RR epoxy kwik kick help!

General Discussion
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I recently glassed a board using Resin Reseach fast for the lam and kwik kick for the hot and finish coats. My friend whom I did it for showed it to me and it now has light greenish stripes across the bottom of the board. He said he left it out one morning for only a couple hours under his patio which has a slatted roof. I’m guessing the sun shone through leaving the discoloration, but it wasn’t out long and figuring the movement of the sun it wouldn’t be stripes if it was longer.

Anyway, I’ve done a couple RR boards using the same Fast batch but this is first time with the kwik and never had this happen before. The discoloration is in the hot/finish coat as it can be seen across both colors. I didn’t add anything but some addtv F, wiped the board with some denatured alch before hot coat, don’t even own acetone, used clean containers… All the usual stuff.

I know Greg does/did post here. Any help to minimize this happening in future builds, explaining what went wrong are appreciated.

 

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I’ve had it happen in the HC with fast RR.  I don’t know why it does it some times…and others not.  I had it happen with 2 boards side by side, same batch…both white boards.

I only use KK now, and I have not had it happen since switching.

 

My guess your issue is a few things. 1) Mixing time and ratios are off. or 2) did you use a second batch of epoxy to finish up the job…if so maybe you were off in your ratios on that one?

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Thanks RH.

In hindsight perhaps I didn’t stir enough, was first time using the kwik and was a hot day, so did feel a little rushed to get it on the board. I use a scale and go by vol, 1: .45 in grams to the tenth, pretty pedantic with that. Will try and try again, hopefully better results.

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WTF !!!

Resin research is 2 to 1 by volume…That’s 2 parts resin and 1 part hardener. KK or CE resin. You need to learn how to read the instructions and you need to learn how to take a photo. The photos you posted look like my local waste water treatment plant ! yuck

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Pretty funny stingray.

Anyhooo,  measure by volume or by weight will come out the same.  The ratios are close, and the outcome should be the same.  What happens in screw up is the mixer gets distracted and goofs the ratios up, or does not get a good stir, and leaves unmixed at the bottom or sides of the cup.  Happens all the time, but most people only do it once…then they learn.

 

 

 

It does look like a sweage treatment plant…nice camera.

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Hello Filzilla , Hi Resinhead…

I have a sad story for you. So sad it could make a grown man cry. I threw my brand new surfboard in the back of my truck and drove to work for an early morning shift. I got off at 1:30 pm and drove 1.5 miles to the beach to surf. The tide was too high and the swell was too small…So I’m standing on the bluff and a good friend shows up…asks about what projects I’m working on,   we walk back to my truck and pull the new board out of the Julie Bag / sock…and…The board is starting to delam. 2 inch bubbles all over…bummer city.

My long term testing with EPS foam and Epoxy resin went very well… My testing with poly blanks and Epoxy resin is not going so good. Heat and direct sunlight…I feel like crying…

Stingray

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Ray - that is a heartbreak!

The issues I’ve had with poly blanks and epoxy resin have been related to the blank, especially when I used some old Ecotech blanks I got cheap, to learn with.  And even those have been repaired, and are going strong.

Most of my poly blank / epoxy resin boards are doing fine, no problems.

I try to keep them from direct sun and extreme heat, but you can only do so much when you’re driving around town in a heat wave with a board on top.  Sometimes too much heat will cause the blank to “puff” a little, you can see a small channel forming at the stringer.  But its minimal, nothing like what you’re describing.  Sorry to hear it.

You know we’re masochists here, especially when its the other guy’s board, haha, post up some pics!

Be interested to hear if anyone else has experienced this.

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I made three boards with poly blank/epoxy resin. USBlanks blanks, and fiberglass Hawaii epoxy. No problems. They are also pretty dent/ding/dimple resistant.
Have left the boards in the car also.

Did you paint the blanks?

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When by WEIGHT I was told 100:45.

Typical Physical Properties

Resin/hardener    1980/2100    2000/2100    2020/2100    2040/2100

Mix by Volume    2 to 1            2 to 1              2 to 1           2 to 1

Mix by Weight    100 to 45    100 to 45    100 to 45    100 to 45

Tensile Strength    10,800    9,800    10,300    9,300

Tensile Modulus    420,000    405,000    395,000    380,000

Flexural Strength    13,500    14,800    14,900    14,800

Flexural Modulus    510,000    480,000    455,000    380,000

Barcol Hardness    84    83    82    82

HDT    125F    122F    117F    115F

Compressn. Yield    16,100    15,400    13,500    11,700

Elongation %    2.3    3.8    5.1    6.5

That’s from RR website. Look who knows so much! The poly/epoxy boards I’ve done have held up great, although I haven’t left them in the sun for hours and are lighter colors. He wanted purple and brown, so I did it, and he loves it. To each their own. 

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The photos are really bad. Hard to tell what is Art , what is SunLight  , and what is yuk

Smile and laugh at yourself…I do it all the time , laugh at myself for stupid surfboard problems. Scale or volume…go for it. it does not really matter 100- 45 is really closse to 100- 50 (2-1)…

I have a surfboard that delamed after sitting in the back of my open pick up truck. 5:00am to 2:00 pm on a very hot day…Surfboard failed the test…We test stuff over here at the Low Tech lab…all the time.

I would like to know more about the orginal poster’s problems and solutions…New game plan…ect…Do you think it was the foam or the resin or the mixing that caused the problem?

Over ten years ago I was told not to glass Poly blanks with epoxy resin…I’m a backyard guy…I plan to ride the crap out of the board that delamed because it has no resale value!!!

