curved stem | SouthernPaddler.com

curved stem

seedtick

Well-Known Member
Jul 22, 2006
1,161
7
Denham Springs, LA
Been some interest in how to make curved stems for your pirogue so I thought I'd give a rough outline.

Lots of pictures so I'll do it in several posts

There's no right or wrong way to make a curved stem as long as you end up with the desired result

Here's the way friend Keith and I do it

start with a panel that's the side of your pirogue, here's the end of a piece of plywood that's 12" wide

lambertpro2010005.jpg


so far so good, next draw in your rake or cut back, on a pirogue this is typically 6 to 12", I'll use 9" - draw that line

lambertpro2010008.jpg



there's hundreds of ways to get a curve, what I did was to move up the cut back line about a third of the way and draw a point 1" out

lambertpro2010009.jpg
 

seedtick

Well-Known Member
Jul 22, 2006
1,161
7
Denham Springs, LA
you have three points, take a flexible batten and draw the curve

lambertpro2010011.jpg


if you don't like the curve, now's the time to redraw because the next step is to cut the end of the panel

lambertpro2010012.jpg


and cut the other side to match

lambertpro2010017.jpg
 

seedtick

Well-Known Member
Jul 22, 2006
1,161
7
Denham Springs, LA
with the sides matched, next transfer the curve to the stem, I'm using a scrap piece of 2 X 4, some folks like to use a larger piece - i'll explain this later

lambertpro2010013.jpg



lambertpro2010014.jpg


now cut the stem (2 X 4) to match the curve in the sides

lambertpro2010015.jpg
 

seedtick

Well-Known Member
Jul 22, 2006
1,161
7
Denham Springs, LA
flip the stem on its backside and draw a line down the center

lambertpro2010016.jpg


we build on jigs so the next step is to determine the angle where the sides come together, I've used an already built boat for the demo

lambertpro2010019.jpg


the angle on this boat came out to 50 degrees, so set the bandsaw for 25 degrees

lambertpro2010020.jpg


keeping the back of the stem on the saw table, cut to the center line

lambertpro2010022.jpg
 

seedtick

Well-Known Member
Jul 22, 2006
1,161
7
Denham Springs, LA
flip the stem around and cut the other side

lambertpro2010027.jpg


and you now have a curved stem piece that matches your sides

drop it in place and fasten

lambertpro2010028.jpg


notice that the backside of the stem stands proud from the sides, if you use a wider board or trim the stem before inserting, you can reduce or eliminate the part that stands proud and have a stem whose sides are flush with the sides of the boat

however you do it, you end up with a curved stem in your boat

lambertpro2010030.jpg


I'll add this disclaimer that this was done with some scrap wood and if i was using real wood and building a real boat, i would plane or sand the bandsaw cuts to get a better fit for the sides and i recommend that you do likewise
 

seedtick

Well-Known Member
Jul 22, 2006
1,161
7
Denham Springs, LA
don't know what you're building without stems or what materials you're using, but

neither planks nor 1/4" marine plywood likes to easily bend the way we bend them

for us, the stem pieces hold the sides together at the ends and also provide for sealing against water intrusion

i can't imagine touching the ends of plywood or planks together and getting a water tight seal

but then maybe you're making your seams and joints water tight with fiberglass and epoxy
 

seedtick

Well-Known Member
Jul 22, 2006
1,161
7
Denham Springs, LA
not sure i understand,
the inside angle is the same as the outside angle, you could always cut away the back side of the stem if you don't like the part that stands proud

reckon you're right about stitch and glue not needing stems, never built a stitch and glue
 

mosportsmen

Well-Known Member
Jul 29, 2005
299
0
Kirksville MO
mosportsmen.com
Stems just caused me more of a conundrum when I built my second pirogue (a compilation of several designs). Couldn't figure out or cut a nice angle on the stems with the tools I have available.

Tying the ends together and filling it with fillet epoxy is lots easier. I forced quite a nice compound curve on my TV with zip ties and spacers.

I do like your curved bow and or stern though, looks good, probably could make the bow a little less susceptible to damage when coming in for a beaching or graveling as we do here in Missouri.

Makes sense, don't know why I didn't think of that.

Tom
 

oldsparkey

Well-Known Member
Aug 25, 2003
10,479
123
Central , Florida
www.southernpaddler.com
seedtick said:
reckon you're right about stitch and glue not needing stems, never built a stitch and glue

The standard way of fasting the stems on a stitch and glue boat is to tie the ends together with copper wire or the quick ties.

The bow of the Sasquatch 14 x 30 I made.
14x30%20011.jpg


Then epoxy them to hold them in shape and create a leak proof area. When that is done the ends are poured with epoxy to stiffen them. Usually a dam is made about an inch back from the junction and that void is filled with epoxy. Or the boat can be stood on end and the epoxy pored in there and left to cure. The epoxy takes the place of the wood stems that you use.

Personally... I like to dam the area and then use left over epoxy to fill the void as I use epoxy on the rest of the boat. It cuts down on the amount of epoxy that would be wasted.
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,976
171
86
Okemos / East Lansing Michigan
oldsparkey said:
<SNIP> Personally... I like to dam the area and then use left over epoxy to fill the void as I use epoxy on the rest of the boat. It cuts down on the amount of epoxy that would be wasted.
I do that too. And, on kayaks that do not employ bulkheads for separate cargo areas, and hatches to gain access, I'd stick a loop of parachute cord into the top of the end pour. I'd tie a small pulley to that, and rig a circular rope (ends tied together) through it and back to the cockpit. I tie on the first piece of cargo that goes into the hatch, and run it up to the end. For unloading, I pull on the rope and upset the load that is stuffed up under the deck (fore and aft decks both) and unload the gear.
 

captaindoug

Well-Known Member
Nov 18, 2009
142
0
71
Tampa Bay, Florida
I for one appreciate the tutorial, and like the man said, he doesn't build stitch and glue boats, so how ya'll do it with that kind of construction doesn't really apply to this post. Thank you for the lesson Seedtick, and for you folks that don't want to do it that way,..don't :lol:
 

mosportsmen

Well-Known Member
Jul 29, 2005
299
0
Kirksville MO
mosportsmen.com
Well I guess I am put in my place. Reviewing my posts I guess i did fail to express my appreciation for Seedtick's work on this post.

Don't mean to be a detractor, just a devils advocate, I suppose.

The use of the band saw and showing how to draw it out are great tips for making stems.........if you want stems.

Thanks Seedtick!

Tom
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,976
171
86
Okemos / East Lansing Michigan
Well, Mo, I don't think anyone is trying to be critical of you. Each of us do things differently.

The only power tools I have are a 3/8" drill and a sander (not counting my electric shop lights). I saw with a Japanese hand saw that cuts on the pull. Not as quick (or accurate) as a band saw, so if I cut out a stem piece from a larger chunk, I'd still have some planing and sanding yet to do. If my tools were much more primitive in design, I suppose I'd be using a chunk of flint or a clam shell. :wink: