Has anyone used system three epoxy on polyurethane other than sb-112. Such as the #1 hardener with pigment, did any yellowing appear since it does not have uv resistantance to it. I thought maybe with pigment it would not discolor. Any thoughts?
Here is the deal: Sb112 is designed not to have a blush on the surface. This is ok, but when doing a sandcoat you need to remove the blush on the laminate. The blush will wash off with water and a scotch brite pad. Epoxies cure in different ways, the sb-112 goes into a brittle b-stage, which makes sanding the lap easy. Their other system may cure in a tough but flexible b-stage. I don’t know. I would also suggest curing the board at at least 140F. If you don’t you wont reach the epoxies full strength properties and will take up to 2 weeks to cure at 77F. If you don’t heat cure epoxies, expect a low heat distortion temp. Most windsurf builders coat the epoxy with a 2 part urethane. Very toxic. Better suggestion, use polyester with Direct Size E-glass or S glass. You will probably get better results. Good luck, Sluggo>>> Has anyone used system three epoxy on polyurethane other than sb-112. Such > as the #1 hardener with pigment, did any yellowing appear since it does > not have uv resistantance to it. I thought maybe with pigment it would not > discolor. Any thoughts?
Here is the deal:>>> Sb112 is designed not to have a blush on the surface. This is ok, but when > doing a sandcoat you need to remove the blush on the laminate. The blush > will wash off with water and a scotch brite pad.>>> Epoxies cure in different ways, the sb-112 goes into a brittle b-stage, > which makes sanding the lap easy. Their other system may cure in a tough > but flexible b-stage. I don’t know.>>> I would also suggest curing the board at at least 140F. If you don’t you > wont reach the epoxies full strength properties and will take up to 2 > weeks to cure at 77F. If you don’t heat cure epoxies, expect a low heat > distortion temp.>>> Most windsurf builders coat the epoxy with a 2 part urethane. Very toxic.>>> Better suggestion, use polyester with Direct Size E-glass or S glass. You > will probably get better results.>>> Good luck,>>> Sluggo Sluggo, thanks for your info, i used sb-112 on the last board i built and it turn out fine, i was thinking of using the system three with #1 hardener instead of the sb-112, the main reason being it is about half price. although it is not as clear as the sb-112. have you used it?do you think it would work with pigment? or would it be to cloudy?
I have not used their #1, but a few things to think about. Viscosity, Polyester surfboard resin is around 450 cps and I think SB-112 is similar, This system will probably be around 800 cps. It will be thicker than standard resin. Gel Time: Ten Minutes (In a 100 gram mass at 77F). Doesn’t give you much working time. I would suggest pouring the material into a paint roller tray to help keep the exotherm down. HDT: 119F. Carefull leaving your finished board in your car on a hot summer day. They also describe this as a medium modulus resin and the SB-112 as a high modulus resin. This refers to the stiffness of the product. This resin will not be as stiff as the SB-112. Again, I would heat cure my board at at least 140F. Yes you can pigment the resin, it will help with UV and will look nicer. Good Luck, Sluggo>>> Sluggo, thanks for your info, i used sb-112 on the last board i built and > it turn out fine, i was thinking of using the system three with #1 > hardener instead of the sb-112, the main reason being it is about half > price. although it is not as clear as the sb-112. have you used it?do you > think it would work with pigment? or would it be to cloudy?