Malahini side planking question

Designs for inboard or outboard power

Moderator: BruceDow

Post Reply
Posts: 54
Joined: Sun Dec 30, 2012 3:39 pm
Location: Mount Pleasant, SC

Malahini side planking question

Post by obd » Thu Oct 12, 2017 4:44 pm

I have a big weekend planned. The framework is faired. Side panels have been rough cut, joined, and dry fitted. Stem to transition joint properly trimmed and fitted. Today I purchased a small can of extra slow hardener(West 209). All that is left is to glue and screw. I really don't want to screw this up. My plan is to clamp the side planking in place and begin driving screws starting at the stem and working aft down the chine and the sheer equally. I have a ratchet strap to pull the planking snugly to the transom. To those who have already walked this path, have I left anything out, is there a better approach, can I be confident the screws won't cause the "skin" to creep out of alignment, is there anything I should do to prevent the creep? I know some builders advocate for few to no screws but I am planning to use screws approximately as directed in the plan. Any and all advice appreciated! Bob

User avatar
Posts: 3376
Joined: Wed Apr 15, 2009 7:36 am
Location: Indy

Re: Malahini side planking question

Post by vupilot » Thu Oct 12, 2017 5:19 pm

Is your planking already scarfed together into one long piece per side? I actually would suggest starting at the middle and working toward the bow and stern.

I did not pre join my forward and aft panels. I first installed the aft half and then the forward half. I butt joined the plywood in the middle with a butt-block and screws. Even before that I spent a lot of time clamping, marking, trimming, screwing in place, remounting so that I wouldnt have to trim it much once installed with epoxy which I thought might be awkward. The ratchet strap and hot towels soaked with boiling water helps on the bow and stern where the curvature is most pronounced. You may not be able to fit and install them in one weekend and this isn't a step to rush. It often needs to be bent halfway and left overnight to "learn" the new shape so it can be bent the rest of the way without cracking.

The bow area requires a lot of fitting and trimming. It helps to not trim all the excess away in areas like the bow and stern where you might need some extra leverage but not trimming enough can also make the panels harder to bend.

Posts: 697
Joined: Mon May 11, 2015 12:52 pm
Location: McKinney TX

Re: Malahini side planking question

Post by Hercdrvr » Thu Oct 12, 2017 7:05 pm

I wish a had some magic technique to share with you but I mostly remember muscle and anger were the best tools for the job. Seriously, I used steel screws to dry fit the panels then came back and glued / screwed panels on. For me, the most challenging was the bottom bow panels. I had someone hold the panel up in the air at an angle so I could secure the forward area along the stem and chine with no spring tension on the panel. Then I layed it down along the keel. Worked good except it didn’t lay down exactly along the centerline of the keel. I had about 3/8” gap between the bottom panels 8’ Back on the keel. No biggie, just poured in some poxygrip.

Have fun,
Matt B
Gap along the keel

Post Reply

Return to “Power Boats”