I do some sprinting and hill climb in my white MGB and I have been considering painting permanent black roundels on the car after which I would use self adhesive white numbers.
If it has to be painted you could get a sign/sticker shop to make a mask from low-tack vinyl, or frisket or similar. Remove before the paint is fully set up, a gentle waft from a heat gun makes the mask lift without drama.
same as. they are cheap enough from tweeks. Ive seen it happen on many a rally car where its had a slightly quick refinish that when the numbers are taken off before the next event, the adhesive is so strong on competition numbers, it has taken the top coat with it.
Nick
A few years ago I pulled paint off when removing the championship sponsor's stickers at the end of the season. So I know about using a bit of hot air.
Normally I polish the car doors just before I leave for an event, (I always drive there), in the hope that when I take the numbers off to drive home the paint will stay on the door.
I should say, that as a result of this site my painting has become much better and I would hope my more recent efforts would stay on better. So I would like to thank all the experts who generously share their knowledge on this site and the experimenters who share there problems, successes and failures.
The red oxide, Finnegan's number one etc have all been consigned to the bin in my garage
Normally I polish the car doors just before I leave for an event, (I always drive there), in the hope that when I take the numbers off to drive home the paint will stay on the door.