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FAQ's:
BUILDING YOUR BEAR MOUNTAIN CANOE OR KAYAK
The following reference will assist you in understanding the lofting process used in the revised CanoeCraft and KayakCraft. You may also use these handy instructions.
DRAWING THE SHAPES
LOFTING:
References:
1. "Lofting Demystified" by Greg Rossel "Wooden Boat Magazine" Part 1 WB issue # 110 p. 66
Part 2 issue # 111 p 35.
www.woodenboat.com
2. Building Small Boats by Greg Rossel published by WoodenBoat Books 1998
The definitive book on plank-on-frame and lapstrake construction for boats under 25 feet, beautifully and clearly presented. Traditional small boat construction, useful information on plans, tools, jigs and materials. Excellent chapter on lofting.
3. Lofting by Alan Vaitses Re-published by WoodenBoat Books Brooklin, Maine 1999
Devoted strictly to the subject of lofting, Vaitses very readable text covers several different hull forms.
Q In the newly revised Canoecraft, my understanding from the text of the book is that the points are to the outside of the planking, however the points in the table of Half-Breadths seem to be 1/2 an inch shy of the lines when compared to the corresponding diagram. Can you please verify that the points as given in the tables are correct (to the outside of the planking?
A The numbers are fine but the text was incorrect. The lines for the drawings are to the inside of the planking. This has been corrected in more recent printings.
Q The table containing the stem offsets for the Ranger in the 2000 version of Canoecraft is not working out - are there errors there?
A The stem offsets unfortunately did contain some typographical errors. In Offset Revisions, you will see the Ranger stem offsets. Click here to learn how to plot offsets, Full size plans are available from Bear Mountain at a reasonable price if you wish to ease this stage of the process. These errors have been corrected in more recent printings.
Q What are buttocks?
A Buttocks are vertical slices parallel to the centerline.
Q When I cut out the bow and stern sections and place them on the strongback they are 5 in. higher than the station molds.The station molds call for a 2 in. space from the sheer line - should this be more or am I doing something wrong?
A The baseline that becomes the strongback line is common to all stations - you must have added the 2" on to the sheer line of each individual station mold instead of making it a common line for all molds. It is a common line - this is why we suggest drawing the molds on one sheet of paper to avoid this confusion.
Q I'm plotting the molds for my second cedar stripper. I am using the plans for the Redbird as outlined in the book CANOECRAFT. I would like to respectfully ask for a bit of assistance: In Chart B, the bottom line designates the last horizontal measurement for each mold. But along with the last point there are numbers in parentheses. As an example: 15 3/8+ (13 1/8+ up) or 3 (17 15/16 up). What are these dimensions inside the parentheses followed by the word 'up'? I have read and reread the instructions for drawing the plans and the answer eludes me.
A These numbers show the exact point of the sheer line. The first number is out from the centerline and the number in parentheses is up from the base line. In the first few printings of Canoecraft a simple calculation was required to find this number - we provided these numbers to make it easier - when you draw your stations it will be obvious.
Q When I cut out the bow and stern sections and place them on the strongback they are 5 in. higher than the station molds.The station molds call for a 2 in. space from the sheer line - should this be more or am I doing something wrong?
A The baseline that becomes the strongback line is common to all stations -
you must have added the 2" on to the sheer line of each individual station
mold instead of making it a common line for all molds. It is a common line -
this is why we suggest drawing the molds on one sheet of paper to avoid this
confusion.
Revised Canoecraft 2000 +
Q I was very excited to get your new book. The updated instructions were very helpful. However, the table of offsets was a bit of a challenge - how do I draw the plans from the new version?
A We had many people confused about the method of expressing the plans in the original Canoecraft. When Ted revised Canoecraft in 2000 he decided to use a traditional table of offsets to express the plans. This method requires some knowledge of lofting. Lofting is a universal system used to express boat lines.
Lofting is not complicated but it does require learning the system and working through the steps.
The plans in KayakCraft and the new Canoecraft are expressed in the traditional table of offsets. Steve Killing kindly produced these additional instructions for people who want to draw their own plans. Full size plans are available from Bear Mountain plus offset lofting specs.
