I’ve found a small crack on my EPS board that upon inspection had soaked some water. I’ve heated the board and quite a bit of water has come out, but no way it’s all. Question: If I heat board to the max temp I expect it to ever reach and patch it up at that temp, shouldn’t that minimize the chance of the patch blowing out even if there is water in there? Or should I cut/sand a hole to let the water out more easily?
regards,
Håvard
If you don’t get any better suggestions, try drilling a 1/4" hole at crack midpoint and stuffing in a strip of ink blotter paper as a wick. Leave it for a few days in outside shade. Replace the wicks when damp, repair when the wicks stay dry. It worked for me in Florida.
with cracks, i like to run a razor blade on it, and take out a small sliver of glass. what you can do is put rubbing alcohol in it, just a little, and it will help dry it out faster. if you can suck on the ding, and still get water out of it, it’s not dry. EPS sucks up a lot of water i believe, so be careful, and get it all out before patching!
idealy you want to get all the water out before fixing it…
do you have a vent in your board???
a vent makes it easier to get water out…what i do is blow air into the vent at very low pressure that pressure will push the water out ,(like heating it did coz the air behind the water expanded and helped push the water out).then the air moving through the core dries it out real effectivly…
if you dont have a compressor or some other means of pushing air through,then a vent is still your best option…
each day you have a rise and fall in temperature,set your board up with the ding as the lowest point…then at night as the board cools make sure your vent is undone ,coz theres two holes in your board (the vent and the ding) the board will cool down and suck air in through the path of least resistance(the vent ,the water is blocking the other hole)…
in the morning do your vent up …as the board warms the air pressure will push more water out…4 or 5 days of that and it should be alot drier…
you have to be real careful not to seal water in a board…
boyles gas law states ,for every 1 degree kelvin you raise the temperature of a gas its volume expands 1/273rd or raise the temperature 273 degrees kelvin and a gas will double…
but if you have water in your board it has the ability to turn into a gas with heat and will build up way more pressure than if the space was filled with just air…
so if your board stays unvented and theres water in it ,it has way more potential to delam…
also dont bother to try and bake your board to get the water out , that only works while the pressure is building and can push the water out ,once the board reaches a constant temperature there no pressure to push the water out,plus the beads of foam are sealed units like a ping pong ball ,but they can expand and contract them selves with hot and cold ,when the foam gets hot the beads expand more ,closing off the gaps between the beads ,thus traping the water in there…
thats why pressurising the core works so well, a slight increase in pressure keeps the beads smaller allowing the channels between the beads to be more open ,plus the pressure moves the water…
but if you try to suck the water out with a vac pump , the lower pressure means the beads expand into the vacumn and close the gaps between the beads again trapping the water…
ok hope all that stuff helps…
even tho in most cases vents arent needed with the heavier eps .they do help for repairs …
regards
BERT
Hi Bert,
what kind of vents do you use, where do you get them and how do you install them? Vents might be good, but I’m worried about the tumbscrews sticking up causing injuries.
regards,
Håvard
This may sound crazy but at least it’s something to think about.
If you drill a hole in the middle of the deck and drill a hole large enough to put a cylinder of solid material with a hole taped in it the same tread size a will receive an air fitting. You can put a screw in it that will finish flush with the board. If you have a ding you can pressurize the whole board (no stringers to interfere) to about 5 psi or so and (correct me if I’m wrong) the moderate pressure will gradually force the water inside the board out through the opening in the shell. After that’s done it’s time to clean things up with the vaccum bag technique to renew the integrity of the shell on the board. If the air pressure won’t pass through the blank this is all just hot air so treat it as such.
Back to the fin shop, Rich
my first vents were something like that …id drop a circle of what looked like really thick fin panel ,about the size of a legrope plug and glass it in …
when the board was finished i would drop a router into the solid mass ,12mm bit about 3 mm deep ,then i would drill a smaller hole in the middle through to the core , drop a tap through it to thread it , then a stainless dome head small bolt with an o ring ,it would sit flush when done up…
now i make a finished molded unit with thread and all and glass it in …
regards
BERT