Cast surfaces.. How?

Apply liquid glue, wait a few seconds, then use the stiff brush you used to apply the glue to create the rough look (just use the tip of the brush to 'stipple' the surface).

Another way, is to use a motor tool and some grinding attachment. Use low speeds. It works well, but the liquid way is faster, and often much easier to control..!

I thought as much.. Thanks for that!

Oh, and this is for all slabs of armour (such as the horizontal and vertical panels on a tiger) or just stuff like gun mantlets?

disregard last transmission.. slabs are ofcourse just that, thick, rolled slabs..

DJ's pretty much got it nailed. Just to add to his knowledge, I've found that using a stencil brush (available at most craft stores) gives excellent results, and you can cover larger areas a little quicker. I used it to simulate the cast texture on my Academy Merkava II. After stippling, you might want to go over the textured finish a bit just to knock down any high areas and bring it a little more in scale.

Gip Winecoff

Excellent idea, Styrene. I'm gonna get one of those brushes too!

There is also a product by Gunze-Sangyo called "Mr Surfacer" This is a paint - type material that has a texture to it. You can apply it directly to the model and let dry. They also sell a special thinner for the surfacer.

I ordered several from this site along with the thinner. Here it is:

http://www.best1hobby.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=168&Product_Code=GUSF285&Category_Code=tool

Erock68 is dead on,

This stuff is great, Mr. Surfacer looks awesome when stippled, I used Mr. Suracer 500 and thinned it with acetone when needed, and if you are not happy with the results you can wipe off small areas with acetone and re apply.

Here's a technique I use to get a cast look on 1:24 / 25 auto engine blocks, and all you need is a can of spray paint (flat white seems to work the best). Hold the can about 12 inches away from the part and hit it with short bursts from the spray can. The droplets will have partially dried by the time they hit the part resulting in a rough surface. You may have to experiment with different paints and distances, and while it doesn't look quite as good as the stipple method, it doesn't look too bad.