painting problems

There could be several solutions to your problem.
1. Did you wash the model prior to painting to remove all oil from the molding process and from handeling the model?
2. Was the paint properly cured prior to masking? Testers silver takes several days to cure and dry.
3. Did you use low tack tape or plain masking tape? Always use low tack tape when masking over metal colors. A great masking materal is wet paper such as newspaper. When wet it will stick like tape and is much easier to remove.
Check some of the other replies on use of metal paints and masking found in other areas of the forum. There is a lot of good advise on masking

I've never use Testor's gloss enamel silver, but I can tell you for a fact that Testor's chrome silver comes right off if you try to mask it. You might try a protective clear coat over the areas you want to mask prior to applying the tape. I am also told that SnJ spray metal is impervious to tape.
Good luck!

My experience with the various enamels, like Testor's silver, is that they are best for details. They seem to never completely dry, and like other gloss enamels, they form a dry skin that slows the drying of what's underneath. I assume the kit you're working on is the Trumpeter, and I have heard that they are very liberal users of mold release, so that may be your non-stick problem. I can recommend SNJ for aluminum, and many modelers are saying good things about Alclad. There is also the Tamiya silver spray, which is reportedly very durable after the two weeks cure time is up. If I had an overall aluminum subject in a large scale, I might even use an aluminum enamel like Testor's, since the drying time is good, and the slight graininess is not a problem in the larger scales.