Can you reinforce a steel hull houseboat by "fiberglassing" the exterior of the hull? Pros/cons to doing this to the hull. The boat in question is a 1972 River Queen. Before glassing the hull, I plan to have it sandblasted, bad areas cut out and replated, and primed. I will also clean and prime the interior of the hull as well. Thanks for any info, advice in this matter.

Better to replace the bad sections, sandblast and do 2 coats of Coal Tar Epoxy.

OHB is right. Just replace bad sections, sandbalst, 2 coats coal tar epoxy. Should be good for 5+ years. Forget the fibreglass. You'll create a nightmare.

Interesting to read the responses to the question.  A year ago (seems like yesterday) we purchased a 1966 steel hull houseboat that had been fiberglassed over.  Had no idea what we were getting, but the boat was a great price.  Since we have never owned a houseboat and had no knowledge of steel hulls, we went into the purchase blissfully ignorant.  We have been keeping a close watch on the bottom and so far all is well.  The fiberglass job seems to be holding up OK.  Don't know what the future holds though.  Anyway, we have spent this year renovating the interior of the boat.  I'll post a new topic with before and after photos. 

Steel hulls are usually glassed when the bottom looks like a sive to get a couple more years out of her. Bad idea to glass a good bottom.