RV-8 and the Smoking Rivets
Sunday - 5/23/21 - Yesterday was supposed to be a pretty nice day. The fog was supposed to burn off earlier than it had the past few days and it looked like we would be able to go somewhere for lunch. In fact, the fog didn't burn off until about 2:00 and that didn't leave me enough time to go for lunch. I got in a good 1.8 of flying, but didn't really go anywhere and wasn't sure what I was going to be doing and I forgot to turn on the video cameras before I got in the airplane. No video, but no big loss.
Sunday's weather was even worse, so I planned to use it as an opportunity to start on the gripe list I had left over from the Condition Inspection. Today's chore was going to be replacing the 2 smoking rivets I had along the aft edge of the Vertical Stab on the right side. A couple of years before I bought the airplane the top 9 rivets on the same side were replaced for the same reason.
That's 11 so far, all on the right side. One theory as to why that I have heard is that the early instructions called for countersinking .032" skins where the more current instructions call for dimpling those same skins. These must have been countersink just a little too much. In any case, the skin started to work over time. In theory, this should be a relatively easy fix. Pull the rudder, drill out the rivets, install new rivets, put the rudder back on. What could go wrong. OK, nothing went wrong, it just took a little longer than expected, but then, what doesn't.
Getting the rudder off was pretty easy. After disconnecting the rudder cables and the steering chains from the rudder horn, it's just three bolts. It is a good practice to remember to put some tape around the opening so that you don't scratch the paint swinging wrenches around.
With digital photos being so convenient now, I try to photograph everything before I take it apart. This ensures that everything goes back together the way it was. It is also handy in situations where there are washers, and/or bushings to get back on in the proper order.
Notice how dirty all that is? It is also a good practice to clean everything you take apart before putting it back together. I mean, why not, it's only time. I also try to put things back together with new hardware when practical. Sure, the hardware is pretty robust, but it isn't very expensive either.
Once I take each bolt out I slide an alignment pin in the hole to hold it until I am ready to remove the surface. You can just use the bolts, but I find the pins easier to work with, particularly for putting things back together. I don't remember where I got these pins, and I don't use them that often, but when I need them they really come in handy.
Once the bolts are out, the rudder comes right off (it's almost as easy as removing an F-15 rudder). I didn't have to fight it or anything. I try to be careful how and where I put things down once removed in order to minimize the chances of scratching anything. For the same reasons, I try not to handle the parts any more than I have to.
The next simple step was to drill out the old rivets. Because I can't drill a straight hole to save my life I start with a mark from an automatic center punch, then start the hole with a center drill, then drill it out with a #40 drill. Unfortunately, the drill slipped and I chipped the paint on the upper hole. Naturally it would be in the blue where it shows up the most.
For riveting I like to use this yellow tape that my Dad bought at Boeing Surplus many, many moons ago. I have no idea what it's intended purpose is, but it is great at protecting the surface while riveting. It is slower going because I cover one rivet at a time, but hey, why rush the fun part.
The upper one was easy since a squeezer got in there to smash the rivet. The lower one, on the other hand, was in a terrible place. The rivet was right over one of the -4 rivets that holds the hinge bracket not leaving enough space for a squeezer.
Thank goodness for tungsten bucking bars. I happen to have a relatively small one that has an angled face that just fit in there. Barely.
That chip in the paint is going to annoy me every time I look at it.
Now that the actual work is done it's time to do the drudge work which is to clean everything up and get it ready to reassemble. While I try to get it as clean as practical, I don't get too carried away, one will, upon close inspection, still be able to find some dirt and crud in there.
One area that needed special attention was the rod end bearings used as hinges. As these are 20 years old if they're a day, they were pretty stiff. The top one wouldn't even turn by hand, but when I cleaned all of the gunk off of the ball in the center, I was able to free them up, so I don't think replacement is called for. Yet.
Reinstalling is pretty much removal in reverse. Align the rudder in place, work my pins into the holes, once everything is lined up, replace the pins one at a time with bolts. Once all the bolts are in, it's just a matter of putting nuts and washers on the bolts and tightening them up. These are easy in that there are no washers that have to go on either side of the rod end as is the case in other applications.
In the past, I would have said "Sure, just", as that always sounds easier than it really is. This time however, I had a new tool in my arsenal. It's always great to try out a new tool and things like this are why there is no such thing as "enough" tools. There's always at least one more. In this case, it is the Handee Clamp that I bought at Aircraft Tool Supply Company. This makes getting the nut and washer on so easy it seems like cheating.
Once all the hinge bolts are installed and tightened the tape can be removed. You didn't forget to put new lube on the bearings since you cleaned all the old gunk off did you? Of course not, don't be ridiculous. They each got a shot of LPS-3.
Now it is just a matter of reinstalling the rudder cables and steering chains to the rudder horn, with new hardware, of course.
I had this planned out at a 90 minute job, but with the need to run up to my Dad's hangar to get some tools and the search for new hardware, plus a friend stopping by to chat, it took about twice the estimate. Since the labor is free, I guess that's OK.
All that's left now is to go out and get it dirty again.