Looks like a great solution.April 18 2007 at 9:49 PM
Curt in Portland, OR (Login Commander1)
Response to My solution to cracked engine stringers has arrived !
Thanks for your note Paul.
In addition to being strong, those engine beams will look pretty cool after your retrofit repair. Gosh, it would be tempting to paint the wood first, and then add the aluminum pieces and leave them shiny.
You may want to give a little thought to roughing up the hidden side of the aluminum and the mating wood surfaces with course sand paper, and install the plates using a bit of "PL Polyurthane Construction Adhesive" between the aluminum and wood (Home Depot, about $4 for a calking gun sized tube). That stuff is kind of like a cross between Gorilla Glue and Liquid Nails, and would really make a nice connection that would add a decent amount of shear strength between the materials. Then as you said, add plenty of fasteners -- perhaps a combo of thru bolts and stainless screws that don't quite go all the way through. Just as with pressed-on plate connectors installed on the 2x trusses used in residentual and light commercial construction, many small connectors result in huge shear carrying capacity.
And I know you will fill that crack with glue first and clamp that sucker until cured. And one or two 9/16 or 5/8 bolts installed top to bottom through that cracked area with fender washers on each side wouldn't be a bad idea either.
Anyway, whatever you do, I know it will be a quality job, and we will all look forward to the pictures of the completed project.
--- Update on Portland ----
The weather was warm here a couple of weeks ago and the lawn took off growing like crazy. But we have had a LOT of rain (and even hail storms), and the temps have really dropped (mid 30's at night and mid 50's in the day). I have 3 acres of lawn at my place to keep mowed, and there are numerous places where I just can't run the mower due to surface water and soft ground. I have a 51 hp diesel powered 4WD golf course mower (that's right, 51 hp!), and I even managed to get that thing burried to the frame out there one day and had to drag it out with the tractor! The lawn in that area is totally destroyed, and I will have to add topsoil, regrade, and replant lawn when the weather permits. With things so wet and cold here, as you can imagine we have not been too enthusiastic to do much boating recently, and are patiently awaiting more summer-like weather.
So our Chris Craft is sitting quietly waiting. Jim has been working on a couch/bunk that will fit in the main salon (lower wheel house) -- it will be installed along the starboard bulkhead below the windows, and will fold up vertical below the windows when we want it out of the way, or when we need to pull the engine hatches. The cushion will simply be a black futon mattress we bought. So the matress will form a seat and back for sitting or single sleeping, or it can just be dragged onto the deck for double sleeping should we ever need that. The wood Jim used for the structure is original CC mahogany plywood that at one time was one of the bunks in the galley cabin (Sport-Fishers had bunks rather than a dinette, but our is retrofitted with a dinette that makes into a bed). I fabricated some custom designed steel brackets to support the new couch structure from the starboard bulkhead. I will post pictures when we get it installed.
Best wishes, Curt...
1967 fiberglass 38' Chris Craft Commander Sportfisher with twin 427 CID 300 HP engines.