Form Making

Welcome to the new Bear Mountain Builders Forum - an interactive internet service we provide to encourage communication between canoe and kayak builders
User avatar
Its Me
Posts: 143
Joined: Fri Jul 09, 2004 12:21 pm

Form Making

Post by Its Me »

My Redbird forms just aren't coming out as nice as some of the forms I have seen on these pages. So far I have four station molds and two stem molds made. I went with 3/4" BC plywood. I am tracing the pattern off the Bear Mountain plans and using a jig saw to cut. I am trying to hold a 1/16" off the line but I can't always maintain that gap. Sometimes it goes out to a 1/8" sometimes down to 0. I then try to sand it true with an orbital sander and a rasp.

To what tolerance do I need to hold to get a fair hull and how can I get that tolerance? :?:
Last edited by Its Me on Wed Sep 01, 2004 8:38 am, edited 2 times in total.
guest

molds

Post by guest »

It's Me -

You will be OK. I also used a jig saw and orbital sander to cut the molds and mine came out fine. What I tried to do was cut about 1/16 to 1/8 from the line and finish up with the sander. This will work fine. Obviously the better you cut the molds the fairer your canoe will be, but believe me no body is going to notice a difference of 1/16th of an inch (probably even 1/8ths of and inch either). Having said that, do the best you can and it will be fine.
patrick pfeifer

Post by patrick pfeifer »

my dad and i just finished cutting our molds, we just put the blade of our jigsaw right on the edge of the line, while you are cutting, if you cant see the line, you are too far in, if you can see wood between the blade and the line, you are too far out. we got pretty good molds, and we will fair it up with a sureform and mabye sandpaper.
User avatar
KARKAUAI
Posts: 362
Joined: Sat May 08, 2004 3:06 pm
Location: Hickory, NC / Princeville, Kauai, HI
Contact:

Post by KARKAUAI »

Try mounting your belt sander sideways in a vice and use it like a stationary sander (if you don't have a stationary sander). You can probably hand hold the pieces, but a flat board adjacent to the sander would make them easier to control.
A hui ho,
Kent
Steve Lansdowne

Post by Steve Lansdowne »

If you have a table saw, you can get a metal blade-sized disk that has sandpaper glued to both sides of it. I got mine at Sears. This turns your saw into a stationary sander which is wonderful for sanding to the line on such forms after you've cut them slightly proud of the pencil line.
User avatar
Erik, Belgium
Posts: 344
Joined: Fri May 14, 2004 5:31 am
Location: Gierle, Belgium
Contact:

Post by Erik, Belgium »

hi Kent,

That's exactly how I do it. Beltsander mounted on a table, and slide your roughly cut molds against it: precision garantueed. I also put wax on the table in order the molds glide nicely.

cheers
jcolten
Posts: 30
Joined: Mon May 10, 2004 12:12 pm

form making

Post by jcolten »

mounting the belt sander with the belt vertical (rather than horizontal) allows you make use of all the belt's surface. better for belt life and also heat dispersion
User avatar
KARKAUAI
Posts: 362
Joined: Sat May 08, 2004 3:06 pm
Location: Hickory, NC / Princeville, Kauai, HI
Contact:

Post by KARKAUAI »

Why didn't I think of that? Duh!!!
A hui ho,
Kent
KenC
Posts: 190
Joined: Tue Jun 01, 2004 10:42 pm
Location: Oakville, ON

Post by KenC »

I also used a table-saw sanding disk, as Steve suggested. It works great, not only for finishing the edges of forms, but also for making accurate, repeatable bevels when scarphing strips (with a piece of scrap clamped down for a guide, of course). Takes about 5 seconds per strip.
IslandStripper
Posts: 16
Joined: Thu Sep 09, 2004 12:40 pm

Form Making

Post by IslandStripper »

Givin the challenge in transfering a plot of the forms to the plywood (battens, carbon paper, finishing nails), has anyone glued the paper right to the plywood and then rought cut with a jig saw and then sanded to the "true" line.

I haven't tried it but I can't see why it wouldn't work.
User avatar
Glen Smith
Posts: 3719
Joined: Sat May 08, 2004 9:08 am
Location: Baie-St-Paul, Quebec, Canada

Post by Glen Smith »

Yes, I used 3M spray on glue (Super 77) and it worked fine. Make sure the edges are well glued or they may lift when you cut and sand the forms. Some builders brush a coating of diluted wood glue on the forms and let it dry. Then they spray it with a bit of water and lay the plans on the wood and press well. I haven't tried that one yet but I would test it first.
KenC
Posts: 190
Joined: Tue Jun 01, 2004 10:42 pm
Location: Oakville, ON

Re: Form Making

Post by KenC »

IslandStripper wrote:...has anyone glued the paper right to the plywood and then rough cut ....
That's how I did mine. I used a bandsaw and sanding disk on the table saw, in place of the jigsaw & ROS, but its the same principle. Doing it this way, you can arrange & rearrange the paper form patterns on the plywood sheet to nest them as close as possible together, and therefore minimize waste.
form

I have a 15ft form already built

Post by form »

contact me if interested, reasonable

portcarlingboats@hotmail.com
reinbilt
Posts: 80
Joined: Tue Aug 31, 2004 7:35 am
Location: northern michigan

Post by reinbilt »

A large sanding drum in a drill press works good too. I attached a 2 foot by 3 foot piece of 3/4 inch particle board to my drill press table with a hole in the middle that is the same size as my sanding drum then lowered the drum into the hole about 1/4 in.
User avatar
psimer
Posts: 14
Joined: Mon Jul 12, 2004 1:51 pm
Location: Lake Lanier (Gainesville) GA

Post by psimer »

I use a 12" disc sander which I made by attaching it to my 14" Delta band saw's pulley.
It works great and is usefull for many other projects such as scarfing etc.[/img]
Dana H P'Simer Sr.
Don't start a vast project with a halfvast idea.
Post Reply