Three more for the Wisconsin Air National Guard

[billn53]

I applied Mr Surfacer 1000 to all the seams

 

 

 

Sanded it smooth when it was dry, and airbrushed the seams with Mr Surfacer 1200 (thinned with Mr Color Leveling Thinner) to check for places needing more work. All the seams looked great, but the engraved rib pattern on the elevator (which I had filled with PPP), was still showing through:

 

 

 

Frustrated with that, I applied a thick coat of Mr Surfacer 500:

 

 

 

I next glued the fuel tanks to the wing tips, and ran a line of putty down the gap at the join:

 

 

 

It was now time to add the nose. The question was, now much weight would be needed to keep the Scorpion on its feet?

 

I temporarily attached all the major pieces:

 

 

and taped a plastic rod to the belly, about a half inch forward of the main landing gear. The rod was a pivot point in the steps that followed...

 

 

 

I placed the model on a scale, with the pivot rod just off the edge of the platform. The force exerted where the rear fuselage met the scale measured out to approx. 35 grams.

 

 

 

The moment arm from the pivot rod to the rear contact point was 1.5 inches. The distance between the pivot rod to the center of the nose piece is 2.5 inches. With a longer moment arm, less weight is needed to offset the rear center-of-gravity. I calculated about 20 grams of nose weight would be sufficient, so I added lead until I reached that number:

 

 

 

and taped the weighted nose in place. Voila! Tail-sitter no more!

 

 

 

I used 5-minute epoxy to fix the weights in the nose piece:

 

 

 

then glued the nose in place. As I mentioned earlier, I used shims to spread the forward fuselage to match the slightly wider nose piece:

 

 

 

After the glue had dried, I sanded the bare nose-to-fuselage seams and applied Mr Surfacer 1000.

 

 

 

When I'm satisfied that all my seams are good, I'll install the wings and tail feathers. Painting is not far off...

 

 

[billn53]

The Scorpion's wings are now in place.

 

The attachment points for the wings might as well be butt joints. The wings do have alignment tabs, but the corresponding slots in the fuselage provide nil support. Also, the slots are deeper vertically than the tabs, so the fit is not snug.

 

 

 

Compounding that, the wings' mating surfaces are not flat -- the lower wing piece protrudes further than that of the lower wing.

 

 

 

I used a scraper to even out the surface and ensure a good join. Also, I added a shim to the tab to snug up the fit. I then glued the wings in place. There were very small seams along the wing root (larger on the bottom), which I filled with stretched sprue.

 

 

 

Once the glue is dry, I'll sand down the wing roots and fair in the joins with a layer of sprue gloop.

 

I'm very happy with how the Scorpion is shaping up:

 

 

 

[Marklo]

18 hours ago, billn53 said:

but the engraved rib pattern on the elevator (which I had filled with PPP), was still showing through:

I think PPP shrinks as it cures. I had this happen to me more than once with PPP. Used it on my Smer walrus and like that all the filled lines reappeared after paint, now as happens we as it looked ok but smooth it wasn’t.

Edited February 4, 2021 by Marklo

[billn53]

I got the sprue gloop on the wing roots, and while that was drying, attended to a few detail items on the fuselage.

 

HobbyCraft included three holes in the fuselage which appeared questionable to me. Referencing photos, I modified the holes as follows.

 

The first is on the port nose. Photos of F-89Cs show a pitot tube in this location. I filled the big hole and drilled a smaller one to accept a pitot tube, which I'll fabricate and install later:

 

 

 

On the starboard side, over the intake, is another circular hole. Photos show a rectangular vent at this location. I used a small chisel and strip of styrene to replicate the vent:

 

   

 

The third hole is also on the starboard side, just above and aft of the wing. I couldn't fine any clear photos of "C" model Scorpions in this area, but "D" models do have a hole here. However, instead of passing directly into the fuselage, the hole is at an angle. I used a drill to re-shape the hole to match the photos I found:

 

 

 

[opus999]

Wow!  Terrific job reshaping the hole and putting that rectangular vent!

 

So, I've got to ask what "PPP" is, I've seen it three times tonight... 🤔

[Jackson Duvalier]

3 hours ago, opus999 said:

what "PPP" is

 

Perfect Plastic Putty, a fine product from Deluxe Materials LTD.  It's water-based, really good for fine seams near canopies since it can be smoothed with a damp swab.

 

It shrinks a bit.

 

Not my go to for every seam what needs a'fillin' but it's good to have in your quiver.

 

 

Loving the F-89, Bill. That aircraft has character.

