Home |
Search |
Today's Posts |
#1
posted to rec.boats.building
|
|||
|
|||
Questions on UV curing polyester resins.
Two questions for people with knowledge or experience with the UV curing polyester resins: 1) Are they (any of them) compatible with polystyrene foam? 2) Once the UV light has initiated the polymerization, will it spread through the layup even into places where the light did not penetrate? *I'm thinking, for instance about the underside of carbon fiber cloth. Thanks. -- FF |
#2
posted to rec.boats.building
|
|||
|
|||
Questions on UV curing polyester resins.
|
#3
posted to rec.boats.building
|
|||
|
|||
Questions on UV curing polyester resins.
On Mar 14, 12:31*pm, Paul Oman wrote:
wrote: Two questions for people with knowledge or experience with the UV curing polyester resins: 1) Are they (any of them) compatible with polystyrene foam? *2) Once the UV light has initiated the polymerization, will it spread * * * through the layup even into places where the light did not * * * penetrate? *I'm thinking, for instance about the underside * * * of carbon fiber cloth. *Thanks. -- FF it makes more sense to use thermo set epoxies. Stronger, better bond, probably cheaper. epoxies will not dissolve foam Thermo set meaning that they don't begin to cure until they are heated? I ask because I am looking for a very long working time. If so, do you have a recommendation? Otherwise, can you answer the first question? I was quite aware of the other issues. |
#5
posted to rec.boats.building
|
|||
|
|||
Questions on UV curing polyester resins.
On Tue, 16 Mar 2010 13:42:41 -0400, Paul Oman
wrote: wrote: On Mar 14, 12:31 pm, Paul Oman wrote: wrote: Two questions for people with knowledge or experience with the UV curing polyester resins: 1) Are they (any of them) compatible with polystyrene foam? 2) Once the UV light has initiated the polymerization, will it spread through the layup even into places where the light did not penetrate? I'm thinking, for instance about the underside of carbon fiber cloth. Thanks. -- FF it makes more sense to use thermo set epoxies. Stronger, better bond, probably cheaper. epoxies will not dissolve foam Thermo set meaning that they don't begin to cure until they are heated? I ask because I am looking for a very long working time. If so, do you have a recommendation? Otherwise, can you answer the first question? I was quite aware of the other issues. ---------------------- thermo set means a chemical reaction between parts a and b and these reactions produce heat. This is how epoxies work. You can get slow epoxy curing agents and you can also slow down the reaction by working in cooler temps. paul oman - progressive epoxy polymers inc More importantly, it means crosslinks between molecules, as when parts a and b or their reaction intermediates have more than two reaction sites per molecule. This leads to a network molecule with no melting point, although it will decompose with enough heat. I made a variety of thermoplastics (more or less linear molecules) using epoxy and a reactant in my old r&d job. Pete Keillor |
#6
posted to rec.boats.building
|
|||
|
|||
Questions on UV curing polyester resins.
On Mar 16, 5:31*am, Bruce wrote:
On Tue, 16 Mar 2010 01:35:54 -0700 (PDT), wrote: On Mar 14, 12:31*pm, Paul Oman wrote: wrote: Two questions for people with knowledge or experience with the UV curing polyester resins: 1) Are they (any of them) compatible with polystyrene foam? *2) Once the UV light has initiated the polymerization, will it spread * * * through the layup even into places where the light did not * * * penetrate? *I'm thinking, for instance about the underside * * * of carbon fiber cloth. *Thanks. it makes more sense to use thermo set epoxies. Stronger, better bond, probably cheaper. epoxies will not dissolve foam Thermo set meaning that they don't begin to cure until they are heated? I ask because I am looking for a very long working time. If so, do you have a recommendation? Otherwise, can you answer the first question? *I was quite aware of the other issues. I believe that any of the polymer based resins will destroy polystyrene foam. ... Yes, that is correct. By the way, UV curing polyester is not essentially a different resin. It is polyester resin with a UV catalyst added to it and it is the resin that attacks the foam. Good to know. I'm not a board builder but I believe that the polyester boards are made using polyurethane foam. It is quite correct that polyester and epoxy resins, mineral spirits, gasoline and various other solvents do not attack urethane foams the way they do styrene foams. Some epoxies (e.g. WEST system) attack polystyrene. Most do not. Have a look athttp://www.compositesworld.com/articles/techonologies-for-uv-curing-o... for more details of using UV polyester Thanks, that answers my question. What are you building? I'm working on plans for a glider. I'm interested in a long working time. |
#7
posted to rec.boats.building
|
|||
|
|||
Questions on UV curing polyester resins.
