I have found and reprinted my epoxy comparison below. I think I did one with Aeropoxy also at some point, but could not find it. Surprising to me that nobody else has ever reported a comparison or commented on mine. I really would like to hear comments from others that have used different epoxies. I guess most people use what they use and don't see a need to try something different.
from 5/31/08 post We have had a lot of discussions on this list in the past about which epoxy is best. 99% of the posts are usually from people that like the epoxy that they are using and they have not tried anything else. I had always used EZ Poxy in the past and was in that same boat. For the past few days I have been using West System epoxy and I can finally make a comparison between the two. They are both very low odor and pleasant to work with. Viscosity is pretty similar, they both seem to wet out the cloth about the same, and they both get real thin and wet out cloth better when heated with a heat gun. Mixing with micro or flox and sanding are about the same. They can both be used with different hardeners for faster or slower drying. I have used the EZ in cold and hot weather with great results, but have only used the West in fairly warm weather. EZ Poxy is $112 for a 1.5 gallon kit. West is about 23% more expensive at $122 for a 1.26 gallon kit. Looking at the specifications at: http://www.aircraftspruce.com/catalog/cmpages/ezpoxy.php http://westsystem.com/ under the physical properties tab EZ Poxy is about 4% lighter and has about 4% higher tensile strength not post cured. West does not show a tensile strength when post cured. I don't know if that means that they just don't publish it or if it does not get any stronger with post curing. From searching the net I am fairly certain that West is not able to be post cured. The EZ Poxy is nearly 20% stronger if post cured. EZ Poxy will handle heat better when not post cured and much better when post cured. As far as working with them, I like the EZ Poxy better for several reasons. The mix ratio for the EZ Poxy is about one part resin to a half part hardener. West is five parts resin to one part hardener. Weather mixing by volume or weight you can get more precision on your hardener ratio when there is more hardener used, especially on very small batches like I mix a lot of. West has the pumps, but I do it on a scale because you have much better control of how much you mix when you don't need to use full pumps and can do it by the gram. I often hit my layups with a heat gun to make the resin flow better and sometimes to dry them faster. I never had to worry about getting the EZ Poxy too hot, but the West could be overheated pretty easily. I have also a lot of times with the EZ fairly hard, but still a little tacky been able to heat an area some to get it a little soft, bend it as needed, and held it there a few minutes till it cooled and stayed in the new position. With the West it would not bend and would turn white and separate the resin from the fibers. When trimming cured layups I found that the West would tend to have the glass ends fray and come out of the matrix much easier than with the EZ, especially if you cut rapidly with a cutting wheel and got it hot. Some areas even delaminated a little when doing rough cuts and cutting fast. EZ poxy is a brown color and West is clear. A lot of times when I finish a layup with the EZ Poxy I will put it out in the sun and it will heat up and dry faster. I also put dried parts in the sun to post cure some. West would heat up with a carbon layup, but it never gets warm with just white fiberglass. So to sum it up, West is good, but I can't find anything about it that I like better than the EZ Poxy and there are a lot of things about the EZ that I like better. To be fair I guess there are two things about the West that are better, being clear if you wanted to do an unfinished carbon layup instrument panel it would be best, and it is available at local boating stores if you run out on a Saturday. Other's comments are certainly welcome. Brian Kraut Engineering Alternatives, Inc. www.engalt.com -------- Original Message -------- Subject: Re: KR> Epoxy From: <brian.kraut at eamanufacturing.com> List-Post: krnet@list.krnet.org Date: Wed, October 30, 2013 6:03 am To: "KRnet" <krnet at list.krnet.org> I recommend EZPoxy although most people that have not tried it use West or Aeropoxy. If you check my name and epoxy in the archives you will find a comparison that I did a few years ago. change options
