[Public-List] Public-List Digest, Vol 1701, Issue 2

[David Tessier]

Charles,


I did my beam in 2009.  Despite the information int he Alberg 30 Manual (which includes a single plate way not to do it!), I considered beam strengthening a custom project.  So I spent some time to make custom patterns from 1/8" plywood for the fore and aft aluminium plates respectively because:

- the fore and aft surfaces differ, including small differences/imperfections in the tabbing

- I wanted to get in as much metal as possible without crushing the slightly irregular tabbing.

 

After discussing the cutting with a couple of machine shops who wanted a digitized shape (to do my pro bono job), I decided to cut the aluminium with a reciprocating jigsaw with proper metal cutting blades and, importantly, oil or water as a coolant/lubricant. The cutting went well, although I am rather stubborn ;-).  The resulting plates fit perfectly without the fiddling which would be needed with templates from another boat (see Alberg 30 Manual).  After careful dry fitting (and refitting), I sanded and degreased the plates, carefully etched/pretreated/rinsed the mating surfaces of the aluminium plates, and epoxied + bolted the plates in place.

 

Give me a shout offline if you want any more details (e.g. my treatment of a couple of existing bumps on the beam surfaces) or pictures. 

 

Cheers,

 

David

TROIS BOULEAUX #319

P.s.: I also upgraded the chainplate bolts and installed thick backing plates; and installed a fixed custom gooseneck.
> 
> bikecharles wrote:
> > Thanks to all who provided input on my last inquiry about the mast beam. I'm still pondering the best approach to repair the mast beam on Sea Hawk #221. I've contacted the outfit mentioned on the A30 website about the Aluminum Sister Plates for the mast beam. They've become a bit pricey these days...$420.00 before shipping. Considering the simplicity of the repair and the relatively low cost of the raw materials, (about $145.00 for for the Aluminum),it would make sense to fabricate them myself. Does anybody know of an existing pattern or schematic for the plates. Additionally, I was curious if those that have done this repair removed, repaired or did anything to the old tabbing on the beam or is it just left and covered? 
> > Thanks again
> > Charles
> > Sea Hawk #221

 		 	   		  
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