Maybe I should have stuck with the long-winded version:

I gave a very polite and simple answer. I'm already working for someone else on similar projects, and am getting paid to do this. I don't have time for additional work, even for money, and it probably wouldn't be all that ethical for me to split my time.

I work at a computer most of the day, shoving CAD files, Photoshop renderings, and spreadsheets around. My computer has sufficient horsepower that keeping a couple of internet windows up in the background, including this one, has no performance penalty. Flipping off the occasional post here or looking some articles up doesn't use up much time, about what a normal engineer would spend at the water cooler.

That, and I have to take care of a couple of kids, which as other home parents know, is no picnic in the summertime.

I don't think that warrants you getting upset. I appreciate the effort you went to to send me information, and the stuff that was outside the sealed envelope--I never opened that one--was intriguing, particularly your references to a new composite polymer (graphite is light, but prone to invisible damage.) But I can't take on anything else right now.

There is a lot of talent out there, and I have no doubt you could find some people at least as bright as I am with little trouble, and I do wish you luck. Believe me, we all started out where you are now.