Scarfing Ratio

[mugsman]

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

[daiquiri]

Hi mugsman,
I think you should check this discussion: 8:1 ratio
Cheers!

[mugsman]

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

[daiquiri]

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.

[PAR]

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.