acerc

That is the heavy duty type hinging I have going on. I bet our idea of 3D is nothing like theirs, especially from a Pitts.

ghoffman

My Feedback: (3)

There really is no downside to a few extra hinges.

raptureboy

Well your usual attention to detail is excellent and although this type of aircraft does not interest me I enjoy seeing what your doing and learning techniques I may use in my future endeavors. I can't seem to stay out of the repair shop these days and yet again damaged my stearman when a wheel came off at landing and tore off the landing gear and knocked the vertical stab loose when it flipped over. This after just having repaired the same thing from an engine out and going down into a cow pasture last week. On the upside I purchased some Sierra Giant landing gear for my P-40 and they are just absolutely an amazing piece of workmanship. Well worth the $ and when you see them in person they look like real landing gear. I think once the repairs are made I am going to hang it up for the season and do some actual building.

Melchizedek

Raptureboy, are the Sierra gear for an existing P-40 or one you are building ?

If building, who's ? And are you doing a build thread ?

Kevin

VincentJ

Here's a photo of the first 1/16" sheet I glued to the top of the wing. Using such thin balsa is like using a piece of paper to cover it with! You have to make sure that what you are covering has the shape that you want the balsa to conform to because it will show any type of uneven blemishes underneath...I was concerned using Titebond on such thin sheeting that it may warp the sheeting, but it did not.

If you note the plans on the left side of the wing, it shows the top (and bottom) sheeting is supposed to butt up against the TE of the wing. I thought this to be much too difficult to get a nice tight joint, so I opted to trim the top and bottom of the TE down to the ribs and have the sheeting run proud over the TE to be easily trimmed later.

I also cut up some basswood strips and epoxied them together as these pieces will become the framework that will hold the servo hatch cover in the wing. For those of you that have followed my other projects I have used this same method before.

ovationdave

My Feedback: (16)

Looks Good Vincent. I am wondering how you go about (especially on such thin stock) gluing down the sheeting. If this is described in one of the other build threads I will go look it up, but it seems I always have trouble getting a good tight fit to the ribs in these cases. 1/16 of a inch is too small to use "T" pins or something to hold the sheeting against a rib, is there a trick to getting the sheeting to lay up tight to the contour of the ribs?

thanks,

Dave

acerc

Ohhh Dave! Has Vincent got a tutorial for you.

maekju

I would love to be a student of this tutorial as I have the same problem.

VincentJ

I'll post later on tonight with how I get the sheeting glued...

ovationdave

My Feedback: (16)

Thanks Vincent!

raptureboy

Thick CA what else I wet the balsa and lay it on the wing then weight it down with sandbags I made up using heavy duty freezer ziplock bags. I wet the sand to make them heavier then when the wood dries, I remove the sheets and then apply wood glue to the ribs and lay the sheets down and weight them and when I get to the leading edge I use CA. You could also use all those back issues of MA for weight

maekju

Raptureboy, so you wet the sheeting, lay on wing and weight down before gluing. Then when dry the sheeting has the curverture of the wing. Apply glue to ribs, lay sheeting on wing and wiegh down until dry. Sounds like that'll work pretty good, I apply thick CA, lay sheeting on wing, hold down with hands, when dry let go, reapply CA as needed. I like your method better. Still can't wait for VJ's tutorial

raptureboy

Yep, his method works well. I tried the thick CA routine myself the first time but it was tricky, the wood glue allows more time. I use a 50/50 mix of alcohol and water in a small spray bottle and lightly wet the sheeting on the upper side. It's pretty much an old technique used for years. If you guys have never used this tape before you should get a roll http://fiberglasssupplydepot.com/3M-...ing-Tapes.html It works really well even with dusty balsa and comes off with no residue. I have used it to hold sheeting in place by wrapping it around the fuselage or wing. Even sticks to damp surfaces, I buy it at my local Sherwin Williams paint store but I'm sure you can find it else where.

acerc

Seeing as others have spoke their method, so will I. I mark the sheeting everywhere it will contact the wing/fuse. Then I put a thin layer of wood glue on both the sheeting and everywhere the sheeting will contact. Let that dry until touchable with no tackiness to the feel, about 6-8 minutes. Then I lay the sheeting in place, spray the surface with water real good. I then use an iron set to around 300degs and iron the sheeting in place. I use a scrap piece of the same sheeting to get a time of how long it takes for the heat to get through it enough to not be able to keep the finger there, usually 6-8 seconds. The water helps with the heating via steam and it curves the sheeting as I go along helping to form fit it.
That's how I do it, other's may differ.

maekju

I’ve used the water and alcohol / ammonia method before to curve balsa. I don’t know why I never thought of using it to sheet wings. Probably another good reason to switch to wood glue the CA is causing me to lose brain cells
acerc – So the heat will make the glue tacky again and it cures quickly enough so you don’t have to pin or weight down the sheeting? I like it

acerc

Yes maekju, the heat instantly joins the two surfaces. And also, in my opinion, plain water works just as well all by itself.

VincentJ

Here is what I've completed for tonight. I almost have the top of the wing sheeted, just one small piece left as you can see.

