Still Life of Vacuum Cleaner?

Dear Rich: I'd like to create still-life oil paintings (and prints of them) of objects that have been commercially produced. I intend to blur or render vague logos or other trademarks on the objects in the course of painting them. Is a painting of a functional commercial object inherently transformative, as it completely changes the intended use? Does it matter (or help) if the design patent has expired for the object? As a couple of examples: a still life painting of a 1980s VCR machine (expired design patent, no longer marketed) vs. a still life painting of a Dyson vacuum cleaner (still under design patent, actively marketed)? Turning commercially produced objects into "art" -- particularly if you blur the trademarks -- is unlikely to trigger legal action.
What about copyright? Copyright protects aspects of industrial designs that are separable from the functional object -- for example, a three dimensional design from a belt buckle, or an image silk screened on a car trunk. In the objects you describe --  a VCR or a vacuum -- the function and the form are inseparable and therefore unprotectible under copyright. (However, you might be infringing if you based your painting on someone else's copyrighted photograph of the Dyson.)
What about design patents? The presence or absence of a design patent doesn't matter. You would only infringe Dyson's design patent if you sold competing products that looked substantially similar.
P.S. Dept. We clean the Dear Rich headquarters with a Miele, not a Dyson, so we had to use that for our rendering.