Call me crazy! 1/72 Northrop YB-35 Flying Wing

[LorenSharp]

Outstanding job billn53, especially with the turret. Where did you find the 1mm chisel at? I could use something like that with what I'm working on now. I tried a jewelers screwdriver but not sturdy enough to shave through fibreglass /resin.

[billn53]

1 hour ago, LorenSharp said:

Where did you find the 1mm chisel at? 

Mine is made by Master Tool, which is also sold under the Trumpeter label. They come in a variety of sizes and styles. I got mine through eBay. 

[Thom216]

Incredible progress! Loving all the added details. Shame about the ill-fitting glazings, but I'm sure you will overcome and endure!

[billn53]

1 hour ago, Thom216 said:

Incredible progress! Loving all the added details. Shame about the ill-fitting glazings, but I'm sure you will overcome and endure!

Speaking of glazings, it occurred to me that I have a second YX-35 in my stash, and it’s the original 1995 ERTL/AMT release. I bought it when it first came out and got only so far as the interior before putting it aside. 

I thought maybe the clear parts would be in better shape than the ones I’m presently using (Italeri’s 2008 release), the molds being brand new instead of 13-yrs old. I checked, and it turns out my suspicion was correct. So I swapped out the clear parts for my current build. 

Vacu-forming is still an option and I’ve ordered some casting resin to give it a try. 

 

[Retired Bob]

Great work as usual Bill, I had to get my "wings" out of the number 1 stash so I can join in the fun and appreciate your problems, here they are in their AMT glory:

As you can see it is molded in a hard white plastic, the clear parts are in a similar condition to yours, and a very big box.  Price of $18.50 but I stand corrected it was not Spangdahlem, but Bitburg AFB.

I also got:

And while not a real flying wing, who does not like pancakes?

I think I got this from a toy shop up in the Highlands of Scotland, go figure.

[billn53]

It's been a couple of days since my last update, so I thought I'd bring everyone up to speed. Most of my time has been spent filling and sanding seams -- boring work, to be sure, and I'm not going to bore you with it. So boring, in fact, that I decided to take a break from that and instead do some constructive work.

 

I'll start with the main center section. 

 

I've not yet installed the tail cone and thought I could make it a bit more interesting. Northrop had a proposal to add guns to the tail cone, which is seen in this drawing:

 

 

 

So I said, why not? This is going to be a production aircraft, after all. This is what I came up with:

 

 

 

Next up for the center section are the exhausts for the turbosuperchargers. This is the kit's version -- cylindrical projections from the turbosupercharger bulges, blanked off at the ends:

 

 

 

It would be nice to replace the plastic exhausts with some thin-wall brass tubing. On top of that, notice that the kit's exhausts are different lengths... I could not think of any reason why that should be the case, and then I found this photo which confirms my suspicion that the exhausts should all be the same length:

 

 

 

That said, I haven't yet decided to take the plunge and correct the kit. Your suggestions are welcome!

 

Next up are the four fairings at the rear of the center section for the driveshafts and reduction gear. In assembling these, I discovered that there is an error in the kit's instructions. Each fairing is unique, so it is important not to mix up the pieces. Unfortunately, that's exactly what would happen if you follow the instructions. Specifically, in steps 11 and 12, the part callout for the outboard engines is wrong. The left wing's outboard fairing should use parts 12E and 13E (the instructions say 10E and 13E), and the right wing's outboard fairing should use parts 10E and 11E (not 11E and 12E). It's a good thing I did my test fitting before gluing the fairings together!

 

Another problem encountered is that two different sizes of air scoops for cooling the reduction gear are provided (which size you use depends on if you are building the single prop or counter-rotating prop version). But, the kit only includes two of each kind of scoop, instead of the four that are needed. My solution was to steal the missing pieces from my other YB-35 kit, but most people aren't crazy like me by having two kits in my stash.

 

Anyway, I'm hoping I can build and paint the fairings separately, and add them to the center section near the end of the build. To help make that possible, I added shims to the fairings to minimize the gap between fairing and wing:

 

 

 

 

 

 

 

The fit for the air scoops is very poor, so I gave them a generous dose of sprue gloop:

 

 

 

One more thing I will need to do is add the warm air outlet for the reduction gear at the rear of the fairings, which are not represented in the kit:

 

 

 

That will involve removing the rear portion of the fairings and replacing with plasticard:

 

 

 

Moving on to the outer wing sections...

 

Each wingtip leading edge slot needs five "fences", as shown in this drawing:

 

 

 

I gave it a good college try, and I'm not totally happy with my result, but it's gonna have to be good enough:

 

 

 

That's all for now!

 

 

[SafetyDad]

Looks great to me! I think your 5 fences are just fine.

