370 hours on the hobbs - Starting on the Left Elevator

SO I installed 4 MK319BS pop rivets in the trailing edges of both sides of the right elevator as shown below:

I may need to order some more of these rivets from Vans before the left elevator is finished. I also need to order an E703 tip rib from Vans as I will be using that for the inboard riblet on the trim tab.

Time to put the right elevator up for a bit and start on the structure for the left elevator. As I look back on it, not a very good track record of working on the plane. I "officially" started on October of 2009, and after enduring about 6 months major home improvement delays and a host of other interruptions, including cold weather, major screw ups requiring major repairs, etc., here I am 2 years later, still trying to finish the tail. Hard for me to swallow, especially when you consider that there are others that have managed to finish the tail kit in about 9 months or less, and at about half the time hour-wise. Oh well, it is what it is. A "one day at a time" approach will net a completed airplane one day, so you just keep at it.

One more pic of the right elevator in all its riveted glory. Had to move it off the tables and benches so I could start working on the left elevator skin. So here it is on the dimpling table. Can't wait to get both of em attached to the HS.

Now on to the left side. This skin is a bit difficult to handle because part of the trailing edge is removed to allow the space for the trim tab. What is a trim tab you may ask? The best way to describe  it is that it is basically a small elevator within an elevator. Thus the use of the word "tab." It's main function is to allow the pilot to make small adjustments to the control surface to lessen the control forces that need to be applied to the elevators to maintain a given pitch attitude for straight and level, climbing, or descending flight.

It does this by changing the amount of force being applied to the horizontal components of the tail. To accomplish this, it moves in the opposite direction of the elevator, which basically makes the elevator move in the opposite direction. For example, if I want to move the elevators up to establish a climb, and I want to hold that attitude for relatively long period of time, your arm may get tired of holding the amount of force it takes to keep the airplane's nose in that attitude. So to fix this you "trim the airplane up," which basically means that the trim tab moves down, which actually adds lift to the elelvator, forcing it to move UP, which raises the nose of the airplane.

The way that I describe this to my flight students is that it is basically a poor man's autpilot, allowing one to fly the airplane essentially hands off of everything is set correctly. So it is a very helpful thing to have on any airplane. In fact, when it is all said and done, I will be able to trim the elevators and the ailerons. Unfortunately Vans does not include a trim tab designed for the rudder, but it looks like this is something that would also be handy, as many pilots report having to hold the rudder just a bit in level flight due to a variety of different factors.  There are other means of addressing any rudder trim issues, and I will cross that bridge when I get to it.

Confused yet? Don't worry, it be more clear as the components are completed. Why am I devoting so much to explaning what a trim tab is? Well, a recent event at the Reno Air Races involving the crash of a modified P-51 resulted in death and severe injuries to many many people. Thus far the pictures and initial investigation as to the cause of this tragic accident appear to be focused on the apparent failure of the trim tab on that airplane. Jimmy Leeward was the pilot, as well as a fellow EAA member, and so this trategy has affected us all. It leaves you wondering how such a small part on the airplane could be responsible for such an accident, but it can.

While I have no aspirations to modify my airplane to go 500 MPH (200MPH is quite enough for me, and is a realistic cruise speed for my airplane), the trim tab system is still a very important one, and so it bears spending the time to ensure that this assembly is done correctly. Failure of any component of an aircraft that directly affects the controllability of that aircraft is one of the continuously sobering thoughts that one has as you embark on a project such as this.

Back to the build.....
This is the left elevator skin with a trim reinforcement plate clecoed to the bottom. This plate serves as the mounting platform for the electric trim servo. The big cavity in the back is where the trim tab will be located.

And another shot of the back side of the left elevator skin clearly showing the cut out for the trim tab. When finished the tab will fit neatly in the space created by the cut out, and when everything is aligned, it will look as though it is just a normal part of the elevator. Here the vinyl has not been trimmed yet.

And a pic after the rivet lines for the stiffeners and spars has been trimmed away with the soldering iron. This is a real crappy job of cutting the vinyl, but the side shown was the last of the 4 that were trimmed, and by that time I was getting tired.

