[Public-List] Mast Beam Failure on #133

[crufone at comcast.net]

Hello all, 



On my boat the failure of the mast beam has been the failure of the original Resorcinol glue and not the wooden components of the beam.  I know from experience that as Resorcinol glue ages it crumbles into a grainy powder.  When the beam was in the collapsed position I could actually see light through (between) the laminates. 

In a discussion with Philip Beigel Sr. in 2004 he told me that was possible to remove the mast beam because that on the early boats it was basically bolted to the main bulkhead.  There is some tabing but that is easily cut and removed.  This discussion encouraged me to persue the removal, repair and replacement approach to this issue. 

Since the Resorcinol glue had failed and become brittle I felt that the laminates on my boat could be separated once the beam was removed. 

I have done some tests while sailing and using measured reference points have determined that the entire beam does not flex/move downward in my boat.  Rather it tends to 'flatten' in the middle, (as between the door jambs).  This also suggests that the beam as a whole may not extend in length athwartships. The failure of the glue allows the laminates to slide against each other and the beam to loose it's arch. As the arch flattens the rig loosens. 

This observation leads me to question if the 'cleats' added to the bulkhead jambs to increase the surface area supporting the beam at that point have much of an effect on mitigating the flattening of the center of the beam. Hummmmmmmmm.... 

As I am removing my beam I will inspect carefully the bolt holes in the bulkheads to determine if the beam has actually elongated the holes and moved in relation to the bulkhead.  If not, then the task is to retain the arch of the beam, particularly in the span between the door jambs. 

I assume this can be accomplished with metal, adhesives, mechanical 'keys' or a combination there of added to the original or a replacement wooden beam. 

I know that the aluminum plate sistering method is a time tested and durable repair.  I also don't wish to be irresponsible and use a method which is any less durable and sea worthy.  I also don't question the fact that the aluminum plate method is a relatively efficient way to affect this repair. What I don't appreciate is what it does to the appearance of the interior of the boat. 

Perhaps I am just a frustrated plastic boat owner who wished his boat were made of wood!! I believe that the original mast beam was engineered well enough. The glue failed and I can replace the glue with a stronger more durable adhesive and she can sail on with that minor modification for another 43 years. 

Michael #133
 1263230866.0