Archive for June, 2010

On Vacation

June 20, 2010 Leave a comment

No new posts for the next few days as I am on vacation with the wife.

Categories: General

Left HS and Elevator Tips – 1.5 hrs

June 17, 2010 Leave a comment

Thursday June 17, 2010

After further sanding of the left elevator tip on Wednesday night I was not happy with the shape of the leading edge. It as not square to the inboard edge and the radii were too large. So I wrapped blue tape around the edge to form a dam and poured on a layer of dry micro filler. Here is how it looked.

Tonight I removed the tape and sanded the leading edge. First I sanded it flush and square to the inboard edge. Then I put a slight convex curve on the surface with about an 8.5 inch radius. Here is how that looked. The edges are just slightly rounded here. I’ll round those a bit more later after I am fully satisfied with the general shape. If you look close you can see what appears to be irregularities in the surface. That is actually just color variations in the dry micro layers, the shade of which varies depending on how thick it is mixed. The surface is actually very smooth. You can’t feel those lines at all. There are a few pin holes but I’ll probably deal with those with a coat of UV Smooth Prime or two.

Here is the overall view of the left elevator tip filled and sanded.

I mounted it to the horizontal stabilizer to check the fit with its mating tip. This tip was sanded flat on the trailing edge surface so I removed it and sanded in a matching radius like I did on the right side. Here is the gap between the two parts installed. I will next trim the upper skin just slightly where it overhangs the white fiberglass tip near the dogleg corner.

Categories: Fiberglass Tips

Fill and Sand, Fill and Sand – 1.5 hrs

June 15, 2010 Leave a comment

Tuesday June 15, 2010

Step 1 today was to sand out the right horizontal stabilizer tip trailing edge again. The surface is slightly concave with about an 8.5 inch radius so the surface matches the profile of the elevator leading edge nicely. This one is just about done. There is one tiny surface dimple that I will fill next chance I get and then I will put on a coat of UV smooth prime for the final surface finish in this phase. Painting is a long way off. Look closely at this picture and you might see the dimple.

Then I did some major rough sanding on the left elevator for the first stage of dry micro filler. The peel ply layer helped reduce the waviness of the filler surface and so reduced the amount of sanding considerably. I am satisfied with this for a first cut on this side. The other side only got about half as much filler as it needed because I didn’t mix enough yesterday so it will need another rough layer.

There are some obvious voids in the first layer of dry micro but the area is relatively small. These will be filled in the second layer.

Here is the other side which was only partially coated in the first try.

So I mixed up another batch of dry micro after sanding and cleaning the parts with a clean damp rag. I applied a generous layer on side two and again applied peel ply over that to smooth out the surface and I filled the voids on the other side. More sanding tomorrow.

Categories: Fiberglass Tips

Fiberglass – Part 49, 1.5 hr

June 14, 2010 Leave a comment

Monday June 14, 2010

OK so it’s not really Part 49 but it feels like it.I can’t believe how many days I have been working these fiberglass pieces so far.

Oh, and I did something stupid yesterday. I should have put peel ply over the deck cloth on the left elevator but I just forgot. So now the surface of the epoxy is nice and shiny and the next layer of dry micro won’t stick well to that so I had to sand the deck cloth layer to break the sheen and rough it up. The peel ply would have prevented the need for that sanding except for a few high spots. Live and learn.

After sanding for a good half hour the surface was ready for the first layer of dry micro filler. So I mixed it up and smeared it on in as uniform of a layer as I could and put peel ply on top. I used a block of wood to smooth out the peel ply which helps even out the filler layer as well.

Now back on the right horizontal stabilizer tip, I sanded the trailer edge after adding filler to it yesterday but there were still a few spots that were not “perfect”, so I added a little more filler in select places.

Categories: Fiberglass Tips

More Little Steps on Fiberglass – 2.5 hrs

June 13, 2010 Leave a comment

Sunday, June 13, 2010

I decided that I was not satisfied with the shape of the right elevator tip. The issue was that it was slightly off  perpendicular to the inboard edge of the counterweight skin. So to make it square I made a little dam with blue tape and poured some filler in to build up the thickness enough that I can sand the surface back down at the correct angle. Here is the simple setup.

Later in the day I sanded it using some 100 grit paper wrapped around a block of wood. That gave me a good flat surface first, then I progressively rounded it in one axis to give me about an 8.5 inch radius, which is the distance from this surface to the hinge axis.

Now the leading edge is nice and perpendicular to the inner edge of the skin.

However, this now made the surface of the horizontal stabilizer tip slightly askew relative to the elevator leading edge. So I sanded that more to try to get the surfaces parallel. It became obvious that I needed to add some more filler to that part also to get the profile I wanted so I made another dam and put some dry micro filler on one end.

In the mean time I decided to get back to the left elevator to try to catch up with that one. This one is more challenging because I put flat head screws on this side and the surface of the skin is not as flat. So I mixed up some epoxy and cut strips of deck cloth and put down one layer on each side to bridge the seam between the tip and the skin.  This is for reinforcement and hopefully to prevent cracks in the future.

Categories: Fiberglass Tips

More Filling and Sanding – 4.5 hrs

June 12, 2010 Leave a comment

Saturday June 12, 2010

This morning I mixed up a batch of epoxy with filler and applied it to the rudder tip to fill low areas. I tried to keep it thin to minimize the amount of sanding later.

