[Public-List] Mast Beam Repair

[crufone at comcast.net]

Jeff Fongemie, 



If you plan to change the species of wood for the mast beam I believe that the on-list consensus would be to switch to Ash and not White Oak.  It was explained on-list that the Oak family of woods are and remain acidic which degrades any glue or adhesive used over time. 


It has also been suggested that the laminates be fashioned to be vertical versus the original horizontal. Slots or grooves should be placed in the faces of the laminates to allow the adhesive to act as a 'key' to help prevent sheer failure of the adhesive, though this would not be as prevalent in vertical laminations. 



Another owner suggested that a vertical plate of metal or 'flitch' be used as the central laminate in a vertical arrangement of wooden laminates.  Another variation would be to lay up the laminates with fibreglass cloth between the wooden components. 

Still another suggested wrapping the original horizontal laminates with fibreglass cloth in at least three locations while laying them up with Epoxy resin. 

Something referred to as G-30 Epoxy mfg by Gougeon Brothers was considered to be the adhesive of choice. 

Jeff, this is a summary of what folks on-list provided over a short period of time when I presented the idea of removing and then reusing the original mast beam.  I plan to digest this information and try to incorporate all the best ideas to affect my repair. 

Michael #133 


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