I am in the process of trying to remove water from an EPS core board. This is not something I have any experience with. I know I will never get it 100% dry but its better than nothing.
I am not familiar with vacuming boards in any form. The pump I have is capable of 28 in/mg vacum. Is this too much vacum? Or should I run a lower vacum to not damage the board?
The board is EPS foam with 6 oz glass (no fancy sandwich construction). However I’m not sure how many layers.
jessutton, Trying to remove water by vacuum doesn’t work very well. Something goes on with the beads under vacuum and the foam seems to seal itself. Place the board in the sun and position it so that gravity will help it drain. It can take several days. I use air pressure which works very well but this method has the potential to do major damage. The pressure needed is less than 1 psi. I have a rig with two regulators in series that I use. If the board doesn’t have a vent I make a small one so that I can attach the air fitting. There was a very old thread where Bert Burger addressed using air pressure. Good Luck.
regards, Dave D
Normally pulling 25+" hg. wouldn’t hurt a cured board if you were pulling from the outside skin as in a bag…
If you are going to pull 28" through a hole or crack in the board you might deform the inner eps because it’s not normally capable of handling that pressure on it’s own…
Years ago, I read about a pro winsurf builder / repair guy who rigged up a washing machine motor with a support cradle bracket mounted to the motors shaft…He would then bungee the board down to the cradle and plug in the motor… After drilling 2 @ 1/4" or 3/8" holes in the extreme nose and tail area of the board the water would come out quite easily due to the spinning centrifugal force applied by his home grown rig… Once as dry as possible , he’s seal up the holes with epoxy and filler…
Cool huh?? Ahhh, The good old eighties…
After water intrusion, installing a vent is a good idea…
I remember the board lady website. Put a hole in one end opf the board, and draw vacuume from the other. She used to pull cups of water out.
Yeah if it’s open on both ends It would probably work fine … A bleeder valve on the pump would be a good idea though…
You could probably pull up to 16" safely with eps close to 2#…
He should check out the Board Ladies site…
I’ve never had to try it, so I’m no authority on leaky boards…
Dave D. for moderator!
Go Low Tech. Find a simple solution.
Go to the nose and drill a small hole on each side of the stringer. Drill into the foam not into the stringer. Go to the tail and drill a small hole on each side of the stringer. Put the surfboard in a safe location in the vertical postistion. Use wood blocks on the floor so that the water can drain out. Wait until all the water drains out....days or weeks! No risk, just time. No riggs or jigs. No pumps. no hurry no worry.
if you have a pump already i would try to vacuum it out as much as possible. once it can't vacuum it out more water, you should use the paper towel/gravity methord like above to get the rest of the water out. probably weeks depend how much water get in. i have vacuum out two cups of water out of a damage fin box. Depend on the fg layup i will keep it low, like under 10 hg first and slowly increase the vacuum. i have board with light layup/#1 eps and have create a double concave. The depression wont happen instantly i might take 10-15 min so if you see it, just back off the vacuum a little bit.
I ran the vacuum at around 10 in for a while. It got out some water but stopped. After no noticeble change for a while I tried increasing the vacuum some with no real results.
So I put a small hole in the other end of the board on the same side of the stinger. After rigging up some plywood with an airfitting and attaching it with vacum tape and some weights I turned on the air. This way if someone screws with the air pressure while I’m not around it will blow off the plywood instead of killing the board. I have gotten out more water since switching from the vacuum to pressure.
I’m not sure how much water was in the board or how long. It is the result of a small crunch on the corner of the tail with a temporary epoxy patch. The patch came loose and started leaking. Which wasn’t apparent until it started bubbling water in the sun one day. And I don’t have an original dry weight for the board.