Extra hole

For those who did SB wings: is the extra hole in the spar web flange countersunk? It's the hole in the middle of the 2 rows in the pic. Looking ahead I cannot see if/how that hole is used. Obviously the inboard/outboard rows have the leading edge/skins attached, but cannot see how the extra hole is used. Thanks!

I don't recall that hole during my build, but that could just be lack of memory on those tasks. I don't recall the hole, nor can I fathom a use for it. But I've been wrong before.

There is a joint of the leading edge skin, which uses the forward hole and the rear skin which uses the aft hole. That hole would be right in the middle of the joint.

After riveting the skins on, I would use a little proseal from the bottom to splug the hole to minimize the chance for water leaks.

Not a big deal, build on......

It's mentioned on Page 13-2 in the slowbuild plans. I think it's only purpose is to mark the bottom flange of the spar extensions. You don't need to countersink but if you did, consider it to be deep deburring...

flion said:

It's mentioned on Page 13-2 in the slowbuild plans. I think it's only purpose is to mark the bottom flange of the spar extensions. You don't need to countersink but if you did, consider it to be deep deburring...

Click to expand...

I had to go look that one up, which is why I couldn't remember it. It's amazing how much and how quickly you forget these details.

Extension to the W-SPAR ASSY-L Spar AssemblyLeft using four W-1006F Spar Splice Plates. Correct orientation of the main spar web extension places the "extra" hole in one of the flanges on the bottom. See Figure 1.

NOTE LOCATION OF "EXTRA" HOLE IN LOWER FLANGE OF W-1006E-L

Build on........

Bob, Patrick - thank you both. One thought was, as you mentioned, that it was only to mark the bottom flange, but I found it odd that this would be done. Plenty of other pieces that are dedicated left, right, top, bottom, etc, after match-drilling, but there nothing to identify as such other than a Sharpie..

Good idea about the pro-seal, as, yes, that hole will be right in between the two skins.