Centerboard Trunk Assembly

[mdevour]

Hello again, everyone. The last week and a half Alegra and I have put in a lot of time on our Weekend Skiff (http://www.eskimo.com/~mdevour/boatproject.html) project. We've nearly finished carpentry on the hull and are trying to get ready for the fiberglass work.

I think I've made good use of the many wonderful suggestions I've received here. I promise pictures and a progress report Real Soon Now(tm)!

Meanwhile, I'm planning to start final assembly of the centerboard trunk tomorrow. As always, I still have a few questions about it. I'd appreciate any comments, questions or criticism. Don't assume I know anything, please!

A picture is worth a thousand words. This shot is from a while ago and doesn't show any of our recent work:
http://www.eskimo.com/~mdevour/other_pictures/trunk.jpg

Remember it's a 16 ft. plywood skiff. That trunk is about 10 inches tall and 20 inches long, and will be bedded in 3M 5200, held down with about a dozen bronze screws from below, and braced by a thwart.

Seeing as I'm new to 'glass work, I'm planning for us to do the trunk slot, centerboard, and rudder fin by way of rehearsal for the hull.

I plan to glue up the trunk parts leaving one side off, apply and fill the cloth on the insides of both halves, then assemble them for good. Once things are set up but not fully cured, I'll run fillets in the corners of the slot with thickened epoxy.

This will leave me with a nice assembly ready to bed to the keelson.

First question that I can think of is should I glass over the trunk to keelson joint in the slot after assembly? Or should I glass inside the hole in the bottom and keelson separately, leaving the 5200-filled seam exposed?

Lastly the hull gets 'glassed, so the trunk mounting screws are (hopefully) permanently entombed in epoxy. I take it this assembly is intended to be pretty much permanent. If it ever needs repair or replacement, it'll call for some destructive disassembly.

It seems like it should be a relatively simple job overall, but am I looking at it right, or missing anything that you can see?

Thank you again, folks. I can't begin to tell you how much of a difference your input has made to our progress. I hope the pictures I'm taking tonight will help show you, though! smile.gif

Peace,

Mike

[ 04-14-2003, 03:15 PM: Message edited by: M. G. Devour ]

[Carl Simmons]

My CB trunk mounted similarily and I decided to glass over the joint so that no seam edges were exposed.

Here is a pic of what I mean:
http://www.imagestation.com/picture/sraid60/p12dea4c22c92109ef9fff7f484f539b7/fc5682fc.jpg

I wouldn't work about disassembling, the 5200 will pretty much require destruction to seperate.

Carl.

[mdevour]

Originally posted by Carl Simmons:
My CB trunk mounted similarily and I decided to glass over the joint so that no seam edges were exposed.Thanks, Carl. I suspect this is one way to do it, but I haven't found a whole lot of help searching the archives. A couple of others describe doing it this way, but no detailed discussion of alternatives.

If that's the consensus, I've got no problem with it! :D

I wouldn't wor[ry] about disassembling, the 5200 will pretty much require destruction to seperate.Yup, get out the saws-all! :eek:

Be well,

Mike

[Don Maurer]

This is just supposition, so take it for what it is worth. If you fiberglass up inside the slot, constant movement of the centerboard may begin fraying the edge and, over time, allow water to get under the glass. I don't see where the extra strength of the fiberglass is required on the joint, so why not just coat the assembly with several coats of epoxy? On the bottom, I would feather the glass as it approaches the centerboard slot, and add extra coats of epoxy around the slot for protection.

[mdevour]

Originally posted by Don Maurer:
... constant movement of the centerboard may begin fraying the edge and, over time, allow water to get under the glass... That's something to consider, Don. I'm 'glassing inside the slot at all as an attempt at abrasion resistance. I guess I will simply need to keep a close eye on it for any such signs of wear and catch them early.

We're working on the boat tonight at the school. I've got the second coat of googe on now. One more to go, then assemble the halves and fillet the corners. It seems to be going well enough, considering how little I know about what it's supposed to be like. :D Gotta learn sometime, I guess!

Lots of other little things getting done between googe sessions. Pictures soon!

Be well,

Mike