Happy is a good thing…Happy to have a job…happy to surf on my day off…Stingray

 

 

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Hi Ray,  sorry to hear what happened; your boards always look so good.  Delam problems can’t be related to the blank on poly since there’s no expansion when heated.  This would be some kind of air spaces between the lam and blank (or between the paint and the blank) that expanded, however small they may be.  If painted and it didn’t fully harden in some places + there were air spaces, then the expanding air will go to the path of least resistance (i.e. where the bond isn’t good and start peeling and expanding).   Cut a piece of the delam off and see what’s sticking to the glass.  If paint is, then you know it was the bond between the blank and the paint. 

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Seeing something you’ve worked hard on be destroyed before your eyes isn’t easy, hope you get some great rides on it!

Dont think it was the foam as the lam coat would prob seal off any contaminant. And the stripes run across both colors. I’m gonna say it was one or a combo of 3 things: dirty container from hc the top, numbers were off, didn’t mix well enough. Normally good about these and first time it happened, so need to be more careful.

doing a quick hc while he wife is waiting on me is prob. It a good idea :headslap:

Pics are turdballs. Knew when I took 'em, best I could do with phone, apologies. Here’s the top, bottom is reverse colors. Green and white board I did right after so see how that holds up and if it does the same. Thanks all for responding!

Hope these are sway approved! :wink:

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I’ve never mixed poly blanks with epoxy resin.  I only use EPS with Epoxy.   I think if i was going to do a poly blank I’d only use poly resin.   The only benefit I see with Poly and Epoxy is the lack of smell.  This just confirms some of my thoughts.

 

Poly boards with poly resin make prettier boards too.

 

Sorry to hear about your loss Ray.

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Uh-oh, I was told it wasn’t a problem, been doing it for years, was I given bad info?  Not supposed to glass poly blanks with epoxy?  Are my boards going to go bad on me someday?

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Bottom line is that whenever there is some air space between the blank and glass, it will expand when heated.  Doesn’t matter if it’s epoxy/poly or epoxy/eps or poly/poly.  The difference is that epoxy is more sensistive to the surfaces it’s bonding to than poly.  There could be a number of  tiny air spaces on a poly/poly lam which remain benign due to the peel strength.   We’ve all seen this problem start with a tiny heel dent which lost bond and became a huge balloon when in the sun.  Or, the rice paper clear lam added over dark glassing which bubbled all over in the sun.  I quit painting blanks because of the risk regardless of whether it’s poly or epoxy.  Without a hotbox, I never can tell if it’s really dry unless I let it sit for weeks.  On restorations where I’ve painted over a hotcoat then clear lam’d, I haven’t had a problem.  This is likely due to the smooth surface the paint and lam were on with no air spaces.    Just my observations though. 

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I’ve done it a number of times without problems.  Greg Loehr even said it was OK! 

I had previously thought that since polyester resin melted EPS foam that epoxy would melt urethane foam… not so.   I’ve been told by clueless shop guys, even guys who are considered “knowledgeable”, that you can’t do it but you can and it works.

If there is any thing I can say that might be negative it would be this…  epoxy tends to be a bit more flexible.  If you use epoxy to laminate a light schedule lay-up on light density urethane foam there is more of a chance of denting since the urethane foam doesn’t spring back like light weight EPS.  I’ve found that with the heavier density EPS like 2+ lb/cu ft, that it will stay dented as well.  It’s the 1 lb EPS that springs back like a sponge.

I’ve not had bonding or delam issues with glass to foam (urethane or EPS) using epoxy.  XPS foam is another story.

I would suggest that Ray’s troubles are related to the board being left out in the hot sun for too long a period. Epoxy softens in heat.  If the resin softened and the pressure built up inside the board, a delam could easily develop.  That’s one reason why people in some other industries post cure their epoxies - so they withstand higher temps without softening.

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I think the same as you John. Post cure and decent lam schedule give epoxy durable boards. On pu be carreful to use a good uv blocker.

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The reason I asked about the paint is because after seeing Otis’s video on doing a foam stain with poly resin, I wanted to try with epoxy resin. I tried with two of my boards, i.e. I painted a coat of epoxy on the blank prior to glassing. I am about of as a noob as it gets, so I was curious if I had some dumb luck and doing that helped prevent delamination .
I used regular density poly blanks and s glass also. Not sure if that is why I haven’t gotten any heel dents, but I have ridden those boards in lots of overhead surf, and I am not light on my feet.
Also didn’t mean any disrespect towards you stingray. If it wasn’t for your thread on using epoxy, and the one on installing a FU box, I wouldn’t have any boards glassed period. Thanks man.

Also in response to one of the original questions, on my first board when I was doing the final coat of epoxy, I put some acrylic sealer on the outside and some other stuff to give it a gloss, took it out to surf , and when I got out of the water, it had a white swirl in it. I either contaminated the epoxy somehow in mixing or didn’t wait long enough for the epoxy to cure. For me it was only on the surface, so I was able to sand it out.

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Thanks for posting Filzilla…thanks for posting good photos…something told me there were  better photos out there…and thanks for starting a thread that I can learn from…shit happens…we have to learn from our mistakes…and learn from others…oh boy…The green one I like…

…not sure where to go from here…poly/epoxy/eps/epoxy…

my delams are resin tints…US Blanks with RR epoxy resin…too much direct sunlight…???

If I cannot leave my surfboard on the beach all day…the board is not for me…

 

 

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Hi Ray - 

No disrespect intended and I’m not trying to be argumentative… one of the worst delams I’ve seen was on an EPS/epoxy board (manufacturer purposely unnamed) that was left on top of a car on a hot day. 

Dark colors get hot pretty damn quick in direct sun although the board mentioned above was yellow.