Komatex or Sintra skins?

General Discussion
1

Has anyone ever tried using Komatex or Sintra skins on a compsand. I know in “The Bert Thread” he used Dcell and others have used corecell but they are both expensive and difficult to get here (and Komatex comes in white).

wondering if it had been done (I couldn’t find anything in archives) and what advantages/disadvantages it would have. Or is it the same as Dcell?

I was thinking of using type 2 EPS with a Komatex top skin, and perimiter stringer similar to DrewTangs recent corecell board.

2

…Sintra is PVC

and for me is somewhat rigid compared with D cell…

I use sintra for the templates

cutted with a CNC router

3

Thanks Reverb, I have easy access to Komatex although i haven’t used it yet. I was reading though the archives and noticed that a lot of people commented that it had very similar properties and feel as wood stringers in EPS but still more flex than a PU, so I thought I could maybe try it (3mm) as a top skin instead of balsa (I can’t get balsa veneer here at a price that is anywhere near affordable). It doesn’t look like anyone else has tried it though so I guess I’ll just have to try it and possibly sacrifice a board to the everlasting glory of collected swaylocks wisdom.

cheers

4

While Sintra or Komatex is PVC foam, with solid skins over the foam, it is HEAVY compared to

dcell or corecell, the neat thing about it is that you can thermoform it,

(heat gun and vacuum bag or lots and lots of clamps).

You will need to give it a very coarse sanding(60-80 grit) to get epoxy to bond to it, and then

it is only a tenuous mechanical bond, can delam

I’ve built a skim and a kiteboard out of it,(1/2" thick or 12 mm) no glass on skim, just heat formed

and single 8oz uni carbon on the kiteboard.

Heavy compared to anything else short of solid glass, can be brittle, marginal impact resistance, will shatter.

better for box reinforcements, footstrap inserts etc. Be careful about making sure your corners are well rounded,

don’t create any stress risers at corners, especially inside corners.

Have fun with it, it is fun to work with and planes like butter.

I get mine from the local sign guy.

Did I say it was heavy?

Pete

5

Hey Pete, thanks, that’s the kind of info I was looking for. Do you think the Komatex is heavy because it soaks up a lot of resin like dcell does (and can maybe be fixed by sealing) or is it just heavy in general like luan?

6

Shoeless,

The best I could come up with is Sintra/komatex weighs approximately as follows:

31#/cu ft for thicknesses greater than 10 mm( just over 3/8")

47#/cu ft for thicknesses less than than 10 mm( just over 3/8")

Resin absorbtion is negligible, as the board comes with a slick skin and a foamed core,

still needs a good rough-up to get adhesion (80 grit minimum)

It looks alot like this:

_________________solid pvc skin

oOoOoOoOoOoOoOo foamed PVC

                                solid pvc skin

Think PVC like plumbing pipe not “foam”

It is NOT like Divinycell or Corecel or any other structural foam,

more like PVC Plywood with foamed pvc core instead of 0/90 plies

It WILL SHATTER when cold.

Look at your local sign shop for scraps to mess with, usually they will give it away,

or dive their dumpster.

Pete

7

Thanks again Pete, I am reconsidering using it as a skin now. cold is definatly an issue here. couldn’t surf my reg spot yesterday as big chunks of ice had been blown into the lineup. back to the search for core cell.

cheers