On Mar 16, 1:42*pm, Paul Oman wrote:
wrote: On Mar 14, 12:31 pm, Paul Oman wrote: wrote: Two questions for people with knowledge or experience with the UV curing polyester resins: 1) Are they (any of them) compatible with polystyrene foam? *2) Once the UV light has initiated the polymerization, will it spread * * * through the layup even into places where the light did not * * * penetrate? *I'm thinking, for instance about the underside * * * of carbon fiber cloth. *Thanks. -- FF it makes more sense to use thermo set epoxies. Stronger, better bond, probably cheaper. epoxies will not dissolve foam Thermo set meaning that they don't begin to cure until they are heated? I ask because I am looking for a very long working time. If so, do you have a recommendation? Otherwise, can you answer the first question? *I was quite aware of the other issues. ---------------------- thermo set means a chemical reaction between parts a and b and these reactions produce heat. This is how epoxies work. *You can get slow epoxy curing agents and you can also slow down the reaction by working in cooler temps. That is correct. The longest working times available are only about a hour or so though, right? Low temperatures might extend that, but would also thicken it making it harder to get good penetration of fabric. |
#8
posted to rec.boats.building
|
|||
|
|||
Questions on UV curing polyester resins.
|
#9
posted to rec.boats.building
|
|||
|
|||
Questions on UV curing polyester resins.
On Mar 16, 7:46*pm, I am Tosk wrote:
In article , says... On Mar 16, 1:42*pm, Paul Oman wrote: wrote: On Mar 14, 12:31 pm, Paul Oman wrote: wrote: Two questions for people with knowledge or experience with the UV curing polyester resins: 1) Are they (any of them) compatible with polystyrene foam? *2) Once the UV light has initiated the polymerization, will it spread * * * through the layup even into places where the light did not * * * penetrate? *I'm thinking, for instance about the underside * * * of carbon fiber cloth. *Thanks. -- FF it makes more sense to use thermo set epoxies. Stronger, better bond, probably cheaper. epoxies will not dissolve foam Thermo set meaning that they don't begin to cure until they are heated? I ask because I am looking for a very long working time. If so, do you have a recommendation? Otherwise, can you answer the first question? *I was quite aware of the other issues. ---------------------- thermo set means a chemical reaction between parts a and b and these reactions produce heat. This is how epoxies work. *You can get slow epoxy curing agents and you can also slow down the reaction by working in cooler temps. That is correct. *The longest working times available are only about a hour or so though, right? *Low temperatures might extend that, but would also thicken it making it harder to get good penetration of fabric. With respect to Paul, who spends a lot of time here on this board helping I used to get slow cure hardener from Larry at Raka in Florida. I am not sure if Paul has a similar option. Did you ever say what it is you are trying to make? I'm planning on a glider. |
#10
posted to rec.boats.building
|
|||
|
|||
Questions on UV curing polyester resins.
On Mar 16, 7:46*pm, I am Tosk wrote:
In article , Did you ever say what it is you are trying to make? I'm looking at materials and techniques that would be useful for a homebuilt glider. -- FF |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Questions on UV curing polyester resins. | General | |||
Vinylester Resins | Boat Building | |||
Using epoxy & polyester resins on the same boat? | Boat Building | |||
I have heard of sailing curing disease. Any comments? | Cruising | |||
How long curing time for Epoxy before priming and bottom paint | Boat Building |