Scarfing Ratio

Looking at scarfing some Sitka spruce together for stringers. Anyone suggest the best ratio - 1 in 12, 1 in 16, etc.
Thanks again

 

Hi mugsman,
I think you should check this discussion: http://www.boatdesign.net/forums/boat-design/8-1-ratio-40864.html
Cheers!

 

Thanks for the information; interesting reading indeed. Looks like it can be summarized as 8 to 1 minimum.

 

Even 6:1 (minimum) can be ok for frames and keels, if you have good woodworking and glueing skills. Below that, a scarf should be reinforced.

 

As pointed out the 8:1 thread, the ratio depends on a few factors. Lightly loaded and/or bent elements can use a steep slope scarf, but more heavily loaded and/or tighter radius bends require a shallower slope.

Try to position the scarfs in relatively flat, straighter areas of the stringers if possible.