I have a question concerning an article that appeared in the July 1994 issue of Model Railroader. The article is titled Easy Renumbering for printed cars and locomotives by Rudolf Slovacek (page 108) The article talks about removing numbers from cars with an abrasive cleaner (such as Comet or Ajax) and replacing them with new number decals. The question I have is if the method described in the article can be used with all makes of HO scale cars or with only from certain brands. I am interested in renumbering certain types of freight cars for my model railroad. Specifically Athearn’s 57’ PFE Mechanical Reefers and Accurail’s series 2000 ACF 3-bay covered hoppers for UP, MP and WP. ( I am modeling Union Pacific’s Eastern Idaho Division circa 1990.) If you could provide me with any information I would be greatly appreciative.
Alan
Yes it should be usable with most freight car kits (The cars Mr. Slovacek used were Athearn ribbed side cars) that article was listed in Freight Car Projects and Idea’s.
I cannot vouch for HO, but I have used the process on Micro-Trains and Atlas cars and KATO locomotives in N scale
Another way of removing is to use a cotton bud lightly dipped in metholated spirits then gently rub the decal you wi***o remove.
As always check that the meths does not affect the plastic, though in 20yrs I have not met any problem.
I prefer using “soft scrub”,without bleach. It isn’t as harsh an abrasive as comet, or ajax. Decal setting solutions sometimes work very well, and sometimes a “typewriter eraser”, the kind that can be sharpened in a pencil shapener,also works. A little soft scrub on the tip of the finger can poli***he area to restore the shine prior to applying decals.
Be careful with metholated spirits on Athearn numbers. It can remove the paint AROUND the numbers leaving the numbers untouched. Don’t ask me how I know this 
I’ve had good success with Denatured alcohol, which can be purchased at a hardware store. I’ve renumbered several atlas and kato engines using this method. Use a cuetip and just rub slowly and with moderate pressure. Be careful not to saturate the cue-tip: a little goes a long way. Some numbers come off easier than others, but it works. Good luck.
Alan. Good Question! No matter how you do it, you may end up repainting! Denatured Alcohol and a Q-Tip, 400 or 600 Steel Wool, for Laser Print or Painted Lettering. Solv-A-Set, will remove regular decals. And, if you want to start from scratch…soak the whole car body in Hexol, until the paint starts to peel. Scrub off with running water, and dish soap, using a tooth brush. Works for me! And, Hexol, won’t “eat” the plastic! Don’t use Brake Fluid, or Oven Cleaner. It’s not only rough on your skin, it will also melt the plastic!