I was wondering if there was any difference in using epoxy resin with PU blanks instead of poly blanks. I understand that there are bonding differences, but I am looking to make a light weight performance longboard for our NJ beachbreaks. I was hoping that epoxy would make a more durable and lighter performance board, but i am not familiar with shaping an EPS blank. I would prefer to shape a PU blank and then glass with epoxy. I also am more familiar with poly glassing as i have done all of my boards with UV poly resin to allow ample time for all of my mistakes. With epoxy i worry about the temperature variables and the bonding properties and i am forced to work outside, so therefore i am a slave to the weather conditions. I am looking for the lightest and most high performing board that I could possibly make, so any input from all you lurkers would help. Thanks
pssurf,
I have laminated 3 PU boards with epoxy in an open carport. No problems. The boards are strong and light and I have not had any bonding problems. The stuff is easy to work with and doesn’t smell. Only draw back is it takes longer to harden and is more difficult to sand. Not much more difficult with the sanding additives some resin manufacturers offer. Our weather is not as extreme as yours, however. Mike
i don’t recommend using epoxy outside…it’s very touchy with things like humidity, or even the slightest breeze (although, how do you use UV polyester resin outside???). also, if you want a lighter board, i’d definitely recommend using EPS foam. there are some differences, but you’ll figure 'em out along the way…no worries. you can use epoxy over PU foam, but i generally like to use a higher density PU foam to minimize denting (which is not conducive to your goal of a lighter board). you see, because epoxy flexes more than polyester resin, it will compress more into the blank as you paddle and surf it. with EPS foam, these compressions tend to bounce right back with the resin. PU foam, however, does not bounce back the way EPS does. the result is that the blank dents, and the glass pulls back…which can lead to lots of delams down the line.
“PU foam, however, does not bounce back the way EPS does. the result is that the blank dents, and the glass pulls back…which can lead to lots of delams down the line.”
I wonder if the heat curing thing prevents / reduces this ? [‘hot box’ , or whatever the correct term is]
I ask , because my 9’ mal I made a few months ago from polyurethane foam , and glassed with epoxy , now has HEAPS of decent sized compressions on the deck [and I used 2 layers 6oz cloth there ], and on the bottom [1 layer of 6oz used there].
The rails are GREAT …very strong , but the rest of the board is fairly dented after only three months [?!]
okay , that is just my observation of my board , anyway …
I hope this helps mate ,
cheers ,
ben ,
west oz
by the way …for the record , I am only 5’10 and 70kgs [154lbs/ 11 stone] , so I ain’t no heavyweight big guy , that’s for sure !
Hola,
Well, I think you’re a bit confused:
Which makes an EPS/epoxy board lighter than a PU/polyester board is the EPS core.
So, if you build a PU/epoxy board, its weight at the end of the process will be almost, if not exactly, the same.
1 kg of resin is 1kg of resin, no matter what kind of it. It’s true that epoxy resins are quite low viscosity and you’ll need maybe 400-500gr less epoxy resin than polyester resin to wetout the same amount of glass cloth, but be sure you won’t notice it.
If you want to drop weight down, go for an EPS(#1)/sandwich/epoxy combo.
Just my opinion.
We’ve had crazy rain here but because it’s cold the humidity is not that bad. However, my hot box is just a space heater under my makeshift table (open carport with wet ground from all the seepage) covered in painters plastic. The heat draws the water out of the ground and into the air under my table (you can see condensation on the plastic.) I’d say it’s 80-90 degrees under the table most of the time.
I’ve been using RR resin with Add F on a paddle and stuffing it under the table everytime I add some resin. I haven’t seen any blushing…
What other bad effects can happen from humidity Soulstice? Or is it just the Add F that is saving me.
I was wondering if there was any difference in using epoxy resin with PU blanks instead of poly blanks. I understand that there are bonding differences, but I am looking to make a light weight performance longboard for our NJ beachbreaks. I was hoping that epoxy would make a more durable and lighter performance board, but i am not familiar with shaping an EPS blank. I would prefer to shape a PU blank and then glass with epoxy. I also am more familiar with poly glassing as i have done all of my boards with UV poly resin to allow ample time for all of my mistakes. With epoxy i worry about the temperature variables and the bonding properties and i am forced to work outside, so therefore i am a slave to the weather conditions. I am looking for the lightest and most high performing board that I could possibly make, so any input from all you lurkers would help. Thanks
pssurf,
I have laminated 3 PU boards with epoxy in an open carport. No problems. The boards are strong and light and I have not had any bonding problems. The stuff is easy to work with and doesn’t smell. Only draw back is it takes longer to harden and is more difficult to sand. Not much more difficult with the sanding additives some resin manufacturers offer. Our weather is not as extreme as yours, however. Mike
i don’t recommend using epoxy outside…it’s very touchy with things like humidity, or even the slightest breeze (although, how do you use UV polyester resin outside???). also, if you want a lighter board, i’d definitely recommend using EPS foam. there are some differences, but you’ll figure 'em out along the way…no worries. you can use epoxy over PU foam, but i generally like to use a higher density PU foam to minimize denting (which is not conducive to your goal of a lighter board). you see, because epoxy flexes more than polyester resin, it will compress more into the blank as you paddle and surf it. with EPS foam, these compressions tend to bounce right back with the resin. PU foam, however, does not bounce back the way EPS does. the result is that the blank dents, and the glass pulls back…which can lead to lots of delams down the line.
“PU foam, however, does not bounce back the way EPS does. the result is that the blank dents, and the glass pulls back…which can lead to lots of delams down the line.”
I wonder if the heat curing thing prevents / reduces this ? [‘hot box’ , or whatever the correct term is]
I ask , because my 9’ mal I made a few months ago from polyurethane foam , and glassed with epoxy , now has HEAPS of decent sized compressions on the deck [and I used 2 layers 6oz cloth there ], and on the bottom [1 layer of 6oz used there].
The rails are GREAT …very strong , but the rest of the board is fairly dented after only three months [?!]
okay , that is just my observation of my board , anyway …
I hope this helps mate ,
cheers ,
ben ,
west oz
by the way …for the record , I am only 5’10 and 70kgs [154lbs/ 11 stone] , so I ain’t no heavyweight big guy , that’s for sure !
Hola,
Well, I think you’re a bit confused:
Which makes an EPS/epoxy board lighter than a PU/polyester board is the EPS core.
So, if you build a PU/epoxy board, its weight at the end of the process will be almost, if not exactly, the same.
1 kg of resin is 1kg of resin, no matter what kind of it. It’s true that epoxy resins are quite low viscosity and you’ll need maybe 400-500gr less epoxy resin than polyester resin to wetout the same amount of glass cloth, but be sure you won’t notice it.
If you want to drop weight down, go for an EPS(#1)/sandwich/epoxy combo.
Just my opinion.
We’ve had crazy rain here but because it’s cold the humidity is not that bad. However, my hot box is just a space heater under my makeshift table (open carport with wet ground from all the seepage) covered in painters plastic. The heat draws the water out of the ground and into the air under my table (you can see condensation on the plastic.) I’d say it’s 80-90 degrees under the table most of the time.
I’ve been using RR resin with Add F on a paddle and stuffing it under the table everytime I add some resin. I haven’t seen any blushing…
What other bad effects can happen from humidity Soulstice? Or is it just the Add F that is saving me.