DT 26550

[fin17]

9 across Old sea dog (5)
22 dn and 24 across What a buttoned up 18 down might be(5,9) 18 down must be nightie?
Any help much appreciated, last two

[BigDave44]

22d/24a FLAME RETARDANT

[BigDave44]

For those who don't follow my blog (just add .com to my userid), I should have given an explanation!

If the nightie in 18d is buttoned-up it might cool the passion of a lover – as it is it makes said garment resistant to catching fire

[Euphemia]

Clever clue!