Hanging knees

This is the place to post your ideas, thoughts, questions and comments as relates to general boatbuilding and reconstruction techniques and procedures (i.e. recoring, epoxy, fiberglass, wood, etc.)
Post Reply
smcgrath67
Bottom Paint Application Technician
Posts: 12
Joined: Wed May 29, 2019 2:00 pm
Boat Name: Leah Mae
Boat Type: C&C Corvette
Location: New Hampshire

Hanging knees

Post by smcgrath67 »

In the course of the refit of my C&C Corvette, I discovered that the chainplates hanging knees were soaked and rotting. I cut them out and I'm now making new ones out of oukume marine ply that I had leftover from a previous boat build. How thick should the ply be for the knees? I have some 3\4 inch stock. Is that enough or should I laminate two pieces to be at 1.5 inch?
Thanks!
Sean
svMira
Master Varnisher
Posts: 104
Joined: Wed Aug 08, 2018 10:16 pm
Boat Name: Mira
Boat Type: Pearson Wanderer 30
Contact:

Re: Hanging knees

Post by svMira »

What was the original width and material? That's be the starting point.
Marvin - s/v Mira - 1971 Pearson Wanderer #174
svmira.ca
User avatar
atomvoyager
Moderator | Revitalizer of Classics
Posts: 421
Joined: Thu Jul 12, 2018 7:48 am
Boat Name: Atom
Boat Type: Pearson Triton
Contact:

Re: Hanging knees

Post by atomvoyager »

I'm rebedding the chain plates an a Cheoy Lee 33 now and the knees, including the f-glass over the wood, is only about 1.125" wide. I usually make them 1 to 1.5 plus glass. 1.5 is probably overkill and doesn't matter in most cases either way. Depends on how well you glass them in and the strengths of the deck, hull, or shelving or anything else they are bonded to.
User avatar
atomvoyager
Moderator | Revitalizer of Classics
Posts: 421
Joined: Thu Jul 12, 2018 7:48 am
Boat Name: Atom
Boat Type: Pearson Triton
Contact:

Re: Hanging knees

Post by atomvoyager »

After looking at the video linked below I recall using 1" to 1.25" plywood plus fiberglass in most cases. If I was using 3/4 ply I would add twice as much glass rather than the two layers of medium weight I normally use.

https://www.youtube.com/watch?v=LnAsYbcRJds
Post Reply