Shawn's -4 re-build

[ShawnR]

I did test the bolts today and they will all come out. When I was disconnecting things the other day, I found the inboard flap fasteners difficult to access. It seems the fuselage is in the way or I need a custom wrench. I am going to go over the build manual and plans again tonight to see if it hints at when control surfaces are installed. I would think after the wing is on, therefore, they should come off first but this morning, I was looking at the build manual online to see if the control surfaces were installed before or after the wing was one. It looks like it was before but not sure....

So, thought maybe I could just ask. The controls are disconnected in the plane. Flaps and ailerons are still installed on the wings. There are the 2 bolts (one in the front and one in the back/rear/trailing edge of the wing) just outside the fuselage but in the wing to remove and I think that is all that is left

Do I need to remove the surfaces? I am picturing a lot of effort required but hoping they just slide out. Any input? I wondering what getting a grip on it will be like.

Thanks Dan. I don't understand the "clamp" part. I think I need to look at the plans and construction manual more before I slide them out. It looks like they slide into a structure so not sure how I can clamp the spare..

[ShawnR]

Thanks RV7guy2

I do plan on visiting Southern Ontario a bit when I get it flying. I have a few friends down there. Even in an RV, it is a 3-4 hour flight. I have done the down trip in a C150, up in a Tomahawk and to Montreal in a Warrior. Nice trips, all of them. The -4 won't be going anywhere before next spring, if I have a good winter of working on it.

mim

Originally Posted by rv7guy2

Congrats Shawn and welcome to the great world of RV flying. Come on down to Stratford CYSA, someday for a coffee. Maybe join the Windsor RVaviators Facebook group which is dedicated to RV flying here in Southwestern Ontario. Weather has been great and we continue to fly. Larger engine air dams.,oil cooler baffle , engine preheat, and ticker socks keep my -7 in the air many times well into December and sometimes past Christmas!

[Flyhud]

I own a 94 -4 that I completely refurbed and modernized. My interior was painted that same hideous blue, It kept me up at night…I was never so happy when I repainted it. Used a flat gray epoxy primer, turned out great and is very durable. My apologies in advance if you are partial to the blue.

[Dan 57]

The spar caps are made of multiple layers, thick and thin. The close tolerance bolts holding the joining plates are normally, and should be, hard to install or remove. If you have to hammer them out, a C-clamp holding the spar together at the top and another one at the bottom, next to the bolt you hammer out, best on the plates, will prevent damage to the spar.
Another point, some builders have to put some down (or up) pressure on the trailing edge of the wing in order to drill the rear spar hole to the required edge tolerance. This induces some twisting in the wing, and therefore removing the rear spar, and the tank bracket bolts first, is a good idea.

Control surfaces. Having them off will prevent damage to them, and the wings will be lighter and easier to handle. Take some pictures, or/and organize little bags for the hardware as you remove it, there might be some washers used for shimming on the ailerons. As for the flaps, easy, disconnect the rod and pull the hinge rod

[ShawnR]

lol....I too cannot sleep, sometimes for such concerns, and that has probably been one. That blue has to go! I never thought of just grey epoxy primer. Grey is what I wanted as well but wondered about primer, then paint, and keeping weight in mind. That small amount would not be much but I am trying to stay mindful of weight implications as I make changes.

Just E-primer is great with me!

Thanks!

Originally Posted by Flyhud

I own a 94 -4 that I completely refurbed and modernized. My interior was painted that same hideous blue, It kept me up at night…I was never so happy when I repainted it. Used a flat gray epoxy primer, turned out great and is very durable. My apologies in advance if you are partial to the blue.

[ShawnR]

Thanks Dan! That helps. When I was tapping on them yesterday, they were not easy to move, and the hammer I was using (brass capped head) was not large, but they did move so I feel good about the fit. It sounds to me the same as what you describe. That is all that I was checking yesterday. I have a better idea of what tools to take tomorrow.

Originally Posted by Dan 57

The spar caps are made of multiple layers, thick and thin. The close tolerance bolts holding the joining plates are normally, and should be, hard to install or remove. If you have to hammer them out, a C-clamp holding the spar together at the top and another one at the bottom, next to the bolt you hammer out, best on the plates, will prevent damage to the spar.
Another point, some builders have to put some down (or up) pressure on the trailing edge of the wing in order to drill the rear spar hole to the required edge tolerance. This induces some twisting in the wing, and therefore removing the rear spar, and the tank bracket bolts first, is a good idea.