I've also continued with the servo hatches that I started on yesterday. Since the epoxy had cured on the basswood rail strips, I cut them to length and dry fitted them in between the ribs. Satisfied with their fit, I cut out the servo hatch cover from some 3/32" birch ply. Next I drilled four 1/8" holes at each corner of the hatch cover for the 4-40 button head screws that I will use to secure the cover. With the drilling completed, I reassembled the rails to the hatch cover so I could use the already drilled holes as a guide to drill into the rails, doing this will ensure an exact fit later. Tee nuts was then epoxied to the bottoms of the rails and set aside to dry.

VincentJ

Before I explain how I sheet wings, I would like to mention that this method works for me and is no way better than anyone else's method of sheeting a wing. There's more than one way to skin a cat!

OK, first off I believe the initial complaint was to get a better fit between the ribs and the sheeting. So let's start at the beginning. Your build table has to be flat and level or your wing will take on the shape of the uneven build surface. with that being said, pay attention to the ribs that you remove out of the die cut sheets, stack them and sand them as if they were one if possible. This was not possible on my Edge as each rib was a different size than the next, however the ribs on my Spacewalker were all the same size...

Make every attempt to build as square as you can, this will save you a lot of unnecessary sanding later. Assemble the wing dry (without glue) to see if everything fits to your satisfaction, if it does then you have to disassemble the wing to get the glue between the joints...remember I don't use CA so if you use CA then you don't have to take the wing back apart.

Once the glue has set then comes the tedious task of sanding the ribs so regardless of their shape or size they take on a nice straight even line. If one rib is higher than the next you will never get the sheeting to meet unless you use excessive outside force with weight to close the gap. You will more than likely end up with a very wavy outside surface to then deal with.

You must be equipped with a variety of different types of sanding blocks that range from a few inches to many feet in length. It is also helpful to have these blocks in different grit sanding paper so you don't have to waste time changing the paper. These sanding blocks can be purchased or you can make them from straight lumber or better yet you can go to the hardware store and buy aluminum stock of varying sizes and shapes to get the job done. Which ever block you use make sure that it goes from one edge of the wing to the opposite side. Then with the weight of the block alone make some very easy deliberate strokes. I caution you about using too much pressure, if you are attempting to sand the 1/16" ribs let's say on my Edge they will easily succumb to the pressure. If your ribs are stout and can take the pressure don't be tempted to use more force as it may flex the wing resulting in an uneven surface.

Once you are satisfied that your wing is straight you are now ready to glue the sheeting to the wing. Depending on the thickness of your sheeting I would use caution on the use of water. 1/16" sheeting bends very easily as you can see in the photo, and that piece was only 3" in width, wetting it is not necessary! Wetting thicker sheeting can and does work, but with thinner sheeting you stand a very good chance of it warping. Since 1/16" sheeting bends so easily, heavy weights laid atop the sheeting is not necessary. The weight of sanding blocks or straight edges are often heavy enough to accomplish the task. I like to spread the load placed upon the sheeting, otherwise too much pressure on one location may cause the sheeting to sag in between open bays.

Also when edge joining, do not use CA, as the glued joint will become harder than the adjacent balsa and you will have one heck of a time sanding it level.

Again, the key to good sheeting isn't any simpler than the preparations that you do beforehand, their is more than one way to sheet and my way isn't the only way, but it works for me... Hope this helps!

acerc

Gee Vincent, I thought all that was a given.....
Now! On to the previous post, I really like your hatch work. It give me a few ideas to try out myself.

All Day Dan

My Feedback: (5)

Vincent, I’m trying to follow your thread since you are doing such a great job but I am having trouble every time I get a reply. When I open the reply, I get to your very first post and you’re on page 5. Am I doing something wrong or is the new RCU still screwed up? Dan.

raptureboy

Dan, it's still screwed up. If you are subscribe then just go to your subsciptions and then click on the button that says go to first unread post. See Vince I told you just use your old copies of MA Very good instruction on the sheeting a light touch and patience are needed in sanding balsa especially with 1/16 ribs and sheeting. I prefer 3/32 sheeting so it takes a little more pressure to put a hole in it.

All Day Dan

My Feedback: (5)

Vince, thanks for the rsponse. I know that I must sound like a real jerk but where is the button that says go to first unread post. Thanks, Dan.

Leroy Gardner

Vincent that is some mighty fine joinery and I agree about the sanding especially uniform ribs, without them you will never get a uniform skin on. I never use magazines or bags to hold skin down (I know many do) I do the same thing you do, use bars because there is nothing straighter.

I was surprised you didn't put the sheeting on as one piece by taping the joints, fold and gluing, how did you manage to keep that joint straight with some of it on the wing, "you are really good".

Leroy

maekju

Good sheeting tips VJ. I do practice some of those procedures but I have to get away from using so much CA. I have an old Hot Kanaray kit on the building board and I'm going to go with wood glue where ever posible. I also wondered why you didn't put the sheeting on as one piece by taping the joints, fold and gluing. I also want to know how you got that joint so staight, inquirung minds want to know. By the way your work is excellent, as usual.

All Day Dan

My Feedback: (5)

Found it. Sorry for the useless intrusion. Dan.