Glass vs Epoxy

analbirth · Post by **analbirth** » Thu Jan 08, 2009 11:17 pm

Austo hope you didn't get a stringer, if it's a full carbon laminate deck & bottom [ equiv to at least 7oz glass ] with 4 or 6oz glass on the deck for knee patch etc. you don't need a stringer they flex just fine also you need the high density eps
you can also get extruded eps blanks but they are a bit heavier i've been refining the glassing of my boards for about 7-8 years through peter mo
[ Modeck ]at currumbin who dave is using, DP has been shaping my blanks and has now started offering them in his range [ took him long enough think he wanted to see how they held up] i've posted pic's on this site sorry not savvy enough to post link but check my pic's and for sale section [ carbon styrene quad ] my signature says it all
AB

RMcKnee · Post by **RMcKnee** » Fri Jan 09, 2009 5:14 am

skansand · Post by **skansand** » Sun Jan 11, 2009 2:13 pm

RUshing to finish my 6'5 before santa cruz! ...stressed.... still needs a sand and hotcoat and glass on side fins.....

ended up glassing it 6ozx2 bottom / 6oz x2 deck w/ 6oz full length deck patch laid up on its axis to the other lams..

i think this is a way to get S cloth like strength without the extra weight.. not really sure..

.......

...DVS: ... nicest lookin carbon/kevlar boards!....i pretty much stole his RAstovich fish fin setup for my twin fin....

red · Post by **red** » Sun Jan 11, 2009 6:41 pm

I think you have to cure epoxy at elevated temperatures (say 45 degrees C) to get the strength benefits of epoxy.
Put it in the car in the sun.
Also the warmer you cure it, the less likely you are to get delam owing to gas coming out of the EPS (if you're not venting)

Post pics

Red

analbirth · Post by **analbirth** » Mon Feb 09, 2009 7:04 pm

red the biggest killer for eps epoxy boards is a hot car or the sun it will cause them to delaminate if not blow up trust me AB

red · Post by **red** » Tue Feb 10, 2009 2:14 pm

AB
Usually it's the hot car followed by cold water.
The warmer you cure epoxy (to a pointr) the better the board's resistance to elevated temperatures. Also you promote the flexible cross links that makes epoxy so much stronger than polyester. Room temp cured epoxy is no better than polyester.

The delam problem is very much reduced by using 1.5lb EPS rather than the 1lb Home Depot/insulation stuff. Breather vents are not needed.

But EPS varies in weight, so nominal 1.5lb can be anywhere from 1.2-1.8lb. Have to specify requirements to the supplier to limit the tolerance.

analbirth · Post by **analbirth** » Tue Feb 10, 2009 3:13 pm

red, how many eps epoxy boards you have?

skansand · Post by **skansand** » Tue Feb 10, 2009 6:37 pm

I havnt had any delams with my either of my paipos or my 6'5 ...all 1 ib eps not heat cured/no vents... the 6'5's pretty new but the paipos are over a year old now...

Still i cant reccomend not venting 1ib eps boards just from what ive heard...

i DID kinda cure the shaped blank before painting.....only by leaving it in a black car on a hot day.....

BtW Red , Epoxy is not all created the same....

Industry Standard, Resin Research has a very weak X-link structure but its overlooked because of its simple mix ratio ...

I use East Systems which im told is much stronger... One Particular gallon i bought was extra flexible and had a 6: 1 ratio...

ive tried 3 kinds as well as RR..,, dont ask me whats my favorite....

RMcKnee · Post by **RMcKnee** » Wed Feb 11, 2009 4:22 am

frankfqr · Post by **frankfqr** » Wed Feb 11, 2009 8:55 am

Good stuff, wise words RMc. Application guidelines on any high end product should be strictly held to, not just from a litigation standpoint but also pride in workmanship. The shear volumn of literature, and the learning curve envolved with the shift to eps/epoxy has bogged down my current endeavors. Props to ska for taking the leap!! You to red

. Back to topic---would it be possible to avoid the gassing by just applying epoxy over PU. Is it the core or the skin? Disadvantages?

RMcKnee · Post by **RMcKnee** » Thu Feb 12, 2009 4:42 am

frankfqr · Post by **frankfqr** » Thu Feb 12, 2009 7:04 am

Color of the substrate makes since, I've gotten the same reaction with dark PU boards. It just seems I've heard more in regards to epoxy? I've only made approx. 30 boards, all PU and would prefer to stay with comfortable shaping techniques but want to gain epoxies strength and flex properties. The more I read up, the more discouraged I get.

skansand · Post by **skansand** » Thu Feb 12, 2009 9:34 am

ive messed up the mixing before and its such a headache..gave up, try again.. but really properly mixing your epoxy isnt that hard just gotta be patient and measure everything...

No eyeballin like PE....

Ive heard great things about using Fairing compound as a sealer for the blank....

im still using spackle, "the creeping evil"

For me, the health benefits of using epoxy instead of PE is the greatest benefit....

I pretty much glassed my last board with no protection outside and brought it inside to
set-up/cure over night......

some people are allergic though so be careful!

Frank, using a hard epoxy would work for PU blanks but a more flexible epoxy would alow the blank to flex beyond the capacity of the stringer...

board green splints, boards dead....

Stringerless! or more glass.....