Next is the trim access reinforcement plate after match drilling, deburring, and dimpling, including the skin area to which it is attached. I used my 3 inch yoke to reach all but 2 of the holes that needed to be dimpled. For the remaining 2, I used the flange yoke, which allowed me to insert the yoke inside the hole in the skin in order to reach the last couple holes.

I am using two of my support blocks to hold up the upper skin where the trim tab cavity exists. One problem I found with this skin is that when it is left unsupported in this area, the corner on the end will bend down and it contacts the skin on the opposite side, and this causes scratches and gouges. So you need to be careful when prepping the skin during these times so that you don't damage the skin.

And finally, a pic of the frame parts. I have drilled and deburred the holes for the two rod end bearing support brackets that attach to the forward spar, and I have fluted the two end ribs, exactly the same as was done for the right elevator. The skin for the trim tab is also shown here. Lots of work to do yet.

All for now.

365 hours on the hobbs - Right Elevator almost completely riveted

Took the day off yesterday and got a lot of work done on the elevator. First off, thanks Steve for pointing my incorrect reference to the rudder in my previous post - man what a slip that was.... I have changed to header to read "elevator" and not rudder.

So it started with drilling out the 4 rivets attaching the counterweight skin to the elevator skin so that I could address the missing dimples described at the end of my previous post. Then I had to carefully remove the skeleton so as not to destroy the seals I had created with the blue RTV before I clecoed everything together. This turned out to be a non-event. The RTV had hardended and held what ever shape it had been conformed to after removing the frame from the skin.

Now for some pics to explain my dilemma about the missing dimples. I had done a fair amount of research on VAF about attaching the fiberlgass tips with either screws or rivets, adn found one pots in particular with lots of good pics and explanations about what was done from Rick6A. He is a builder/mechanic with lots of experience in the industry, and tends to do his own thing and has a lot of really inventive ideas about tools and the building process. Anyway, the discussion was about using a number 4 screw vs. a number 6 screw for attaching the fiberglass. Number 8 screws are too big, and most were saying that the number 4 screws are too fragile and damage easy, and are too small in comparison with the surrounding rivets. SO the consensus was that if they could do it over again they would use a number 6 screw.

Number 6 means that it has a diameter of 6/32. That lead me to the hardware that came with my electric trim kit. During my review of the plans for the left elevator, I noted that it was using some #6 screws and K1100 nut plates to create a bracket and service pate cover for the electric elevator trim tab servo that I am using to trim the elevators. I'll get into more of a discussion about trim tabs and systems when I start building the left elevator. The service plate for the servo is attached using small half inch long 6/32 or #6 screws. So I was able to use those screws to determine how they would look if I used them to attach the fiberglass tips to the elevators.

SO I committed to that screw size, and proceeded with the dimpling. Cleaveland Tools included both a number 6 and number 8 dimple dies for two different sized screw heads, and you may recall that I have used a #10 dimple die for the screws that attach the lead counterweight. I took a practice peice of metal, drilled a hole with a number 28 drill bit, which by the way is also listed in a wonderful pull out chart that Cleaveland tools inserts into their catalogue. It has decimial conversions, drill bit size charts for specific applications, and  a host of other useful info. Anyway the screw head seemed to fit nicely into the dimple, so I then went ahead and drilled and dimpled the two #28 holes in the counterweight skin E713 and the skin E701 R ( 2 top and 2 bottom holeswhere both parts overlap each other), and then dimpled each hole with the hand squeezer with the #6 dimple die.

One note of concern is that Vans had prepunched all of these tip attach holes with a 1/8 inch CS4-4 countersunk pop rivet in mind. This means that all the holes are spaced from the edge of the skins to provide adequate clearance (2 times the rivet diameter) from the edge of the skins. After drilling adn dimpling using these same prepunched holes as a guide, I am about 1/16 of an inch short of what the proper edge distance should be. However, I think that this rule is only for proper rivet spacing, and does not apply to other fasteners such as screws or bolts, but that may also depend on the material used. IN any event, I am not concerned about this, because there are several other screw attach points for the tip to be attached to the elevator, and if I need to I can drill other holes on the skin to provide a bit more adequate clearance from the edge of the skin. Will cross that bridge when I get to it.

