Aeropoxy PR2032/PH3663 for Resin Infusion 

Just an fyi, when we use a stethoscope to check for leaks, we prepare it by removing the chest piece and replacing it with a piece of hard plastic tubing (in fact, I have used the body of an ink pen for this). The problem with leaving the chest piece on is that it is designed to only pass either low or high frequency sounds, depending on which one it is. What we want is something that allows us to pinpoint leaking sounds, of various frequencies, while rejecting other sounds close by.

Last comment. When you get pin holes between the weave of the carbon tows, thats often due to low pressure. When the part cures, the resin shrinks and gas retreats to areas with low pressure, such as between the tows of carbon. Almost always where youll find those pin holes. Find a pump that can pull full 30 inches, then degas your resin for a solid 5 minutes until its stops boiling. Just here to learn from watching others, but also have done about 700 bagging layups so hopefully my advice will help.

Extend the vacuum spiral along the entire end edge of your layup. Make sure your peel ply comes in contact with the vacuum spiral. This will prevent the resin front from stopping in areas that do not have flow media. You can use this same method to slow a resin front from hitting your vacuum port (which allows gas to escape because it is possible to boil your resin under the bag if it is not degassed). Oh and awesome improvements since your last layup.

Would the 3663 hardener work well for open (wet) layup, no vacuum bag construction methods such as the Rutan mold-less foam core process? I'm wondering if it might be too thin, and end up running out of the fabric. On the other hand, Aeropoxy data shows it sets up pretty quick, doubling its viscosity in 50-60 minutes in a small mixed batch. So it might not be an issue whatsoever. Being that it has a much lower viscosity than the 3660 hardener, at least when first mixed, Im wondering if it might have an improved wet-out of the heavy unidirectional fiberglass spar caps found in the LongEZ. Or if it might offer a higher fiber fraction ratio for the wing skins, if squeegeed in accordance with the instruction manual, especially if peel ply is used to absorb any excess. Seems like it might warrant a try for improved wet out and reduced weight. Although its mechanical properties show it's 10% worse, on average, than the tried and true 1hr 3660 epoxy combo. I appreciate your input.

You getting leaky tape because you waxed the tape area... Also try polyester batting as flow media from a fabric sewing store, its cheap.