Floorboards: Screw or Rivet? I gotta decide

OK campers, I am at a crossroads and I have to make the big decision. The plans tell me to rivet down the rear floorboards on my 8A, but I know some studs have used screws and nut plates to make them removable "because ya never know". For cryin out loud, that would be 73 extra nutplates (unless I miss my count). Will I die and go to **** if I don't use nutplates? I need to know now, because I am down in my basement drilling. Are there any flyers out there that regret either riveting or screwing (get your mind out of the gutter, you know what I mean).
Waiting expectantly on your sage advice,

Mine have been riveted for over 14 years. The only reason I had for pulling them up was to install my steps. I riveted them back down. Still easier than all those nut-plates in my opinion.

Steve Ashby said:

....at a crossroads....

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Before you are done with your project you will have encountered DOZENS of decisions about doing this or doing that. You just have to decide for yourself. Personally, I couldn't stand the idea of closing up structure forever and made all the floors removable. I can hear the naysayers now. "Why bother? Extra work and extra weight." Fact is, I've already removed the floors in my 6A to reroute things....twice now. Of course, having the right nutplate jigs is a major help. A few weeks ago, I made these floors removable with a time investment of about 3 hours work and used mostly #6 and #8 floating nutplates attached with NAS1097 rivets. Its easily worth it to me but you just have to decide for yourself if the value and utility derived is really worth the effort to you.

build it per plans

if you get wrapped around the axle like i do, you will waste months of time debating. i changed my mind to do 99% plans so i could minimize wasted time. i would like to fly in this century. however if i already had a rv flyer of any make i would really do some custom stuff to the one im building now
.

I've done it both ways. But what continues to annoy are round rivets or screws proud of the floor to snag or scrape bags, boxes, etc, and in turn have their paint scraped off. Never a need to undo the floor unless you put something in there like an ELT. I recommend dimpling for a flush surface (what's a few more dimples after 12,000 or so elsewhere?), and before closing, have a few extra holes poked though ribs for fore-aft wire and tube routing, JIC.

John Siebold
Boise, ID

Wait until the last possible moment and then rivet em down. If you ever have to take em off (unlikely), drilling out the aluminum rivets and rerivetting is still way less work than installing all those nutplates.

Rivets vs. Screws

Steve:

I debated the same thing when I built my -8 but decided rivets would be a lot less work and if the floor has to come up (which will be rare) then removing rivets will probably be the least time consuming task you're going to do. With screws you not only have to put in nutpates but you have to drive the screws too -- and unscrew them when you remove the floor. So which would take longer, unscrewing screws or drilling out the soft rivets -- I'm thinking it would be close.

To illustrate, I just removed and replaced the floor in my RV-8 to install the wiring for my new TruTrak AP. It took about 60 minutes to drill out the rivets, most of the time was spent on a couple of hard to reach ones under the flap bar that required me to unbolt the flaps so I could move the bar out of the way of the drill. Replacing the rivets took about 30 minutes with a pneumatic rivet puller (power tools are a wonderful thing ).

I think you'll be happy in the long run with the rivets.

Chris

Don't make the mistake I made!

Ah, the shame of it all. I used nutplates and regret it. Okay, maybe someday I'll pull the floor, but those nutplates were a pain. Since we don't yet have AN grade velcro, I'd opt for rivets!

Bob Kelly, Done with testing!

Nut plates & screws here! It was a little time consuming, but I thought it was worth it. I'll be able to check for wear on the rudder cables,snap bushings, and God forbid something gets spilled inside the cockpit I'll be able to clean up their blood from under the floor before it causes any corrision!

Screws

Flush screws, especially where your feet go. Did mine with rivets and regret it.

If we continue collecting data from everyone, you'll just prove that it's a tie vote...

Rivets on mine - and I have already installed and wired a pitch servo after I was already flying - didn't have to pull the floor to do it.

Paul

Screws

I decided to use the screw/nut plate deal in my -7A. Spent a few hours of time putting in the platenuts but as I'm getting close to closing everything up here is my thoughts.

The rear baggage area was silly to use screws. I cannot think of any reason I would pull up the floors in that area especially since I ran conduit under it.

The seat pans are a different story since I have lots of wiring from my Infinity sticks encompassing a ground block and terminal strip under the drivers side. I want to be able to inspect it at my annuals. If it wasn't for this I would just assume rivet them down.

Alternate Option

One word: nutCLIPs!

how do you even know when it is time to put them in for good?

I'm working on a QB fuse and am starting to run into steps like installing the flap actuator and rod which clearly is going to have to come back out and go back in again later. Do I just skip these steps and move forward? I sort of don't like to leave too many things undone for the fear that later I'll realize that I painted myself into a corner.

I riveted mine. Pulled them out one time in 14 years to install my steps. Riveted them back in.

Corrosion?

So how do all of you that start primer wars and alodine and/or prime everything see under there during your condition inspection? Under the floors is where I see corrosion on certified aircraft. Seems to me like water, coke, and pee always goes to the lowest level and sets there.

Just a thought - Try http://www.gen-aircraft-hardware.com/template.asp?pagename=nutclip It's easier than rivets.

mikeangiulo said:

how do you even know when it is time to put them in for good?

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The day before you move to the airport is a good time. By then all the wires and everything else should have been run and tested.

