Across:
   8. Theatre is a contest of popularity and love (6)
   9. Rare stroll with king, following low grassy area to the west (8)
  10. Use process of Waelz, in chief to obtain 7 30 (4)
  11. Made so much room turning out last of rabble (one of 46 in my cell!) (10)
  12. Blogs fall into disarray, as some got hit by 4 on 8 14 (4 5)
  14. Such images can show inside? (5)
  17. 7 112, made from 10 and 25... ( Cu - P ) + Ni + ( Ca - Al - C ) (11)
  20. Names ruined providing financial support (5)
  21. Tearing fabric hem is trying when you investigate materials (9)
  23. Something put on social media containing close to enough rope for hanging 5  (10)
  25. Main role of 7 82 (4)
  26. Dissolved rufie, putting it in bit of rum with extra lime perhaps (8)
  27. Your old corny piece, at first crude (6)
Down:
   1. Disaster attendant on one slip, often signifying only a tiny difference (7)
   2. He may be a smart one, tying lace in knot (4)
   3. Arrogant 4 briefly took its place and hid (9)
   4. Briefly ranked oldest fellow ever on a 9 or wandering Mars' parched land (4. 4 7)
   5. 23 dropped, with finishing of rum, into unresponsive state (5)
   6. Slow work of Members of Parliament (4)
   7. Part of me immersed in ultimately futile religious observance (7)
  13. With change of sides, unhappy look quickly gone (5)
  15. Beginners in cryptic language essentially guess little pieces of information (5)
  16. Bolted, embarrassed, after bogus exercise class (9)
  18. "19 Reprise" arrangement (7)
  19. Cook herb when about to consume - if you don't you'll die (7)
  22. Big influence or small part? (5)
  24. Fit for a 9... you'll 19 easier having one! (4)
  25. A bit of fun in boat next to port (4)