HOW TO PLOT
Offset Tables
Q I've started lofting the Prospector using the offset tables from the 2000
revision. After finishing the center station I noticed that the dimensions
don't match those from the specifications table that is printed along with
the offsets. For example, the beam is a half inch narrower than the
specification. This makes sense if the offsets are to the inside of the
planking, but the book states that they are to the outside. I realize that this
issue has been raised before, but I'm still a bit confused and I'd like to get
it right. Are the offsets to the inside or to the outside of the planking?
A The offsets are for the station molds and therefore you do not need to
deduct any thickness for the planking. Unfortunately this is stated
incorrectly in the text. The specifications are for the finished boat.
Q I am building one of your kayak's, can you give me more detail on building the stem mold?
A For those building one of the four boats presented in Ted Moore's book KayakCraft we offer these additional offsets to help with the stem mold layout.
Q
As a first time canoe builder, I am proceeding very cautiously. I am
building the Redbird. I am at the point where I have to start
shaping the stems. I usually don't make a move without consulting
your book. Here is my question: Looking in your book, page 117, at
the various drawings for sections A to E, I am not getting any
profiles like that. Due to the sharp angle the stern and bow on the
Redbird I am having to take the wood on the inside stem all the way
to the 1/2 inch width of the stem mold. So I am not getting any
profile like C or D on page 117. On the other hand, the photo on
page 116 appears to show the spokeshave all the way to the stem mold.
And, I assume the photo on page 116 is a Redbird. Does it sound like
I am doing the right thing? Or, do I have to make a new inside stem
and start over?
One last question. The width of the bow and stern, before the outside
stem is attached should be 5/8", 1/4" X 2 for the strips and 1/8" for
the shaped inside stem. But, the outside stem is 7/8" wide which
will require a lot of shaping to have it fit in with the cedar
strips. Why is the inside stem trimmed all the way to only 1/8"? If
it were trimmed to 3/8", it, along with the cedar strips would be
7/8, the same as the outside stem.
Thanks for your patience and any help you can give me.
David Rand
A You should not need to start over but you may have already figured
this out. You must cut off everything on the stem that will be in the
way - ending up with 5/8" - put tape over. It is very good practice
with the spokeshave. Be sure to cover the cut away part with tape so
that the planking will not stick to it. By the time you get to the
outside stem it will be 3/8" which is the standard width for brass
stem band.
Q I am building a Venture 14 from plans I purchased from the Bear Mountain
Boat shop. I am about to cut out the molds, but discover that the sheer
clamp cutout on station 10 is dimensioned differently than all of the other
stations. It is only 11/16" deep rather than the typical 7/8". Is this a
mistake on the drawing?
A Thanks for your note on the Venture 14 plans. The notch in station 10 is indeed shown the wrong size. They should all be 3/4" x 7/8" as noted on the drawing. I appreciate your bringing that to my attention. It has now been corrected and when the next printing comes up will be corrected.
Q I have purchased your book "Canoecraft" and want to build the Chestnut Prospector. I plan to tandem and solo waters similar to the Boundary Waters Canoe Area. My wife says "a man can not have too many boats", therefore, I am not limited to only one boat. We already own a royalex, but plastic does not have the appeal of the wooden boats. When I plotted out the stations all have slight tumble home with the exception of station 5 which has a slight flare - is this correct, did I do something wrong, or is there a misprint in the book? Also in the bow/stern section there is a slight indentation between points:chart A 20 - 7 1/2 and chart B 10 - 22 1/8. Again, did I do something wrong? I want to make the Chestnut as exact to the originals as possible - are the numbers in the book from original Chestnut plans or measurements taken from a boat?
A I would say that you want to fair the lines so that they follow the contour - in other words if they don't look right they are probably not..there may be a misprint there. Our lines originally came from Bill Mason who made templates from his favourite old red canoe and sent them to us.... altho our research points more and more to Bill calling all his canoes Prospectors when in fact
they may have been the Ranger or Fort models....but they were all part of that family of high load carrying canoes that he liked.
Steve refaired all our plans three years ago and these changes are reflected in the revised Canoecraft and in all the full size Bear Mountain plans - tweaking Ted calls it. It makes sense when one considers that the templates Bill Mason sent to us were from a canoe that had seen alot of use and may not have been all that close to the original shape given how would expands, canvas absorbs water, etc.
Q Are there any typographical errors in the revised CanoeCraft?
A Yes. Please check out the CanoeCraft Offsets Revisions for more details.
