Shaping Stems. Need Guidence

Welcome to the new Bear Mountain Builders Forum - an interactive internet service we provide to encourage communication between canoe and kayak builders
Stephen
Posts: 102
Joined: Fri Apr 18, 2014 12:36 am
Location: Eastern Ontario

Re: Shaping Stems. Need Guidence

Post by Stephen »

Grumple

In Canoecraft Ted tells you to trim the ends of the planking flush with the inner stem as you go to provide a flat surface for the outer stem. If this is continued all the way up, the width of the flat spot will eventually exceed the width of the outer stem. Not good. You need to switch your method just before the flat spot becomes too wide. This post describes the problems that ensue: viewtopic.php?f=1&t=378
Is there a hard rule to know when the strips should start going all the way to meet each other at the bottom of the stem instead of leaving this 1/8" leading edge of the stem?
My understanding* is that the 1/8" edge is still there, just covered. You need it later as a reference for how deep to make the outer stem mortice. viewtopic.php?f=1&t=4276

* You should bear in mind that I'm strictly an armchair canoe builder who has shamelessy absorbed most of his knowledge from other members of this forum :)
User avatar
Grumple
Posts: 108
Joined: Thu Jul 03, 2014 7:38 am
Location: Halifax, Nova Scotia

Re: Shaping Stems. Need Guidence

Post by Grumple »

Hi Stephen,

Thanks, that was helpful. I can't 100% visualize it yet, but I will go searching for some additional descriptions, re-read that CanoeCraft chapter, etc.

Unfortunately it looks like the link to Glens tutorial on mortising is no longer valid.

I'm at least glad I asked before I started shaping the bottom of my inner stems to a sharp edge... =P
User avatar
Cruiser
Posts: 867
Joined: Sat Apr 27, 2013 10:21 am
Location: Bowmanville, Ontario

Re: Shaping Stems. Need Guidence

Post by Cruiser »

I stand corrected on the width of the inner stem, fortunately, I still tend to read the book, before I do any section ... so do use the 1/8".

I am not sure if these pics will help or confuse ... but I am always one to try and help, I got so much on my first build, I like to try and help back.

First pic shows how when you get near the turn on either stem, you have to stop trying to cut them flat, as the book says, it's pretty apparent where that is ... and you have a little leeway.

Image

Next you get to the point where you will just fill out one side, others can wade in here, but I do this about 1"-2" before the end of the stem.

Image

Once you complete filling out one side, you will cut all the strips straight down the middle, if you look at the pic you can see the inner stem and the end of the inner stem. The first piece on the other side will have to be fitted in to match the strip at the end of the stem. If you look carefully, you can see a pencil outline running beside the gap in the strips over the stem area ... this is the outline of where you will mortise in the outer stem. The outer stem will be cut shorter than the inner stem, you can see that from the pencil outline (the angle makes it look less than it is, follow the book). It is also why you don't need to be too fussy about trimming after you make the big turn towards the bottom.

Image

I included these just to give you an idea of the next steps.

Hopefully I haven't muddied the waters.

Brian
JesseP
Posts: 46
Joined: Fri Apr 10, 2015 11:13 am
Location: East Central, AB

Re: Shaping Stems. Need Guidence

Post by JesseP »

Thanks for the pictures Brian. You have not muddied any waters, if anything you have cleared the waters. I have finished shaping the stems to receive the first strips and will shape as I go ( once I finish bead and cove on all my strips..) I like seeing the method of mortising for the outer stem I was wondering about the tapered end at the hull. Is that a 3/8" taper?

Thanks for sharing and caring.

JesseP
I'm up to my torch.
User avatar
Cruiser
Posts: 867
Joined: Sat Apr 27, 2013 10:21 am
Location: Bowmanville, Ontario

Re: Shaping Stems. Need Guidence

Post by Cruiser »

Yes sir, I followed the book for that ... here is a pic just before the outer stem was installed, the mortise has been completely wetted out with unthickened epoxy in the pic

Image
User avatar
Grumple
Posts: 108
Joined: Thu Jul 03, 2014 7:38 am
Location: Halifax, Nova Scotia

Re: Shaping Stems. Need Guidence

Post by Grumple »

Hi Brian,

That was an awesome summary of the process, thanks! It definitely cleared up a few misunderstandings I had. I guess having been through the process you know how much getting this help is appreciated!

The only part I am still a bit hung up on is the last bit of inner stem past the end of the outer stem mortise, where strips will start needing to meet each other at center. Is this last section of the inner stem also shaped to a 1/8" leading edge? If so I assume the ends of the strips are floating ever so slightly above that flat edge where they meet?

I keep coming back to whether this last bit should still have the 1/8" leading edge because of the following description from CanoeCraft (2nd edition, page 115):
Now draw two parallel lines, one on either side of the center line, to show the 1/8 inch width of the leading edge. This leading edge will narrow down to the centerline where the stem begins to flatten out as it turns into the bottom of the boat.
On one hand, I feel like transitioning from 1/8" leading edge to a sharp 'V' would be strange, but on the other hand, it also seems a bit odd that the strips should meet each other above a flattened leading edge.

