u/Civil-Librarian-4274

Beam troughs can be a contentious issue for Wharram builders with many trying different modifications to ensure strength and longevity, and of course prevention of rot.
Our plans were drawn in 1972 so we opted to use more modern methods for the beam troughs under the guidance of a retired professional boat builder Pascal Petit.

We have built the first four now for the Bulkheads 1&6 — these sit aft and stern of both hulls — and it's been one of the most enjoyable projects so far!

Hopefully the video we made about learning how to do epoxy fillets and then use double bias glass cloth to reinforce the joins for the beam troughs can be helpful for others.

https://www.youtube.com/watch?v=I2aup60qR0U

We went with scarf joins for our amateur Wharram catamaran build, encouraged by volunteer professional boat builders who helped out and guided us to learn the skill. It took much longer than the normal butt block method as noted in the Wharram Designs plans for our 12m Narai Mk IV, but now I am pleased with the results.

We are documenting our entire build in videos to share the process — by no means does this imply we know the 'best' way to do anything, but we are taking decisions based on varying advice from experienced boat builders in France and the UK and keeping in mind we're on a budget and want to get the boat in the water in two years.

Do you do scarf joins?

https://www.youtube.com/watch?v=v9xG7ZSs3fw&feature=youtu.be