OK, so pics now. Here is the #6 screw, and the nut plate for the trim hardware, and two of the four holes on the edge of the skin and counterweight skin that are now drilled and dimpled for this screw size:

And  a slightly burry pic of the screw inserted into the dimpled hole:

So of course the dimpling had to be done AFTER the frame had been removed from the skin, and then I re-inserted everything again adn clecloed it all together. I also drilled the other holes along the edge to 1/8 or #30. I did not final drill them to # 28 yet just in case I need to adjust the edge distance for he remaining screws.Nore have I dimpled the remaining holes because I can get to them later, and they are not overlapped (or underlapped, as it were) by any other parts like the two holes shown above. So I can drill and dimple the other holes later, even after the elevator is riveted together.

Which leads me to the next two pics. Right elevator is almost completely riveted. Just deciding about pop rivets in the final 2-4 holes closest to the trailing edge. the only thing remaining after that will be the dreaded rolling of the leading edge. I will wait on that until the left elevator is also done. Then I will roll the LEs for both of them to finish them up. It was nice to finally get this one riveted together.

On that note, since I dove into my hardware for the electric trim system, I decided to have some fun and crack open all the parts for the trim system, and I even temporarily wired up the components and attached them to a 9 volt radio battery to see if it works. I also trial fit the trim servo to the attach brackets and trim servo mounting plate. More pics of this to follow as I start on the left elevator. There are bascally three components to this system, the trim tab servo that actuates a pushrod to raise or lower the trim tab, the switch, and an indicator that displays the position of the trim tab relative to the movement of the trim tab servo. I wired it all up and attached the power leads to a 9 volt battery and whala, it worked! Very cool to be messing around with electrically driven parts!

359 hours on the hobbs - Right elevator frame riveted!

Man I love it when I am able to rivet a frame together without botching it up somewhere along the way. I think the biggest contributing factor to my success was the fact that I finall ground down all my yokes so that they would not interfere with the parts, and I also established a pattern of bucking the AN 470 rivets SLOWLY so that I could check the rivet shank for signs of clinching or other problems and correct them early before the rivet was set all the way. I did not have to drill out a single rivet on the frame. Truly cause for celebration!

Ok, so more pics:
Here is one side of the control horn all riveted in place:

And a wider shot of how I clamped it all down so that everything was solid and non-moving during the riveting.

Also in the above pic was my "Fat Man" tungsten bucking bar. I used the angle part of the par to get into the inside corner of the joint between the rib and spar. The two rivets closest to the inside edge were very tricky. I ahd to hold the bar in just the right attitude, position the fingers of my left hand to ensure that the bottom of the bar would not strike either the spar web or the rib web depending on which rivet I was bucking. I also used my rivet cutter to trim some AN470AD4-6 rivets down to the proper size by using my ruler to adjust the cut to just the right length. Next pic shows the rivet shaft at the correct length. Van's calls for 4-4 rivets here and they are just too short, and a 4-5 rivet is just too long.

And here is the outside of the control horn, riveted in place on both sides. I wanted to make sure the rivets were the correct size here because this horn attaches to both the center hinge bearing on the HS and also to the end of the pushrod that ultimately attaches to the control stick. So this is an area that will be exercised by both movement and force for the life of the plane, and so it needs to be as solid as possible.

And the inside shot

Next comes the attachment of the counterweight skin to the elevator skin. You have to do it this way if you want to set four of the rivets with solid rivets. If you don't, then you have to use pop rivets for these holes because the ribs will close off the area where these holes reside, and you cannot get a squeezer or bucking bar in that area once the frame is in place.

to set the rivets (2 on each side), I used my hand squeezer. Before doing so I decided to take it to the grinder based on a post I read a long while back. I was tired of being told that this is the tool that everyone uses for close quarter riveting, when my experience had been that the taper of the yoke was still so wide that you cannot get it into these tight places. I printed out a post that I found that describes a method to take a C clamp and grind it down so that you insert into a tight fitting area to buck or squeeze a rivet. The process was the same for the yoke - just grind down the tip of the yoke far enough to be able to insert it where you need it, and squeeze away. I am probably not done refining it yet, but you get the idea of what I trying to do from the photo: Notice the "notch" about an inch back from the tip where I have flattened it out.