Jesse, please post pictures as you start stripping! I might have missed you already saying it, but which canoe are you building?
Stephen
Posts: 102
Joined: Fri Apr 18, 2014 12:36 am
Location: Eastern Ontario

Re: Shaping Stems. Need Guidence

Post by Stephen »

Grumple

Confusing.

I was basing my remarks on the five stem cross-sections in Canoecraft on page 117 which show a 1/8" leading edge all along, but the section you highlighted does indeed seem to suggest that the stem is brought to a point nearing the bottom of the canoe.

I have noticed a few other places in the book where the text and pictures don't say exactly the same thing.
JesseP
Posts: 46
Joined: Fri Apr 10, 2015 11:13 am
Location: East Central, AB

Re: Shaping Stems. Need Guidence

Post by JesseP »

I am building the Hiawatha 15' and will try and post pictures of every stage of the build.
I'm up to my torch.
User avatar
Grumple
Posts: 108
Joined: Thu Jul 03, 2014 7:38 am
Location: Halifax, Nova Scotia

Re: Shaping Stems. Need Guidence

Post by Grumple »

I agree Stephen....I'm sure the answer is simple to any of the experts that have been through this a bunch of times, but as a newbie I'm genuinely confused...

At face value I think your original suggestion to just carry the leading edge through makes sense, but that one paragraph from CanoeCraft seems to be contradicting the diagrams you are referring to. I can't help but think its a bit strange that the strips would be coming in and butting up against each other with a gap underneath along this flattened edge...
User avatar
Cruiser
Posts: 867
Joined: Sat Apr 27, 2013 10:21 am
Location: Bowmanville, Ontario

Re: Shaping Stems. Need Guidence

Post by Cruiser »

You may be just over thinking the issue at this point.

If you look at the last picture I posted (the mortise for the outer stem), you can see the flat continued all the way to the end. You can also see that all of those strips also get trimmed to complete the mortise. So there isn't/won't be a point where the stems overhang the inner stem ... except (there is always an exception) the very last strip that is in between where the outer stem stops and the inner continues for a bit. The outer stem is deliberately cut shorter than the inner stems ... that is in the book and the explanation ( If you look close you can still make out the centreline on the inner stem).

Continuing the centre strip all the way back, allows a direct connection between the inner and outer stems, it is also a handy guide as to how deep and where the mortise goes.

The only tricky part is having the faith to simply cut those strips at a little less than centre so that you can use that centre line as a guide, don't worry about being neat after you turn the corner to the bilge, the mortise is cut through the centre anyway.

Brian
User avatar
Grumple
Posts: 108
Joined: Thu Jul 03, 2014 7:38 am
Location: Halifax, Nova Scotia

Re: Shaping Stems. Need Guidence

Post by Grumple »

Yeah maybe I am just over thinking it at this point. It's literally the thing I will be doing next, and I've seen a lot of stories of first timer mistakes on this part, so I'm being pretty cautious.

I did mention in a previous post that it is specifically that last bit past the end of the outer stem that I am concerned about. Maybe the angle is shallow enough that it isn't noticeable, but it seems like that flattened leading edge would be visible from the inside of the boat as a gap between the bottom of the inner stem and the strips of the strips at the keel.
User avatar
Cruiser
Posts: 867
Joined: Sat Apr 27, 2013 10:21 am
Location: Bowmanville, Ontario

Re: Shaping Stems. Need Guidence

Post by Cruiser »

I should have read closer .... but that last strip, it won't matter if you shape it a little more, but the strips do need to fit in with the line (fair curve) rest of the planks.


Brian
User avatar
Grumple
Posts: 108
Joined: Thu Jul 03, 2014 7:38 am
Location: Halifax, Nova Scotia

Re: Shaping Stems. Need Guidence

Post by Grumple »

Yeah good point about the strips maintaining that curve. I guess I'll just do the 1/8" leading edge all the way, and if there is a visible gap at the end of the inner stem, I'll see about filling it later.

Thanks again for answering all these questions!
Stephen
Posts: 102
Joined: Fri Apr 18, 2014 12:36 am
Location: Eastern Ontario

Re: Shaping Stems. Need Guidence

Post by Stephen »

You just need to pick a bow paddler with poor eyesight ;)

All joking aside, I think the gap will be pretty tiny.
User avatar
Grumple
Posts: 108
Joined: Thu Jul 03, 2014 7:38 am
Location: Halifax, Nova Scotia

Re: Shaping Stems. Need Guidence

Post by Grumple »

Haha that sounds like a plan, Steve.

I think (hope) your are right about any potential gap being tiny. I assume it's pretty important that it gets filled completely though, otherwise it would be a potential place for water to get into the inner stem.

I'll be sure to update once I've gotten through that section...I figure another half dozen or so strips and the inner stem should be covered. However, as Brian suggested earlier, I'm finding I can really only add one strip at a time now, so the going is slow!

Thanks!
Post Reply