stamped butt rib?

[Dot_AK]

Asking for help twice within 2 days, must be making progress on the project...

It was recommended that I buy two experimental stamped butt ribs from D&E aircraft instead of trying to salvage my broken built-up butt ribs. What arrived looks very, very different, to say the least. The more I look at it, the more nervous I become. See, what was described to me was a box-shaped structure, but what I got were two stamped metal ribs that are in three sections - nose, middle, and tail - and each piece is only a single stamped piece of metal.

The gent at D & E said there would need to be a few modifications made to adapt it from a metal spar to a wooden spar, but no instructions came with the parts.

I'm getting Real Close Now to putting all the hardware on the wing and trying to figure out how to put the fuel tank in - so I thought I'd ask, am I missing something, or are these single pieces of stamped metal really all I need for a butt rib? Anybody gotten these before? And last but certainly not least, does anybody have a picture of a stamped butt rib, so I can eyeball it and see that the parts in hand really do assemble to parts on struts?

Thank you!

[crispy critter]

Re: stamped butt rib?

What I have done in the past is taken a complete,full lenght stamped rib from one side and another one from the other side and put them together to fit the butt end of the wing. It takes a lot of close careful trimming, and a little bit of creativity but it will work fine.

[Buell Powell]

Re: stamped butt rib?

Wish I had taken more pictures before covering these wings but here are a couple that may help.
Best of luck,
Buell

[Laz]

Re: stamped butt rib?

Buell,

I am about to instll a new leading edge on my wing. I noticed in you pictures that there seems to be a strip of alluminum running between all the ribs under the leading edge. Is this a mod or original? I am having trouble trying to locate the original screw holes in the ribs. This strip sems to make sense but my wing does not have it.

[Buell Powell]

Re: stamped butt rib?

Laz,
On these F19 wings the factory used L shaped pieces to go between each rib to keep them from bending in between the ribs and glued them in place but some of them had fallen off. I don't think my 41 had anything when it was built either and yours may not have but it does support the leading edges between the ribs and keep them from bending between the ribs if you are using the .016 material and are pretty easy to make. I think it works better and less trouble to just use 2" strips the length of the leading edges. Place them where you want them,mark and bend them 90 degrees 1/2" from each side between the ribs and leave the pieces flat on top of the ribs on each end and centers & tape to hold until the leading edges are in place. Aircraft Spruce has the 016 2024T3 18" wide and I just used the 2" pieces that I trimmed off to make the the leading edges.

[Ragwing nut]

Re: stamped butt rib?

Asking for help twice within 2 days, must be making progress on the project...

It was recommended that I buy two experimental stamped butt ribs from D&E aircraft instead of trying to salvage my broken built-up butt ribs. What arrived looks very, very different, to say the least. The more I look at it, the more nervous I become. See, what was described to me was a box-shaped structure, but what I got were two stamped metal ribs that are in three sections - nose, middle, and tail - and each piece is only a single stamped piece of metal.

The gent at D & E said there would need to be a few modifications made to adapt it from a metal spar to a wooden spar, but no instructions came with the parts.

I'm getting Real Close Now to putting all the hardware on the wing and trying to figure out how to put the fuel tank in - so I thought I'd ask, am I missing something, or are these single pieces of stamped metal really all I need for a butt rib? Anybody gotten these before? And last but certainly not least, does anybody have a picture of a stamped butt rib, so I can eyeball it and see that the parts in hand really do assemble to parts on struts?

Thank you!

Sounds like you got standard internal ribs. The stamped butt rib is one piece with a middle insert and rear insert. They must be nailed to the end of the spar. You can buy them from Univair still.

[Buell Powell]

Re: stamped butt rib?

Sounds like you got standard internal ribs. The stamped butt rib is one piece with a middle insert and rear insert. They must be nailed to the end of the spar. You can buy them from Univair still.

If you do use the stamped ribs be sure to trim the ends of the spars and glue on a cap. I have seen some that had the ribs nailed into just the end grain and the nails didn't hold and after the nails had worked loose they rusted and the wood was rotten around them. Just my opinion-but it's usually best to keep what it had and unless yours are really in bad shape repair them or look for some built up replacements.

[Ragwing nut]

Re: stamped butt rib?

Good point. I always install and end cap to seal the end grain. Just did not mention it. Built up butt ribs don't work very well if you have installed a wing tank. You can't install the middle reinforcement braces.

[VictorBravo]

Re: stamped butt rib?

A very well known and highly qualified wooden wing expert here in California recently advised me that it is actually not good to put the little plywood end cap on the edge of the spar, but rather to soak in as much epoxy as the wood grain will take, two or three times until the wood near the end is completely saturated.

The reason is that the end cap will prevent you from ever seeing that there is a crack in the grain. The epoxy will greatly strengthen the wood and prevent moisture or rot, but it would still allow you to see a crack from overstress.

I am NOT a world renowned wood wing expert, but the guy who said this to me is one. We were standing in front of a brand new scratchbuilt Staggerwing wing panel that he built, and it was beyond Oshkosh Gold quality.

[Buell Powell]

Re: stamped butt rib?

Hi Bill,
Sounds like the epoxy is a good idea to seal the ends but just wondering if saturated in epoxy if you are able to tap the tiny nails in and get them back out ok after the epoxy sets up and how well it keeps the nails from loosening up. Could you ask what epoxy he uses?
Thanks,
Buell

[astjp2]

Re: stamped butt rib?

Dororthy, I called D&E, there was a miscommunication, you can order the other right and left ribs to give the box structure, this is similar to the pics posted above. The way that they are currently using a metal strip riveted to the upper and lower section of the rib will work but I found that it bends easier than the box structure like we talked about. Its up to you if you want to do the extra rib sections to box it. Discuss it with John and see what he says. Tim

[VictorBravo]

Re: stamped butt rib?

Hi Bill,
Sounds like the epoxy is a good idea to seal the ends but just wondering if saturated in epoxy if you are able to tap the tiny nails in and get them back out ok after the epoxy sets up and how well it keeps the nails from loosening up. Could you ask what epoxy he uses?
Thanks,
Buell

It is the West Systems slow cure structural / laminating epoxy, style 105 I think, with the slower of the two hardeners. I have worked with this stuff a little and it is phenomenally good. I cannot vouch for the strength one way or another if it were used to build spars or ribs (but it's stronger than the wood for sure), but in my limited experience it's really good stuff. The boat builders love it. It is impervious to water and little microscopic critters.

[Ragwing nut]

Re: stamped butt rib?

I use West Systems and love it, but any epoxy still should not be used in structural applications. It will lose some of its strength with the high temperatures that can be reached inside a wing, especially with darker colors. I have seen near 200* surface temps before on dark colors.

Mike

[N96337]

Re: stamped butt rib?

There's a Tiger Moth in the Seattle area that has a restriction on it as to what internal temperature the wing can be and still fly. It has T-88. That epoxy loses a bunch of strength at pretty low temps. They had to put a remote thermometer in the wing, and the guy said he couldn't believe how hot it got inside there on a seemingly cool day! Here's a temp chart that DuPont put out a few years ago...something to remember when choosing colors....
John

[Ragwing nut]

Re: stamped butt rib?

I would never use T-88 period. It has no binders like West System products have and have seen mulitple failures from the use of T-88. West Systems is no better though if you don't use a binder with the resin, but at least it is available.