This actually worked well for the flush rivets I had to set to attach the root rib to the spar prior to attaching the control horn. Next is a method I used to set the 4 solid rivets on the counterweight skin that I mentioned before. I used one of my cleco clamps and no hole yoke pictured above to set all four of the rivets.You have to remove the clecoes in order to get the squeezer far enough in there to set the rivets, so to keep the skins together to ensure a good fit I used the cleco clamp

With the counterweight skin riveted in place, it was time to prep the skin with the ceremonial blue RTV/Syringe exercise, similar to what I did for the rudder before riveting it together.

To get the rest of the frame inserted into the skin was a bit of a chore. I enlisted the help of my good friend and neighbor, Kevin Shepard, to help get things into position so I could cleco everything in place. Once you squeeze the RTV on the ends of the stiffeners, you have about a half hour to get everything in place before it starts to set up and harden. The trick is that you have to hold the lead counterweight against the counterweight skin that we just riveted in place, while the end ribs of the frame are inserted behind the weight, and then the entire frame is swung into the correct position so that the ribs line up with the holes in the skin. Having an extra pair of hands for this was definitely helpful. Here is the assembly all swung into place and clecoed together for final riveting:

So, now we are all ready to rivet, right? Uh, not so fast. After getting to this point I realized something. Steve Riffe has pics of this step in his log, and I kept seeing two copper colored clecoes in two of the holes on the top and bottom of the tip of the elevator, which indicates that the holes were drilled to 1/8 inch diameter. In my haste to assemble the frame, I neglected to pay enough attention to the area outside of the end ribs where the coungterweight skin, the rib, and the elevator skin all overlap. I thought I could leave all the holes for the fiberglass tips alone until I was ready to fit and attach them later on.

The problem is that the counterweight skin has two holes that overlap then ends of elevator skin where the attach holes fo the tips are located. Therefore those holes need to be dimpled to accept the correct size rivet or screw head, depending on your preferred method of attaching the fiberglass tips. I have decided to use #6 screws and nut plates as discussed in this forum post on VAF so that I can rmove or replace the tips as needed. This is very desireable for the wing tips due to all the wiring for lights and such that may require periodic maintenance, and thus removal of the tips from time to time, and I want to be able repair or replace the fiberglass stuff as quickly as easily as possible.

Regardless of the decision to rivet or screw, you still need to DIMPLE the holes, which I obviously forgot to do. So, all that careful slipping and sliding of the frame into the skin was all for not. I have to drill out the four flush rivets holding the counterweight on, and then uncleco the entire skin and remove the frame so I can dimple 4 lousy holes in the counterweight skin and the elevator skin. I am going to use #6 screws for this so I will need to use a #6 dimple die, after drilling the hole with the #28 drill bit. I just have to be careful not to break the seal from the RTV when I remove and replace the frame after I dimple the holes. DANG IT! And I was doing so well....

355 hours on the hobbs - Pounding rivets on the right elevator!

Airplane building notes aside, I am going to start a new Label called Motivation. VAF often has motivational posts like this on their home page that include scenic in flight photos with awesome scenery backdrops, and tug-at-your-heart pics like dog rescues. So here is some "off-into-the-sunset" motivation that I hope to chnage into a reality one day when the plane is finally done. One of reasons I love living in Colorado is that the Fall season is absolutely spectacular. The temps are just right, the air is calm and still, and the sunsets, similar to the one captured in the next two pics, are also spectacular. Just picture my RV flying off into the sunset to some exciting destination, just me, the plane, and the sky, all to myself........

Now back to "reality," or the unfinished airplane. Have to finish it to allow the motivation described above to become a reality. As the caption states, I finally got past the priming fiasco - sort of. I finished one can of my expensive two part self-etching primer, and opened up another quart can that I purchased some time ago. As stated in the previous post, The first coat of primer was less than desireable, so a second coat for some of the parts was absolutely necessary. I opened and mixed the primer, and expected it to apply in a similar manner as the first coat. Unfortunately, this primer came out a slightly different color for some reason. So now I have some two-tone colors on my parts here and there. Not a big deal for me, as the only reason is it there is to provide some means of corrosion protection.

