Fairing or beveling the mold stations of a strip build Kite canoe?

[Spuvak]

Hi everyone - I've recently begun work building - you guessed it - a Kite. The strongback is assembled, stations are in place and aligned, strips are cut, beaded, and coved, and stems attached (but not yet shaped).

I have a question regarding fairing the mold. That is, beveling the sides of the stations so that strips lay flat against them. I've only seen a couple of brief, mostly uninformative references to this in print. I can't seem to find any mention of the practice in this forum, nor have I seen any YouTube videos demonstrating it. What I've read stresses the importance of doing this to avoid distortions in the hull at sharp station edges that have not been faired. I'm using 3/16" strips and plan to paint the exterior, so naturally this warning caught my attention. What's your thinking on this?

Thanks!

 

[Cruiser]

I will assume, you have aligned all the centers along the base and then checked that top center lines are all in alignment as well... and that each form has been adjusted to be at 90 degrees to the strongback.

The actual "shape" the forms are describing, occurs at the lines where each form is installed, so the "distortion" of shape you are reading about is going to be dependent on the thickness of the forms you have selected. As each strip starts to curve towards the ends, it contacts each form at a slight angle, so it only touches the form on the corner (the curve at the center is neutral, so usually the strip lies flay across the form there). This is usually so small that shape distortion is unlikely to be of any consequence and you would be more likely to introduce errors by trying to bevel the edges as you describe. Commonly 1/2" material is used for forms and the difference is so small, it doesn't matter IMO.

I am wondering if maybe you have confused 2 separate operations, while the beveling is step I don't use and feel it has no consequence to the build, my understanding of "fairing the forms" is something different. Fairing for me is to place a baton/strip against the forms to make sure it evenly touches all the forms and then sighting down the strip to make sure all the transitions are smooth or "fair". If you see a form not touching the strip or you see a bulge in the strip at a particular form, that means you have a form alignments issue, which is something you need to address. Sometimes the initial form setup is just not good enough, if you see a bulge ... then something is amiss at that form station, if a form doesn't touch the strip again some thing needs attention.

When I use the term attention, I mean 1) check the form, make sure it is correct 2) check the alignment on the strongback .... checking that the forms are giving you a smooth curve from one end to the other is a step I don't skip, if it doesn't look right at this stage it is critical you take the time to get it fixed now.

Keep us informed of your progress, we love to see new builds progress, hopefully some of that rambling helps you towards an answer.


Brian

 

[dogbrain]

I have built a number of canoes from plans and with the Kite I found that if you have properly made and set up the forms, there will be no need to bevel anything but the stems. In this case, fairing will only invlove the process described by Brian. Of the different designs I have built, 2 of them needed some fairing that involved removing material from the leading edge of a form or two. I was curious enough about the problems I had that I later digitized the plans and brought them into Delftship software. Indeed the unfairness of the plans showed up right away, which confirmed the issues I was having.

As far as setting up forms, I do it different than most I assume, but I've never seen it described. Going off Brians description above, the 12" spacing is referring to where the strip touches the edge of the form. It will be the leading edge towards either stem. As he says, the center form or a few more will have the strip laying flat, but as you move towards either end, the strip will be touching the leading edge towards the end. What this means in practice, is if you spaced your forms exactly 12" on the strongback, you have inadvertently added the thickness of one form to the total length of your boat. That 1/2" to 3/4" isn't much, and it probably has no practical effect, but it is something and easy to compensate for. In the end, the spacing of one form in the center should be 12" minus the thickness of your form.

Mark

 

[Jim Dodd]

I SLIGHTLY bevel the edges, of the forms, where the strip contacts the form. This eliminates an unsightly dent on the inside, that requires extra sanding on the inside of the hull.
Extra layers of tape, on the forms, will help also.
You don't need to remove much.
You certainly don't want to alter the form shape.

 

[stripperguy]

I too have built a couple Kites.
The forms didn’t need any special bevel, only the stem pieces.
I also painted my Kite, after initially using tinted resin.
The red tinted resin did not adequately covering the cedar grain and color, and no amount of sanding and polishing could make it as vibrant as I wanted, so a couple coats of paint finally made the hull “pop”.

 

[Cruiser]

I SLIGHTLY bevel the edges, of the forms, where the strip contacts the form. This eliminates an unsightly dent on the inside, that requires extra sanding on the inside of the hull.
Extra layers of tape, on the forms, will help also.
You don't need to remove much.
You certainly don't want to alter the form shape.

Agree, taking the edge off is a good idea, not a full bevel, but easing the edge makes it harder to dent the inside of the strip.

 

[Thestripper]

Hi everyone - I've recently begun work building - you guessed it - a Kite. The strongback is assembled, stations are in place and aligned, strips are cut, beaded, and coved, and stems attached (but not yet shaped).

I have a question regarding fairing the mold. That is, beveling the sides of the stations so that strips lay flat against them. I've only seen a couple of brief, mostly uninformative references to this in print. I can't seem to find any mention of the practice in this forum, nor have I seen any YouTube videos demonstrating it. What I've read stresses the importance of doing this to avoid distortions in the hull at sharp station edges that have not been faired. I'm using 3/16" strips and plan to paint the exterior, so naturally this warning caught my attention. What's your thinking on this?

