Polyester Resin on Polystyrene Foam? Of course its a no because of the styrene. But what if you wanted to make a cheap prototype board? Or it was the only materials you had? Is there a cheap effective way to seal the foam before laminating? Seal the foam with epoxy (not cheap), pva glue / paint, spackle? Of course delamination is a concern. The first longboard i bought in the sixties was PE on EPS that had been wrapped in newspaper and that never stopped it catching waves.
try it on a scrap, you'll see that sealing EPS is 1) required 2) difficult to be sure.
Just don't. You'll waste your time, or get a lousy bond and thus a board that will buckle quickly.
Not being able to afford something suggests your hopes are greater than you capabilities. Let not your reach exceed your grasp.
There’s a product called ZeroVOC that seals EPS foam and lets you glass with polyester. I don’t know much about it though…
~Brian
Matt from Resin-X makes and sells an undercoater which can do want you want.
We have a retailer here who offers a styrene-free polyester resin that is specially formulated to be used on EPS.
http://www.neovents.fr/Résine-polyester-spéciale-polystyrène-5-kg-†-catalyseur-150-gr-1-305-1.html
Agreed Reverb, To me, the core is really the foundation. Like the old saying goes; "well begun is half done". Even the enigmatic "Huie" states with uncharacteristic clarity that the foam/core is really key. Like you, I'm a pe guy and prefer it but, stories like Kokua really make me pause and think about the "biggest picture".
Today is St. Paddy's Day with a strong west swell running. I'm off for some of the "Goodness". To all my fellow Micks: Deo Duit Slainte`.
TIOCFAIDH AR`LA`!!!
…hello Tblank,
you are right about the complete package; but I bet all my shaping tools that a bad core + bad fiber + the best epoxy resin will be worst than a fine core + premium fibers + Reichhold, Silmar, Cry Valley, etc polyester resins
Bear in mind that I said “was” or “were” so not talking about new RR models, for ex.
and YES, still epoxies (most of them) are a very trouble to work in less than fine room and climate.
You cannot have a more durable board with epoxy; remember that
normally they re stronger cause those boards have light cores and lot of fibers but not for the resin.
A normal board laminated normally with poly or epoxy…I dont believe in miracles
cause I made some in the past and used a couple and see new also.
exactly the same disadvantages.
I have been hearing all the mumbo jumbo in the last 25 years with epoxies…I dont see any different except the newer RR (that you dont find in any part except on a few states on USA and couple more countries)
Saying that, Im not narrow minded and if all the factors that I mentioned before, are avoided right now I prefer to pay more and use epoxies on my boards; but still after almost 50 years epoxies have better adhesion but poor in the other fields for handcrafted surfboards.
GR…Have you ever tried it? PM me if you want.
no smell w/o styrene????
Howzit balsa, Do you know what they use ti thin the resin so it is a liquid since that is what styrene is for in polyester resin. Aloha,Kokua
Polyester Resin on Polystyrene Foam
Go for it..you only live once.....
Please post photos of your progress here..............
One time I poured gasoline into a Foam Coffee cup........funny stuff.....total melt down is no problem with a coffee cup.
Maybe not so funny with your surfboard.
Please glass your polystyrene foam surfboard with Polyester resin. Please post step by step photos too....It's going to be a lot of fun.......That's why were here...To have FUN.......
elmers glue.
herb
Howzit Herb, I agree but I have been told to apply 2 layers to insure it is sealed. Aloha,Kokua
I recall back in the days of “Hydrofoam” : Clyde working with Rod Shaver using the SP115 epoxy that they told people to seal the EPS with white glue then repair the ding as usual with polyester.
Basic barrier coat thinking even back then.
The bigger question is what the end result is when you compare the flexural modulus, tensile strength, etc of epoxies and polyester resins… or more specifically Resin Research or FGH’s epoxy to Silmar ortho, Iso, or 1421 blend?
If the polyester held up well over the EPS for flex, denting and bond, then heck, why not…other than the melt down risk in construction. Sure, if you are a novice, I can understand why people would issue a “kids don’t try this at home”.
But if you are in the industry, and could quantify positive results, then this approach is merely a logisitic like many others that we have to pay attention to.
I have to be honest, I looked at this last year and lammed a test piece of EPS with some of my 1421 UV poly, and to my surprise, I didn’t notice any appreciable melting of the EPS on the samples I did. I even let it sit for a bit before curing in the sun. It kind of shocked me. I did a resin rich sample too. I didn’t do any pull tests to check for bond, or impact tests using a ball and tube, but it might merit further review.
