Cowl side piano hinge

My cowl now fits well. Looks pretty good, too, with nice gaps and all. Just have some filling to do around the front and seal and paint the inside.

Here's my problem. I had one minor blunder. The plans have you position the side piano hinge on the bottom cowl first and the eyes stick up over the edge. Then on the top cowl the eyes are fully hidden by the top cowl edge. I reversed this (just a dumb oversight).

The affect is that it makes installing/removal of the top cowl tricky. This is because with the bottom cowl installed, in my case, the eyes are below the edge (not sticking up above the edge). From the top the eyes stick down below the top cowl edge. It requires a little pressure to flex the top cowl sides in to get the eyes in behind the bottom cowl edge while the rear portion interlocks with the firewall hinge. Getting it back out I have to reverse the process, which as stated, is tricky.

I'm debating on whether to bite the bullet and redo these side hinges. I hesitate because it fits really good right now and I hate to risk screwing that up. And although it does require some slight-of-hand to get the cowl on and off, it does, in fact, come on and off.

Should I just leave well enough alone or redo these hinges? Thoughts?

jwilbur said:

Should I just leave well enough alone or redo these hinges? Thoughts?

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There is no way I would leave that mistake.

The reason the hinge has to be as prescribed is that with the top cowl held on by hinge at the firewall and down each side, the top cowl has to be able to be flexed outward at the back so that the hinge loops on the firewall hinges at the rear corners disengage and allow the cowl to lift vertically.

The cowl can not lift vertically if the rear hinge loops are still engaged where the cowl wraps around the sides.

If you have camlocks or some other type of fasteners around the back then it might be ok, but even then it would always be a bit awkward and a higher risk of damaging paint, etc.

rvbuilder2002 said:

The reason the hinge has to be as prescribed is that with the top cowl held on by hinge at the firewall and down each side, the top cowl has to be able to be flexed outward at the back so that the hinge loops on the firewall hinges at the rear corners disengage and allow the cowl to lift vertically.

The cowl can not lift vertically if the rear hinge loops are still engaged where the cowl wraps around the sides.

If you have camlocks or some other type of fasteners around the back then it might be ok, but even then it would always be a bit awkward and a higher risk of damaging paint, etc.

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This is why I have to flex the top cowl to remove it. First inward for it to release from the side hinge and then up and outward to release from the interlocked hinge at the back. It definitely comes in and out. I've done it several times. ... Your comment about the paint is what I'm thinking about right now. My removal "trick" will be rough on the paint.

Any suggestions on how to redo these hinges while preserving the very nice fit I've managed to achieve?

Any suggestions on how to redo these hinges while preserving the very nice fit I've managed to achieve?

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I think you have more than just "managed" to achieve a good fit.
You are becoming a pro with fiberglass and you can get an even better fit
the second time around.

Take Scott's advice.

N427EF said:

I think you have more than just "managed" to achieve a good fit.
You are becoming a pro with fiberglass and you can get an even better fit
the second time around.

Take Scott's advice.

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If only.... But thanks. I've already ordered the new hinges.

sounds like an "easy fix", still "hurts"

Been there done that, have had to redo way too many hinge assemblies from similar perspective induced oops......I suspect very little fiberglass redo will be needed and your fit should stay perfectly intact. Filling in the old hinge attach holes will be your secret and will never be seen again and have/has absolutely no structural effect on the final product. How you knock out the old rivets is wide open, always so nice when you don't have to use the "old" hole, all yours will be new in metal and fiberglass since this will move each hinge assembly up ~1/4" and you can stagger some if wanted. At least the expensive parts are all good and all your nice fitting stays intact.... that is no easy task, as you know.

Cheers, Mike

WrightsRV7 said:

Been there done that, have had to redo way too many hinge assemblies from similar perspective induced oops......I suspect very little fiberglass redo will be needed and your fit should stay perfectly intact. Filling in the old hinge attach holes will be your secret and will never be seen again and have/has absolutely no structural effect on the final product. How you knock out the old rivets is wide open, always so nice when you don't have to use the "old" hole, all yours will be new in metal and fiberglass since this will move each hinge assembly up ~1/4" and you can stagger some if wanted. At least the expensive parts are all good and all your nice fitting stays intact.... that is no easy task, as you know.

Cheers, Mike

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Yep. The fix is done and the holes are filled. It wasn't that hard. And because I didn't care about reusing the holes or the old hinges I was able to drill out the ~160 rivets pretty quickly. Then I staggered the new holes compared with the old holes just as you suggested. Lost some time for being stupid but I'll never regret that I redid it. It's so easy to get the top cowl on and off now compared to before. And the fit is just as good as before. (Maybe even a little better . )

One interesting thing. Nothing to do with this fix, but the hinge along the back of the cowl on the top that so many people complain is difficult to get in and out. Not sure what kind of magic I used but I have absolutely no difficulty at all inserting and extracting those pins.

Thanks for the kind words Mike,
-Joe

told you so

Not sure what kind of magic I used but I have absolutely no difficulty at all inserting and extracting those pins.

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because it is a perfect fit!
Not magic, you are getting very good at it.