Ok, I’m going to take the time to post the different types of composites resin matrixs here and sticky it. This will take some time and if anyone wants to chip in, please do. Please ask any questions on the materials in a new thread, thank you.
All resin goes thru 3 stages:
A Stage Liquid (before and just after adding the cataylst) and the stage to work the resin into the reinforcements & to clean the tools.
B Stage Gelled state, Not liquid and not fully cured dry, Pilable. This is the most important stage to trim with a hook blade metal cut off knife.
C Stage Fully click cured hard. Get the saws & sanders out to trim it now
Polyester Resin (PER)
[SIZE=2]The cheapest, weakest and most readily available resin. You use MEKP (Methyl Ethyl Ketone Peroxide) as the catalyst which makes a chemicial reaction to the Cobalt in the PER to cure it. If you have old PER you can add more Cobalt to use it up, but be real carefull!
To remove the nasty smell of PER, get and use an odor suppressor! I get Citrus one from Revchem Plastics and old students remark when they drop by the classroom now how it doesn’t smell like a hazard waste dump anymore!
It was $61 for a quart of it back in 3/06 (I write the date and prices on them to remember…) but at this ratio, this will last a long, long time:
Gallon 1.2 CC
5 gallon pail 6cc
55 gallon drum 66cc
But it seems like after almost a year, it may need to be readded to keep the odors down…
2x main groups or grades of PER: Othro (cheaper) and ISO (tooling grade PER).
PER will melt some plastic foams & sheeting like PS (Polystyrene). Foam use on a foam product, you will have to use PUR (polyurethane) foam or coat the PS foam with tapes, water base paint or whatever…
Lamination resin: Cheapest and less refined PER, stays sticky after curing to aide adding more FG layers (unless you add surfacing agent / liquid wax), changes color after adding MEKP, usually 1/2% to 10% depending on thickness of the laminate, room temperature, mositure in the air…more mass - less MEKP %, colder temps or mositure in the air - the more the MEKP%, hot day - less MEKP %, etc…
Gel coat resin: More expensive (some custom mixed colors are really expensive) which has color (unless you buy base gel coat and color pigment it 3 to 5% yourself like what we do in the classroom), also many other additives to be able to have it stay put where you spray, brush or apply it. Very thick based. This is the first resin that goes on or in to make molds or parts. You want to use less % of MEKP as the lamination will help to finish curing of the gel coat and also help to prevent aligatoring (Gel coat wrinkles after lamination)!
Surfboard / Sanding Resin: Same as lamination resin but much more refined, clearer and has surfacing agent (liquid wax) in it for the wax comes to the surface to seal off the resin to the air and gets a full hard curing. Easy to sand after full drying because of the liquid wax.
Crystal Clear casting resin: Highly refined PER, can cast perfectly clear parts or embed objects into it and finish look is like the object has been embedded in glass. Has some liquid wax / surfacing agent but you have to lay eack layer just after it B stages or gels.
[SIZE=4]Vinylester Resin (VER)[SIZE=2]
I’ll need help here (or do some digging for facts in my books…) as I never work with this material, but I’m told it is more slightly costly than PER and near the strength of Epoxies.
[SIZE=4]Epoxy Resins (EXR)
[SIZE=2]No or very little odors from Epoxy resins.
Will stick to almost everything and without melting PS and other plastics too.
[/SIZE][/SIZE][/SIZE][/SIZE][/SIZE][SIZE=2]Epoxy will NOT melt any plastic foams & sheeting even like PS (Polystyrene).
The hardners are deadly and with reason Epoxy resins should NEVER be sprayed, even with special hazmat rebreather suits too! Even the so call safe to spray new versions!
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