I have just glassed the base of my board. It is a sandwich construction, so it was 4oz cloth onto Airex PVC foam using RR Quick kick Epoxy.
I have made a number of boards in the past, but this is the 1st time I have had this problem. I have found loads of areas where there is no bond between the cloth and the foam.
The only things different from past builds are that I used RR Kwick kick. I did notice a problem with air pockets under the glass when I was laminating, but thought I had removed them all by pricking them and pressing down the glass before the resin had cured. (Obviously not!)
I hand laminated, used 2% additive ‘F’ temp was 20 deg C and I was careful to blow all of the sanding dust from the surface of the foam using compressed air. Although using KK, I had plenty of time to get the glass down before the rein started to kick. Only possible mistake was that I laid the glass on dry and let the resin soak through. (Never been a problem in the past)
I now have a board with loads of areas where there is glass missing, and areas where I cannot remove the glass.
Any advice?
Do I glass over using 6oz then hope it hides the voids, or do I try to sand off all of the glass, knowing that there will be problems gouging the foam?
Also, any ides as to why I had the problems? I could vacuum the lam down next time, but really it should not be neccessary.
I just used three gallons of KK and also found it hard to use to laminate with. It is much thicker and will gel up enough to retard wetout in a few minutes instead of like twenty min. Once you spread out the thickened resin over a dry spot it’s hard to get it to push through the cloth. My answer to keep from getting dry spots was laminate with CE and hotcoat with KK then back to CE for gloss coats. Hope this helps. Aloha.
I suspected this may be the problem but was reluctant to blame materials, especially after reading all the good stuff about KK.
Strange as I was not hanging around when I did the lam, I certainly couldn’t have got it poured and spread any quicker, and at 20 deg C it was at the lower end of the recommended temperature. Also a small board (5’8") and cloth which normally wets out real quick.
I only used KK because the supplier here in UK has run out of the normal RR epoxy which I have used previously (RR2000). I think he is waiting for the new formulation to arrive, but not due till new year.
The KK resin is an awesome product. It has sped up repairs and flip times for hot coats considerably. It also makes a nice hard shell. I think it gets a little harder than CE or 2000.
I use KK too because my supplier don’t have 2000 any more (seabase). I found it quick faster and harder but no problem with adhesion. I a put a coat of resin after laying fiber.
I am sure KK is a great product, Just that I did something wrong. I will use it for the hot coat, but will wait until I can get some 2000 or the 2011 replacement.
I’ve had troubles with wet out also,S-glass is very hard to wet out with kwikik.I’ve seen the adhesion issues that you describe except with slightly different materials,h-80 divinycell foam with surf source epoxy using S-glass.the resin would drain through the glass and the foam would drink it up,then the glass would lift up from the foam slightly.I’ve become a firm believer in doing test panels when using different materials for the first time.
You may have encountered the same problem as Jesus experienced??
I only like to hot coat with K.K., it’s ok for bagging on wood skins too, but you have to be fast…
. I need more time for glassing though, as I vac bag my laminates… I don’t feel the viscosity of K.K. suit’s the way I laminate , with multiple (2 or more) layers of 3.2oz. glass at one time… It’s hard enough to push thinner/slower resin through a weave this tight…
Did you seal the airex with a thickened slurry mixture of epoxy and micro balloons before glassing?? I swear by this, as it stops the excess “drink up” that Jesus mentions above and ensures no dry patches of glass in the laminate…I also seal bamboo and balsa with thinned resin prior to gluing on the skins as this seems to promote a better bond too, probably for similar reasons…
I always seal my EPS blanks with epoxy/micro-balloons, but guess I thought the Airex wouldn’t need it. This was my mistake. A few years back when I was making twin tip kiteboards using Airex cores, I always vac bagged, no pre- filling, so I guess I never saw the problem.
To recover the situation I am thinking remove all 4oz glass where it has not bonded, then patch the bald areas with same 4oz glass. When cured, sand, then re-glass the whole lot. it’s going to be a bit heavier than I planned, but completely removing the glass will be difficult as I would probably end up gouging the foam.
Before you go stripping the glass you might try dabbing a little heated epoxy in a couple of test spots and squeegeeing it in to the weave. It usually works through a single layer of 4 oz cloth. If it looks as if you're able to resaturate on a few test spots, go ahead and 'cheater coat' the whole thing. Have a clean squeegee ready and really force the resin in to the weave. If you're lucky the Airex won't suck too much more resin and you'll be good to go.
Kwik Kick is very fast and it was initially formulated for pro builders who have always wanted something faster. I was concerned from the start that some of the DIY crowd was going to have problems going fast enough for it. As a result we’ve always continued to offer CE and 2000 and these continue to sell well, even to the pro guys.
One issue with KK is that you must get both the cloth and the foam wet very quickly and the foam must be wet thoroughly early in the game. If it isn’t you’ll get the result above. Add to this, the Airex I’ve used, can flat take on some resin, so to get that stuff wet thoroughly takes some doing and some time. I’m sure this wouldn’t have been a problem provided the foam had been sealed before the laminate and my suggestion for the future would be to include a sealing. In the meantime, John makes some good suggestions here.
Seems like the 2000 resin with the 2100F fast hardener is a good alternative to KK for lamming, still goes off pretty doggone quick, but I don't think as fast as the kk. Then KK for hot coat. Haven't tried the CE yet, its on my list.
Howzit Greg, I sure wish I was able to still be building boards because I would really like to try the KK since the slow kick of Epoxy was the main reason I didn't use it in my over 40 years of making boards. I think you have done a great job and keep up the good work. Aloha,Kokua
I am not pro but i use many kind of resin, i find that KK is really better than 2000 and not as faster as poly i use in the past, really stronger and harder laminate but style flexible. Really good surfboard resin for me.
Thanks for the advice. I can see now where I went wrong by not sealing the Airex. The daft thing is that I have been sealing all my blanks with epoxy/glass balloons up until this board. I found the KK nice to use, so in future will seal my blanks first and will try KK again.