Missed step locating F721B, DWG 18, 25

[wirejock]

Need help! I skipped a step locating F721B, DWG 18, 25

I was just getting ready to rivet the canoe and found a problem, maybe. I completely missed a step in the manual.
"Tape a piece of 0.032” aluminum to the outboard surface of the longeron and fit the F-721B aft deck to the top of
the longeron. Carefully establish the fore/aft position. The shim will simulate the F-770 side skin. When the
outside edge of the side rail matches the outboard surface of the shim, drill the F-721B to the longeron.
Leave it clecoed for now."

I used the aft deck to double check the bend of the longeron but I never match drilled it. I know the curve was correct but somehow I missed the curve by a tiny bit.

I read forward and noticed this step.
"See DWG 25. The F-721B side rails have already been drilled to the longerons."

I placed both F721B aft decks in the exact place called out in the plans 28-1/4" from the forward end of the longeron and the outboard top edge hangs over the edge of the outboard side of the skin by about 1/8". Notice in the photo. Since the longeron was never match drilled through F721B, I'll have to drill it when the canoe gets flipped. I can pull the skins and bend the longerons with the Buller dies but how critical is the fit. Since everything is drilled, I'm hesitant to bend the longeron and cause a misalignment of parts.

I'm wondering if this edge can be trimmed off since the manual mentions it.

"Carefully file the decks and rails to fit the contour of the side skin."

Any advise is appreciated. I can send it to Vans Monday as well.

 

[bret]

Is this the shim we are talking about, aft deck?

 

[bret]

here is the only problem you may run into if building a slider, room for the slider rail that goes on top the aft deck.

 

[wirejock]

Thanks

Yes. That's the spot. My aft deck overhangs the edge by 1/8".

 

[bret]

Another issue that may or may not come up is the canopy frame matching the aft deck curve, I had a 2012 finish kit and the canopy frame was spot on! no tweeking or bending required, so if that curve is matched to the frame it may cause a problem, in any case I would call Vans, worst case, buy new canopy decks and back drill through longeron with shim in place to simulate side skin.

 

[wirejock]

Aft deck

That was my mistake. I never drilled it to the longeron. I'm pulling the side skin now to apply a little more bend. It worked on a test sample so I will go slow and check holes as I go.

 

[bret]

One more thing while you are here, I did the antisplat almost 14 seat back mod, the plane is like a lounge chair now, so much more comfortable, and you can remove that cross bar if you need to crawl in the back for anything!

 

[wirejock]

Fixed

One more thing while you are here, I did the antisplat almost 14 seat back mod, the plane is like a lounge chair now, so much more comfortable, and you can remove that cross bar if you need to crawl in the back for anything!

Thanks so much Bret. I fixed it. One side done. The left side is done.
I removed the skin, put my vice on a saw horse and used the Buller dies to shape the longeron. It took four passes to get it right but now the aft deck fits correctly.
I was worried the skin holes in the longeron would creep but they didn't move. I tried a sample and at full deflection, the holes only moved a few thousandths so I was confident my solution would work. I still have a few thousandths hanging over the skin but the aft deck hasn't been deburred yet so it should fit flush.

Lesson for noobies...
Read ahead. Had I not looked at the next steps, this would have been a nightmare.