A Photo & Discussion Forum for Wharram Design Enthusiasts

Crossbeams

As I am building my crossbeams I came across one question that I cannot quite figure out:
I understand that the center crossbeam is open because it has holes for the dolphin striker, so it makes sense to put venting holes in the end caps as well for water to drain out.
The front and aft crossbeams on the other hand have no holes. Do you still make venting holes in the endcaps? Isn`t it better to close them off completely and get them water tight? If nothing gets in nothing must come out, no?
please comment, thank you
Ralf

Replies to This Discussion

Permalink Reply by Polinesio - Tarcisio Silva on March 28, 2009 at 10:26am

Yes! I Think so. Last year I made two crossbeams on this way, with no holes, for another 25' design. The old was take off just because in some parts of attachment this develop rot.
Tiki 30' is (stranger way) the single one Wharram cat with box crossbeams. All other designs is laminated wood or plancked wood.
If I build a new Tiki 30' I will recommend and assemble "I" (or "H") cross section as on my Tiki 21'.
Right now I begining to build a Tiki version with 34', but I'll use the combination "H" and "X" section, like on Tiki 46'.

good luck, Ralf.

Best winds!
Tarcisio Silva

Permalink Reply by Budget Boater on March 28, 2009 at 11:10am

I put 1/2" drain holes in the end caps of mine - well epoxied!

Permalink Reply by Steven Straughen on November 23, 2015 at 3:45pm

Just curious if anyone has any follow up on this? Would be interested to know if you have had any issues or wear and tear on your beams from either having drain holes in the end caps or having them sealed. Been a few years since it was discussed, so seems a good time to ask about longevity either way.

Permalink Reply by Ricardo Aráoz on November 23, 2015 at 5:59pm

Well you'll have a huge ammount of air locked up in there under the sun and the stars. That air will expand and contract every day, that means water INSIDE your beam that cannot get out. The designer specifies a vent hole with a breather tube in station 6 to vent the sealed buoyancy compartments under the floors, these are under water and away from the sun (so relatively stable temps) and if the designer thinks they need venting then we can imagine what will be the case with the beams which are under direct sunshine.