One builder told me not to be in a hurry to rivet things together as you will always need access later. That was good advice. I didn't rivet anything together until it was painful not to have them riveted.

rivets

My QB 7a came from Van's with a dozen or so rivets securing the floor. They drilled out so easy, I'll rivet down the the floor and drill them out if I ever need to get under there again.

for those of you who have put the floorboards in with screws did you have to cut the floors into multiple pieces? right now I have a few stiffeners which are not installed so that I can flex the floors into place. Did you adapt those for screws too? otherwise I don't see how you can get the floors back out with the stiffeners in place

Steve Ashby said:

OK campers, I am at a crossroads and I have to make the big decision. The plans tell me to rivet down the rear floorboards on my 8A, but I know some studs have used screws and nut plates to make them removable "because ya never know". For cryin out loud, that would be 73 extra nutplates (unless I miss my count). Will I die and go to **** if I don't use nutplates? I need to know now, because I am down in my basement drilling. Are there any flyers out there that regret either riveting or screwing (get your mind out of the gutter, you know what I mean).
Waiting expectantly on your sage advice,

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Haha!
I'm a first time builder and used nutplates for all the flooring. It didn't seem like a big deal to me and didn't take much extra time. Came out great!

Time will tell if it was worth it or not, I guess.

newbee opinion

This stuff is great I guy like me could get lost in these question and answer dilemma and never start the project!

After completing my -9 and comparing notes with the owner/builder of a local -9A he was wondering why mine was only 990 lbs and his was over 1100 lbs.

There was a long list of "upgrades" he made, including plate nuts on the floor boards. All those screws, rivets, and P-nuts add up. In the end he and his wife with full fuel only had 50 lbs left over for baggage before he grossed out. He was a bit disappointed by that as they had dreamed of traveling long distances.

Building light is a mind set. You have to think about every ounce you add and decide if you really need "it", whatever "it" is.

As for the pull rivets on the floorboards, think about how many thousands of RV's are flying that way without any problems.

I nutplated and screwed mine...I wouldn't do it again.

Steve,
I am building an RV4 and had to make the same decision last summer. I came up with a different solution. I ?roll formed? threads in the existing rivet holes.
When building my fuselage I drilled #30 for rivets (.128 diameter). I often use Roll Form taps at work. If you?re not familiar with these, they form threads rather than cut threads like regular taps. They can be used on malleable metals, they?re great in aluminum. They require a slightly larger tap drill than a regular tap. It just so happens that the tap drill for a 6-32 screw is 1/8? (.125). I tapped my rivet holes with a 6-32 roll form tap and used #6 panhead screws to hold the floorboards.
This isn?t a perfect solution, my seat ribs are 1/8? thick in this area, so there isn?t a lot of thread. You wouldn?t be able to torque these threads as much as when using a thicker steel nutplate. But a #6 shouldn?t be torqued very tight anyway. I?m not flying yet, so I don?t know if they will have a tendency to vibrate out. The threads don?t have a self locking feature like nut plates. If this is the case, I?ll probably put a drop of Locktite on them. I think they should work great. But if not, I can always take the screws out and put rivets in.
If this sounds like something you?re interested in, you can buy roll form taps several places. I would probably suggest MSC industrial supply (mscdirect.com). They should be pretty cheap ($12-13). Put a small drop of oil on them and use like a regular tap.

Cameron Smith
RV4 #68 (prepping for inspection ? still)

I used nutplates and screws on mine. It was a lot of work, but it does open up a lot of space to install stuff...things like the AP brain, relays, all of the trim wiring and relays if you use electric trim, connectors for the electrics in the sticks, access to antennas, etc. However, if I ever do it again, I will rivet in the floors---BUT---I'd put a panel or two in appropriate places in the floor for access.
In my RV8, I did cut the floor up into about nine pieces, which meant remaking several so you had the required overlaps. This allowed me to take out sections, but it was a pain. Trying to use the floor, in the large pieces as provided, isn't really feasible for a removable floor in the RV8.
I think it is purely a personal preference based on whether you want to utilize the under floor space or not. Count up all of the rivet holes and see how many nutplates you would have to install. It's a LOT!

nutplates installed in floor

I drilled and installed nutplates. A little extra work but I think for the long run it is worth it.

Rivet.

I decided to go back and add steps after I already had the floor in, drilling out the pop rivets took me all of five minutes. Probably another five to rivet it back in.

250 hrs since I haven't needed to go inside yet.

Steve,
I had to make the same decision on my RV4. I came up with a different solution. I ?roll formed? threads in the existing rivet holes.
When building my fuselage I drilled the floorboard support angles with a #30 drill for rivets (.128 diameter). Then I tapped the angles with a 6-32 roll form tap. I often use Roll Form taps at work. If you?re not familiar with these, they form threads rather than cut threads like regular taps. They can be used on malleable metals, they?re great in aluminum. They require a slightly larger tap drill than a regular tap. It just so happens that the tap drill for a 6-32 roll form thread is 1/8? (.125). I tapped my rivet holes with a 6-32 roll form tap and used #6 panhead screws to hold the floorboards.
This isn?t a perfect solution, my seat ribs are 1/8? thick in this area, so there isn?t a lot of thread. You won?t be able to torque these threads as much as when using a thicker steel nutplate. But a #6 shouldn?t be torqued very tight anyway. I only have 17 hours (phase 1) on the airplane so far. I don?t know if they will have a tendency to vibrate out. The threads don?t have a self locking feature like nut plates. If this is the case, I?ll probably put a drop of Locktite on them. I think they should work great. But if not, I can always take the screws out and put rivets in.
If this sounds like something you?re interested in, you can buy roll form taps several places. I would probably suggest MSC industrial supply (mscdirect.com). They should be pretty cheap ($12-13). Put a small drop of oil on them and use like a regular tap.

Cameron Smith
RV4 #68 flying and lovin it (finally)