-med they make you take physics...otherwise i probably wouldnt lol). But from what wikipedia says, denser doesnt necessarily mean more buyoant: "

If a substance's relative density is less than one then it is less dense than the reference; if greater than 1 then it is denser than the reference. If the relative density is exactly 1 then the densities are equal; that is, equal volumes of the two substances have the same mass. If the reference material is water then a substance with a relative density (or specific gravity) less than 1 will float in water. For example, an ice cube, with a relative density of about 0.91, will float. A substance with a relative density greater than 1 will sink."

So given what uscomposties says and goold ole physics... I am going to try and make my own block PU foam blanks. Up here in Canada, the cost for a PU SUP blank is $400 ( I am making 4). The cost of the PU pour foam to make 5 SUP blanks to my liking is $256.. Not to mention savings with Polyester resin. Rather a pain in the arse making your own boards up here due to costs and blanks are hella expensive to ship to here.

I am fully aware i may fail in my attempt and that is okay with me. Its a learning experience! and heck, if it works...hot damn!

I will have the help of my lady and will take pictures of the process and put em up here under a different thread titled: "Pour foam blank making" so keep your eyes peeled! Ordering the stuff this week :)

Thank you all for your comments. I appreciate criticism..keeps the mind in check :P

11

I've been contemplating a related project (pour foam in a hws), but have never tried using pour foam, so I'll be watching with interest.

I don't think anyone was saying denser foam has more buoyancy, I think its a strength issue.  I'm assuming these boards are going to need extra glass or some type of skin to compensate for the weakness resulting from less density?

You say your supplier tells you there are several guys doing this, any way you could contact them for pointers? 

Also - any idea how the weight will compare with a factory blank?

12

What kind of project are you doing?

And yes i think i may have misread what they stated. As per uscomposites, he says you could use the 2lb density but would need a more thicker glassing schedule. I would be doing a 1/4 inch wood stringer and 2 layers of 6 oz top and bottom with deck patch.

I didn't ask but will call again when ordering to see if he is able..could be a privacy issue?

Weight comparrison not sure. I would not think anymore than a factory board albeit if the factory uses the same foam. Will be posting pictures soon :)

13

good luck.....you are going to need it! i cant wait to see pics of this!

you are probably going to need more material than you think. You can make your own SUP blanks out of blocks of EPS foam that will cost less, be way easier to make, and be far superior in performance. You may want to consider that route a little more before you start your project. But if you do indeed try to do the pour foam thing, pleeaaaaaaaaase post pics here - i know a lot of people would love to see that!

14

I tried the pour foam in an EPS melting incident where nearly the whole bottom of the board needed to be replaced.  It took three attempts at pouring foam, planning down, and pouring foam again to get all of the huge holes filled in.  Then there was the final sealing.  After all that, the stuff off gassed like crazy and left holes and bubbles in the glass.  Not really suitable for surfboards in my opinion.

15

Thanks mate. I have done the EPS blank route...did not like it at all. All those damn lil foam bubbles everywhere! I did one in the summer and am still finding foam in the house lol.I have heard from a few guys here in town (Victoria BC) that PU boards are far easier to work with interms of shaping and glassing. Perhaps a bias on their part?

16

How long did you let it off gas? Is there a set time for it? like days or weeks?

17

You’re looking for trouble. Don’t say we didn’t warn you.

18

I don't think the UV Pour foam they sell is UV stable so your board wlii likely look like a brown turd after it hits the sun unless you paint it.  Also blanks are made under pressure precisely to increase the foam density and give it strength.

19

Two weeks and it was still off gassing.  I like polyurethane for shaping ease and not having to worry so much about heat.  From Vancouver BC you are only an hour and a half drive from Burlington, WA and the Fiberglass Supply store a US Blanks distributor.  You would save time making the drive for a quality blank and be so much happier than pouring foam.

20

Shades of Del Cannon in Brown's movies.

Yes, PLEASE post photos...even the "wrong" ones.