problem shaping inner stem

doe4rae · Post by **doe4rae** » Mon Nov 23, 2009 11:30 am

Hi,
This problem is best explained with pictures but I'm not sure how to post them here. They are in an album at this link. http://picasaweb.google.com/lh/photo/y7 ... directlink

My problem is that, following the directions in the book, I started shaping the part of the stem where the first strips will lay flush against the inner stem. CanoeCraft says that the inner stem will be a constant 1/8 inch width at the tip of the "V" and the "V" will be various depths along the stem but only work a small part at at time checking it with a batten as you shape it... the first part (denoted as section "E" in the book) is a deep "V" .
I checked several times as I was shaving off material and it continues to be 'unfair'. I mean, following the shear line with the batten, there is a gap between station 6 (butts up against the stem mold at a "T" shape) and the batten. Also, as the batten is lying against the stem mold, it will not lie flush against it. So obviously I can't glue a strip against the stem or very little of it will actually be making contact with the stem. When I'm looking at it, I think the "V" is too fine... or maybe the part that lies agains the stem mold is too wide. (It was 7/8 inch). But I know the older book said 3/4 so I started taking a little off this edge too, thinking it will help bring the batten into better alignment. I'm really freaking out now... because I think I am ruining the stem. Or maybe worse.. I screwed up something with the station molds. I have checked and double checked their spacing, and they are plumb, and completely centered. I used the builder's jig just like in the book to set them up and I also checked for fairness with a batten before tearing into this stem shaping. I feel like I have hacked it to death.

.. grrrr!!! Anyway... at one point I pushed the stem all hte way over so that its thickest edge was flush with the stem mold material... and then I checked if the batten would show a fair curve. Yep. so what this is telling me is that I would have to make the width of my stem (at the widest part - the part which lies against the stem mold) 3/8 inch wide!!! (That's how wide my station mold plywood is.)
This can't be right?? Please take a look at the link and I believe once you get to that image, you are inside the album and can use the arrows to go forward or back to view the other images I took of this problem.

(I just checked the link I posted above only goes to that one picture.. the link below should take you to the whole album. Only the last 10 pictures or so are of the stem mold shaping.)

http://picasaweb.google.com/olson.dawne ... directlink

Thanks!

Glen Smith · Post by **Glen Smith** » Mon Nov 23, 2009 11:50 am

John Michne has some good info about shaping stems at this link: http://www.michneboat.com/Shaping%20the%20Stems.htm

The vertical portion of the inner stem will have to be cut down to somewhere around a 1/2" width only + or - a bit. Keep the 1/8" leading edge. You must shape the sides of the inner stem so the strips lay flush against the stem with full contact. We start with a much wider stem because that extra width will be necessary when you get to the horizontal portion.

doe4rae · Post by **doe4rae** » Mon Nov 23, 2009 11:56 am

Ok.. this starts to sound more feasible! I thought I had to keep that 3/4 to 7/8 width at the side of the stem contacting the stem mold. Thanks for the link. I'm still awfully nervous about taking off so much material.... will hope for the best and at the worst I have to make a new stem I guess. :confused

Glen Smith · Post by **Glen Smith** » Mon Nov 23, 2009 12:09 pm

Depending on the thickness of the stem form you even have to cut right into the form to get the inner stem down to a width which will allow the strips to lay flush. I always use fairly this matierial for the stem forms (about 1/2") and I still have to cut into it in some spots. Some builders use 3/4" stock for all forms and they have to remove almost half the form thickness to get the strips to lay flush. This is normal. Get it even on both sides and don't sweat it.

doe4rae · Post by **doe4rae** » Mon Nov 23, 2009 3:19 pm

The link you sent is so helpful.. thank you!! I couldn't have believed it - or imagined - that I would have needed to cut back so much as to have to even remove some of the form. Wow. That's useful information. Well, my plywood is only 3/8's so maybe I won't have to go that deep. I do know without the stems on the mold that the batten lies fair along all the molds to the stem mold edge. I kept looking at everyone else's pictures of their molds set up and thinking I messed up to use such thin plywood. it seems ok so far though, and actually works to my advantage in the case of having to trim back the width of the inner stem. I also really liked the suggestions for the other tools used in the link you sent. Looks like I need to buy more tools... especially the round file.

Glen Smith · Post by **Glen Smith** » Mon Nov 23, 2009 3:30 pm

John's "sanding stick" with 60 or 80 grit paper from a sanding belt works very well!

BradRob · Post by **BradRob** » Tue Nov 24, 2009 6:29 am

Relax Dawne. Your stem is going to turn out fine. Glenn offers excellent advice. I made a mistake and shaped the entire stem on both sides all the way to the bottom of the hull. When i realized my mistake from reading other postings here i simply rebent a pair of stems and started over. I understand about freaking out though so take your time relax and enjoy your project. I also use sanding sticks that i made and suggest you give them a try. They help in faring the stem with the hull.
Have fun and relax
Brad

doe4rae · Post by **doe4rae** » Tue Nov 24, 2009 10:21 am

Thanks... all great advice! I'm feeling like I have a lot more control over the outcome of the stem shape with the suggestions above.... I made some sanding sticks last night and picked up one of those round microfiles at Ace Hardware. Its not so overwhelming when you get the right tools in hand and have a better grasp of how much wood will be coming off. I kept looking at the diagram in CanoeCraft and was sure I wasn't allowed to take off the 1/8" leading edge OR any of the 7/8" that was my original stem width at the stem mold. Not understanding this was making it impossible to get the batten strip to lay flat against the stem.
Breathing a big sigh of relief after clearing up that issue!

mtpocket · Post by **mtpocket** » Tue Nov 24, 2009 7:55 pm

doe4rae,

I don't want to confuse you but now would be a good time to start thinking about the mortise that the outer stem will fit into. There is some really good information on this forum about that step and some builders have even posted pictures. You sound like you have a pretty good handle on things. I just like to think a few steps ahead so I don't get there and have a surprise.

Good luck

doe4rae · Post by **doe4rae** » Wed Nov 25, 2009 11:04 am

Mortise? Hm... you're right I haven't read anything yet that describes what you just brought up so it seems I might be setting myself up for that 'surprise'. I'll have to browse around here in the forum and see if I can figure out what you mean. Something else I need to do with the inner stem before I can start stripping??

I believe I found it here: http://www.bearmountainboats.com/phpbb2 ... em+mortise

Thanks for the head's up! I'll have to study this a while.

mtpocket · Post by **mtpocket** » Wed Nov 25, 2009 6:40 pm

doe4rae,

Yes, that is a very informative thread. There are many such threads on this forum that are helpful during that step.

Here is a link to a website that has some of the best pictures available. It is Glen Smiths site. http://woodcanoes.multiply.com/photos/a ... uter_Stems