Page 3 of 4

Re: Pocket foilboard divynicell 80 core Ghetto build tips?

Posted: Tue Sep 10, 2019 4:40 pm
by merl
Back to the original topic, a high density foam ghetto build (no rocker table or vacuum). Two questions:

1 Would it be possible to bend 25mm thick 75gm2 PVC foam using a heat gun?

https://www.easycomposites.co.uk/#!/cor ... -core.html

2. What is the best way to butt-join two sheets? I guess PU glue. Any tips for pressing them together?

Re: Pocket foilboard divynicell 80 core Ghetto build tips?

Posted: Tue Sep 10, 2019 6:31 pm
by faklord
merl wrote:
Tue Sep 10, 2019 4:40 pm
Back to the original topic, a high density foam ghetto build (no rocker table or vacuum). Two questions:

1 Would it be possible to bend 25mm thick 75gm2 PVC foam using a heat gun?

https://www.easycomposites.co.uk/#!/cor ... -core.html

2. What is the best way to butt-join two sheets? I guess PU glue. Any tips for pressing them together?
1) Yes I have done this with the exact material you linked to. It ended up a bit brown but no obvious effects to mechanical properties (didn’t go powdery or brittle). I only did this on a scrap piece to see if it worked. Didn’t go on to make a board with it. But it is what I’ll do if I make another board.

2) I just use an epoxy/microballoon goo. Clamp one part to a flat board, covered with polythene, apply goo, squish together and clamp 2nd part to same flat board. No need to “press them together” hard, so long as any gaps in the joint are filled with goo.

Re: Pocket foilboard divynicell 80 core Ghetto build tips?

Posted: Tue Sep 10, 2019 6:56 pm
by rynhardt
Joining the foam with a PU glue will make sanding easier. Epoxy is harder and can create a slight ridge if you sand by hand.
You can form a rocker by laminating several thin sheets together. Many thin sheets would have less spring back than fewer thick sheets.

Re: Pocket foilboard divynicell 80 core Ghetto build tips?

Posted: Tue Sep 10, 2019 8:20 pm
by faklord
rynhardt wrote:
Tue Sep 10, 2019 6:56 pm
Joining the foam with a PU glue will make sanding easier. Epoxy is harder and can create a slight ridge if you sand by hand.
You can form a rocker by laminating several thin sheets together. Many thin sheets would have less spring back than fewer thick sheets.
Agreed. Done this. But the glue between layers adds unnecessary weight.
Kerfing is another option. My current board is this method. Just not the best aesthetically.

Re: Pocket foilboard divynicell 80 core Ghetto build tips?

Posted: Wed Sep 11, 2019 3:36 pm
by TomW
Get one sheet of the 1080 x 1020 x 10mm. Cut it in 2 pieces and glue together - put on epoxy/glass ballon mix or use PU glue, drop it into a big garden garbage bag, Suck out the air using a vacuum cleaner and put it on some blocks of wood or books to form rocker.
With a little thinking youll figure our how to suck out the air from the bag using a regular vacuum cleaner. You might even use your kite pump that has a deflate side...use quick setting epoxy or glue.
You are building a ghetto build- so adding 200g in glue is not an issue.
But getting a good rocker is more important. Theres no reason it cannot turn out looking close to pro built board if you do a decent shaping, lamination and finishing.
And frankly, a well shaped rocker and board with a ghetto lamination and finish is perferred to a shitty shaped board with a good lamination and finish.

Re: Pocket foilboard divynicell 80 core Ghetto build tips?

Posted: Wed Sep 11, 2019 4:15 pm
by merl
TomW wrote:
Wed Sep 11, 2019 3:36 pm
Get one sheet of the 1080 x 1020 x 10mm. Cut it in 2 pieces and glue together - put on epoxy/glass ballon mix or use PU glue, drop it into a big garden garbage bag, Suck out the air using a vacuum cleaner and put it on some blocks of wood or books to form rocker.
With a little thinking youll figure our how to suck out the air from the bag using a regular vacuum cleaner. You might even use your kite pump that has a deflate side...use quick setting epoxy or glue.
You are building a ghetto build- so adding 200g in glue is not an issue.
But getting a good rocker is more important. Theres no reason it cannot turn out looking close to pro built board if you do a decent shaping, lamination and finishing.
And frankly, a well shaped rocker and board with a ghetto lamination and finish is perferred to a shitty shaped board with a good lamination and finish.
Would something like these work:

https://www.amazon.de/MRS-BAG-H%C3%A4ng ... U6&sr=8-42

Re: Pocket foilboard divynicell 80 core Ghetto build tips?

Posted: Sat Sep 14, 2019 9:48 pm
by TomW
Merl, yes they do. I use them with my vacuum pump with great results, but using vacuum cleaner for ghetto v-bag is possible too.
It's cheaper and easier than using a real vacuum bag material. Trade off is bag material is stiffer and not well suited for bagging lamination around rails.

Re: Pocket foilboard divynicell 80 core Ghetto build tips?

Posted: Sat Sep 14, 2019 11:36 pm
by bohme
I made one from a single sheet of 15mm 80g/m3 PVC.
PVC is a structural core and way better than XPS and PU. No problems with heat or dents.
I laminated one side at the time with 300g/m2 biax carbon (vacuum). I just used bricks and gravity to get the rocker I wanted.
The strength is in the stringer, which includes a prefabricated KF box.
1.3kg without straps.
It obviously does not have any volume, but I prefer that.
I do not always get it right first time, but this time I did. I have used it 50+ times, and I like it a lot :-)

Re: Pocket foilboard divynicell 80 core Ghetto build tips?

Posted: Sun Sep 15, 2019 2:51 am
by thewindego
Hey Bohme I give that a 10. Nice.

Re: Pocket foilboard divynicell 80 core Ghetto build tips?

Posted: Sun Sep 15, 2019 7:32 am
by omg
Bohme, that*s an awesome board. What material is the stringer? And is the board stiff?