Hi there Cycolac Fan
I understand yours and others frustration using Alclad, but it is a great product and just takes some time and a little help to become successful at it.
I did a posting on this 6 or 7 pages back called TIPS USING ALCLAD. There's 3 pages from different users and may help you some.
I have been using ALCLAD since it came out and have done seminars up and down the West Coast, Calif. to Wash.,including at the 2007 NNL West in Santa Clara, so I've paid my dues on this stuff - LOL
I've never used the Humbrol products you mentioned, but I'll share with you what works for me.
Regardless what the instructions say on the ALCLAD bottle, I can spray it over everything I've tried so far - enamels, lacquers and even catalyzed urethanes. What's important is the "Bite" or grip the ALCLAD has on what you spray it over.
If your base coat color ( Black or clear - I recommend using clear over the black - I'll tellyou why later) is too dry, where the ALCLAD won't stick, or the ALCLAD hasn't dried long enough, in either case, it will rub off EASILY!! There is a window of time for the black to dry - never more than 24 hours, then it's too dry and the ALCLAD will, as I said, rub off - Redundance
Heat and timing are critical to successful painting and to the use of ALCLAD CHROME.
Paint and ALCLAD dont like the cold. Moisture is ALWAYS present when it's cold and any professional painter on this site will tell you that moisture and cold are KILLERS in any type of painting. Moisture mechanically and chemically change the product.
HEAT - I realize that probably most everyone reading this, unfortunately, spray outdoors, which is really the worst case senario, and there is nothing predictable i.e temperature, quality of STILL ( not moving ) air, dust free, etc., even a garage or shed is better, if availabe.
I have a small walk in spray booth that is heated, lit and ventilate. I've been building over 50 years now and got tired of dealing with all that
Anyway, at about 80 - 85 degrees, I seal the plastic with a good quality lacquer primer, I set it aside a week to off-gas and dry.
Next, at the same temperature, I shoot my Duplicolor gloss black lacquer. Three coats - light, medium and heavy. 15 minutes drying between each coat. Wait another 15 minutes and shoot a wet coat of Plasticote clear ( after my last posting on ALCLAD TIPS a lot more guys here are using the clear - refer back to page 6or 7).
At this temperature I shoot the ALCLAD 15 to 30 minutes later and can handle it within an hour without it rubbing off
. ( Because of the heat and timing, the ALCLAD has a "grip" and won't rub off)
If you shoot the ALCLAD at around 72-75 degrees, let it dry for a week before handling.
Don't clear coat it, as it will dull !!
I hope this helps. Any questions
I'll be glad to answere them.
All the best - Dave