Scarf Orientation Question

Welcome to the new Bear Mountain Builders Forum - an interactive internet service we provide to encourage communication between canoe and kayak builders
Post Reply
wb9tpg
Posts: 114
Joined: Thu Feb 10, 2011 7:01 pm
Location: Versailles, KY
Contact:

Scarf Orientation Question

Post by wb9tpg » Sun Feb 27, 2011 1:23 pm

This is a dumb question but I see pictures on this site of people doing it both ways. Which direction should I scarf my strips? I understand the sheer strip under the gunwales is hidden and it does not matter. I'm interested in the rest of the strips. I've decided to scarf rather than use butt joints for the fun of it.

Image
This is the way I think - Call is "A"

Image
But I see people have done it this way - Call it "B"

Thanks, Gary

BearLeeAlive
Posts: 196
Joined: Tue Aug 18, 2009 7:00 pm

Post by BearLeeAlive » Sun Feb 27, 2011 2:02 pm

I did my strips using method B using a 4:1 scarf. It has more than adequate gluing area. Sanding out the A method would leave an irregular joint, with lots of glue on the surface, whereas method B has a tight joint, and if matching strips closely is almost invisible.

I think you are making the right choice for joining by doing scarfs. Butt joints always seem more noticeable.
-JIM-

Ben
Posts: 69
Joined: Wed Jul 08, 2009 11:51 pm

Post by Ben » Sun Feb 27, 2011 2:33 pm

I used butt joints on my first boat. I am now closing the last side of the football using your method "B" on my second boat and I feel that it is faster and looks better than the butt joints. I would only consider using "A" if I was splicing entire boards together before making the strips.

Rick
Posts: 727
Joined: Thu May 27, 2004 9:23 am
Location: Bancroft, Ontario

Post by Rick » Mon Feb 28, 2011 9:56 am

I made the "B" type... the "A" scarf might result in a wider glue line after being sanded down which could affect color after the epoxy soaks in.

Dunno if this actually would happen since I didn't make them this way, the "B" scarfs will create a thin glue line for sure.

podunk
Posts: 36
Joined: Mon Jan 26, 2009 6:04 pm
Location: indiana

Post by podunk » Mon Feb 28, 2011 5:47 pm

See the last post on tips and techniques, whatever route you choose build a jig and make some test pieces. I used method A on my cherry strips just because it it didn'nt look as noticable. I have to look twice to see them now. I think alot depends on the grain orientation of your strips and go light on the glue. Good Luck!

AlanWS
Posts: 209
Joined: Thu Mar 17, 2005 4:30 pm
Location: Shorewood, WI

Post by AlanWS » Mon Feb 28, 2011 9:35 pm

I scarfed using the A orientation with epoxy, which helped the joints to blend in because it's transparent and will cover all anyway. The thin edge helps. Some of the joints are hidden to the extent that they are hard to find even if you know where to look. Some (where I did a less good job of color matching) are obvious, but in my mind less obvious than doing it the B way.

If you want strength (say if you scarf gunwales) then there is a significant advantage to the A method: you can have a much shallower and stronger scarf from the same amount of wood. The A method is easier to clamp in proper alignment, and takes about 1/3 as much overlap for the same strength, assuming the bond is equal. An 8:1 scarf is pretty standard if you are looking for strength.

Edit to add that John Michne's website is an excellent resource, and he covers the topic:
http://michneboat.com/Working%20With%20 ... Strips.htm
Alan

Ben
Posts: 69
Joined: Wed Jul 08, 2009 11:51 pm

Post by Ben » Mon Feb 28, 2011 10:18 pm

My only issue with the "A" orientation is that if you are bending the strip around the boat, the outside face is under tension. IMHO, you are better off having a diagonal face in the area of the largest stress. It probably doesn't matter on the strips, but I would be extremely nervous of that orientation on a gunwale.

Post Reply