Merkava - Anti slip surface

The IDF (Israel Defense Force) uses Ant-Slip on all horizontal surfaces. The grain of the material they use is a LOT courser than what the US uses on - say - the Abrams.

Even in 1/35, the grain should still be visible. As there is nothing molded on the kit, the task falls to the modeller to try and represent this. People use a variety of techniques :

1. Gluing on (very fine) sand
2. Textured paint
3. Baking soda
4. Stippling on Mr. Surfacer 500
5. Tamiya Extra Thin to soften the plastic, then stippling with a stiff brush
6. ...

Most textured paints (#2) seem to be sold in the US/Canada and I'm not about to go on a long hunt for them. Baking soda (#3) or any powder gives a rough effect, which would be more suitable for US-vehicles. The difference in courseness is really big between US and IDF and I really want to see the individual pebbles. Any kind of paste or stippled on anything seems inadequate to my eye. So that ruled out #4 and #5.

So, we go for option #1 : sand. The sand I have leftover from the driveway has a grain of 0.2-0.3 mm. Some research led me to the pet-shop for Chinchilla sand. It measures around 0.15-0.25 mm but also contains even smaller particulates. I was able to sift it, so only the smaller grains remained.

Now, for attaching the sand to the model, also a lot of options here :

1. White glue (Diluted)
2. Varnish
3. Future
4. Pigment fixer
5. Wet paint

I tried the diluted white glue, but - on bare plastic - that just doesn't work (photo directly below). Same goes for the varnish and to  a lesser degree also for the Future. Anything water-based doesn't like smooth surfaces, even when I add some detergent.

The pigment fixer seemed promising (it's white-spirit based) and doesn't bead up, but it lacks some decent adhering quality. AK does have a "gravel and sand fixer", but at this stage I'd like to stick with what I have available and not go around ordering (and waiting for) a bunch of products to test.

Then it suddenly hit me that I'd been trying to attach sand to bare plastic and I might have better luck attaching it to painted plastic. So I quickly painted the inside of the tank and tried again with pigment fixer (left) and varnish (right). Both ended up not satisfactory, but with a less sparse application of the varnish AND another layer of paint over it, it'll probably stick a lot better.