I have used the spray on stuff from the local car shop. There is also some stuff stocked in my local ironmongers/ general hardware/farm supply shop (the advantage of living in rural Wiltshire!), which I haven't tried. For the spray on stuff, you need to have everything fairly warm (at least 20 degrees C), and the spray nozzle tends to clog very easily, in an almost permant fashion. I haven't yet successfully part used a can and been able to use it again. This, by the way, was black crackle, used for restoring a 1939 National HRO receiver for anyone interested.........Blue/grey and olive drab crackles don't seem to be available any more. The spray on stuff is also a fairly 'coarse' crackle, rather than the very fine crackle that you see used on avionics stuff, so it tends to be a 'shiny' crackle rather than the very matt finish beloved in avionics because it minimises reflections. I have genrally gone over to using Hammerite, although the 'hammer' is pretty coarse, compared with the 'oyster hammer finish' we had in my young days at Marconi. For small items, I use a wire brush on the bare aluminium (wearing protective gloves, storeman's dust coat and protective goggles), folowed by a clear spray. Using the wire brush is also useful as a surface preparation when you want paint to stick. Why is it that paint in the wrong place sticks like S*** to a blanket (as the old RAF term has it), but despite careful preparation, drops off a something where you really want it to stay? Peter Chadwick Swindon MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.