I’m not sure how much this will help, Dan, because the last time I used Rub 'N Buff, the experiment was less than satisfactory. I was building a Monogram B-25J and figured that I would at least try the stuff. In all fairness to the manufacturer, I purchased my Rub 'N Buff from a craft store which was closing shop and it was discounted to less than a dollar, so there is no telling if I purchased some really old stock which had gone bad or what…this would have been right around 2000?
Anyhow, the stuff came out of the tube about the consistency of toothpaste, so I place a very small dollop onto an old t-shirt and began to apply the wax onto sprues from the kit. It looked fine, so I put it away and spent a bit of time polishing the bare plastic of the completed model so that the metallic paste would not exaggerate any flaws I may have left in my work. To vary the appearance of the control surfaces, I masked them off and airbrushed some Tamiya primer over the fabric areas which would have been doped. I applied the Rub 'N Buff to the model and that’s where things went bad in a hurry.
It was a pain in the rear to spread it all evenly on the model. Even wearing latex gloves, I managed to leave fingerprints wherever I handled it. In buffing it, the wax would lift, leaving swirls and marks everywhere. It took the better part of several hours to get everything to the point where I was convinced that it was just “good enough” for the time being and I set it aside to dry and cure, even though it was about the same effect as using a silver Sharpie marker on the plastic. After a week, once I had my patience back in order enough to look at the model again, I went to pick it up and left fingerprints all over the bloody thing. The wax just never seemed to cure. In fact, it seemed to transfer everywhere without any real effort - the clear parts, the work table, my clothes, everywhere…if you’re looking to remove it, I can tell you that 98% isopropyl works fairly well, but requires multiple applications.
I tried to place a decal just as an experiment, so I brushed a little Future on the wing. That created a huge mess and caused the silver finish to turn a sad grey color. The control surfaces that were primed for a bit of variation were sort of a brighter grey, but the wax never seemed to want to adhere to the primer very well. In hindsight, spraying it black would have kicked the metal effect up quite a bit, but the grey primer just seemed to rob it of a real metal effect. Utter disaster, so I purchased a new kit and this one was given to the neighbor’s kids for demolition by fireworks. While the plane burned, I watched the Rub 'N Buff literally melt and pool like a silver crayon. I’m not entirely convinced it ever really set up.
For me, it just wasn’t a pleasant experience and I have never touched the stuff again. My heartfelt advice to you is to try it out on a very inexpensive model before you take it to a project you’ve invested a lot of cash and effort into.