Fairing
Q I am following the article "Building Bob's Special" that came with the plans that you sent me. I am at the stage where I will be cutting the station molds and attaching them to the strongback. What I am unsure of from the text is whether I need to shape/bevel the molds like I would the stem - i.e. so that the strips lay flat against the station mold and not just touch the edge of the mold.
A Ted doesn't fair the molds he makes from our plans. He is satisfied that they are so accurate that the less you do the better in reproducing the designers intended shape.
Q I am lofting the forms for the Resolute in the KayakCraft book and have a
question regarding the Profile numbers. From my initial lofting, it appears
that the profile numbers in the hull table of heights refers to the bottom
dimension/keel of the station measured down the center line. However, the
profile numbers in the deck table of heights are throwing me off. Can you
tell me what this number references and how it should be measured? I assume
the deck profile number should also be measured down the center line from
the base line. Your assistance is appreciated.
Q I took a canoe building course from
you at the White River Artisans School, in Arkansas. This past Spring I
successfully completed a Freedom 17, and am very pleased with how it
turned out. Now I need help.
I am trying to build a C1 Marathon Canoe with 1/4" white cedar
strips. I have installed 9 strips, starting at the stern shear line, and
running level with the waterlines. As I approach the wide part of the
wing, it is apparent that soon a strip will not make the bend, which at
times will be over 90 degrees. Part of the strip would be on the top
side of the canoe, and part would be on the bottom.
I saw a marathon canoe, by another designer, that was stripped
level with the waterlines on the sides, and parallel to the keel on the
bottom, and joined with a mitre joint at a hard chine, but this does not
look like it would work with your plans.
A you should use the same principal that you are using - just adapt it for the changing shape of the hull. He commented that he might have begun planking at the wing but you are past that part now.
Q I purchased full size drawings and I have noticed that the dimensions are about 1/16" oversized for each
10" of distance in both the horizontal and vertical directions on all of the
plans. I imagine that I can ignore this if I trace the plans, since it
seems consistent.
A The oversize dimensions would be caused by a stretching of the blueprint paper. That is common when the paper absorbs humidity. The change is small and consistent and we would not worry about it. If you trace the stations the boat will work out fine.
Full size plans from Bear Mountain are supplied packaged in a plastic sleeve. Remember to keep the plans in the sleeve until ready to use in order to avoid humidity changes
Q I would like to extend the cockpit forward so I can use the kayak for fishing and keep my gear in my lap. How far forward can I extend it without impacting the design strength?
A The cockpit size on all the kayaks is comfortable for entry and exit and will take a standard skirt size. If you want to forgo the standard skirt and make a custom one then the cockpit can be lengthened by up to 12" forward without impacting on the strength of the boat.
Q I glassed the inside of my Freedom17 in the fall using West epoxy
105/207. The outside has been completed. I had the canoe sitting
outside on some sawhorses while I prepared my work area to varnish
the inside. The canoe was outside less than 1 hour in the sun,
temperature about 20c. When I brought the canoe back in and turned it
over, I noticed about 6 or 8 places where the glass had separated
from the hull. They range in size from 1/4 inch to 2 inches in
diameter. They are mostly in an area about 1 foot square, but there
are individual bubbles in other places. I cut one of the bubbles and
lifted the edge and noticed that it was sticky and smelled like
uncured epoxy. Do you have any advice on how to fix this and what may
have caused it.
A It sounds as though you may have had an improperly mixed batch of
epoxy. Either it wasn't stirred enough, or the hardener wasn't in.
You need to scrape the un-cured epoxy off, and get down to clean
wood. Then you must patch the area with the proper mixture.
Use lacquer thinner to help make the job easier.
Click here for FAQ information on older versions of our books
Other FAQ Sections
Cost, Time, Tools Required, Experience Neccessary
- This FAQ section outlines what you need to know before starting your Bear Mountain project
Building your Bear Mountain Canoe or Kayak
- This FAQ section includes topics such as Lofting, Plotting, Fairing and more.
About the CanoeCraft and KayakCraft books
- this FAQ section answers a number of questions about our Bear Mountain publications.
Choosing a Design
- This FAQ section provides information on specific Bear Mountain designs, as well as a guide to help you choose the design that is right for you.
Product Feedback
- This FAQ section provides feedback from our customers on a variety of Bear Mountain products.
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