 

Loads of inspiration here for those of us with this kit in the stash. Thanks

 

SD

[Retired Bob]

6 hours ago, billn53 said:

That said, I haven't yet decided to take the plunge and correct the kit. Your suggestions are welcome!

Hi Bill, as I said that I would get my wing out of the stash to join in the fun, well looking at the exhaust problem I agreed that there was no reason for the different lengths and looking at the problem area, the exhausts have only been partially formed and are not completely circular.  So out with a drill and round file, some 1/2 inch lengths of 5/16 brass tube and here is the result,

 

The tubes are just pushed through at the moment, and the insides of the pipes need thinning down but that looks better than the kit offering.

[billn53]

4 hours ago, Retired Bob said:

Hi Bill, as I said that I would get my wing out of the stash to join in the fun, well looking at the exhaust problem I agreed that there was no reason for the different lengths and looking at the problem area, the exhausts have only been partially formed and are not completely circular.  So out with a drill and round file, some 1/2 inch lengths of 5/16 brass tube and here is the result,

 

The tubes are just pushed through at the moment, and the insides of the pipes need thinning down but that looks better than the kit offering.

I am inspired by your example!

[Retired Bob]

Thanks for the encouragement everyone, you know what this means, I have been trying to finish off all the kits that I have started over the last umpteen years, this YB-35 is now started, 😀 so now I can carry on and get it finished, best I get some new natural metal paints. 

[billn53]

@ Retired Bob  -- If you are going to be getting some metallic paints, and you will be airbrushing, you can't go wrong with AK Interactive's Xtreme Metal series of enamels.

 

Here is a great description of the YB-35's powertrain:

 

 

 

And after having seen Bob's work, I've taken the plunge (or should I say, drill) and opened up the holes for the turbosupercharger exhausts. I'll be using 3.5-mm thin wall brass tubing, which matches the size of the kit's exhaust.

 

 

 

- Bill

[Retired Bob]

13 minutes ago, billn53 said:

@ Retired Bob  -- If you are going to be getting some metallic paints, and you will be airbrushing, you can't go wrong with AK Interactive's Xtreme Metal series of enamels.

Cheers Bill, I have just ordered a selection of the very same paint, and for those of a metric nature, the brass pipe I used was 12mm long, diameter 4mm. 

[Caerbannog]

Nice build so far. I once started the YB-49 and was not impressed by the detail at all - especially the blanked off inlets spoil the look. At some point I decided to ignore this and glued the fuselage together... Bad decission. It landed on the over crowded shelf of doom. One day I will try to rip it apart and improve it the way you do.

[Retired Bob]

1 hour ago, Caerbannog said:

Nice build so far. I once started the YB-49.  It landed on the over crowded shelf of doom. One day I will try to rip it apart and improve it the way you do.

I don't call it "the shelf of doom".  I prefer to call it "The Terminator shelf"  because when I put something on there I always say "I'll be back" of course in an Arnie voice. 😎

[Thom216]

On 7/28/2019 at 10:17 PM, Thom216 said:

Incredible progress! Loving all the added details.

What he said!

 

😉

[billn53]

It's Saturday afternoon and exactly three weeks before our local show & contest. Let's see how I'm coming along with my flying wing...

 

I gave the four fairings a coat of Stynylrez gray primer:

 

 

 

followed by Xtreme Metal "matte aluminum" enamel:

 

 

 

So far, so good. Next I masked the fairings and painted a few select panels in a different shade. Imagine my frustration when I removed the masking and found this:

 

 

 

The primer lifted off the plastic in huge pieces. So much for its "excellent adhesion and durability"! I guess it's a good thing I discovered this with the fairings, instead of after I'd primed and painted the entire wing.

 

The only thing for it was to strip the paint and try again. This time, I primed with Alclad gloss black. Alclad is a lacquer, and my thought was that it would be less likely to pull off with my masking tape. Long story short, I am now back in business! Here are pics of the finished fairings:

 

 

 

 

 

 

 

In the last shot, you can see the gearbox warm air exhaust opening I added at the rear of the fairing.
 

Enough on the fairings. The big news is that this morning I glued the wing outer sections to the center assembly! I wasn't 100-percent successful in avoiding gaps and steps at the joins, but it's in much better shape than I had feared! First off, here's the big wing:

 

 

 

Some of the fit problems I'll have to work on include:

 

The left wing upper surface has a small step:

 

 

There is a slight gap/step above the leading edge air inlets:

 

 

Most most serious fit issues are on the underside:

 

 

 

 

 

 

Nothing that styrene strip, stretched sprue, and sprue gloop can't fix!

 

 

 

 

 

 

The good news is that, with the exception of the turbosupercharger bulges, all the joins are simple straight lines. The bad news is that there I have approximately five linear feet of joins to clean up. Fortunately, I still have three weeks to get this build finished!

