HobbyBoss 1/48 MiG-31B Foxhound

[mostrich]

Happy new year, Monty!
Every time I see somebody building this kit, I'm crying out loud "why not AMK, you masochist?!"
I literally can feel the pain while scrolling through your pictures. Looks like a Revell kit from the 90's. Horrible! On top of that the Hobby Boss kit is really expensive over here in Europe, around $80!

But enough of that, you're a brave man, Monty. You're doing it justice, and over all that stands the main topic: No kit is left behind!

P.S.: I really have to finish mine. Ugh, I'm lazy...

[dmminiatures]

Defecto Grande.
The biggest defect of the kit lies in the joints between the intakes and main fuselage. I don't know how to explain it in words, but If I had to try, the flaw was the result of poor design of the fuselage joints in part of Hobby Boss. I first assumed it was just a matter of warping, but it was not. The intakes themselves were excellent, however. Check out these pictures to see how the fuselage joints performs against the intakes:



Above and below pictures shows the port and starboard intake side walls. I took the opportunity to analyze the angle of the side walls and had to confess that there was no way to aligned both sides. Shaving or sanding the inner joints would not work, nor would adding bits of styren.



But in retrospect, I would probably had made the situation better if I HAD NOT GLUED the intakes as a sub-assembly. but instead kept it apart until it was time to mate them onto the fuselage. This was the approach I had for the Academy F-15C Eagle



The lower wall of the intake. Again, if I had known this would happen, I would saw off the lower wall from the intakes and butt joint it to the fuselage as a separate piece. Eventually that was the approach I took, but with the intakes already in one piece, sawing it off was not the easiest tasks.



For whatever mis-alignment of the side and lower walls, I had to make sure the upper wall was flushed and level, and in complete alignment with the fuselage. The gaps are a shame, but I is way easier dealing with a gap then a step.

[dmminiatures]

Hi Mostrich - Yes, I wonder that too. but logistic wise, it was easier getting the HobbyBoss here in Indonesia. AMK is a rarity here and I would have to import them, deal with the high import tariff and a few corrupted customs officials (many are serving honestly, though). There has been many reviews on the AMK MiG-31 and how excellent of a kit it is. I guess I was just going out to look for trouble LOL!

At least now we know to stay away from this Hobby Boss kit. Not worth the $80!

Happy new year, Monty!
Every time I see somebody building this kit, I'm crying out loud "why not AMK, you masochist?!"
I literally can feel the pain while scrolling through your pictures. Looks like a Revell kit from the 90's. Horrible! On top of that the Hobby Boss kit is really expensive over here in Europe, around $80!

But enough of that, you're a brave man, Monty. You're doing it justice, and over all that stands the main topic: No kit is left behind!

P.S.: I really have to finish mine. Ugh, I'm lazy...

[dmminiatures]

The Fix
The fix for the intake joins was to use all available materials and techniques to fill out those gaps and steps. They include sterene plates, Tamiya epoxy putty, Tamiya regular putty, Mr. Dissolved Putty, regular CA glue. Because of the intakes, I decided to try a product called Mr. Dissolved Putty. It was a timely decision as I could try and put the putty into use, and observe how the product performs.





Before-after images of the upper gaps. I inserted styrene strips and filled them up with Tamiya regular putty (white). I used the same approach for the side and lower walls.



I did however stretch and bend as much wall area as possible so that it would level with the intake walls. It actually worked! I was able to avoid using any styrene plates for the side walls, just regular and epoxy putty was enough.





