Flight Journal Veterans day 900x250
Log In
Access Premium Site»
Not a member? Join today!

Workshop Build-Along — Douglas Skyraider Part 8 — Fuselage Sheeting

Workshop Build-Along — Douglas Skyraider Part 8 — Fuselage Sheeting

Well, it has been a little while so I thought I would post an update for the Skyraider project. After installing hardware that would be difficult to get to after the fuselage is all covered up, here’s how I spent the last week getting the fuselage sheeting complet.

For more information on the Ziroli Plans Douglas A-1H Skyraider click here. And to see our entire Build-Along Series click here.

1a

To get a smooth and flowing surface, you first have to build a straight and true airframe. Take your time assembling the framework and install all the stringers and longerons so they fit flush in their slots. Work on both sides of the fuselage, adding one or two to the right side and then one or two to the left. This way you avoid building in stresses that can force the structure out of true. Then give them a light sanding with a sanding bar so you eliminate any glue globs or high points.

I also find it easier to install all the servos and the control linkages and pushrods before completing the fuselage. This way you can reach between formers and stringers and get to the hardware and install reinforcements in the proper areas.

glue

I find that the Titebond wood glue sands easily and dries quickly and I use it for most of my sheeting. I also use thick and medium Zap glue and Zip Kicker for fast application of sheeting in some of the tighter and smaller areas. Also it is great for filling gaps under the sheeting. For sandpaper, I use cheap hardware store grade in 150, 220 and 320 grits. Also, I find Great Planes sanding bars very useful I have both 1 foot and 2 foot lengths and use 150 and 220 grits. For filler, I use Dap Vinyl Spackling often referred to as Sheetrock mud.

imageb

I prefer to start at the front around the cockpit area. Measure the distance between formers so the sheeting pieces can he glued in place supported at their ends by the formers. After they are cut to length, use a mixture of water and ammonia, (I use a pump bottle of Windex), and spritz the outside of the sheeting lightly. Use some masking tape to hold the sheeting tightly in place until it is dry. This will form the wood to the compound-curved shape of the structure.

Apply some Titebond glue to the underlying structure then tape and pin the sheeting in place. The glue will dry in a couple of hours. Once the first piece is done, add the next piece of sheeting, applying glue to the matching edges. Make sure to form a tight seam between the sections of sheeting. If you have to, trim the edges so they fit nicely together, then pin the new sheeting into place.

img_0129

On either side of the cockpit opening, I install lite-plywood doublers to support the sheeting edges. These need to be flush with the formers the sheeting is glued to. Work slowly and sand glue joints smooth and flush.

img_0133While the sheeting on the front of the fuselage is pinned in place and drying, you can move to the tail. The Skyraider’s vertical fin is built into the fuselage structure, so it is relatively easy to add the single left- and right-side sheeting pieces. I cut the sheeting to shape, glued, pinned, clamp and taped it in place. It is relatively flat so the balsa does not have to be wetted before application. I cut the piece slightly over size and used clothespins to clamp it in place against the leading edge. Once the glue dries, trim the leading edge and glue on the other side. Notice also the lower edge is glued to an angled former to support the sheeting and help blend it into the rest of the fuselage shape

img_0137

Here the next piece of sheeting has been glued into place (see above). I call it the Heel piece as it goes on over the keel that defines the vertical fin’s shape. Again it is cut to shape and glued to formers at either end. The grain runs parallel to the F-13 keel piece.

img_0142The section between the heel and the back edge of the top forward sheeting is the most severely curved part of the sheeting. To do this section, I  used two layers of 1/16-inch balsa sheeting. The first layer is applied in two sections (left and right), with the seam running along the top stringer. The second layer however is applied in three wedged shaped pieces. The center piece has its pointed end at the rear and its wide end butting against the top forward sheeting. This eliminates extremely sharp bends in the sheeting. The two side pieces are then glued in place as shown completing the overall section.

pin2

As the tail section sheeting is drying, go back to the front of the fuselage and continue sheeting the sides. Start at the second former as the sheeting forward of the former tapers and is sheeted with separate pieces. Again use pins, tape and clothes pins to hold the sheeting in place as the Titebond yellow wood glue dries. Continue adding the various pieces of sheeting and use tape, clothes pins and pins to hold the pieces in place until the glue has dried. Notice that my T-pins are angled to hold the edges of the sheeting together at about the same level. While doing this, the edges sometimes float up or down and so I try to keep them relatively flush with each other to minimize sanding after the glue dries.

bphoto-2

Here’s the last piece of sheeting which I fitted into place the last time we posted. As a reminder, as I mentioned, I use TiteBond yellow glue for most of the sheeting as it takes a little longer to setup and it really sands easily if any squeezes out between the seams, and it is water-based so you can clean up with a damp paper towel.

pin1

Using the plans as a guide, I then cut open the horizontal stabilizer saddle area as show above. This is easily cut away using an X-Acto knife, starting in the center area and working your way outward. Be sure to take measurements from the plans to get the placement correct. The bottom half is definded by a light-plywood doubler under the sheeting. Once I was happy with the shape of the opening and the fit of the sheeting piece, I applied some glue to the substructure and pinned the piece into place. I also used clothes pins to clamp the part to the lite-ply doubler.

image10

Here’s the sheeting part glued into place. It has been sanded flush with the rest of the sheeting.