 

Last couple of pics before I sign off. Of course, I couldn't resist test fitting my propulsion fairings to the assembled wing:

 

 

 

 

 

She's getting there!

 

 

 

 

[Corsairfoxfouruncle]

Good save after the stynylres. Im surprised that happened after all the raving I've heard about it.  

[Joel Abery]

Patch her up lol. Exceptional work

[billn53]

1 hour ago, Joel Abery said:

Patch her up lol.

Here we go!

 

 

It's been a long time since I've used Bondo, we'll see how well it handles this job. Most of the surfaces are large and nearly-flat. I raided the cosmetic's section at my local grocery and bought these sanders. I think they'll be perfect.

 

 

 

- Bill

[Retired Bob]

Looking good Bill, now the wing is in one piece.  I have been giving serious thought to joining the 3 upper and 3 lower wing pieces together, and then join the upper and lower wings together, it would prevent any steps along the wing surfaces that pass through some panels.  So far I have cut out the leading edge intakes and made a hole to create the intake tunnels into the wing, and finished off all 8 exhausts.  If I do go for a one piece upper and lower wing I will have to make the leading edge bypass slots differently. 

[LorenSharp]

We may have to call you Bondo Billn53. I've found the best sanding boards in the cosmetic section, and a heck of a lot cheaper too.

 

 

[billn53]

50 minutes ago, Retired Bob said:

Looking good Bill, now the wing is in one piece.  I have been giving serious thought to joining the 3 upper and 3 lower wing pieces together, and then join the upper and lower wings together, it would prevent any steps along the wing surfaces that pass through some panels.  So far I have cut out the leading edge intakes and made a hole to create the intake tunnels into the wing, and finished off all 8 exhausts.  If I do go for a one piece upper and lower wing I will have to make the leading edge bypass slots differently. 

One idea: cut out the region of the leading edge where the slot will be and build your slot separate from the wing, before gluing the wings together. Then add the slot after the top & bottom of the three-piece wing have been joined. Some trimming will most likely be needed. 

Bill

[Retired Bob]

On 04/08/2019 at 02:03, billn53 said:

One idea: cut out the region of the leading edge where the slot will be and build your slot separate from the wing, before gluing the wings together. Then add the slot after the top & bottom of the three-piece wing have been joined. Some trimming will most likely be needed. 

 

Bill, In life there is always some trimming required.  I will cut out where the slots are and then see what I can do, whether it is better to assemble the outer wings or still possible to go for a whole top and bottom wing assembly.  I looked at this idea because of the joint passing midway through a couple of panels and the chance of a step or joint showing could be best tackled by a one piece assembly, ironically there is a natural full cord wise joint in the panels 3/4 inch further inboard, lining up with the step in the leading edge, but that would have been too easy. 

[Retired Bob]

On 04/08/2019 at 01:20, LorenSharp said:

We may have to call you Bondo Billn53. I've found the best sanding boards in the cosmetic section, and a heck of a lot cheaper too.

And while you are waiting for some paint or glue to dry you can always keep your fingernails tidy.  Win, win.

[billn53]

I had hoped to be get primer on over the weekend, but the Bondo job is taking longer than expected. Not that the Bondo hasn't done a good job on the joins, but it shrinks when drying. This creates small cracks, requiring close inspection to find and additional Bondo to repair.

 

At this point, I think all the Bondo that will be needed has been applied and sanded down. In this pic you can see how the Bondo has worked on the wing panel step:

 

Before:

 

 

After:

 

 

I didn't think it wise to use Bondo on the area around the turbosupercharger bulges, something with a little more finesse being more appropriate. Instead, I attacked the step with sanding sticks, then applied sprue gloop to even things out:

 

 

 

After I had sanded down the sprue gloop, I gave everything a good coat of Mr Surfacer. It looks ugly right now but should clean up nicely once it's been sanded:

 

 

 

While painting the bulges with Mr Surfacer, I couldn't help but get some on the surrounding Bondo, and noticed minor flaws that weren't readily apparent beforehand. So, I decided to give all my Bondo'd joins a coat of Mr Surfacer:

 

 

 

Which explains why I haven't gotten around to primer yet.

 

On a more positive note, I did complete a couple of minor projects while waiting for the Bondo and Mr Surfacer to dry. First, I polished the clear parts and gave them a clear dip, which greatly improved their clarity:

 

   

 

BTW, while polishing the canopies, I noticed that the hole in the forward canopy for the gunner's sight didn't pass completely through the plastic, and needed to be drilled out.

 

I haven't yet abandoned the idea of making vacuforms for the canopies, but time is running out if I want to have this build ready for our local show, and I will lose a few days for a business trip next week, so chances are I'll go with the kit parts instead.

 

My other completed project is something completely different, but also targeted for the show:

 

 

 

That's it for now!