[Random tips] Something technical to fill microbubble fills nicely

Last week, I was working on the surface treatment of Sirius sculpted by Moteki-san, so I'll summarize that a little bit at a time. This is a review of last week's work. I can't work on the GKs on weekdays, so I'm going to do what I can on weekends.

Since I have reduced the amount of time I spend on models to the level of a hobby, my speed is at the level of a turtle, but I think I've been able to recover my motivation gradually.

I posted about micro-bubble filling last week on X, but here is a summary of the process.

★Kits purchased

1/5 めいどシリアス（アズールレーンより）sculpted by くじら12号

https://kuzira12go.booth.pm/items/5486128

■Process of filling microbubbles

Garage kits inevitably contain air bubbles due to the manufacturing process. Therefore, it is necessary to fill them in during the surface treatment stage.

If the bubbles are countable, it is not so difficult, but there are some cases where there are microbubbles all over the surface.

This can occur not only with private reproductions but also with casts made by reproduction companies, so one cannot be too careful.

Casts made by replicators generally have fewer bubbles, but the possibility of microbubbles and large, bumpy seam lines increases during the busy season before an event.

┃What do you do if you find microbubbles?

Microbubbles lurk especially near the gate and at the seamlines. This is a microbubble that came out when the gate was removed and filed.

When painting parts such as the skin without surfacers, it is better to dig them out and fill them all in as much as possible.

However, if it is deeply buried, it can be left alone.

The problem is the microbubbles that keep appearing on the surface as you sanding. The method to fill these bubbles is simple.

1. Find microbubbles

2. enlarge the hole to about 0.5 to 1 mm (as shallow as possible) using a drill, etc.

3. Fill the hole with some kind of material and sand it smooth.

4. Fill in the visible microbubbles in the same manner.

Repeat this process over and over. There is a backdoor method of filling with crayon, but it can only be used after the mold release agent has been removed.

So, the candidates for ”some kind of material” are

Cyanon

UV resin or UV putty

etc. would be good. If you are not going to do a surfaceless painting, epo putty or similar would be fine, but I wouldn't use it because it is too cumbersome to use for small areas....

┃The Case for Cyanon

So basically use the above two. Cyanon is like filling the hole with the tip of a toothpick without mixing beepowder or talc powder as it is. The reason for not mixing the powders is that mixing Cyanon and baby powder makes it less durable against solvents and also makes it react to heat and turn yellow easily. (My personal impression is that putty made with Cyanon + baby powder tends to yellow easily in heat bending, in which the putty is immersed in boiling water to shape it.)

It is fatal to want to do a surfacer-less paint job and the filled-in area stands out yellow. So I fill it with liquid cyanon even if it is hard and try my best to file it. It is very hard to sand, but the work is very efficient.

┃Cases using UV resin or UV putty

Another method is to mix UV resin and glass powder to make a paste to fill the hole instead of cyanon. Like Cyanon, this one is also filled into the hole using a toothpick or other tip. This is the one I mainly used this time.

I have been using it for a while as a sample given to me by Shoko, and it seemed to work well in practice.

Craft LED Resin 405 (60g) with extra powder (product page)

https://um-project405.booth.pm/items/4078479

If you mix too much powder, it becomes hard to harden with UV light, and it doesn't harden as hard as Cyanon, so you have to use a file a lot... But it is easy to use on a paste, and you can harden it at your own convenience, so it is easy to redo it.

The filled part is also almost white, so it is almost invisible. Both Cyanon and UV resin have their advantages and disadvantages, so it would be good to try using both first.

By the way, UV light can be a pen type, or if the area is large, UV light for nails may be easier.

┃Practice of filling microbubbles

After finding air bubbles and expanding the hole, fill the hole with a toothpick or similar tool to dot the hole finely. If you spread the paste on the hole, the air bubbles will not be filled and you are likely to make a mistake. Even if it is tedious, fill the holes carefully one by one.

   It is easier to work with if you repeat filling and curing with UV light in sections by area instead of filling all of them from the beginning.

The final step is when there are no more noticeable air bubbles.

 The process is simple, but it should take at least an hour to fill in all of the details, and it is a good idea to work while listening to videos or music.

When filling in the microbubbles in the fine details, you should be careful not to cut corners, as too much sanding can change the shape if you are not careful.

 Even if the part is full of holes like this at first, repeated hole filling and sanding will surely reduce the number of air bubbles to be filled.

After about 3 hours of repeated sanding and bubble filling for about 10 rounds, the number of bubbles to be filled will be reduced to this level.

 The reason why filling in microbubbles is so difficult is that after filling and sanding, new bubbles keep appearing. So you have to repeatedly fill them, file them, fill and file the new ones that appear, and repeat the process over and over. You can never fill them all in at once, so patience is required....

As mentioned above, since filing is necessary many times, care must be taken not to inadvertently destroy the shape of the detail.

And this is not an air bubble, but a large dividing line caused by a step shift of the silicon mold.

 
At first glance, it is easy to think that it is faster to fill in with Cyanon because of the large step, but if you fill in this area with Cyanon, it will be even more noticeable. The thicker the cyanon is, the more the color of the cyanon will be different from the color of the resin (cyanon looks white, but it is slightly different from the color of the resin), so it is easy to see division lines even though the surface is smooth. This is usually the reason why split lines become visible after painting.

This is especially true for parts with many microbubbles, such as those introduced in this article,

Fill in the bumps quickly with Cyanon and skip the treatment of microbubbles, while doing your best to hide the division lines by painting.

Reduce the burden of painting by sanding the bumps and filling in the microbubbles.

The two choices are as follows. The cyanon split lines can be hidden by applying a thin coat of white surfacer before painting the skin color, so if you are conscious of time efficiency, this may be a quicker and better option.

So here is the result of last week's work.

 I think it must have worked well enough because I cannot see any trace of microbubbles filled in.

There is no denying that filling in microbubbles is a very patient process. If you can do something as advanced as that, you won't have a hard time.

Good luck filling them in !!!!

That's all.