Sunday, September 23, 2007

Heat cure completed

It all went uneventful. The six thermometers had readings in the range from 51°C to 64°C (124°F - 147°F), the hotter on deck level of course, the lover approximately 5 cm below keel. I kept the heat on for almost 20 hours which is more than required.

I am satisfied with the way this turned out. Now it is fairing, attaching wing net rails and deciding on which version of the F-22 to build. Ian Farrier sure makes this difficult as he provides plans for four different versions, all of them really great boats. Olivers newly published pictures of his main hull made me think maybe I should make as much inner space as possible after all, the cockpit seemed roomier than I had expected and I sure live a place where it can be a challenge being outdoor, all year through!

4 comments:

Jay said...

Tor,

Nice job on your post-cure. This was a step that I chickened out on. (I figured that non-post-cured epoxy would still be stronger than polyester resin, so why spend the time.) I may reconsider for my main hull though.

Also, after post-curing did you notice any substantial difference in the "toughness" of the floats? I realize this is just seat-of-the-pants testing, but I'm curious. Would you please hit your floats with a hammer a few times, to see how they hold up? :-)

Jay

Grant said...

Hi Tor,
I have assumed that the time my floats have spent under a tarp outside has provided the 'not required but recommended heat treatment'. I admire your thoroughness.

Regarding Oliver's new pictures. What is that apparent compression strut in the forward V berth all about? Couldn't tell if this was replacing an missing anchor well, but I cannot see it in the plans.

That said the main hull picture is now on all my desktop backgrounds.

Tor Rabe said...

Jay and Grant!

Thank you for your kind words. I think it was more important for me to do this step thoroughly as the SP Prime epoxy (and also the slow hardener low viscosity Ampreg) requires this cure in order to achieve proper mechanical properties. The regular or fast hardener does not require this treatment.

The float was already very stiff before the heat cure, but it seems even more glass-like after. Tried to get a really sharp needle into a small bubble but the metal deformed and no visible marks in the epoxy. Sorry, I will not do the hammer test, but I have done on some not post cured scrap pieces. I am able to deform the laminate when using substantial force.

From what I remember the anchor well is made up of one molded part and one flat panel, I guess the "compression strut" in Olivers hull is the molded part, the flat panel still not mounted.

biol said...

Hi Tor.
I've seen you've added my blog to your "multihull links" list: thanks a lot !

I'm still waiting for the plans (ETA: 10 oct 07); your blog has been an inspiration for me, as Ed's, Grant's, Jay's, Menno's, Oliver's and Roger's.

Fair winds (and fair temperature, too ;-)

Biol
F-22 #70

P.S. If Oliver will choose to launch his boat in Northern Adriatic, I'll be there !