I have recently had a sales person brag that Entropy Super Sap is a lot stronger resin than Resin Research but when i look at the data sheets to me they look very similar however the numbers dont mean a huge amount to me!
Ignorning what they are like to work with is the actual performace of the resins much different? can you tech guys help with this?
The data sheets i have been looking at are on these links
From links you post, both resin have similar tensil properties. RR don’t give how they measure elongation so it’s hard to compare with super sap. Most 2:1 high quality epoxy like those sale for surfboards have similar mechanicals and chemicals properties. Difference come more from uv stability and viscosity. In general resin with higher elasticity have lower stiffness, they have lower max strengh to break but better impact strengh, they give a softer skin that resits better to dings end less to dents.
Looks like RR edges out SS, but as you say the numbers are close. Ask SS about barcol hardness. RR excels there. Also, from my experience, you have a hard time finding a brighter, low yellowing resin than RR’s Kwik Kick. Buy a little of each and let us hear what you think.
I have actualy used booth in the past the super sap is nice to laminate with but cure times are slower and it does not do that thing were you can press or mould it as it goes tacky. At present i am staying with using RR Iwould switch if SS cured faster
Good point, Charlieukusa. I just laminated a small board and pressed an errant corner into shape after it got cheesy. I also will use 3M 233 tape on the corners after it gets a little cheesy and pull them up tight. Tape comes off easy. Oops highjack. sorry.
I have access to an epoxy resin with 13% elongation but only 60% the flexural and tensile strength of the current surf favorites. Are these spec’s too low for success?
Also, the Super Sap is claiming an ultimate Tg of 150 F while the others I have seen range from 115-125 F HDT, which I thought would be more like initial Tg. I was under the impression that to get to ultimate Tg you have to heat a polymer past the ultimate temp. So would postcuring these other epoxies somewhere between HDT and not melting any EPS involved get the job done of reaching a higher Tg?
Post curing at higher temp your foam can go.
If you use an élastic resin You will ended with an elastic skin. If you make it thick it will feel stiff under tumb, it will be tough under hammer but it will be heavy.
Strength is generally dependent on modulus (stiffness) and the product your building. At Resin Research we make surfboard type resins in four different modulus’. Generally for surfboards you use 2000 resin because it has the best modulus for the foam we use and the conditions we use the product in (lots of water and standing surfers bending the boards). There is also the denting and performance issues so a higher modulus resin is preferable. Lower modulus resin don’t do so well at those aspects. So 2000 has the best (nearly the best, I’ll explain that in a minutre) modulus for board building. A quick for instance of another market we sell in, we sell 2040 resin to the Grand Canyon dory builders which is a high impact, low modulus resin with high elongation so when they hit rocks they get less damage. They don’t have to worry about the bending and twisting a surfboard takes because of the geometry of the boat and they aren’t trying to pull high perfrmance manuevers, just trying to get down the river in one piece. Every product has different specs that must be maintained for that product and surfboards have a long history of things that work. If a company is claiming it’s stronger because it has better elongation then your losing somewhere else. We sell everything so I feel that I can talk about this frankly and IMHO we know what works best through years of trial and error. I alluded to the strongest resin above. That is Kwik Kick. Best modulus vs. elongation balance, room temperature cure resin on the market. Also now available in bio based.