I’ve done about a dozen boards with 2lb EPS foam and RR epoxy resin. My last board de-lammed after i gave it to the customer. now, i know he left it uncovered on the beach and it heated up causing the pressure, but i was wondering what i could do, if anything, to better seal the blank, or anything to prevent this de-lamming. its got me about ready to forget the epoxy and do polyester exclusively.
is a firewire-like de-gassing valve the only way???
thanks.
Make sure your eps/epoxy customers are well educated about what NOT to do with their boards. i.e. leave them in the sun. It’s his/her own fault plain and simple. I don’t think you should be looking at your methods of construction for any answers to questions.
surf3184,
More info please. Did you seal? Spackle or not? Pics maybe? Also I assume it was from block foam. How thick is the board.
regards,
Dave_D
try polyurethane with RR epoxy
two words…
Vent Plug
VENT PLUG!
the board was 9’6" 2.75 thick.
i sealed with spackle, 2 layers of 6oz on top. it de-lammed on the hull by the fin box. i dont have pics but can get some.
is a vent plug like the valve in firewires or something else?
where can i get them?
is a vent plug like the valve in firewires or something else? i’ve seen some contraptions made in the leash plug but dont know if they are in market or where to get them.
know anyone selling either?
Some related information: I just bought an EPS blank from Segway composites and had a conversation with Ken regarding vent plugs. I asked if vents were needed on EPS. Here’s his take on it:
1 lb., 1.5 lb., and 2 lb. foam needs vent plugs because there is so much air trapped inside the plastic that off-gassing i.e. air expansion may cause de-lams. 2.5 lb. and 3 lb. foam don’t need vents because there is more plastic and less air.
Doug
??? I left my 2# eps w/RR in the tropical sun for weeks on end with no problem.
Yer thats it, just like the firwires, bascally its just a sealed hole to keep the water out then can be undone to equalize the pressure on the inside of the board. They have used them on sail boards for a long time but I think they are a little chunky, there is loads of info in the archives but a simple bolt with a rubber O ring inder the head works well, you’ll need to cast the female part and then set it un the board like a leash plug.
BTW I’ve only vented HWB’s as although I use epoxy resin I use PU blanks, Ive never had any delamsbut the foam structure it denser, its the space between the foam beads in eps that allows the air to expand and contract with temprature.
If you dont want to vent the board you could try using a foam with a smaller or tighter bead.
Fiberglass Supply sells and has a picture of vent plugs (down the page) - I have only seen/used them in custom epoxy sailboards. I think others here may have used them in epoxy/eps boards.
http://www.fiberglasssupply.com/Product_Catalog/SurfSailcom/surfsailcom.html
I think someone on sways makes/sells gore-tex vent plugs that dont require a plug to screw in and out with each use.
yoyo
A myriad of things could have happened.
Do you use a very thin seal of spackle or were you too generous? The latter can easily compromise the bond between foam and shell.
Was your spackle thick like peanut butter, requiring you to “work it in” a little bit, or was it a bit wet and runny? If it was too wet, the blank could have easily absorbed some water from the spackle, which could have steamed up inside the finished board creating too much pressure.
Did you rush the glassing after applying the spackle (which could have also trapped water inside the board)?
I’m sure others can add more to this list, but I have to run for now.
Aloha Braddahs! My two cents from a newbie who had the same problem.
I use marko eps 1.9lb and find that all clear or white boards need no vent. All dark colored boards need vent. I used PeteC’s goretex vent to solve this for a customer who can’t seem to remember his board.
The first time a trip to Kona with 90 degree temps and a dark grey board in a black pick up bed. Poof - big as football.
Re-glassed with vent and now he leaves it in the truck allways - no problems in full sun all day.
This was thanks to help from you guy’s!
I have’nt had it since with light tints and clears.
I just had this happen this weekend. I had a pinhole in one of my finboxes and sealed it with Solarez. I laid the board out in the sun for like 15 minutes and got a big old boil between the fins the size of a frisbee. Prior to this I’d left the board in the hot sun for closer to an hour with no prob, so I think that little pinhole was my vent!
The bottom of the board: dark gray.
i use lightweight spackle. i mix it with water making it the consistency of cool-whip (the desert topping) and just spread it. i let it sit for 24 hours then final sand it. i absolutely love how it makes the EPS oh-so-smooth.
also, im not so hot in the firewire-like valve because it then requires must customers to know when/how/remember to utilize it. and for-real for-real, my customers are not typically top tier if you know what im saying…
i think im going to look into this Pete C gortex valve. i was also working with Greenlight surf supply and i know he was developing a kevlar or gortext plug as well. is pete C on sways? how do i find this fella? any leads?
ill search the archives…
senk ju.
… im not so hot in the firewire-like valve because it then requires must customers to know when/how/remember to utilize it…
Firewire’s valves are passive, no need for the user to do anything with it (they are goretex).
I heard there was a 13 foot board with a vent from NZ at pier 17 with a huge delam. They did a pregnancy test and realized the vent was a birth canal and the 13 footer had a healthy 5’10" old school fish. Paternity tests are pending but a premature congratulations to Roy.
Contact Brian from Greenlight about his new “vent plug.” He’s doing som R&D on a new idea and is waiting for some field test results to come in.
I heard there was a 13 foot board with a vent from NZ at pier 17 with a huge delam. They did a pregnancy test and realized the vent was a birth canal and the 13 footer had a healthy 5’10" old school fish. Paternity tests are pending but a premature congratulations to Roy.
LOL : ) - how much did it wiegh