About Vacuform kits...

General Discussion General Modeling Discussion
1

I do not have any vacuform kits. I seen them in hobby shops before. They basically look like a plastic styrene sheet, that was heated and was pressed down onto a mold, to make it look like the mold. So my question is, how do you make it?

It seems like a weird question, but the thing is, it does not have the conventional scale model properties: A plastic sprue. So that means you have to cut all the parts from the big piece of styrene that encompasses the entire kit. I can’t even imagine how hard cleanup is from the mold lines.

Here is a photo.

Like look at it! Just looks how shallow the wings seem to be. It looks really dreadful, and is giving me nightmares already just by looking at it. In all honesty, Painting and glueing is probably the least of your worries in a vacuform kit. Like, look at the cleanup!

So, are vacuform kits hard? What are your experiences?

2

A different skill set is needed.

Enough passion to slog on to finish something very few or no-one will have finished.

These were produced in the days when new kits coming out were once in a year event. Check scalemates dot com to see if, in the intervening decades, someone has produced it in plastic or resin.

IF you start one, the modelling deieties of your choice may be kind & release plastic kits just after you complete it.

Patience. Expect it to fight you back all the way.

Several different types of liquid and epoxy glues, old style tube glues will make a mess.

Very Good References.

Aftermarket Decals.

A well stocked spare parts bin for engines, wheels, props, etc., the vac-formed ones are usually not worth the effort.

Run a thin permanent sharpie round the vacform, then score the parts, and tape a big sheet of wet & dry to a flat surface, so that you can sand the seperated parts to the sharpie line.

Don’t expect parts to fit, or even line up or be correct.

Expect to make your own bulkheads, formers, spars, canopies, etc, just to stop it falling apart.

Get a simple one you don’t care about to practive on first.

But if you finish one, you will definately have a high level of achievement.

3

A lot of times these were made for aircraft that no conventionaol kit was made and in many cases the vacuum kits are still your only option. Some companies did high quality vacuum kits, Rareplanes being one. Others, like the two I have were not as good.

I have two vac kits myself, a C-140 and a T-39, two utility aircraft from the 1970s. I have the T-39 started but thinkg keep getting in the way of finishing it. Eventually I will.

With the vauccm kits you have to cut around the parts, leaving some excess exposed. To get the parts ready to glue you will have to take a sheet of sandpaper, possibly stapled to a piece of wood or just flat on a counter or desk top and sand each piece until the excess is free.

Parts most likely would have to be re-enforced with scrap plastic to give it a larger area for glueing.Plastic strips or a couple sheets would work.

You may also have to eithre build the landing gear from scratch or in some cases find brass wire to put into the gear halves if provided. You could always just mount your project to a base like it was inflight to save time and work. That is most likely what I will do in the end.

What is the aircraft kit you have and who made it?

4

Having built a few, and made a few Vac Form kits from scratch in my time…Welcome to the dark side of modeling.

They can result in great looking builds.

The skill set in not hard, just different.

#1. As posted above, don’t try to cut the parts out perfectly from the sheet. That WILL make a mess of it. Cut about 1/8( 2-3mm) around the part and sand the “flash” off. As said the best thing for this is a flat board with sand paper on it. I glue mine with 3M tack spray. I glue 2 full sheets on, one coarse and one medium. Nothing fancy, just hardware store sandpaper. Have an old household paint brush handy (2-3 inches wide) to brush clean the paper. If you do this the paper will last a long time. Also keep a vacuum cleaner handy to suck up the plastic dust and wear at least a face mask. The plastic dust is an irritant.

#2. Once the parts are all set I take one side of the part and trace it onto some thin sheet styrene and then cut that out, sand it close to the lines and with thin liquid cement glue it to one side/part and then glue the other part/side to the sheet and align everything, then tape the parts together and let dry. This step allows you to have a greater surface area to glue.

#3. Once dry sand the seam smooth, you should not need much filling. Then move on to the next sub-assembly. I like to give the assembly a quick coat of primer now (tape off the area to be glued in later steps) to see how the join is looking.

The most important thing is, as posted, use the proper cement! a very thin liquid works best. Use sparingly, the sheet styrene will disolve away with too much glue.

Many Vac kits have either white metal parts or templets to make landing gear, older ones probably don’t. And as said decals might have to be sourced after market.

Enjoy! They are fun and rewarding to build!

5

Well;

Vac-U-Form kits are what they are. If you are a surface and panel freak they are Not recommended. I built a few over the years -Because that was the only way to get the Plane I wanted. Yes, It requires a different skill-set and lots of patience.

Then there’s decals. I don’t know about now, But when I bought mine, decals were Not included and there was No aftermarket. So you stole the decals you needed from car model kits and regular plastic plane kits!

P.S. What looks like badly formed Bomb halves are actually prop blades. I never use them because with they would be to thick. I would use .020 or .030 sheet for them. Is that a P-3 Orion?

6

One secret to vacu-form kits is to make wood reinforcements for interior. A “keel” structure for the fuselage is the most important. Trace the fuselage profile and redraw another line about 1/32 inside the first. That will be your templete for the keel.

