Marinepoxy

I have 4 epoxies that i want to test for just 2 properties, how they wet out heavy glass and how brittle they are. For my purposes Systems Three general purpose epoxy is good enough so that's what I would compare to.
To test for wetting out the glass i will use a piece of DB1700 and divide it into 4 and mix an equal quantity of each resin and pour it in the middle of its square and not work it at all and just see how far it migrates.
As for testing for brittleness i think i will just fill something like margarine container lids with the epoxy, let them sit a week and see what it takes to break them. What i will be testing will be West 105, Aeromarine, Marinepoxy, Progressive and maybe VE as well. Im not sure when i will get to it though. Ive got a busy week ahead.

Steve.

 

Hi,
I just happened to run across this article on "Determining an Epoxy's Physical Properties", in Epoxyworks magazine, Issue #35 (Fall/2012). www.epoxyworks.com which is what passes as their "current" online issue.
I can't say as to whether or not it'll help, but figured I'd pass the info along.

Good luck with the testing,
Andy

PS: A couple of places where you might look both for test results data are: (The) ASTM, & SNAME. And perhaps at www.Matweb.com
I can think of a few other possibilities, but at the moment need to run. Drop me a PM if you need more info & or ideas.

 

Thanks for that UC, it does confirm that testing the sample without any reinforcing involved is the way to go but that i need to let the sample cure for longer than i was planning. I may shop around for one of those rotational viscometers as it doesn't look like it should be expensive.

Steve

 

Hi Steve,
You're more than welcome. Just as an FYI, I gather that one can send various material samples to WEST System for testing. Albeit, as to exactly what, I'm uncertain. And of course were it me, I'd "feel them out" a bit, prior to sending them samples of their competition for testing. Though of course their response could be completely magnanimous & competitive - aka "bring it on"/"give it your best shot" etc. You never know...

The testing which has always had me curious is their Hydromat apparatus. And it's capacity for testing a multiplicity of panels, made up to the spec(s) of various hybrid laminates vying for use as hull, & or deck layups in custom builds.

You know, "the one" (perfect panel), in that quest for a nigh on indestructible, AND cheap, panel/hull construction schedule, for use in one's own "perfect" vessel.
I got SEVERELY interested in such when I read about the testing concept, and results, when first reading about Schooner Creek Boatwork's build of "Jelik". In an issue of "Professional Boatbuilder", many years ago.
Quite an eye opener into what's possible, materials wise, especially for a young guy who'd only worked in fiberglass, mat, & roving until that time.

Ah, as to your viscosometer quest. I got to thinking (yeah, the dangerous thing). What if you were to pick up a chromometric tachometer(?). The type reads the RPM's right off of the shaft on things, & then say, put a jar of the epoxy into a vice on your bench, underneath of an inexpensive power tool with a relatively low torque/output motor. Then chuck a paddle into said tool, & use the tach' to check the RPM's which the tool is able to put out vs. the viscosity of the fluid in question at set time intervals.

I couldn't with any certainty say that such would be a perfectly calibrated setup, per say. But if the other option is several hundred $, then it might be close enough to give you a good, ballpark idea of how each resin performs.

Just keep things as consistent as possible in your testing. Container, Paddle, Amount of Epoxy in the container, Temp. Time intervals between readings, especially vs. the cure curve, etc.

As I said, just a "thought", but I'd be curious as to what you wind up using setup wise, as well as your results, if you're comfortable posting them. RE; your epoxy test results I mean.

Andy

 

I will probably just test as i described, i really don't need to put numbers to the viscosity, just observing how quickly and how far it migrates will tell me all i need to know. As I have said before, pretty much any 2:1 through 5:1 epoxy is more than good enough in all specs but where they vary is in viscosity and elongation so these are all i focus on when choosing an epoxy. Of course no blush is nice too and a choice of hardeners.

Steve.

 

home test for brittleness - hit sample cube of epoxy with hammer or squeeze in vice.
note epoxies take over a week to fully cure - do give samples 2 weeks or so before testing. see how many pieces or splinters it turns into

note that when using fiberglass cloth with epoxy - the epoxy 'numbers' all go out the door.

hard brittle epoxies and coatings take abrasion better than soft coatings, but soft coatings take impact better.

generally epoxy paints (not the more raw marine epoxy resin products) have more flex etc. and they can still be used with fiberglass cloth


paul oman
progressive epoxy polymers inc
www.epoxyproducts.com/marine.html

 

I know this is a 6 year old thread but I am trying to decide between MarinEpoxy and Progressive myself and I wondered if you ever completed your tests.