What Aves are you using? The stuff I have doesn't flake like what you describe. I only have that problem with the white Mr. Putty stuff.
Aves Apoxie Sculpt.
The flaking occurs when I try to carve the cured part (or do a real whole lot of aggressive sanding on it) - as I approach the boundary between the old stuff and the new stuff it tends to split too easily. But I've been thinking about this and it's possible that some of the Aves I've been putting on has been too far along in the curing process - I think if I get it on there as soon as it's mixed and use more water I might have more luck. But even so, it really seems like poly putty is more effective for additive processes....
So where do you think this project will be in 2 years?
Updates are infrequent, but whenever you do update, you show a lot of work. I would have thrown this project out the window already so I'm impressed you've stuck to it for this long.
I'm really hoping to get it done this year. I think that's doable, the main reason I haven't made more progress on this thing is because I haven't put in the hours that it's needed - there's always other projects, etc, and it's always tempting to put off a long term project in favor of a "quick" one...