When a person is lucky, they were born under the right stars, by which I mean that their luck is with them throughout their life. They have always been lucky and will always be lucky.

When a person gets lucky, their success in some particular thing is to be attributed to luck, to some fluke, not to their skill or their innate power or their innate virtues. Only the unlucky can get lucky.

He made that shot from half court!
--He just got lucky. He can barely make a free-throw.

He came out of that accident unscathed. He won the lottery last year. He was promoted to VP in only two years, and his wife is one of the most intelligent, beautiful, and accomplished people I know. He may be the luckiest guy on the planet.

1. the luck is continuous, the painter is often lucky. (To me it also possibly means the speaker doesn't necessarily think he earns it, or the painter would not need luck. We'd need to hear it to know for certain or have it in context.)
2. This (to me) sounds like the luck, is undeserved. (Again context -- it could be meant very well indeed.)

Or, "He is so lucky (to have won the lottery)!" Or, "He got lucky last night with the girl he met at the party." This means he had sex.