Boat Building Forum

Find advice on all aspects of building your own kayak, canoe or any lightweight boats

An outsider's perspective
By:Brian Nystrom
Date: 4/20/2000, 1:30 pm
In Response To: Re: Safety, two points (Derek)

I have yet to build my first boat, so I have no axe to grind for any particular construction method. I've been doing a lot of reading and web surfing for information on this subject. So far, this is what I've gleaned from my research:

1) Glass is lighter than wood and has a greater impact on the strength of the finished boat. Perhaps a better way of saying this is that it takes less weight and thickness of glass to increase the strength of a layup a given amount, than it would if only the thickness of the wood was increased. The table on page 5 of Kayakcraft illustrates this.

2) Satin glass is stronger than conventional woven glass. Multiple layers of light satin glass are stonger than a single layer of heavier conventional woven glass.

3) Glass to resin ratios are important for optimun strength. Too much resin makes a weak layup.

4) Multilayer light glass layups will flex more before failing than single layer heavier glass layups.

5) Failures typically occur on the tension side of the layup. Hull/deck flexing in waves would stress the outside layers. Impacts with rocks and other hazards would stress the inside layers (and abrade the outside).

Therefore, the lightest, strongest boats will be built with layups comprised of a thin wood core covered on both sides with multiple layers of light satin glass with no more resin than necessary to optimally fill the weave. This is the method that George Roberts advocates.

Impirical evidence makes it clear that perfectly serviceable boats can be built using thicker wood covered with single or partial layers of 6 oz. glass and/or glass tape, as the Schade brothers, Ted Moores and Chris Kulczycki (among others) advocate. Thousand of boats have been built this way and we haven't had mass sinkings. This method is certainly easier to build, especially for novice boat builders. However, it does not produce the lightest or strongest boats.

If you view George's statements about other's methods in this context, you'll understand his points. Yes, he could be much more diplomatic and less inflamatory in making his case, but his points are valid just the same. He hasn't been especially forthcoming about his methods on this forum, but I think this is primarily because he wants people to do the research for themselves and learn from it, rather than just handing it to us. As someone who's done a fair amount of technical training and coaching, I have to agree that the best method of teaching is to get people to understand why they do something, rather than just telling them what to do. In the direct emails I've had with George, I've found him to be very helpful and downright pleasant.

Yes, it's tempting to dismiss his comments because of the way he presents them, but if you look into what he's saying, the principles are sound.

