Butt joint VS scarf joint

[jim in Texas]

I am unable to get long lumber and have no choice but to use shorter strip's to strip my canoe , the question I have is should I use butt joints as canoe craft says to use or use a scarf joint ?If I use a butt joint is there a risk of the joint seperating and seeing light thru the joint ,the scarf joint too me looks like it would be a lot stronger .Thanks for any info anyone can give me on this.

[Jeff in Pembroke]

Hi Jim,

I used butt joints and everything turned out well. A butt joint is easier to do and the joint line is shorter than a scarf joint. The strength of the hull is in the fiberglass/epoxy layers so hull strenth isn't an issue with either joint type. Others have used scarf joints with great results so there really is no right answer.

Happy building,

Jeff

[Kurt Loup]

Jim,

I use a stationary belt sander to make my scarfs while stripping. I try to locate the scarf on a form so that a staple will help hold it in place. See http://www.loup-garou.net/outerisland_waterline.html for a picture.

Kurt

[Michael Freeman]

Jim,

I used butt joints on my Prospector, but rather than making straight 90 degree butt joints I made mine 45 degree butt joints. When well done they are all but invisible, particularly in darker woods.



When viewed from the 1/4" edge, the joint looks like this:
___________
_____/______

Because the joint is angled, you can glue it together. Not as strong as a longer scarf but high strength isn't necessary, it's a heck of a lot easier and less time consuming to make, and light does not shine through the joints.

Happy building,
Mike

[Jack in Stoughton]

I've built 3 canoes from scrap lumber. The lumber is scrap cedar house siding. I can get about 6 strips from a piece of scrap. Some of the scraps are only 4 or 5 feet long. I first cut up the strips, ending up with a lot of 1/4" X 3/4" X 4 to 10 foot pieces. I then cut scarph joints in an 8:1 jig I've made for the purpose. This cut is done on my table saw. I then glue my pieces up using carpenter's glue and end up with strips 16 feet or so long. I then do the bead and cove. The canoes come out pretty nice.

Go for it!

[Bernie in Illinois]

In similar fashion to Jack in Stoughton, I used a 7:1 scarf joint. I had trouble getting a clean enough cut using the table saw and switched to a sanding disk instead. The saw blade tends to tear the strip, but the disk leaves a smooth edge. You can buy a sanding disk for your table saw for under $30 or make your own.
Another consideration, make sure that your strips are of even thickness, otherwise you end up doing alot of extra work sanding around the joints.

[Tom in MN]

I think the main question should be "How much time to do you have?". Using butt joints will save you a ton of time over scarfing your strips. I have always used butt joints and never see light through the joint. I think what it comes down to is that scarf or butt joints really do not make any difference in the final appearrance of the canoe, it is just that one takes a lot more time than other.

I think a lot of folks are first time and one time builders. The idea of using a scarf is more appealling than a butt, especially to those who are particular about what their work looks like. I also think that many first time builders actually think that the strips, and the way they are laid out, actually give the boat more strength and this is generally not the case. I am not knocking the guys who scarf their strips, as in similar woodworking applications it would make sense to use the more sophisticated scarf joint. It really is not necessary in building a canoe. Use your saved time and spend it with the Mrs, then she won't be as upset with all the time you spend with your canoe.