vrijdag 7 september 2007

Starting planking + question

Last weekend me and my twin brother Hans have been busy hoisting the two floats and a lot of wood for making the frames and strongback to my workshop. Then we made the strongback, and leveled it with a tube fillled with water. Last few days I've been busy setting up the frames and putting most of the battens in place. Just like Jay (see the links section) did, I put an extra batten in place to support the (future) plywood insert at the bottom of the hull.
The workshop is quite full now.

Putting the battens on the frames is quite straightforward, except in the bow section where the battens have to be twisted a lot. Tip for future builders: don't put battens in the 'straight section' just below the gunwale-line until you're finished planking the main bottom section. You'll have better access.

I made four 30 cm wide foam strips out of one foam panel and test-fitted one strip. It bends in quite easily without heating the foam. I use Divinycell foam in stead of the corecell most builders seem to use. Maybe corecell is more ridgid and doesn't bend this easily.

Just like Jay I wonder what benefit heat-bending the foam will have? As long as I can bend the foam without breaking and without much force, I don't really see the point in heating the foam with all the extra work and the risk of deforming it in not wanted ways. Any thoughts on this are much appreciated! For now I'll start heating the foam slightly in the first (lowest) curve and see how it goes. I heated the first test strip like this - but a bit too long on one spot which made a brown mark on it. No damage done, however.

5 opmerkingen:

Jay zei

Looks like you're building in tight quarters there. I guess it makes it more fun, crawling around underneath stuff. :)

Are you building the aft cabin model? Your aft-er form frame appeared a bit odd to me, like a mix of both?


Menno zei

Hello Jay,

Yes, the workplace it's a bit small but the best I could find (and afford). I'll have to keep things organized and tidy.

I'm building the aft cockpit version. One frame I build earlier (nr. 11) is just not cut off sideways but to the top of the frame, and that looks a bit odd. I'll cut it this evening.

Today I noticed the battens in the gunwale area in the bow section are at some point a bit concave. As far as I can see it should be a nearly straight line from frame nr. 1 to nr. 5, but there is a curve in the section between frames 4 and 5 (because the batten has to rise a lot in that section), and another to correct for that in between frames 3 and 4. It's difficult to explain for me as my english is not very good, but I hope you'll understand. Put a batten on frames 2-6 in the gunwale area and push down on frame 5 and you'll probably see what I mean. The batten won't lie in a straight line on frames 1-4, but will point up into the air a bit .
I wonder if I should correct this, or just let it be. Maybe I'll ask Ian, but first it would be nice to see if you've got the same situation.


Fram zei

Hi Menno, I think it's the opposite. As fas as I can see most builders are using Divinicell or simular. Advantages are much cheaper and a better fire resistance. On the downside it's more rigid than CoreCell. When you don't need to heat the foam, please don't. The only purpose is to get it in shape and to help the screws holding the foam in place without too much holding force, which is not too good in foam. About the tight quarters, well, I know what you mean ;-)


Jay zei


I didn't see this post until late tonight, so I'm replying without having checked the battens on my own forms. However, I do recall that there is a concave area near the bow. Note that the plans specifically mention this concave area (on sheet 9, right in the middle of the page).


Menno zei

thanks for the info on heating the foam. I will only heat the foam in the biggest curve, and only just enough to bend it in a bit more easily.

the plans state the bow section is a bit concave at the waterline, but I'm talking about the gunwale. I'll mail Ian to ask wether it is necessary / better to cut the battens at frame no. 5.

Meanwhile I'll continue stripping the foam (unfortunately not at the speed Jay manages to do).