Sunday, July 31, 2011

Slow cure

 The temperature is low the last few days, so my bottom sheathing is curing slowly.  I mixed graphite powder into the second coat of resin and there will be one more coat after I do some sanding.  I doubt that the graphite will make the hull any faster or the surface any harder, but it does retard solar degradation and can be left unpainted.
The outer stem laminated in place with long temporary screws to hold it while the glue cured.

I decided to start on the forward cross beam while waiting for the hull sheathing to cure.  I stapled some polytarp down on the table first because epoxy won't stick to it.  I measured out the stations and offsets and screwed down a block at each intersection.  This hollow box beam will have lower and upper chords consisting of two 3/8" (10mm) layers of Kauri laminated together so I'll have 3/4" (20mm) of solid timber on the top and bottom of the beam with solid block spacers.

7 comments:

Will said...

Wow,looks more excellent with each new set of pics, may be a silly question at this point but what do you think it'll carry weight wise?

Hajo said...

Hi Gary,
Looks good. The graphite epoxy DOES have a real effect. I have used the system on all my boats, thinking it couldn't hurt; and looked good. But I never had any REAL data to compare. On the last Florida 120 (This is a flottilla style raid event) I ran into a boat that had just gone through a rough Everglades challenge. It had the epoxy graphite bottom. That boat hit a crabpot in a bad way. It hit right on the waterline. The epoxy / graphite part was undamaged. The section above the waterline was badly scraped up. I am really convinced now that the graphite DOES help by sliding over stuff instead of allowing obstacles to get enough of a hold on the bottom to scrape.

Hajo

Wade Tarzia said...

I use epoxy-graphite on the bottom of my outrigger and overlap it a little up the sides as Gary did in his photo. Not sure about hardness -- it does seem to get scraped as easily as anything else -- but the graphite is sacrificial and comes off as it slides over rough things. You can see the black streaks it leaves. And yet it has not worn through to the weave of the glass except in spots that took a bad pounding (I launch on a corrugated cement ramp and surf can make a rough momentary landing). I will continue to use it -- easier to touch-up than paint too!--Wade

Gary.Dierking said...

The va'a motu hull will carry two adults and enough camping gear for a few days. The forward half of the hull is much the same as Tamanu. I have carried four people in the Tamanu with a lot of wind but did not enjoy it.

Hiro C. said...

Is tht a hole on the side of your hull ? Self bailing system ?

Gary.Dierking said...

Yes, there are four holes (scuppers) to self bail the cockpit. I can leave the canoe on a mooring and not have to bail every time it rains.

sandhiya said...

Hey, nice site you have here! Keep up the excellent work! Solid Timber