Thanks!

Hi Spuvak.
I had this exact same question when I was building the Kite.

In my thinking, fairing the stations should only be necessary if the stations are either designed wrong, manufactured wrong or mounted wrong. This is true but be mindful of the instructions on how to mount the stations to the strongback for the Kite to get the correct distance between them. The "Builders Notes" describes it in a clear way even though you might have to read through the sentence more than once before you get it.

All the people I talked to who had build the Kite said that they had not faired the forms at all, or if they had it was very slight and only on the last two stations at bow and stern. This is what I ended up doing as well.

If you are building stemless then fairing of the station moulds will be necessary to achieve a fair hull.

Martin had this to say and I think he said it well:
"in a “perfect world” with CNC-cut forms and perfect setup and alignment there shouldn’t be a need to fair the mould. That also assumes that the stems are also “perfect”, as well as the strongback, and the positioning and alignment of every station.

But, we live in the real world, so it is always a good idea to check how well everything shapes up after the forms are completely set up, and the stems are in place and have been shaped. You may find that a little bit of fairing is required at the ends for the hull to blend seamlessly into the stems. This is especially true as you are shaping the stems in place, as the fairing process also guides the shaping of the stems. So, basically, you fair only as needed, but do check regardless of how ‘perfect’ you think it is - better to be safe, right?

As a point of interest, I’ve never built a canoe that didn’t require at least a little bit of fairing of the stations near the ends. Also, do keep in mind that this is a wooden canoe, which can and will be a beautiful piece of hand-crafted workmanship - but it is NOT a Swiss watch."



Martin was right. It's not a Swiss watch, but it is a da mn fine canoe and I'm very happy with. I think you will be too. Good luck!

 

[Glenn MacGrady]

I have a question regarding fairing the mold. That is, beveling the sides of the stations so that strips lay flat against them.

Spuvak, I'm not a builder of canoes, so I can't contribute any info about that. However, I am the builder of this site, and I want every thread title to be built so as to be as "searchable" as possible. That increases the site's SEO. Therefore, I have edited the title of this thread so it has clearer and more relevant key words.

Sorry for the administrative tangent. Please carry on. This is interesting.

 

[dogbrain]

I liked the old title: "For the benefit of My Kite". I just wanted to make sure the reference to the Beatles song survived in some way. Quite creative.

Mark

 

[dogbrain]

This is true but be mindful of the instructions on how to mount the stations to the strongback for the Kite to get the correct distance between them. The "Builders Notes" describes in a clear way even if you have to read through it more than once.

I just looked and saw this in the Osprey builders notes. Winters explanation is much better than mine with regard to station spacing. Thanks

Mark

 

[UCanoe_2]

I'm not a canoe builder, but for other traditional boats the rule is: forms forward of amidships go on the aft side of the station line, while forms aft of amidships go on the forward side of the station line. This setup will place one plane of each form exactly on its appropriate station line. Minimal fairing should be needed.

It's hard to visualize from words, but will make sense if you build a model of the boat.

 

[Alan Gage]

I'm not a canoe builder, but for other traditional boats the rule is: forms forward of amidships go on the aft side of the station line, while forms aft of amidships go on the forward side of the station line. This setup will place one plane of each form exactly on its appropriate station line. Minimal fairing should be needed.

I'd read this advice in books and followed it blindly for my first couple builds. On my third build I started questioning why and it took me a few minutes of stopping to sit and think before the light bulb went off and then it made perfect sense.

Alan

 

[Pseudonym]

I'd read this advice in books and followed it blindly for my first couple builds. On my third build I started questioning why and it took me a few minutes of stopping to sit and think before the light bulb went off and then it made perfect sense.

Glad you said so Alan. Having read @dogbrain and @UCanoe_2's posts above, I confess to not comprehending the reason at first. Your post gave me occasion to reconsider it and the lightbulb went off for me too. Makes all the sense in the world.

 

[Jim Dodd]

OK ! Here is the spacings and an illustration, of how I stretched my original Pearl, these were actual spacings, so don't take the numbers for a different design.
I cut new stem forms, to make things Fair, for the stretch.
You could measure from the faces of the center form ( 0 ), but using 3/4" thick center form ? I can't see 3/8" making any significant difference.
Accuracy in cutting forms, can come into play here also.

 

[Boatman53]

I always place the forms forward or and aft (appropriately) of the specified distance so beveling is needed but it gives more support to the planks and more surface area to staple. That is the standard boat building practice.
Jim

 

[Jim Dodd]

I always place the forms forward or and aft (appropriately) of the specified distance so beveling is needed but it gives more support to the planks and more surface area to staple. That is the standard boat building practice.
Jim

That is totally agreeable ! It is however more work, but certainly worth the while of a builder !

I too use staples. There are those that don't.
When I staple ? The stapler is held in the horizontal position, Your method, would allow either horizontal, or vertical stapler position.

Jim