[opus999]

17 hours ago, Jackson Duvalier said:

 

Perfect Plastic Putty, a fine product from Deluxe Materials LTD.  It's water-based, really good for fine seams near canopies since it can be smoothed with a damp swab.

 

It shrinks a bit.

 

Not my go to for every seam what needs a'fillin' but it's good to have in your quiver.

 

 

Loving the F-89, Bill. That aircraft has character.

Sounds about the same as the Apoxie sculpt epoxy putty I use.   The water solubility is a real plus!

[billn53]

Just now, opus999 said:

Sounds about the same as the Apoxie sculpt epoxy putty I use.   The water solubility is a real plus!

Except, you don’t have to mix PPP.

I am a big fan of Apoxie sculpt and use it for a lot of things. 

[opus999]

2 minutes ago, billn53 said:

Except, you don’t have to mix PPP.

I am a big fan of Apoxie sculpt and use it for a lot of things. 

Oh! OK... I can definitely see the appeal then!

[billn53]

But, as mentioned earlier and demonstrated with my elevator example, PPP shrinks when it dries. I’ve not had that experience with Apoxie sculpt. 

[Chemguy3000]

Although “perfect” is in the name, PPP is far from from it.  It definitely has its merits, however, and is the best material for certain applications.  Just another tool in the arsenal.

 

Excellent use of science with the nose weight calculation, Bill.  I love it!

 

David

[billn53]

28 minutes ago, Chemguy3000 said:

 

Excellent use of science with the nose weight calculation, Bill.  I love it!

 

David

Yeah, I’ve been brushing up on aircraft weight & balance calculation for my flight re-certification 🛩️

[billn53]

Today, I built up the landing gear:

 

 

 

You may have noticed that I added hydraulic lines for the nose wheel steering, as seen in this photo:

 

 

 

Also visible in the above pic is the retractable landing light, just forward of the nose wheel bay. Hobby Craft did not include this detail, so I drilled out a recess and glued a disk of foil to represent the light.

 

 

 

After I've painted the NMF, I'll add a clear lens using UV-activated acrylic gel. In the meantime, I protected the light with a dab of Maskol.

 

I next primed my Scorpion with Mr Surfacer 1200, rubbed it down with a polishing cloth, and then applied a coat of Alclad gloss medium gray base.

 

 

 

I'll give that plenty of time to dry before doing the NMF, as I don't want any fingerprints in my finish (ask me how I know?)

 

 

 

 

[VT Red Sox Fan]

Bill great work so far--I have no questions based on the great dialogue--as always, thank you for your rundowns... best, Erwin

[billn53]

I'm expecting my Canadair Sabre 4 to arrive tomorrow (which I'll use as basis for my F-86A, having suspended work on the Matchbox kit). So, I've been working hard to get the Scorpion as far along as I can before I transition over to the Sabre jet.

 

I masked and painted the canopies. The Montex masks worked great and, although the package says they are outside-only masks, when I opened the package I found masks also for the canopy interior and the sealing around the clear sections.

 

 

 

 

 

Fit of the forward windscreen left a bit to be desired, but some quality time with a sanding stick, putty, and Mr Surfacer got that sorted out:

 

   

 

 

And suddenly, it was time to paint the beast! I'm using AK Interactive's XTreme Metal for this build. I've used it before and been very happy with it. Here's the Scorpion with its base coat of aluminum:

 

 

 

 

 

I'll put this in a safe place to let the enamel-based XTreme Metal get good and hard, while I work on the F-86.

[billn53]

I'm all done with the F-89's natural metal finish. I used XTreme Metal paints exclusively, plus a tiny bit of detailing with powdered metal pigments.

 

 

 

 

 

 

Here's a closeup of the wing. The base coat is XTreme Metal aluminum. I then sprayed polished aluminum through a mottle mask to replicate the uneven wear that these aircraft saw in service. The nose and selected panels were shaded using a mix of aluminum and dark aluminum, using photos as reference. Flaps and other control surfaces are in white aluminum. I also used gun metal and jet exhaust in a couple of places, where I needed darker shades. Powdered metal pigments were used on a few small panels, and to highlight the engine access panel lines. Finally, I sprayed a protective clear coat of Pledge/Future, thinned with Mr Levelling Thinner.

 

 

 

One last shot for this update, showing the cockpit with canopy open.

 

 

 

Break !

 

Break ! !

 

Break ! ! !

 

This arrived in the mail today:

 

 

 

so it's time to change gears and get back to work on the F-86A part of this trifecta build.

[Nikolay Polyakov]

Hello Bill,

 

it’s something special going on here with your Scorpion! Excellent progress along with great engineering. 👍

 

24 minutes ago, billn53 said:

One last shot for this update, showing the cockpit with canopy open.

