2006.12 “White” Black Pearl: Setting up forms, stems and cutting strips.
Mar 14th, 2007 | By Dan (CSFW) | Category: 06.12 White BP (NC)
Construction started on Saturday March 10, 2007 on John’s BP by setting up the strongback and cutting out forms. This project is very similar to the last BP, built this winter. See those posts for more information.
Bjorn supplies full-size patterns for the forms. They were glued directly to the plywood, cut out and mounted to the same external strongback used on the last Black Pearl. The internal stems were cut out of red cedar and attached with hot glue.
The tablesaw was then set up for ripping strips. Two 7-1/4″, carbide, thin-kerf blades were installed on the arbor with a spacer between them set to cut 3/16″ thick strips. To speed and aid the strip cutting a small powerfeeder is being used. Set over the blade it feeds the stock at a constant rate into the enclosed blades while keeping the stock down to the table and tight against the fence. This is much safer since the blades are completely enclosed an produces very uniform strips. About 30 linear feet of very clear, 5/4″x6″ western cedar was turned into 3/16″ thick x 1″ wide strips in less than an hour.
Stripping of the hull starts tomorrow.
Hi Dan,
I don’t believe that I saw the stem form on the last build. Can you elaborate on how exactly it is set up and what it involves?
Thanks,
Bryan
Hi Bryan,
Check out the post from the last build:
http://clearstreamwood.com/WordPress/?p=13.
Click on the image for a bigger version. The same pic is in the gallery:
http://clearstreamwood.com/WordPress/wp-gallery2.php?g2_itemId=148&g2_page=9
“… I ripped a piece of 4/4 western red cedar in half (about 3/8″ thick), cut them to shape and hotglued them onto the forms and strongbacks. Small plywood spacers were used to raise the stems to the correct position (scaled off the plans). The stems were beveled for the strips with a block plane.”
I got the rough shape by simply scaling it off of the plans. The tips are held in little cradlea made of scrap wood/plywood screwed to the strongback to keep the tip in alignment and to elevate them to the correct height above the strongback. Daps of hotglue are used to attach it to the other forms. It’s worked well on both BP’s built so far. The stems could have been made out of a hardwood or marine plywood.
Hope I explained it well enough,
Dan
I think I understand. That bigger picture really helps.
So, essentially, you’re just setting up all the cross section forms and skipping a plywood stem form. I imagine that this could be used in any type of kayak build.
Is the strongback simply mounted on a 2×4 or is that a boxbeam of some type?
You got it. It’s the method that Bjorn uses. You should be use it on any kayak built on an external strongback (SB). I don’t know how it would work with an internal SB. I like it. I always found removing the plywood end forms a bit of pain. You get to leave the inner stem in, which adds a bit of strength and you can glue the strips directly to the stem.
The strongback is also similar to what Bjorn uses. He makes his out of long 4/4 stock. I didn’t have any nice boards that long so I laminated some strips of 1/2″ fir plywood with glue and 7/8″ staples. You bring the ends toegther and it ends up having a shape similar to a kayak. It’s a bit easier to work on the boat. The 2×4 you see is my old 1/2″ plywood boxbeam internal strongback that I normally use. There’s no room for an internal SB in the BP. The decks are too low. I found the external SB a bit floppy so I attached it to the internal one with a few screws. The combination is a light, rugged, dead-flat strongback. I like it. If I ever need my internal one I just need to remove a few screws.
Dan
Bryan,
More info/pictures from the last build:
http://clearstreamwood.com/WordPress/?p=9
Dan
Thanks, Dan! Excellent info.