Right elevator parts primed:

Removed all the vinyl from the inside of the skin:

And now on to the next challenge, or as we are often told at work, "opportunity":
I still had some work to do on the lead counterweight. On the right elevator only, the plans call for removal of a specific amount of the lead so that the balance point on the elevator is as close to correct as possible before it gets painted. The left elevator has more overall weight due to the addition of the trim tab and supporting structure, so none of the lead has to be removed for that side. Vans provides the same size counterweights for both sides in the kit, so the one used for the right elevator has to be trimmed down for it to be properly balanced. Just how to perform this removal was not described in the plans, so once again I had to resort to the methods of others that had gone before me.

I checked Steve Riffe's builders log (He uses Kit Log Pro as many other RV builders do), and found that he drilled a 1/4 inch hole after marking the weight for the area to be removed, and then said he used a hack saw to trim the lead. So I started this same approach, and had a terrible time getting the blade on my saw to remove any material once it was deep into the lead. The lead weight is very heavy, and is also oddly formed to match the curvatures of the rib flanges that it rests against, so it is not easy to clamp down and hold in place on a flat surface either. It is so easy to distort the soft lead and ruin the required shape of the counterweight, so you ahve to be careful when securing it. In fact, during this process, I actually dropped the weight onto the concreate floor of my garage, and, you guessed it, I deformed the lead just a  bit. It messed up one of my screw holes, and the countersink for that hole, which also became distorted. Here are just some of the tools I started with to perform this job:

Then I had another brilliant idea - why not use my jig saw and a metal cutting blade. Only problem was, I did not have a blade long enough to penetrate the two inches or so of lead that I would be slicing through, and that would spell disaster. If you have ever tried to do this on a piece of wood where the wood is thicker than the blade, you know what I am talking about. So that was out of the question. How then was I going to get this done without further screwing everything up? Answer, my 14 inch RIGID band saw. Even though it had a wood cutting blade, and the speed is designed for cutting wood and not metal, it worked like a charm, and cut through the lead like a knife through warm butter. Just be sure to lubricate and clean the blade afterward to prevent fouling the wheels on the saw. So I turned a 45 minute fiasco into a 5 minute success. I was even able to re-drill the damaged hole and countersink it again as well. Amazing stuff, lead is...even if California doesn't think so.

Here are pics of the counterweight before and after making the cuts and smoothing the edges. First is the 1/4 inch hole. I decided to be brave and not step drill this since there seemed to be enough material to be able to drill the hole to the final size from the beginning, and I was not drilling through any additional metal. This was a pain in the ass. I used my cordless drill for this task, as I knew I might need the extra torque. I drilled slowly, lubricating the drill bit with oil and then drilling small amounts and backing the bit out repeatedly as I went. Problem was after you get about 3/4 inch in, it gets very hard to turn the bit, and even harder to get it out if it gets stuck. I had to manually back it out several times since the chuck of the drill would only spin around the drill bit, no mater how tight you tried to chuck it. I drilled about an inch on one side and then turned it over and drilled from the other side, hoping that I would meet in the middle. The plans call for 5/8 inch or at minimum 1/2 inch of material as measured from the TOP of the counterweight as drawn in the plans. Both my drill holes ended up right where they needed to be.

Not shown in this next shot are all the preliminary cuts I made with the coping saw and a double sided hand saw. This pic is after I sliced it using the band the saw, which is the preferred method for this task:

And another view:

I purchased a very expensive set of files whne I ordered my original tool kit, including a vixen file, from Ceaveland Tools. This was the first time I actually used several of the different files in the set to finish dressing out the lead after the cuts were completed. I used a flat file to smooth out the recessed area where the lead had been removed, and I used a tapered round  file to remove the cut lines and radius the 90 degree cut lines just a bit. Then used a straight file again to smooth the edges and remove excess slag from the cuts.

Proof that my measurements were pretty good on both sides of the lead. The drill went straight through both sides.

Shows some of the cuts I was making before the lightbulb went off and I decided to push the easy button and use the band saw.

When I dropped the weight, it landed on one end. Here is blurry pic of the damage that I was able to repair:
Note the slightly oblong looking edge and countersink on the end:

Everything all filed clean, holes and countersinks repaired:

Bucked all these rivets for both back plate support brackets and nut plates, similar to what was done on the Rudder.

