I glassed the board a few weeks back using 200gr/m2 ‘normal’ glass. If I did my maths right this should equal about 5oz glass. The deck got 3 layers, bottom 2 layers. I used a slow curing epoxy so I would have enough time to curing, being the beginner that I am. It’s turned coldish over here (5 - 15 degr C) so curing took even longer than normal. Did the hot coat layer this week (again in the coldish temps) and had the board in the house to fully cure the epoxy.
Now I was under the impression that this should lead to a super strong glass layer. However if I squeeze the board with my fingers (pretty hard), I see some flexing of the outside of the board. It springs back but still, this worries me: if I stand on the board, I’m afraid my heels will sink into the foam.
Did I make a mistake somewhere along the line? Or is this normal.
Sorry if this is a total kook question but keep in mind that I’ve never owned a glass board (coming off a NPS ‘playmobil’ board now).
All help appreciated and thanks for a super informative site.
Cheers,
PS I used the search function but couldn’t find an answer to this question
I tried to write a reply, and got this error message. WTF?
“Your submission has triggered the spam filter and will not be accepted.”
The reply I wrote was as follows:
If the glass deflects when you squeeze the board it is due to the foam being relatively soft and not because of your glass job. Extra layers of glass make a board more impact resistant but they do not significantly improve compression properties. You’d likely have to double the amount of glass you used to decrease compression to any great degree.
wrong resin or badly mixed temp to cold what your feeling is uncured resin full stop try to put it somwhere where temp will be much higher like double for a day or 4
you could put 3 layers of that glass on the weakest core on the planet and it should be mighty tough so bro learn all about your epoxies before you venture further next time
@Stoneburner: it was an old Mistral Windsurfboard with some kind of ‘plastic’ type skin.
@Huie: I hope(d) that it’s uncured resin that I’m feeling. “Learn more about epoxies…” I was under the impression that ‘epoxy = epoxy’ (read: I have no clue) and low temps would lead to (much) slower curing times. But yeah, you’re right in that I know next to nothing about this stuff.
I guess bottom line is that I should be patient and that there’s not much I can do about it if it remains this way.
Colder temperatures can create thicker (more viscous) resin/hardener that might not have mixed well. For RR epoxy, I believe Greg Loehr indicates 75 F to be a good temperature and:
Keeping a small room between 60º and 85º isn’t that difficult and gives consistent
quality results
By chance, do you know the density and type of foam?
Don’t have a clue about foam density. I do know that I bought some foam to repair a few holes where wood blocks had been installed for the footstraps of the windsurfer. The EPS from the DIY shop was WAY lighter. I would guestimate this to be ‘regular tv packing EPS foam’ for what it’s worth.
As for keeping a small room at a nice temp: if I do another board I might just try this but I’m working out of my garage with is little more than single bricks and a thin wooden roof. No isolation and lots of draught holes… Kind of like trying to heat up a car with the windows open if you get my drift.
I did give the resin / hardener a solid 2min mix, so I would be surprised if they weren’t mixed properly. But I understand this might be the case despite my best intentions.
Thanks for the response!
PS I had/ am having a ton of fun trying to make this board, so even if all else fails, at least I’ll have that!
Get the hardener / resin mix ratio exact. Many epoxies will cure at quite low temperatures, however they will all benefit from a post cure at higher temperature and that will depend on the epoxy. As long as it eventually reaches it’s cure temperature and stays there for the correct time, it will cure. I think there’s somebody on Sways who puts their boards in a black van and parks it in the sun for a day, great post cure oven.