I also applied it to the right elevator tip/skin transition area on both sides. Then i went off to my flight training lesson in Corona. After returning I spent a good hour sanding both sides of the elevator. Here is the result. It’s hard to tell from the photo but its pretty smooth for the first cut.

Then I went back to the rudder tip and sanded out the fill I put on earlier. Getting close to done with this thing now but i was not happy with the leading edge fit to the VS tip so I sent some time trimming and shaping the trailing edge of the VS tip to match the radius of the rudder tip. After a hald hour or so, here is how it looked.

Here is a side view. The clearance is about 3/32 to 1/8 inch. It’s getting there. I’ll probably add a bit of filler to the top of the VS tip to match the contour of the rudder tip better.

Next I applied a coat of UV Smooth Prime to fill pin holes and reveal imperfections in the finish.

That cured in s couple of hours and so I sanded it out to leave a smooth, albeit thin layer. I’ll spray on another coat later.

I’ll really be glad when I am done with all this dusty stuff.

Categories: Fiberglass Tips

Fiberglass is Slow Going – 2 hrs

June 11, 2010 Leave a comment

Friday June 11, 2010

After work tonight I began sanding the rudder tip again. The epoxy filler was a little thick so it took a while to get it smoothed out and blended into the skin.  I also did some more shaping of the leading edge including making a template with an 8.5 inch radius as a reference.

Here is the other side. There are still a few low areas that I need to fill.

The leading edge shape is good with a few small divits that I also need to fill.

In this photo you can see the 8.5 inch radius I sanded into the leading edge.

Categories: Fiberglass Tips

Sanding Out the Rudder Tip Blend – 3.5 hrs

June 6, 2010 Leave a comment

Sunday June 6, 2010

The next step in the rudder tip work is to apply epoxy with West Systems 410 microlight filler to the seam line between the fiberglass tip and the aluminum skin to smoothly blend the transition. The idea is to make this area seamless. When its painted later it should look like one uninterrupted surface. I mixed the epoxy fairly dry so it would not run. Then I applied it on both sides.

OK, so my technique was not great on this my first attempt. The layer was too irregular as you can see. It was not a crisis, just a lot more work to sand out to get the surface smooth. While it was curing, I trimmed and sanded a small fiberglass patch I had created on the rudder bottom that I documented the other day.

Some hours later I began sanding the filler on the rudder top. It was laborious but it cleaned up better than I expected given the irregular surface I started with. I must have sanded 3/4 of the material off to get a smooth surface.

Here is the first cut at the leading edge area which I am trying to round out to a nominal 8.5 inch radius. That is the approximate distance to the center of the hinge axis.

It was obvious that I would have to fill some low spots on both sides and the leading edge so I mixed some more epoxy/filler and laid it one for round two. This time I used a straight piece of aluminum sheet to squeegee it on in a much more uniform layer. That should make the next round of sanding much easier and quicker. Here is the result at start of cure.

I’ll be on a business trip for a few days so I’ll have to sand this out later in the week.

Categories: Fiberglass Tips

Blending Seams on Rudder and Elevator Tips – 2.0 hrs

June 5, 2010 Leave a comment

Saturday June 5, 2010

I stopped by Aircraft Spruce this morning and picked up some 1.45 oz/yd e-glass “deck cloth” and some flocked cotton. The cloth is for reinforcing the seams between the fiberglass tips and the aluminum skin on the empennage. The first one I attacked was the right elevator. First I put blue masking tape along a line that will define the maximum boundary between the epoxy filled area and the aluminum skin. Then I buffed up the aluminum skin where the epoxy will lay and cleaned the surface. Then I cut a strip of deck cloth about 1.5 inches wide and 40 inches long and laid it on with epoxy bridging the gap all the way around. Then I applied peel ply over the top. Here is the right elevator as it began to cure.

Then I basically repeated the same process on the rudder.

Next I began working on the rudder bottom. There are absolutely no instructions in the Vans kit on how to deal with the rudder bottom. There is a faint line on the surface of the material that appears to be a trim line but nothing in the instructions confirms this. After searching the forums on this I concluded that the edge of the piece needs to be trimmed to the faint line although some builders have apparently not done this. Perhaps that is why some tail dragger builders have had an interference with the tail wheel. So with some anxiety I started cutting the piece with a cut-off wheel on my Black and Decker rotary tool. It cuts it like butter but makes lots of dust. Here is a shot that shows how far the edge is trimmed back.

I cut all the way around plus the two rectangular notches for the rudder horn. Then after a little tweaking and trimming I got it to fit onto the rudder base pretty well. Here is the right side. The gap is pretty tight all the way along except at the far forward end.

Here is a closeup of that area. It’s not as bad as it looks in this photo because it naturally bows out a bit from the rudder skeleton. But I’ll fix this with a little fiberglass patch up in this area.

Here is the left side. It too looks pretty good.

The leading edge gap on this side is fine as is. Again it bows out a little but when I press it down it fits nicely.

Now I need to research the hole placement for this piece and decide if I want to use rivets or screws and nutplates.

Categories: Fiberglass Tips

Rivet on Vertical Stabilizer Tip – 0.5 hr

June 1, 2010 Leave a comment

Tuesday June 1, 2010

The time has come to rivet the vertical stabilizer tip onto the vertical stabilizer so I did that tonight. I checked each rivet first to make sure it was flush and used the countersink bit on a manual deburring handle to touch up the dimples. Here is the finished product.

I plan to pick up some 1.45 oz/yd fiberglass this Saturday at Aircraft Spruce to start blending the tip into the aluminum skin.

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