And the other side

And on the inboard plate:

Time for another area that I have not had much success with until lately - riveting the ribs to the spar. Got a great tip from Steve, who got it from someone else, for the end ribs. The plans say to rivet the end rib E703 to the counterweight rib, and then rivet that whole assmebly to the end of the E702 spar. Problem is, if you do it in that order, you have problems getting a squeezer or even a bucking bar in there to do the work.

Due to the many major problems I have created for myself in the past, I refuse to use the air squeezer in areas where the risk of damaging parts or screwing up AN470 rivets is a very real possibilty. Instead I use my double offset rivet set and buck ALL rib-to-spar AN 470 rivets to ensure they are set correctly. Steve also points out that the rivet call out for this area tends to leave rivets a little bit long. If you use an air squeeezer on these rivets they most often times will clench, or lean over to one side.

If you take your time with a rivet gun and bucking bar on these same rivets, I have found you can actually correct a clenching problem as long as you catch it early enough and maneuver the bucking bar to force the shop head of the rivet back on the right track. I also use a lower pressure than most when I drive these rivets, as I have found that this, in combination with using masking tape in the head of the rivet set, helps prevents smilies in the metal, should you not hold the rivet gun exactly straight on the rivet head while riveting.

 

 Here is the counterweight rib. The trick is to attach this rib by itself to the end of the spar first. Do not rivet the end rib to the counterweight rib as the plans describe.

One rivet set..... E704 Counterbalance rib is show on left side, and the E702 spar is shown in the middle to right side of the pic.

And the other side with shop heads after both rivets are set:

Manufactured heads look good:

Now you cleco the end rib to the counterweight rib, and also to the other spar flange. This allows you to get your squeezer/bucking bar in there...

Securing the work as you rivet the two ribs together...This keeps the ribs from flexing too much which caus smilies on the skin or the rivet from the rivet set not being firmly placed against the rivet head. You need the proper amount of resistance on both sides of the part to ensure a nice, clean, correctly driven rivet. I just used some shims and some 1/8 inch thick hardboard plates from the packing materials that I had lying around the shop.

I like to work on the top side rivets, and then turn the work over and reclamp everything, so that I can clearly see are the rivets that I am about to buck or squeeze. So I do one side of the rivets, the turn the work over, reclamp, and do the other side. That way the other rivets do not get in the way of me being able to see the bucking bar position on the rivets I am driving.

I need to get a pic of the modification I made to my no hole yoke. I needed to put it on the grinder to trim the sides down and to also grind down the top. I should have done this way back while fnishing up the leading edge rivets on the Horizontal Stab, before I screwed them up so bad. The problem was that the no hole yolk still has a significant incline associated with it, so I found that it would still not work very well for close quarter riveting, since the yolk would still bottom out on the other side of the rib or skin. I finally came across some posts on VAF where they explained that they ground down the taper on the yolk so as to allow it to fit inside smaller areas where riveting needs to occur. The pic will explain it better than the text.

Anyway, My immediate need is to make the yoke skinnier so that I could get it into the area of the E709 root rib and E702 spar. This rib flange is angled over 90 degrees to allow for the proper amount of rudder travel on either side of each elevator, and it makes riveting the 4 flush rivets that attach this part a bit of challenge. After grinding down the no hole yolk I was able to get it onto the flush rivets using a half inch long by 3/8 inch wide rivet set in my hand squeezer, without having to bend the rib out of the way to set the rivets. Here are the shop heads of all four flush rivets after squeezing them.

And finally, once the flush rivets are set, you get to attach the control horn onto the end. The pushrod from the control stick in the fuselage attaches to the control horns and allows the elevators to move up and down. The control horns are powder coated and welded pieces of steel. The rivet call out in the plans is for AN470AD4-4 rivets, but these end up being a little short. I have had this same experience when riveting other powder coated parts. I don't think that vans allows for the thickness of the powder coat, and this is why the call out seems short. If the rivet is too short you will not get a proper shop head on the rivet. So I finally experimented with my rivet cutter for the first time. Since a 4-4 rivet is too short, and a 4-5 rivet is too long, what I really needed is a 4-4.5 rivet. Problem is that the cutter is not set up for such odd dimensions. So what to do? I determined that my ruler is about 1/32 inches thick, and so I used that, in addition to a 4-6 rivet, to create the proper sized 4-4.5 rivet. The cutter defaults to a 2/16 inch cut on the end of the rivet without using any of the spacers, which are each 1/16 of an inch thick. This seems to give me just about the right rivet length to work with, and they appeared to set just fine.