Cut a piece of 1/4 basswood. Now glue each side halfway unto that keel. That will make a strong join. Some people just glue a 1/4 wide strip of styrene to get a shelf for the join, but the keel allows you to add other reinforcement.

The next reinforcment I had is for a main spar for the wings. I usually make this from 1/8 basswood. The spar does not need to go the whole span of the spar. I only go out about two or three inches on each side. Make it a one-piece spar and cut a hole in the fuselage keel. Glue it in place carefully to get even dihedral. Cut a hole for the spar in the fuselage sides before gluing them onto keel.

7

The only vacu-form kits I did were tank conversions, mainly German Sdkfz 251 types. There are plenty of Dragon kits of them now, at least I have plenty of them. I did a very few of them 30 + years ago. None have survived the years, they have been replaced by plastic kits. I still have a couple of the vac u form models around. No body wants them. They are not good. I did not really like vacu- form.

8

I don’t have a vacuform kit, or plan to have one.

9

Hm, I don’t know. I just took the photo randomly from the internet.

10

If that’s the case, what made you ask about them?

They are something of a fading niche for plastic models. And they required a different skill set for assembly. But for quite some time, they were the only way to get a model of a particular subjects, or convert mainstream kits into their less common variants.

11

These kits take skill. The modeller has to be a problem solver.

Having experience in scratchbuilding is really important as the modeler can’t expect the kitmaker to solve all of thier challenges.

The value is has been noted; they are often the only option if the modeler wants to build a particular subject without a complete scratchbuild from drawings.

In truth finishing a vac becomes a asplit proposition.

The modeler will use the vac for the main airframe, use styrene kit parts like landing gear, engines and propellers from a plastic kit of an aircraft that shared those components, and scratchbuild things that are not available.

A good example would be a prototype or “X” plane that was later developed into a more heavily produced operational version.

And as Don says, these don’t always hold themselves together, requiring a skeleton built, or filling the parts with rigid foam.

But forty years ago if a modeler wanted an Il-2, a Vac Wings vac might be the only thing available.

Now, there are all sorts of models available in all scales in styrene.

Bill

12

TB, yes; that is a P-3. With the Hasegawa offering being on the market for 40+ years, I dunno why anyone would’ve done a vac version. I can only assume that’s a really old release.

Teen, if you ever want to try one, FSM did a three or four part series back in the day on the ins and outs of building them. You can contact them to see what issues they were and order back copies. If nothing else, they’ll be good references for the day you decide to jump into it.
I once bought a 1/32 scale vac F-106 that I ended up selling.

13

StrayCat1911;

Correct me if I am wrong. I was told to cut the pieces straight down from the part. Then Sand the remainder off to get the proper profile.So which is correct. I have always done it this way and the planes come out the round or oval they are supposed to be.

14

TB,

The general rule is to cut around the parts, leaving maybe 1/8" all around. It’s better to have a little extra material as you slowly sand off the excess plastic.

15

A few years ago I purchased a vacuform B-47. I opend the box, looked at the sheets of vacuformed plastic, closed the box and placed it on the Shelf of Doom. [:(]

16

Back in the heyday of vac kits (1970s) detail parts needed to be sourced from injected kits. If there were no equivalents, it was scratch city or living with some substitute.

But today, the aftermarket provides thousands of bits, making part hunting a bit easier. 3-D printing takes the game even farther, as it makes unique parts possible.

So ironically, vac form kit builders never had it better than today. But yeah, we are losing the DIY skillset because of the availability of esoteric injected kits and aftermarket detail sets.

Someone recently built the Sanger 1/48 B-47 kit and it looked spectacular.

17

BTW, my biggest thing about vac kits is avoiding the dreaded fat, dull wing trailing edge. It’s kind of a tell that the kit is a vac, but if the builder gets the trailing edges razor thin, it really makes a difference.

18

According to the FSM series, the recommended method was to mark the outline with a Sharpie and then cut at the base with a new #11 blade at a 45 degree angle. Then you’d do the sanding, checking your work frequently.
I never got that far, so I couldn’t comment further.

19

For what it’s worth, here is what I do. The kit is a Star Trek TOS phaser that I pulled myself out of .020, .030, and .040 sheet styrene.

Here is the pull:

And how I cut them out.

I used the .020 and a sharp #11 blade to cut around the parts:

I then sanded all the “flash” off using sandpaper glues to a board:

Next I trace the parts on sheet styrene for the mid plate. This adds much strength and give a larger glueing surface.

Glue the mid plate to one side:

Then glue and tape/clamp the other side on:

Sand and putty the seams:

Then collect the detail parts, as said sometimes you need to get creative:

Paint as normal:

Then final assembaly:

The final product:

The built up phaser is VERY strong and looks the part of a “stunt” phaser used in the show.

20

My first vacuformed kit was an Estes model rocket TIE Fighter. At the time it was released, I think the only TIE fighter in kit form was the original Vader’s TIE Advanced and the snap tite Return of the Jedi TIE Interceptor.

So I bought the model rocket and built it. I think I used regular model cement on the fighter itself. The cardboard rocket tube required Elmer’s white glue.

There is more clean up of the parts to ensure it fits together. You have to tape a piece of sandpaper to a very firm, flat surface, like a glass from a picture frame.