Hi Jmac ,Believe me you have nothing to fear with Alclads .
Here is what I did .
After all the joints were sanded (which didnt require any filler ) using 800 grade wet and dry ,I sanded them again with 1500 and finally 2000 ,you need to make sure any sanded areas are completely smooth and scratch free .Once that was done the plastic was degreased ,I used an automotive degreaser that I normally use in my paintshop its called Panel Wipe .From then on be sure to wear latex gloves so as not to put any grease back on the plastic . After that the plastic was polished again using cotton balls ,this time the whole aircraft was done .The key is to have a completely clean dust and grease free glossy surface .By the way ,spraying onto the plastic only works for the Alclads that are NOT high shine ..ie Aluminium .
Now ,when the plastic is clean I start spraying ...Very light coats at first this is the KEY coat ,in other words it gives the rest of the coats something to bite too. Let it dry ...about 10 mins then buff with a soft cloth . Do the same with the second coat ,only make this coat a bit heavier .A third coat is then applied ..same as the second ,leave to dry for about 20 mins then buff again with soft cloth to remove the drieness and bring up the shine .
Thats all there is too it ,just make sure the plastic is really clean ! For high shine finishes such as Chrome ...yes a gloss black base is required .
Oh ..and do make sure where you are painting is warm and dry ,Alclads dont like cold moist air
Heres a link to the How To page on Alclads site
http://alclad2.com/how-to/
And thanks for the comment
Chris.