I should be able to finish up the control horn and start riveting the frame to the skin tomorrow. Felt good to set some decent rivets again.

343 hours on the hobbs. Priming RIght Elevator parts

Or more appropriately, TRYING to prime them. I used my two part etching primer for the spars and ribs of the right elevator. I have a real problem doing this inside the garage. The sun glare from the outside provides enough light to see the parts fairly clearly, but the sides that are facing the inside of the garage bcome very shadowy and hard to see details without additional light added.

I decided to get lazy this time and did not rig any additional lights, and the results were predictable. Decent coverage on one side and really crappy coverage on the other. Lots of runs this time from applying too much primer without moving the gun enough over the surface. I also had problems on the root rib with the bend line of the flange on one side not accepting the primer for some reason. I had scuffed and cleaned this area the same as all the others, but for some reason the primer is separating along a small line that follows the inside bend line of the flange. Another possible contributor is the fact that I am finally at the bottom of my first quart can of the expensive stuff. It has been sitting in the hot and cold garage for some time, so I am also questioning its integrity at this point.

I have a new can ready to go, so I will use that for second coat. Will also spend more time on the next batch getting the flow and pattern from the spray gun setup correctly. You could tell I had not sprayed anything for a while. As a footnote, when I start working on the wings, I may switch to Ron's method which is alumiprep and nobel ekzo epoxy primer, but we'll see. No real reason other than I like the way it looks, and the epoxy primer is suppsed to be a bit stronger and more accepting of polyurethane paint. I also need to mask off parts of the rudder to re-prime some scuffed areas along the bottom. and the top.

My neighbor Kevin came over to help me finish setting the last 4 dimples in the elevator skin using the close quarter dimpling tool. Worked like a charm as always. It helps to have someone hold the skin while you set the dimples. Thanks Kevin!

I still need to remove a bunch of lead from the counterweight per the plans, and I have been communicating with Steve Riffe about the process of creating the riblets for the left elevator and trim tab. I will be departing slightly from the plans by adding the riblets instead of bending the tabs that are provided on the skins. Lots of folks have troubles with the trim tab, and I intend on getting this done correctly the first time. I want to finish the tail and move on to the wings as soon as possible.

Have not done much the past couple of days as the college kid came home from school with a car problem that has now progressed into a completely blown engine. That, combined with the first really cold weather of the season, has prevented me from getting all the priming done. Seems like every time I get close to wrapping up another sub assembly, crap like this always happens.

341 hours on the hobbs - Dimpling the right elevator parts

So a few pics to help better undestand my previous post -  This frst one is titled "HAVE A NICE DAY!"

Am I having too much fun building an airplane or what? I just couldn't resist this. Actually this is the front of the counterweight skin after dimpling the screw holes with a number 10 dimple die.

Next is a close up of the countersunk holes on the flange of the root rib that will receive the dimpled holes of the Front spar web. I did a trial fit to see how well the dimples fit inside the countersunk holes, and everything seems to come together very nicely.

and here are the support plates for the rod end bearings that attach the elevator to the horizontal stabilizer when the time comes:

And here is the counterweight with the mounting holes drilled out and countersunk with a number 10 countersink bit.

And the next one shows a little more work to do on the counterweight for the right elevator only. The marks are cut lines where I will need to trim off part of the counterweight according to the plans. This is part of the balancing process that will take place both before and after paint is applied to the control surface. I expect that when the plane is certified for flying I will most likely not have it painted yet. The control surfaces will still need to be properly balanced, without the paint, and will need to be re-balanced after the weight of the paint is added. A very critical step in the build process.

And lastly is a pic of yours truly in the process of dimpling the ribs, spars, and skin of the right elevator. Tomorrow morning I will be scuffing, cleaning, and priming parts, and hope to be riveting it together later in the day. I have to make a decision about fixing some slightly proud rivets on some of the skin stiffeners - something I should have addressed before I bent the trailing edge. There are three that I am not happy with. Just not quite sure what I am going to do about it at this point. Anyway, I am using my trusty close quarter dimpling tool to get to the holes on the trailing edge of the ribs, which are too close together to use the squeezers.