Epoxy Wars

AlamOso · #1 (**permalink**) December 21st, 2003

The following link is to a site that provides good information about epoxy coatings. It is linked to an article on post curing, which states that "many resin systems will not reach their ultimate mechanical properties unless... postcured". All in all, the site contains enough information to make anyone dangerously knowledgeable about the subject.
http://www.netcomposites.com/education.asp?sequence=13

What does Flexcoat, Envirotex, Devcon, Crystal Sheen, System 3 (and others) have in common? They all contain Bisphenol A (in some form) as their main constituent resin ingredient (see MSDS links below). The differences in the mixtures lies in the addatives. For most resin systems, the hardener is only 3% to 5%. The rest of the 50/50 mix is just more resin with agents to keep it from reacting until it is mixed.

So, if most of what we use is at least based on the same product, how do we quantify which is best? Debate based upon observable performace is practical, but mostly left up to judgement. Saying that "Brand X scratches easier than Brand Z" can go on forever. I challenge everyone to come up with some scientific data so that we can compare apples with apples.

Just the facts...mechanical properties...hardness (durometer reading), tensile, compressive, and shear strength (psi), density (lbs/cu.in), impact resistance (ft-lbs/sq.in), etc. Devcon has an excellent example cut sheet on their product, found at http://www.devcon.com/techinfo/179.pdf I've had trouble locating similar data for other products.

So if we know that Devcon has a hardness rating of 83D, we can compare that with the hardness rating of Brand X and all agree which is best in regards to that particular property.

Come on, we know that you are lurking out there somewhere, you chemical engineer. Step up to bat and give your two cents worth.

MSDS links
http://www.eti-usa.com/MSDS/Envirote...te%20Resin.htm
http://www.eti-usa.com/MSDS/Crystal%20Sheen%20Resin.htm
http://www.devcon.com/techinfo/14310.PDF
http://www.systemthree.com/msds/MSDS_Clear_Coat.pdf
(Watch out - there's a lot of stuff out there called "Flexcoat", but the package I have says contains Bisphenol A).

AlamOso

clemmy · #2 (**permalink**) December 21st, 2003

sorry, i'm confused already...what does "Watch out - there's a lot of stuff out there called "Flexcoat", but the package I have says contains Bisphenol A" mean? is it good or bad to contain it?

AlamOso · #3 (**permalink**) December 22nd, 2003

Sorry to be vague about that. I meant that I could not find the MSDS for Flexcoat online (I found other products also called "Flexcoat"). But, it is made with Bisphenol A (on the label). That only means that all of the topcoat brands I mentioned contain the same main ingredient - Bisphenol A.

You know, it may take some time, but I am going to make a comparison & contrast chart for the topcoats we all use here. It should help us decide what is best. Post any manufacturer's info you can find.

Thanks,

AlamOso

RiverMan · #4 (**permalink**) December 22nd, 2003

Alam,

An interesting post you put together. It would be great to see a more "scientific" approach to the various resins. Like yourself, I like to be "convinced" that something is good because the "data" shows me it is. This reminds me some of a chat that came up some months ago at another site I like to frequent. For a long time guys at the site were talking about their favorite fishing line. Everyone thought that theirs was for sure the "best", without a doubt. Finally a saltwater magazine put together a sound and unbias measurement of each line measuring tensile strength, abrasion resistence, etc., and put all (well most) argument to rest. Certainly the same could be done with the various resins and we would all know without a doubt which was the "best". I am guessing, however, that you would ultimately find a considerable amount of among and between each of the products. Devcon for example seems very hard to me but probably wouldn't score as well as FlexCoat in flexibility or UV protection.

Take care.

Jed

muskie1958 · #5 (**permalink**) December 22nd, 2003

You can find the data you speak of for all Environmental Technology products( Envirotex Lite, Crystal Sheen,EX 88 etc.....) on their website. Just remember , glass is one of the hardest substances we know of. I spoke of bouncing baits on my basement floor on a previous post. Seemed to irritate a few people. Rocks and just as hard as concrete and I know any bait I make will eventually end up contacting a rock. Just trying to communicate my findings.

robertjp · #6 (**permalink**) December 22nd, 2003

Im not an engineer but here are my opinions after having just tried Envirotex for the first time. I had only used Devcon previous to this.

Envirotex is easier to put on.
a little goes a long way.
drying time is alot longer.
its much more a pain to mix and messier.
the warnings are a little scary.
the finish appears to be similar to devcon when dry.
not sure what to clean the brush with but acetone didnt work too good.
Looks very similar when applying but its a little lighter.
We'll see when it slams the river bottom as to how it holds up.
I didnt smell any fumes like warned in the instructions.
I'll try anything once.

Seasons greetings Bob P.

boatnik13 · #7 (**permalink**) December 22nd, 2003

I like what you say AlamaSo! I guess its what your looking for > good looks or tough finish. I'll stay with chip proof finishes (expensive but worth it) and at the conclusion of smacking the lures on rock rip-raps and stream bottoms > I'll know for sure if this is the better finish. So far so good. Every time I see the word 2 ton epoxy> I wonder how they messure that! now I really wonder!(not a user of the product).

Skeeter · #8 (**permalink**) December 23rd, 2003

muskie1958,
No dude, you didn't irritate me. (well maybe alittle). But you are not the first. I guess my point is that sometimes we can take something that is simple and make it very complicated. Like I have said, the lures need to hold up to fish hitting them, not an atomic blast. Rocks and stuff have always taken its toll on all baits of all types. Everything eventually wears out. This is an interesting post. I will be following it.
Skeeter

Celticav · #9 (**permalink**) December 23rd, 2003

Well said, Skeeter! Couldn't agree with you more, JIM

robertjp · #10 (**permalink**) December 23rd, 2003

Lets not forget one thing guys...everyone has a different need (well alot do anyways) The guy who largemouth fishes (and I do that too alot) doesnt need the bulletproof finish Im looking for for my musky baits. Remember when I tie on one of theese 8-10" bombs with the huge metal lip...it is slamming into the bottom of a river with 5-6 mph current and trolling speeds can hit 6-7 mph or more. It is a violent thing going on on the end of your line not to mention when a musky with some nasty teeth gets ahold of the bait. Point is ...whats good for one is not good for all. In essence though for general freshwater fishing, I think devcon is fine and up until now its ben ok for musky lures about 7 out of 10 times. Still experimenting. Bob