Touch upâs should be done minimum 4-6 weeks post the initial treatment. This allows time for eyebrows to heal fully before perfecting them for the second time. Free touch-ups are only valid up to 3 months from initial procedure date.
Re: The Tinny sound? Most folks that are concerned about a tinny noise with aluminum boats are referring to the noise generated by the hull moving through the water (which can be modulated/reduced through many different avenues). You mention vibration and rpms, so I'm guessing that you're not referring to that sound.
How loud is your tinnitus? Extremely mild, I hear it only in silence and/or when plugging my ears 14 vote(s) 3.8%. Mild, I hear it in quiet-ish conditions, but most everyday sounds mask it 71 vote(s) 19.3%. Moderate, I almost always hear it, however tv/music/outdoors noise can mask it 157 vote(s) 42.7%. Intrusive, I hear it always and nearly above everything, barely nothing masks it 121 vote(s) 32.9%.