Either way, the bottom line (at least for me) is that epoxy is superior to polyester. Polyester is convenient and good overall, but the molecular linkage of it is far superior when you look at the two side by side. Both have their place.
Do you want quick turnover of a good afforadable product, or a higher priced, more durable board?
The densities of the newest, fine celled PU’s are closing the gap and offer the advantage of cosmetic appeal while the EPS has memory and doesn’t crush like a fixed cell structure. Aside from everything else, that consideration is the greatest difference between using one or the other.
At the end of the day, how does a PE glass job on EPS stack up against a quality epoxy on EPS when it comes down to strength to weight ratio?
Thank you for that dissertation DS. Message received.
…hello DS, all we know about epoxy is better glue than polyester
but for a handcrafted process in a show environment lack of several things.
I mean, epoxy never breaks through cause always was yellowish, super super difficult to have a perfect hot coat, etc on colder climates (the surf industry is bigger than S Calif), poor in humidity climates environment; always were problems with blush, with bubbles with contaminations on everything, etc a pain in the arse in other words
A good polyester does almost everything right in almost all work conditions.
for me is far more important the core and the fibers
the glue is a superthin coat on a surfboard and not probide gobs of advantages compared with fibers + cores.
With all due respect Reverb, it seems to me that you can't discount any of the factors. You can't maintain integrity of the core and fibers without the "glue". It is one complete package that we are trying to make monolithic. The whole is sum of the parts as it were.
I've been a pu/pe guy from the beginning and (Eggs too, really dig yours) but if I can get a more durable unit from epoxy, then that's where I'll go. I will say the weather factors that trouble you don't occur here too often. Everyone has to stay with what works for them. Won't miss the vapors either. Cheers, Keep making those beautiful boards.
Some of the people here have seen EPS test panels I have that were sealed with urethane resin. One brand "Styro Spray" is pretty tough even with no reinforcement fabric at all. I have not tried laminating over it with polyester resin but after performing peel tests with epoxy, I know that epoxy sticks to it just fine.
"ZeroVOC" UV resin is shown in a video being used as a sealer for EPS. http://www.youtube.com/watch?v=4vNAa0XO33g
The guy says it works fine with polyester resin as long as the blank is completely sealed. He is shown mixing the ZeroVoc with microballoons to make a sealant that appears to be superior to spackle by a long shot. If ZeroVOC is anything like Styro Spray, I would have to agree.
I think he makes a mistake at 3:56 when he says the "polyurethane resin" will get in and eat the styrofoam. He probably means polyester resin.
I've used more epoxy than I have poly, only because I've been building wood boards for the last few years.
But i've used both on PU foam a fair bit, and like them both!
Just musing over the "engineering" side of things after tblank mentioned this:
it got me thinking…
The matrix phase of a composite (the resin) has two main jobs, to bond the fibres together, and to bond it all to the substrate (the blank).
Exactly what you were saying…
The thing I see about the surfboard application, is that it appears that neither of these matter much!
Take bonding to the core - the foam is always going to be the weak link - the foam will tear away from itself, the fibreglass will have a layer of foam stuck to it.
It doesn’t matter which is the better adhesive. (The exception is for wood, as wood is much stronger).
As for bonding the fibres together - I’ve never seen a board snap because the double 4oz layer on the deck delaminated - it is some other thing that went first, then the board self destructed.
The resin keeps the fibres aligned - but it the case of surfboards, the cloth is usually orientated with the weave at 0/90, so along the length of the board, you can basically said it is acting as a unidirectional fibre, just with a bit of crimp inolved. There is no special orientation of the fibres that the resin has to maintain.
Now maybe the movement of the crimp contributes to the failure of the laminate, in which case there’s an argument for epoxy as the better adhesive, but I doubt it.
The resin does afford some impact resistance of it’s own, and it that case epoxy has the edge. But, the fibres are far and away the most important component in this respect, the minor difference between two resins probably won’t make a significant percentage difference.
I love both and use both all the time… I use epoxy when I need high bonding strength and with special fabrics, but over good 'ol PU it’s UV polyester all the way.
Undoubtedly looks better, faster, and I can’t really tell the difference in ride and durability.
As an after thought, epoxy doesn’t fracture quite as easily the round points of a swallow tail, so thats a plus!
The skin nor the core will fail unless there is de-lamination. Dings and rocks excluded.