Messages In This Thread

Safety, two points
Nolan -- 4/20/2000, 9:32 am
Re: Safety, two points
Rehd -- 4/22/2000, 3:59 am
Re: Safety, two points
Erez -- 4/22/2000, 10:16 pm
Re: What information do you want?
Nick Schade - Guillemot Kayaks -- 4/21/2000, 11:49 am
Re: What information do you want?
Nolan -- 4/21/2000, 12:33 pm
Re: P.S.
Nolan -- 4/21/2000, 12:36 pm
Re: Seat of the pants tests
Nick Schade - Guillemot Kayaks -- 4/21/2000, 2:10 pm
Re: Seat of the pants tests
Don Beale -- 4/21/2000, 9:09 pm
Re: Seat of the pants tests
Nolan -- 4/21/2000, 2:46 pm
Re: Seat of the pants tests
Nick Schade - Guillemot Kayaks -- 4/21/2000, 4:19 pm
Re: Seat of the pants tests
Ross Leidy -- 4/21/2000, 4:43 pm
Re: Seat of the pants tests
simon king -- 4/21/2000, 5:07 pm
I do agree
Marcelo -- 4/21/2000, 5:58 pm
Re: I do agree
Ian Johnston -- 4/22/2000, 2:18 am
Re: I do agree
Dean Trexel -- 4/23/2000, 1:29 pm
Off topic: Banana Republic Citizen
Marcelo -- 4/22/2000, 3:16 pm
Re: Off topic: Banana Republic Citizen
Ian Johnston -- 4/22/2000, 7:02 pm
Re: Diesels for marine use ...
John B. -- 4/22/2000, 6:47 pm
Re: Avoidance/responsibility
Ian Johnston -- 4/21/2000, 3:37 pm
Re: P.S.
Ian Johnston -- 4/21/2000, 1:22 pm
Re: martial soap operas
lee -- 4/21/2000, 7:54 pm
Re: Well Put
Mike Hanks -- 4/21/2000, 2:05 pm
Re: Well Put
Dean Trexel -- 4/21/2000, 2:23 pm
Re: What information do you want?
Dean Trexel -- 4/21/2000, 12:22 pm
Re: What information do you want?
Bill Heuser -- 4/22/2000, 6:07 am
Time to step back and take a deep breath
Brian Nystrom -- 4/22/2000, 9:36 am
Re: Your Flame Sucks
Spidey -- 4/23/2000, 1:27 am
A little testy, are we?
Brian Nystrom -- 4/23/2000, 7:18 am
Re: Time to step back and take a deep breath
Bill Heuser -- 4/22/2000, 5:17 pm
Re: What information do you want?
Richard -- 4/22/2000, 7:54 am
Re: What information do you want?
Don Beale -- 4/21/2000, 12:19 pm
Re: What information do you want?
Nick Schade - Guillemot Kayaks -- 4/21/2000, 12:33 pm
Re: What information do you want?
Don Beale -- 4/21/2000, 8:58 pm
Re: There are no standards
Nick Schade - Guillemot Kayaks -- 4/22/2000, 9:53 am
Re: Propriatary data
Don Beale -- 4/23/2000, 11:55 pm
Re: safety,reality,and b.s.
lee -- 4/21/2000, 12:54 am
Well put Lee (nt) *NM*
Doug Keaster -- 4/21/2000, 9:05 am
Re: safety,reality,and b.s.
Nolan -- 4/21/2000, 8:03 am
Re: Good morning
lee -- 4/21/2000, 9:24 am
Re: safety,reality,and b.s.
Brian G. -- 4/21/2000, 9:10 am
Re: safety,reality,and b.s.
Brian G. -- 4/21/2000, 1:55 am
The right to make unsupported statements.....
Bruce -- 4/20/2000, 4:03 pm
Re: oops!
Dean Trexel -- 4/20/2000, 9:47 pm
Re: oops!
Bruce -- 4/20/2000, 10:12 pm
Re: oops!
Brian Nystrom -- 4/20/2000, 10:58 pm
Re: oops!
Brian G. -- 4/21/2000, 12:37 am
Re: The right to make unsupported statements.....
Dean Trexel -- 4/20/2000, 5:31 pm
Safety priorities....
Will Brockman -- 4/20/2000, 8:49 pm
Now THIS I agree with!!!
Doug Keaster -- 4/20/2000, 4:48 pm
Well written points by Nolan.
Allen R. -- 4/20/2000, 2:19 pm
Re: Well written points by Nolan.
Nolan -- 4/21/2000, 7:44 am
Re: Safety, two points
Dean Trexel -- 4/20/2000, 12:24 pm
Re: Safety, two points
Chicken Little -- 4/21/2000, 10:39 am
Re: Safety, two points
Ken Finger -- 4/20/2000, 11:38 am
Re: Safety, two points
Nolan -- 4/21/2000, 7:50 am
Re: Safety, two points
Derek -- 4/20/2000, 11:37 am
An outsider's perspective
Brian Nystrom -- 4/20/2000, 1:30 pm
Re: An outsider's perspective
Dean Trexel -- 4/20/2000, 2:05 pm
Not true, from what I've seen
Brian Nystrom -- 4/20/2000, 2:48 pm
Re: Not true, from what I've seen
Dean Trexel -- 4/20/2000, 5:13 pm
Re: Not true, from what I've seen
Brian Nystrom -- 4/20/2000, 10:41 pm
Re: Bryan
lee -- 4/21/2000, 1:39 am
Here you go.
Brian Nystrom -- 4/21/2000, 8:02 am
Re: Strength Data Graphs *Pic*
Nick Schade - Guillemot Kayaks -- 4/21/2000, 12:28 pm
Re: Strength Data Graphs
Brian Nystrom -- 4/21/2000, 12:51 pm
Re: Strength Data Graphs
Shawn B -- 4/21/2000, 4:04 pm
Re: wood density
Nick Schade - Guillemot Kayaks -- 4/21/2000, 4:25 pm
Re: wood density
Bill Heuser -- 4/22/2000, 4:38 pm
Re: Optimized Boats
Nick Schade - Guillemot Kayaks -- 4/21/2000, 3:01 pm
Agreed
Brian Nystrom -- 4/21/2000, 5:08 pm
Re: Agreed
Ian Johnston -- 4/21/2000, 5:45 pm
Re: Well Said, Nick!! *NM*
Ian Johnston -- 4/21/2000, 3:42 pm
Re: Here you go.
lee -- 4/21/2000, 8:59 am
Fair enough, but...
Brian Nystrom -- 4/21/2000, 10:19 am
Re: p.s. guys in a snit
lee -- 4/21/2000, 9:17 am
Off topic, but since you went there...
Brian Nystrom -- 4/21/2000, 10:56 am
Re: Off topic, but since you went there...
lee -- 4/21/2000, 7:36 pm
Re: Lee
Ian Johnston -- 4/21/2000, 3:16 am
Re: Lee
lee -- 4/21/2000, 9:07 am
Re: Hondas and Suburban/Guillemot and Roberts
Ian Johnston -- 4/21/2000, 12:54 pm
Re: Lee
Bill Heuser -- 4/21/2000, 6:03 am
Re: Lee
James Neely -- 4/21/2000, 7:32 am
Madness continues
Dale Frolander -- 4/21/2000, 3:10 am
A nibble of crow.
Dale Frolander -- 4/22/2000, 3:38 am
Good points, Dale.
Brian Nystrom -- 4/21/2000, 10:34 am
Re: Good points, Dale.
Dale Frolander -- 4/21/2000, 11:57 am
Raka
Brian Nystrom -- 4/21/2000, 12:16 pm
Re: Raka
Ross Leidy -- 4/21/2000, 2:18 pm
Raka glass with MAS epoxy
Allen R. -- 4/24/2000, 3:32 pm
Re: Raka glass with MAS epoxy
Dan Lindberg -- 4/24/2000, 5:50 pm
Re: Experience with this layup *Pic*
Mike Hanks -- 4/21/2000, 1:04 pm
Practice makes perfect
Brian Nystrom -- 4/21/2000, 5:02 pm
Re: Raka
Dale Frolander -- 4/21/2000, 12:37 pm
Re: It runs when you leave the room
Shawn B -- 4/21/2000, 3:52 pm
Re: Raka
Dean Trexel -- 4/21/2000, 12:29 pm
Re: Madness continues
lee -- 4/21/2000, 9:29 am
Re: Safety, two points
Ross Leidy -- 4/20/2000, 10:11 am
Re: Safety, two points
Rob Forsell -- 4/20/2000, 9:57 am