Filling the Seams

Before applying filler, I use a moist sponge to dampen the wood where I want to fill. I then use some scrap balsa sheeting to spread the DAP Vinyl spackling along all the seams between the sections of sheeting. I like to apply it at an angle to the seam and press it down so it flows into the recesses. Once a section is filled and repeat going down the length of the seam, and then I scrap the access off to minimize sanding after it dries. The spackling takes about an hour or so to dry.

image3

Here you see the spackling applied and drying. It looks like a mess at first but after it dries and you hit it with a sanding bar or sanding block, almost all of the filler material with sand away leaving only the sub-surface recesses filled.

image9

Once it all dries it’s time to sand.

sanding

When using a sanding bar I sand it at an angle to the sheeting grain and edge directions. Being stiff and straight, the sanding bar knocks off the high points and produces a smooth wave-free surface. So before doing any filling of seams or dings, smooth all the surfaces with the sanding bar, then wipe the whole fuselage down to remove all the dust. I use an automotive tack cloth.

image1

Here you see the first application of spackling sanded smooth. It usually takes two or three applications to get everything nice and smooth.

image8

Once the fuselage has been sanded with the 150 grit, switch to the 220 grit paper and now, you can use sheets of sandpaper folded into thirds and sand the surface by hand. You will be able to feel if there is a sharp seam or bump which you can address again with the sanding bar.

image4

Here is the nose of the fuselage with the sheeting around former F-1. The firewall will eventually be glued against this former. Also note that the bottom chin section is left un-sheeted for now. This is so we can fit the wing into place and install the big alignment dowel through Former F-3 and into the leading edge of the wing.

image2

Apply more spackling along any seams in this area, let dry and then use a long, narrow sanding block to dress out the corners. Don’t rush, take your time and apply as much filler as needed to end up with a blemish free fuselage. We’ll come back to the fuselage when we setup our engine installation and firewall details, but for now most of the sheeting is done.

fuse-photo

Once you happy with the smoothness of the sheeting, wipe it down and set aside so you don’t add more dents that will need filling. After the firewall is attached it will be ready for glassing using Z-Poxy Finishing Resin and .75 oz. FG cloth. Also, I love my Robart Super Stand as it is made of foam and does a great job supporting your fuselage keeping it up off the workbench. So for now, lets start on the wing!

plan2

Next time we’ll be digging into the wing construction. Checking the parts with the plans show everything fits perfectly.

ribs

Yes I did clean off my workbench! Here are the ribs… Stay tuned!

Click here for the next post.

Click here for the previous post.

 

Venom Fly 600x120
Digital Downloads 600x120

22 Comments

Add a Comment
  1. This is a great article, fantastic detail and pictures. However the typos tend to detract from the article. For example, “cloths pins” above should be ‘clothes pins’. you comment “after the glue dies”, I suspect it should read “dries”

    There are several other instances in this article, but no need to call them all out.

    Please take my comments as constructive feedback.

    1. LOL! that is funny. we will have to invest in an online copy editor. most of my posts are done with my workshop laptop.
      thanks for your comments

  2. R3a11y c0nstrut1v3 Cr1t1c1sm 1’m sur3 y0u understood, pedantic of note!!

    Thanks for the great post, not many people building kits today, is it a scratch built or kit? Keep posting even with speling erros 🙂

    1. Hi Allen, thanks for your comment. This Skyraider is a 15% reduced version of the 100-inch span 1/6-scale Ziroli design. it is about 1/7-scale and I did this as I like the Top Flite giant scale ARF warbirds in the size range. It is basically a short kit build. I reduced the plans locally, sent them to LasercutUSA.com and they laser cut all the parts on the plans. Pat the owner of the company also corrected all the slot and notch dimensions so stock size wood could be used. I bought all the balsa from Balsa USA. if you go to http://www.modelairplanenews.com/zskyraider, you can get to my landing page for all the posts in this Build-Along Series.
      Cheers
      GY

  3. Always nice to see how others approach building. Thx

  4. It’s a proven fact that humans can extrapolate teh wrods form a sentance quikly and effesiently as lnog as the frst and lsat leters of the wrds our carrect and thay are in contaxt.

  5. Hi Ger, The idea of the reduced size war birds is a great one, my only question is where did you get or have made your smaller sized canopy and cowl?

