Mast Corrosion????

[andrewbowman]

We have looked at two Catalina 34s in California and both had significant mast corrosion at the step as well as other places.  Is this a common problem?  What can be done about it?  How much would it take to fix? 

[Mike Denest]

Gain access to the area in question.  Using those scotch brite pads you can use with a high speed rotary tool, sand away until you get to clean metal.  Since the mast is an aluminum extrusion, you will need to etch the cleaned area with acid etch.  Then prime and paint.  If you have, like I do, corrosion spots around a stainless steel sheet exit fitting as an example, remove the fitting and perform the process.  After painting and before you reinstall the fitting, take some chrome mylar tape and stick it on the underside of the fitting to act as a barrier between the two metals.  Untreated holes are the reason for the corrosion forming on aluminum.  What you can't see however is what is going on inside the mast