Control surfaces. Having them off will prevent damage to them, and the wings will be lighter and easier to handle. Take some pictures, or/and organize little bags for the hardware as you remove it, there might be some washers used for shimming on the ailerons. As for the flaps, easy, disconnect the rod and pull the hinge rod

[ShawnR]

Wing removal was successful! Dan's suggestion to use a c clamp worked great! Before I put the clamp on, I noted the layers that form the spar were separating and the bolts stopped moving. Other than that tapping, twisting, cussing, etc. seemed to work. I was not able to get the flap pin out while on the plane but once the control rod was disconnected inside, the flap did fall free, which allowed accessed to the rear spar bolt. Otherwise, it was very difficult to access.

In addition to using new hardware to replace the wings, I am thinking that reaming the bolt holes as per the build manual would be a good idea. I am wondering if wrestling the bolts free, if some galling of the aluminum plates may have occurred that may make installing more difficult. Anyone re ream after wing removal? Standard practice or not necessary? Can it do any harm?

Now to start picking away at a long list of items to address.

[fixnflyguy]

The bolt holes for your spar need to remain as tight as possible, as the load transfer is reliant on zero gap between bolt and hole. Seeing that it was already bolted up once is proof enough it will go back together. The bolts come cadmium plated for corrosion resistance, and some of that gets peeled off during installation, which isn't a big worry for strength concern. I do heavy jet overhaul and modification for a living, often working with assemblies using bolts un-imaginably larger than the ones you are working with. I built my -4, and used the same principals as Boeing and Airbus use. I would recommend you simply tidy up the holes with small piece of ScotchBright taped to a piece of 1/8 or so steel rod and spun in a drill for a quick pass to get light corrosion ,ect. out. If you choose to use new hardware, pre-assemble the airplane with a dozen or so "stove bolts"of same size cheapo hardware from big box store and just put the nuts on finger tight. When you install the real bolts in the remaining open holes, mix up some epoxy primer and swab the holes (as you go) then immediately put the bolt in "wet". Properly installed close-tolerance bolts will require a little taping in..much better than if they just drop in. The primer will do two things, lubricate and protect from corrosion. The stove bolts will keep the layers from separating and because they fit "slightly sloppy" the NAS bolts will pull everything in line when they go in. Good luck..winter will pass fast and you have a long list!

[N999BT]

Originally Posted by fixnflyguy

The bolt holes for your spar need to remain as tight as possible, as the load transfer is reliant on zero gap between bolt and hole. Seeing that it was already bolted up once is proof enough it will go back together. The bolts come cadmium plated for corrosion resistance, and some of that gets peeled off during installation, which isn't a big worry for strength concern. I do heavy jet overhaul and modification for a living, often working with assemblies using bolts un-imaginably larger than the ones you are working with. I built my -4, and used the same principals as Boeing and Airbus use. I would recommend you simply tidy up the holes with small piece of ScotchBright taped to a piece of 1/8 or so steel rod and spun in a drill for a quick pass to get light corrosion ,ect. out. If you choose to use new hardware, pre-assemble the airplane with a dozen or so "stove bolts"of same size cheapo hardware from big box store and just put the nuts on finger tight. When you install the real bolts in the remaining open holes, mix up some epoxy primer and swab the holes (as you go) then immediately put the bolt in "wet". Properly installed close-tolerance bolts will require a little taping in..much better than if they just drop in. The primer will do two things, lubricate and protect from corrosion. The stove bolts will keep the layers from separating and because they fit "slightly sloppy" the NAS bolts will pull everything in line when they go in. Good luck..winter will pass fast and you have a long list!

This is good advice.

[ShawnR]

Originally Posted by fixnflyguy

The bolt holes for your spar need to remain as tight as possible, as the load transfer is reliant on zero gap between bolt and hole. Seeing that it was already bolted......, lubricate and protect from corrosion. The stove bolts will keep the layers from separating and because they fit "slightly sloppy" the NAS bolts will pull everything in line when they go in. Good luck..winter will pass fast and you have a long list!

Thanks fixnflyguy. Sounds like a good plan for me.