Background- P-P, cove and bead. Not staple free, but avoiding them where possible. I’ve done the sides and I’m at the chine transition. Between forms 7 and 11 (ish) the first bottom strip is very flat but the hull has a pronounced curve so it has to bend across the flat.
The P-P is a curvy beast, so I’ve gotten pretty comfortable with using a heat gun to impart twist and bend across the thin dimension. So one approach is to whip out the heat gun and bend across the thick. I guess I could also plane a curve into the strip.
Any other suggestions? Thanks!
Hi, yes the petrel play has a distinct hard chine aft of the cockpit. Trying to bend the strips across their width isn’t really possible, but if you look at the videos that the designer Nick Schade of guillemot kayaks has produced you will see that the solution is to strip past the chine.
Then you will need to transfer the chine lines to the outside and use a sharp saw the create the chine itself. Some planing with a rabbet plane and you can then proceed with the rest of the hull. The videos show this much better that I’ve described it though!
I ended up watching the whole series of videos several times while building my petrel play.
Thanks for the reply-
To clarify, the issue comes up after I’ve stripped the side past and then cut back to the chine - and beveled. It’s the placement of the first bottom strip that I’m facing.
In Nick’s video, he ends video 4 with beveling the side, and starts video 5 with the first few bottom strips magically (or done out of frame) in place. In his Petrel strip video, he spends a lot of time on the bevel, and the first bottom strip is no issue. Two things with the Petrel (non-Play) video - I don’t think the Petrel is quite as curved as the Play, and he’s using 3/16 inch strips which are more pliable than my CLC 1/4".
Here’s a picture of the bottom in Plan view, with a straight piece of strip:
That gap needs to be addressed, along with the rolling bevel. I’m playing with two approaches;
These are test strips. The upper one has a bevel, but I’ve also planed away material at the ends so it fits the curve. I’m just not sure I can do that for the aft four feet of the chine and have any material left. I could do it in sections, like a cheater strip, but I haven’t seen anybody else do it that way
The lower strip in the second picture is full width, which is bent with the use of a heat gun, then beveled. More work, but I’m taking my time and enjoying the journey. That will carry the plan view hull curve into the next bottom strip, which I assume requires all of them to be heat- bent as I close up the bottom.
This is my first boat, so I’m hoping to leverage the experience of others that have already gone over this literal edge.
Thanks-
Ari
Peter describes it and the video he identifies is an excellent reference. The pictures below show this part of the construction from my Petrel Play build. this is the most difficult part of the build and where you have to put the tongue/groove away for a bit and pull out a block plane and rabbett plane.
the first picture shows the overbuild along the chine area where the strip goes beyond the chine with the red circle higlighting how the strip goes beyond the chine line:
The next picture shows the strip that went over the chine line after it was cut into a smooth curve along the chine - this is the most difficult element and, as peter mentioned, a rabbet plane is the tool of choice to do this. in this picture (which is taken from the back of the boat being in the right side of picture and bow is towards the top left, you can see how the top strip is carved down (i have circled it in red):
this is the same step shooting a picture in the opposite direction confirming that the line is smooth left side of picture (you can see hanging curls of wood left over from the rabbet plane):
and this picture is the strip that goes next fitting nicely around the chine:
at the end you get something like this - if you look carefully you can see the carved strips around the chine detailed above:
add some more work, you hopefully get your version of something like this:
Thanks for the detailed pictures! A beautiful boat!
My specific question has to do with getting the bottom strips to curve “on the flat’ for the portion of the aft section with a pronounced plan-view curve at the chine. The strips bend relatively easily at the strip thin section (1/4 in) but not so well across the 3/4” width - especially the white cedar, which is particularly stiff in my batch.
Ari
got it…
yes, in the flats, now you have to bend against the full width of the strip…and the highest curvature is towards the aft.
my first approach when i need to put a lof of bending pressure (after blue tape doesn’t do the trick) is to work with packing tape with filament. and as you mentioned, applying heat would also loosen things up. in my builds, i usually don’t go for heat unless i can’t make it work with tape and staples…but i will use it if i have to.
the only other element that is relevent in this step is the curvature of the flat is influenced by how you sight the line for carving the strip to allow you to make that break around the chine.
in this picture, in particular, you can see (sort of) that the line i picked allowed for a relatively gradual blend (the lower right is the aft section behind the chine).
you can also see the upper (top) right side of the picture the next strip after the chine was laid in already and you can see that the curve is ‘relatively’ gradual. but i can see i was using a combination of blue tape, two pieces of blue tape between staples that are 12 inches apart (or a pressure point every three inches), to hold that first piece in…which suggests i was needing to apply a lot of force.
Hi Ari,
ahh, that makes sense. No you don’t need to heat bend or plane a bevel on those bottom strips, they should bend easily, you just need to make sure that they are snugged up tight while the glue sets. If you aren’t using staples then Sheetrock screws into the form edges and wooden wedges works well. Cedar is pretty flexible and takes the curve nicely, and you’ll end up with a graceful curve along the chine and across the bottom. I used a lighter strip at the chine which highlights this section, I hope this picture of the bottom makes sense.
Pete
Ok, that’s all making sense. I now have a plan. I’ll look for particularly compliant strips and cutting off the bead (for the bevel) will make it ever so narrower - every bit helps. I’ll probably use the heat gun in a short section near the aft, and break out my entire torture chamber of clamps, wedges, levers, and aircraft tape. No one solution, but a bunch of them.
Just knowing 'that section really needs muscle" really helps.
Thanks!
Update - the plan worked, thanks for the advice.
I used a heat gun to pre-bend the strips so I didn’t need much force to keep them in place. Because I only have 8’ strips, I installed them one strip at a time, a full 8 footer and a 5 footer, spliced with them on the boat. Having a strip no longer than 8" made handling it much easier than 13 feet of wiggle in close quarters.
Here is a picture of the two strips just before installation. The heavily bent on is the 8 footer that starts at the stern. The curve along the width of the strip was pretty easy. I also pre-twist at the bow and stern.
I made it work with just the Scotch rough surface painters tape and clamps at each form.
