Mark1977

I was trying to remember, I think they are 3/8 or 7/16. Drill the hole the same size as the bolt, or maybe 1/16 bigger, then you can hammer the bolt thru. Drilling that ferro is not easy or simple. If you can find the verticle 'rebar' reinforcement poking thru at the top edge of the gunnel then you can use that as a guide for where not to drill. Keep aware, the angle that your bit goes thru the cement will greatly affect the angle the bolt goes thru the wood. My appologies if your on metric.

PART 5:
I actually had to completely secure the outboard planks to trace the scuppers, then remove the planks, jigsaw the scupper holes, and re-attach the planks...pain in the arse but definately worth the result.

You could go with a thick ouboard plank and not use an inboard plank then you would have enough top wood surface to secure the top cap. However, in my opinion, I wanted to beautify the ugliness of my gunnel and completely encapsulate, and , I really believe this to be the strongest method.

Reply if you have any more questions. BTW, I could not have attached the ouboard planks with the boat in the water.

PART 4:
Inboard, I ripped a 4" plank into (2)-2" planks. THese I did not have to steam, and I, one bolt at a time, lined up with and secured with the same bolts as the outboard plank. Essentially I sandwiched the cement gunnel between the Sapilli, combined the thickness is 3". I am currently in the mid east and the boat is not finished but The top cap will be 4" wide to cover the 3" wide base. I shall screw the cap into the Inboard and outboard planks to give the best strength. I routered the edges of the planks with a 1/2" curve with gave the planks a beautiful professional look. But I did not router the top edges of the inner and outer planks because I wanted to ensure the tightest fit with the top cap.

PART 3: The after section of gunnel is fairl straight but near the mizzen stays there was an aweful sharp angle which required me to use a full length plank to force the bend once steamed. I tried for a week to get it without steaming...waste of time. I cut a plank and hoped to form together over the bend but that was follie thinking on my part. In the end, steaming full length planks was the best and only took 3 planks per side(outboard).

PART 2: On the bow I used clamps and rope to draw and hold the plank in place. But I couldn't get the whole piece in place without putting in bolts to hold the tension of bending the wood. SO, starting at the bow I clamped the plank along the outboard side of gunnel and flush with top edge, then bent it as far as it would go and secured in place with line. I then placed 2 bolts furthest forward and about 24" apart. Once the bolts were in place I could increase the bend of the plank, adding bolts as the plank lined up with the top edge of gunnel, until the whole plank was secured. For the midships I had to steam bend the planks to get the right form, when these steamed planks were in place I had to work fast (with a helper) to drill the bolt holes in wood and tighten down the bolt before the board cooled. It was very successful. I could not pre-drill the bolt holes in plank becasue as you bend the plank it would misalign.

Hi, Mark, thanks for leaving a message. I love my boat and enjoy sharing my experiences. As you know, our boats are very similar, mine is a design cross of C-Bird and C-Shell which was a part of the engineered design by Samson.

To your question: I thought long and hard on how to do this and sought advice as well. My boat has a 2" tall gunnell x 1" thick, formed with cement. The boat originally had wood caps but were removed prior to my ownership so the bolt holes thru the gunnel were already in place (thank the Lord). I chose Sapilli Mahogany for the wood because it is strong, workable, beautiful and not as expensive as other Mahoganies, its a mid grade that is very freindly for marine application. I purchased 4" x 13' x 1" thick planks and selected the best grain and lines I could.