Comparable timber strengths

[Jordan Balbresky]

I am moving along in the construction of my tiki 30. Getting ready to put the decks on hull #1. when purchasing my lumber I left out the hardwoods as I knew some could be procured locally. When putting together the deck beam support boxes can mahoganny be used instead of oak. I know it is less dense, but I've been told by several wood workers that it is comparable in strength for that purpose.

[Jordan Balbresky]

Nevermind I figured it out...can anyone instead tell me why the materials list and actual plans never seem to match? 20x70 deckbeams instead of 25x45??? Pretty costly error for a freaking typo! And why is bulkhead 5 not even close to the right dimensions on alternative starboard hull?

[boatsmith]

IMO there aren't any places where oak would be my first choice on a Tiki. I might think of some later , but none come to mind. Mahogany should suffice for all of your needs. Good clear doug fir is also suitable. Where you wish to leave the wood raw or oiled it is difficult to surpass teak. Just my opinion. Oak also has tannins in it which will deteriorate epoxy over time.

[boatsmith]

Hi Jordan,
I read your post again and noticed that you are building the support bkes for the beams. I used plywood for all of these parts. I did change to the lashings instead of the straps and am happy I did. I only heard negatives about the straps. I just uploaded this photo and looky there, I used teak at the top of these boxes. The plans do call for a hardwood block and I followed them. I don't believe it is neccesary or even as strong as plywood. I generate a lot of teak scrap with my carpentry work and that is why we used teak instead of mahogany or fir.
David

[Jeff Kittle]

I have had mahogony split/snap on me. Sometimes it seems hard but brittle. If there is much stress against(with) the grain in Mahogony you might put 2 layers together with perpendicular grains.