Image of the Mr. Dissolved Putty and how I applied it. In reality there are a few ways to apply this putty by using a brush or a toothpick. The Mr. Dissolved Putty performed as mentioned in the advertisement and also on YT videos. IBut I like to add that it beats Mr. Surfacer 500, despite by a small margin. Nevertheless I would still use this to fill small gaps over Mr. Surfacer 500. Some of the notes properties include:

• - Best for very tiny and small gaps
  - Apply using toothpicks or a brush.
  - Dries rather soft, not as rock-hard like Mr. Surfacer.
  - It dries very slow. I had to wait a few hours before I could sand
  - Light sanding with a fine grit sand paper is enough to level the putty. No need to use force or rough sand paper.
  - Slightly shrinks, but just a little. Best to add in this layers compared to just one thick blob.
  - It stinks!! no Different than other Mr. Hobby lacquer products. you need good ventilated room and a good respirator
  - Acetone wasn't a good cleaner to clean leftovers of the Dissolved Putty

[BorgR3mc0]

Nice mini review of Mr Dissolved putty in this wip. I often use mr Surfacer 500 but this might be a good alternative.

[jkim]

Great to see such a descriptive build! I really enjoy the documentation, especially when it comes to the bad stuff that inevitably occur with each build. Very informative and helpful even if we never build this particular kit since the techniques will translate to other models. I use both Mr Dissolved Putty and also the Mr Surfacer products and agree with your comparisons, although I find that Dissolved dries just as hard if not harder than Mr Surfacer 1000. Mr Dissolved shrinks less than Mr Surfacer and that in itself can be a big advantage.

[dmminiatures]

Borg and JKim - Thanks. I am still new at this and there were times when the putty didn't perform as expected. For example, when I sanded the area, the putty got sanded and washed away. I think also, as JKim mentioned, I might have started sanding when the Putty was less than 100% cured. and perhaps I should have waited a few more hours until it became rock hard.

Nice mini review of Mr Dissolved putty in this wip. I often use mr Surfacer 500 but this might be a good alternative.

[dmminiatures]

Re-creating the Details
As a consequence for the extensive filling and sanding of the intake area, many surface details were lost. Not just the intake area but all areas that were filled and sanded. The first order of the day was to return the many rivets and panel lines.



I used RB Production riveter to do the job. They come in 3 discs with different size riveter and a metal holder. You need to get yourself an OLFA-type cutter pen holder and insert the head piece. That is the only way to hold the tool.

The only caveat of this tool is that it has a large nut to bolt down the punch disc. That nut is very large and would obstruct the modeler's view when he/she moves the disc in motion. So they way I use is always to face the screw/bold-head.



Another tool that I used was a Tuner Model Manufacturer stainless scriber. They are purchased in sets. one set contains 10 scribers with different type of heads. each scriber is about 3 cm in length. Most popular one is the straight and hook type scribers. To have a better grip on the scriber, you need an OLFA-type pen holder like in the picture above.



Sadly I don't always succeed in my first attempt. Priming the surface revealed that there were parts of the re-scribed surfaces need to be redone again. Most cases was because I didn't correctly pull the scriber, thus the new line didn't match up to the existing line. For the rivets, it's mostly because I missed a few spots.

[dmminiatures]

The Cockpit Canopies
I have never seen so much effort was used to construct and detail the canopies for the pilot and co-pilot. A single canopy consisted of a frame, the clear plastic part, and an assortment of photo-etch details.



The frames need to be dealt delicately. I used a stainless mini saw to carefully severe it from the sprue gates.



laying out the parts after sanding and cleaning them up.



The canopy after the PEs are installed and the clear parts are masked off. I will paint them both sides so they were masked from the outside and inside.



The inner part of the canopy with PE cleared been installed. I used regular CA glue (brand UHU) to secure them. Ejector pin marks were filled with Mr. Dissolved Putty.

[dmminiatures]

After I painted the interior and exterior canopy with Russian interior green ( by mixing Gunze acrilic Acrision paint No.25 with No.46 with a ration of 1:3). There were some injector pin marks on the base of the frame and were later re-filled and sanded.



Installation of the windshield was done after some PE bits were installed.



The windscreen fits perfectly. I glued them using TET.



However there was a ugly step at the base of the windscreen. I dealt them by adding sheet styrene, epoxy putty and sand it smooth.