M_Boats: New Member Question Re: Centerboard on my M-17

I have a 1981 M-17 and the centerboard will not drop because it has rusted in place. After having taken it to two different marinas here in Michigan, with no luck from either of them on getting it down, I'm getting a little frustrated. One of them suggested contacting someone who owns a sandblaster. Does anyone have any advise? Thanks! Carol B