I'm building my first SIG 4* 40 and have a question on the attachment of the fin. The directions say to epoxy the fin to the horizontal and optionally re-inforce the attachment with triangle stock if you want to. They say that the tri stock is not really required because the test models performed fine without. My question is, I have built a lot of planes and in almost all of them the fin goes through the horizontal and down somewhat into the fuse for additional strength. I am tempted to drill holes through the horizontal and laminate dowels into the vertical and then push the dowels through the drilled holes in the horizontal and fuse when attaching the fin. Any thoughts or experiences on this particular item on this particular build??

Thanks,
Andy

I used the tri stock method on mine. I sanded each, smoothly curving down to points. It looks pretty good. I think the dowel method would be tougher to align. I covered the tri stock before gluing.

I also used the tri stock method. In fact I think the wood was included in the kit. I agree with Mole Hunter that dowls would be dificult to align and I do not think that they offer any benefit over the proposed tristock method.

You can hardly see the tristock in this photo. But definitely agree that it is better to cover before gluing to plane.

Wow! Lots of mods on that one. It looks like a different plane. Great work.

Mole Hunter,<div>That's a sharp looking 4-Star you're flying there!!!</div><div>
</div><div>Ken</div>

That dowel method wouldn't be that tough to do, plus you could doll it up with some tail wire braces for extra support.
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I've successfully used bamboo skewers as dowel material. The advantage is one end is already sharpened to a point. Attach to rudder first with points down, align, then push down lightly and drill where the dimple holes from the skewers poked in.

Walmart's Neighborhood grocery stores sell some skewers that are ideal for this. 100 for about $1.20.

I have used the triangle stock on all my 4 Stars and never had any issue's t all. Good Luck, Dave

I flew the heck out of mine with no additional bracing.
John

I built mine with extended tabs on the bottom of the rudder for the leading and TE stock to go down into the fuse. Also turned the canopy around and rounded the wing tips. Checkerboard bottom... Sweet flying plane.