i only use kiln dried sand which i put through a sieve to get any larger bits of sand out.

what most big boat builders do is put the gelcoat on the deck first and then sprinkle the sand or whatever you want to use over the gelcoat.

once the gelcoat has cured they then go over with a flowcoat.

it means masking the non slip patches twice.

i mask area off and sand up to edge of tape and then apply my flowcoat with the kiln dried sand mixed in.

use a 3" paint brush and when area is covered i go over it all in one direction with the brush to get an even finish and then peel tape off before the flowcoat starts to cure.

 

I used granulated sugar, to good effect, all nice consistent sized grains and its cheaper than getting a big bag of sand.

 

http://www.smlpaintsandcoatings.co.uk/home

they do aluminium oxide chips, sprinkle onto wet deck paint or better still flow coat and roll in, give it time to dry, wait for some decent weather no good at the present temperature nothing will dry.

 

I have success in the past sprinkling B&Q kiln dried onto the resin and using a paint brush to stipple the finish. A roller tends to make it uneven.
Beware of leaving the peaks too sharp.

 

garry mixed me up some antislip....great stuff.

 

http://www.pbo.co.uk/gear/deck-paints-test-17514
you might find this helpful.

 

Thank you all for your advice. I shall see how I get on. Now if you could order me a couple of dry mild days that would be great!