[walter]

Well...
I'm getting fascinated by this 8% Holy Grail mix, even though I don't plan on using it for my projects (my sweet spot is in safe and predictable 20-25% area).

I sort of tested it with water- about 10% by volume. Surprisingly, the mix behaves very well. It is very dry, but the particles fit together so well it doesn't seem to matter. Very interesting. I'm not sure if I want to try it with epoxy but that's not the point. The point is dry mixes compact better and enable you to use press compaction. At 20% epoxy by volume there will be no press compaction- you have too much liquid, which doesn't compress. Smaller particles are suspended "midair" and there is nothing you can do. It barely flows, and you can't even press compact it. The upside is, you don't have to worry about results- you dump it into the mold, shake a bit and there's your 1000psi E/G. Air bubbles or not. And it doesn't matter if you use 20% or 23% epoxy, or miscalculate the aggregate, etc. It's foolproof. You get your 1000psi no matter what. Pretty awesome, innit?


Not so with "on the edge" 8% mixes (IMO). You have your 92% of aggregate and instead of drowning it in 20-30% of epoxy- you decide to use only 8% and make a bet that you will be able to squeeze it and fit together just right. If you succeed, you triple the strength. But if you miss just a bit - the mix will fail like an old cupcake. There is no in-between result- you have to do it 100% right, every time. That bothers me.

I sort of worked on it from post #1084 when I did the super dry batch and decided to press compact it. A pleasure to work with these powder dry mixes.. I was able to squeeze them to 1/2 the size (tests and pictures in post #1165 page 98). They were pretty dense but not dense enough and ended up as cupcakes. As I recall, I did not use vibrocompaction- which is the key to the process (the particles need to rotate in place to fit and lock in place). I think I didn't understand what I was doing.


My point is: I'm pulling for you Cameron. I found my peace, I hope you find yours. You really deserve it.


Speaking of BYK A525 deairing agent, the left sample seem to have less air voids! I dug something else up: "BYK®- A 525 will also improve the substrate wetting because it reduces the surface tension." (from BYK technical forum).

Cheers!
_