    Lee

    1. Hey Lee! good to hear from you. yes, cowls and canopies are always an issue aren’t they. Well it just so happens that the Sig Mfg. 13 inch ww2 bubble canopy is a perfect size in profile for the 85 inch Skyraider. When I found this out, I was motivated to start the build. I have both the 13 inch and the 15 inch Sig canopies (15 inch is a bit wider), and I will see if I can cut it down in length as well. But that it for the cockpit covering. As for the cowling, I will be making a wood built-up plug on the fuselage and then after I cover with glass and resin, and sand it to a smooth finish, I will be sending it to Lenny Stanko who has agreed to make a mold and layup a couple of cowling for me. I have a few gas engines we are thinking about bartering with. So far, the project is coming alone nicely. I have been wanting to make a 85 inch Skyraider for like 10 years now!

  6. Good job Gerry. Nice to see, in this world of ARF’s, that there still is interest in building. This is an area, perhaps, you folks at MAN could investigate. Maybe more articles on building of all sorts, could stimulate more interest across the board for those new to the hobby that would like to try it. Although the orient is building some nice models there is always that ‘pride’ when you do one yourself. You think?

    1. Hi Bruce. Yes I agree, more building articles would be a good thing for growing interest in the workshop side of our hobby. ARFs have affected our hobby greatly. Less (almost no), new kits are being introduced, and too, the demand for glue, epoxy, sandpaper, covering materials, etc., have all diminished greatly. The local Mom & Pop hobby shops are all but extinct. Being a longtime modeler, I am actually only one of very very few magazine editors that actually still scratch builds, designs airplanes and builds wood kits. But that’s not a dig at any of my fellow professionals in the publishing industry, it is just a fact. I think it has more to do with my age than other’s talents and expertise. In the meantime, I will, as the project develops, be publishing how to articles in MAN covering various aspects of this build. Watch out for my detailed “Sheeting a Scale Fuselage” article in the upcoming February issue of MAN.
      Cheers
      GY

  7. Nice work. I am Looking forward to the wing construction coverage. I noticed the tip ribs shown on your bench, do not have holes in them. Where then, will you put the lead outs? 🙂

    1. Hi Paul, sorry I did not see your comment sooner. Actually, the wing panels will be joined to capture the W-1A rib between them. As the panels are built, I will only tack glue it to the main spar. Each panel will be assembled, and then removed from the building board, flipped over and the bottom sheeting will be applied. it will then be reattached to the board and the wingtip washout shim (5/16 inch) will be added and the top will be sheeted. Before that however, the servos and the wing joiner tube and sleeves will be installed. I will also use a razor knife to cut guide cuts in the leading and trailing edges. Once the top sheeting is in place, I will cut through and separate the removable wing tip sections. Stay tuned, I just got my retracts so the wings will be started this week. Cheers. GY

  8. Nice build Gerry, I’m building a Top Flite FU Corsair and I’d like to attach the control surfaces very much like your did with the rudder, I’d be using Robart hinge pins. Are there any articles on this or any other build showing and explaining the correct way to do this.
    Thanks. Mike Hulas.

    1. Hi Michael. thanks for your comments. I like using Robart HingePoints very much, and will be also using them for the elevator and ailerons for my Skyraider. I also used them for my 1/3-scale Fokker Triplane. Here is a link: http://www.modelairplanenews.com/blog/2013/06/04/workshop-tips-giant-scale-hinging-made-easy/
      Good luck with your Corsair!
      GY

  9. Who really cares about spelling errors ?REALLY great article please continue the good work and all your Tim. Oh I spelled that word wrong . Get a life .

  10. I’ve been accused of having a hobby shop in my basement! I learned that if the materials list calls for 10 sheets of wood, order 15. The extra sheets – even the rejected pretzel wood – will eventually get used. Also, over the past 20 or so years, I’ve lugged home bags of wheels, tanks and all manner of fiddly-bits from the “orphans” tables at the swap meets. For pennies on the dollar, I now have a treasure trove of stuff that is no longer being manufactured. Yes, I do have a small “hobby shop” … of hard-to-find, mostly American-made parts. As a builder, it all helps to keep me building.

    1. Steve. I like the way you think. I too have a scrap wood box(es) and find it difficult to throw away any of my scraps. As far as a hobby shop in the basement goes I think this is a common symptom for us RC modelers. There is no cure! You should see my collection of gas engines, new and old!
      Cheers
      Gerry

  11. Very nice. Look forward to future posts.

  12. All the comments and replies to this build series is like a class of students and emeriti hunched over around an operating theater watching surgeons perform. I’m hunched over among them. Great build process!

    1. Vic. Thanks for your comments it is a great visual! This week I am working out my wing construction with the plug in wing tube installation. It will be fun and a change of pace to work on the wing and work out the control surfaces, linkages, retracts and the alignment for the wing tube and internal sleeve. Stay tuned!

  13. Nice to see a good old fashion ‘build’. My last one was the Giant Top Flite Corsair. (all electric) Looks like this is going to look great. Hope you give us a look at the first maiden flight with some pictures then.

Leave a Reply

Your email address will not be published. Required fields are marked *

Airage Media © 2018
WordPress Lightbox