Question
I read your Q&A concerning crimped leaves on Brassia, and am wondering if I
have them in the right mix. I have 4 brassia, 3 of which I had shipped to me
from a vacation in Kauai several years ago, one from a local trader Joes. New
growth on these (I've only succeeded in having one re-bloom, and only 1x) is
also coming in crimped. I have them in a mix of pine bark, coconut chips,
lava rock, pumice. It's pretty hot here in so cal and they are under shade
screen and behind polycarbonate facing West. Any suggestions much
appreciated.

Answer
The mix should be OK depending upon the proportions.  
Less than half of the mix should be fir bark.  Some growers have had trouble with coconut chips due to salt content so I would keep the proportion of mix that is coconut chips low.  Brassias and their hybrids seem to do well in tree fern fibers as it allows more air theough the mix than most other mixes. You might take one of your plants and repot it in tree fern and see if that helps.

You didn't mention air movement which they also like.  Your breezes should be predominantly from the west and you seem to have protected them from that air movement which they might enjoy.  With increased air movement, however, you could experience increased drying so you may need to mist or water more frequently. A more open potting mix will also require more frequent watering but that mix will also dry more quickly.  The heat also is not enjoyed by these plants.  In summary, try cooler, more open mix, more air movement, and more misting/watering.