The building and painting accuracy is over the top. Keep up the good work on these little birds! 😉

[billn53]

4 minutes ago, Nikolay Polyakov said:

Hello Bill,

 

it’s something special going on here with your Scorpion! Excellent progress along with great engineering. 👍

 

The building and painting accuracy is over the top. Keep up the good work on these little birds! 😉

Thank you very much! 
 

The F-89 was never a favorite, but I’m finding it is growing on me 

[Nikolay Polyakov]

5 minutes ago, billn53 said:

The F-89 was never a favorite, but I’m finding it is growing on me 

I’ve never thought of building it too, but now I can say that it’s a very attractive airframe! 🤩

[Jackson Duvalier]

That mottling effect applied to NMF looks smashing, Bill.  

 

The fact that Xtreme Metal (so xtreme! 🙄) can be sealed with Future is a big selling point.  I've grown accustomed to Alclad but it greys out and loses all it's metallic-ness under Future.

[Chrisj2003]

8 hours ago, billn53 said:

The F-89 was never a favorite, but I’m finding it is growing on me

WI ANG used a lot of F-89 variants so can we expect a family of brilliant models? And at a base near Madison?

 

Chris

[billn53]

2 minutes ago, Chrisj2003 said:

WI ANG used a lot of F-89 variants so can we expect a family of brilliant models? And at a base near Madison?

 

Chris

I definitely plan to do a “J”, beyond that, I don’t know... 

[billn53]

It's time now to re-invigorate the F-86A part of my build project.

 

To recap where I was a week or so ago... I had planned to build the Matchbox F-86A, enhancing it with the cockpit and other parts from a Hobby Craft F-86F that I had found cheap online

 

   

 

I had gotten so far as to install the Hobby Craft nose gear bay and cockpit tub:

 

 

 

But, the Matchbox nose is a problem area:

 

 

 

 @Sabrejet suggested I might do better by using a Hobby Craft sabre as starting point for my F-86A build, which involves modifying the fuselage rear, wings, and canopy. Having already sacrificed key parts of the Hobby Craft F-86F, I ordered another kit from eBay. I chose Hobby Craft's Sabre 4, primarily because it comes with slatted wings (like on the F-86A). That kit arrived yesterday.

 

Let's inspect my new acquisition. First off, it was advertised as used (partially built), so I knew I was taking a risk. As it turns out, everything was still on the sprues, although the fuselage and wings had been painted silver:

 

 

 

 

 

The brush-painted silver is not a big deal for the fuselage (I'll use the fuselage from my F-86F kit, instead), but I definitely need to clean up the wings. I did a test run with a couple of products I've used in the past -- VMS Clean Slate and Tamiya Polycarbonate Body Cleaner. Both work for removing the silver paint, although the Clean Slate needed a bit more "elbow grease". Nonetheless, I'll likely use Clean Slate simply because I have a bunch of it and it costs less than the Tamiya product.

 

 

 

So, I have my work cut out for me there.

 

By the way, I haven't given up on the Matchbox kit. I happen to have a Heller sabre that I had planned to use as a parts donor. I intend to transplant the Heller nose to the Matchbox kit. The nose fits pretty well, but I'll have to do something about the gap in the intake trunk (which I had cut short for the Matchbox nose)

 

    

 

I'm also continuing to build up Matchbox's cockpit area, using parts from the Hobby Craft F-86F kit:

 

 

 

With all the different parts swapping going on, I'm beginning to feel like Victor Frankenstein!

 

 

 

 

 

 

One last thing before I head back to the laboratory workshop.... Today's mail included a couple of Pavla F-86A canopies, so at least I have a path forward as far as the canopy issue goes 🙂

 

 

 

 

[opus999]

On 2/10/2021 at 8:38 PM, Jackson Duvalier said:

That mottling effect applied to NMF looks smashing, Bill.

+1 I have struggled with this look for a while, trying different things to achieve that look.  My most recent attempt was on the Ki-84 Frank where I used the paint masks and used a light gray (which is now one of those "what was I thinking?" moments).  Several tests looked great, but botched it on the real thing.  Better to be lucky than good: I was able to fix it, and it actually looks pretty good.  Your method, however is smarter and I'm going to give it a try on my next worn metal build.

 

The Scorpion really looks fantastic Bill.  What did you use for the darker panels?  BTW, I really like using the AK xtreme metal.  I've been an Alclad fan for a long time, but I found that some of the AK stuff really hits that sweet spot between shiny-new and old 'n' worn.

 

 

[opus999]

I'm really looking forward to the F-86.  One of my all-time favorite aircraft.