From: Don_Schmitz@transarc.com
Date: Mon Aug 3, 1998
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Part 5
Part 5
** More General how-to questions
**
** This section is an extension of part 4, it covers frequently asked
** questions regarding construction techniques that can be answered in a
** few paragraphs. Questions with longer answers have their own FAQ
** section.
[Q] My superglue never seems to set the same. Sometimes it is slow,
sometimes very fast, why?
[A] urf@icl.se (Urban Fredriksson)
Superglue sets through humidity in the air. When the humidity is
higher, the CA will tend to set quicker.
[Q] Should I use an accelerator to speed up the setting time of CA?
[A] urf@icl.se (Urban Fredriksson)
There is no definitive answer to this. There are advantages and
drawbacks. Accelerators such as Zip Kicker tend to result in a
weaker, more brittle bond than if you let it set normally. This is
isn't a real problem if you are using the CA for filler, but if it is
your main adhesive, a sudden jar, or a shearing force could break the
bond. On the flip side, accelerators really do speed up the process.
Especially in using thick super glues for filling.
A problem unrelated to the bond is the reaction of plastic to
accelerator. Accelerators such as Zip Kicker contain 1,1,1-
trichloroethane. This is a solvent of styrene. It can mar the
surface. This can be quite detrimental if the model has already been
painted and decaled.
[Q] Is it true that CA glue is made from Cyanide? Can I poison myself with it?
[A] Shingend@ix.netcom.com (Mark and/or Mary Shannon)
[I had to wade through several layers of email attributions to figure out
who authored this - please let me know if I got it wrong.]
As a qualified chemist (Ph.D. in the ruddy subject), let me try to
clarify the point.
Cyanoacrylate glues contain the group H2C=CH-CN: Where the =
represents a double bond between two carbons and there is a triple
bond between the carbon and nitrogen of the CN. CN is the 'cyano'
group, and a three-carbon chain with a double bond next to another
type of multiple bond (or some other form of electron rich group such
as a radical or anion) is an 'acrylic' group -- the combination gives
a relatively high reactivity to the compounds and allows them to
polymerize like a plastic. Many non-toxic compounds contain both
types of groups, and many medicines have cyano groups. Along with this
group, there are other chemicals and can be other chains attached to
that cyanoacrylate group in place of one or more of the hydrogens.
There is NO, NONE, NADA cyanide released on curing these glues and
hardening. There are some obnoxious fumes released -- some of them
just parts that boil out from the heat of the curing reaction. BUT,
whenever an organic chemical that contains nitrogen is burned, some
cyanogen/hydrogen cyanide is released. This happens with tobacco,
meat, veggies, fireplace wood, etc. This release is worst when there
is not enough oxygen present in the burning zone to ensure complete
combustion -- so if there is a lot of smoke formation, there is more
likelyhood of cyanide formation.
As with any chemical process, it is best to have good ventilation when
dealing with these compounds, but most Cyanoacrylate glues have been
formulated as non-toxic (some of the original uses were as skin and
tissue glues to replace sutures in surgery). If you are burning CA
glues, do it in the same hood you use for spray painting. This goes
for operations where you are using CA glue to hold parts for
soldering, especially, since the fluxes and the modest burning
temperatures add their own brew to the mix. Combustion Chemistry is a
field in itself, and there are many things not understood about
general rules of chemical formation in various conditions of burning
organic compounds. I would suggest that everyone play it safer than
they might normally when they are burning any of the materials used in
this hobby.
[Q] What are some basic safety notes about using CA?
[A] urf@icl.se (Urban Fredriksson)
Super glues are not unsafe to use if common sense is
applied. If you use CA to glue a seem together, don't use too
much. If you do, you are likely to find yourself unable to
remove your fingers. Don't wipe excess CA with your fingers.
If you do happen to glue a part of your body, use acetone to
remove it.
[A] denatale@nando.net Rick DeNatale
On the other hand if you ever get CA in your eye, DO NOT ATTEMPT HOME
REMEDIES! Get expert medical attention immediately. This is a true
medical emergency [The glue probably won't do permanent damage to your
eye, but you may very well do so trying to pry your eye lid open!]
[A] schmitz@transarc.com (Don Schmitz)
I've also heard of CA reacting with certain materials - the stuff in
"microballoons" for one example - to give off gasses that are powerful
eye irritants (and probably no good for your lungs either). As
always, use lots of ventilation.
[A] urf@icl.se (Urban Fredriksson)
This isn't a safety factor, but something to keep in mind. Keep
your CA tube, dispenser, or whatever clean. When you finish
using, clean the nozzle before replacing the cap. If you don't
CA will build up, and make it difficult to remove the cap later,
and will cause the seal to be less effective, and the CA to set
up in the tube prematurely. As in all areas of modeling,
cleanliness is next to godliness.
[Q] Any other opinons on glue?
[A] ??? (Tuomas Viljanen)
My standard styrene plastic glue is Ethylacetate. In my opinion,
it is superior to all commercial liquid plastic cements.
It runs thinner than most so it has good capillary action, it
evaporates quickly and thus runs little risk damaging surface
details if some of it ends up outside the joint. Additionally it
is reported as being far less harmful than those containing
Tolouen and Xylene, as well as substantially cheaper (but try to
purchase less than a litre...).
I find that I also need some sort of thicker, but still liquid
glue, at present I use Revell's "Contacta Professional" as it has
relatively little tendency to form strings. Most types that comes
in bottles which has a thin metal tube to put the glue where you
want I've tried have been OK.
I used to use ordinary white glue, thinned, to fix canopies and
the like, but now I use Kristal Kleer. I've never been able to
decide if this is just thin white glue, or if something else has
been added.
To mount already painted parts, like bombs, where it's difficult
to scrape off the paint, I use (very little) of some type of
"universal" glue. You know, the sort which is supposed to glue
plastic, wood, leather and so on, and is rather thick but clear.
(Karlsons is my preferred brand, but Uhu and others work just as
well.)
For resin, you need some sort of epoxy glue.
I haven't had any Cyanoacrylate glue at home since 1990. Must mean
I don't like it much. But I guess it's essential for some types
of jobs.
....
Have you used any of the so-called 'liquid glues' ? Oh well, they all work
on the same principle: they dissolve the plastic surrounding the joint and
then evaporate, leaving the plastic around the joint welded together.
The liquid glues are either aromatic or aliphatic solvents, ketones or chlor-
inated hydrocarbons. Aside the commercial brands (f. eg. Humbrol, Testors or
Super Weld) the following chemical substances can be used:
- Xylene (slow evaporating, thus leaving long working time)
- Toluene (similar to the previous)
- Acetone (evaporates very, very quickly, not recommended)
- n-Butanone (methyl ethyl ketone, MEK) (good and very popular, but has
very strong intoxicating fumes, which are very odourous)
- Ethyl isopropyl ketone (expensive, not recommended)
- Benzaldehyde
- Benzyl alcohol
- Dichloromethane (my own favourite)
- Chloroform (excellent, but have a good ventilation)
- Trichloroethane (very good, recommended)
and so on.
If you have never worked with the liquid glues, the procedure is following:
- Press the parts to be glued together. If possible, use masking tape
- While the parts are tightly together, apply the liquid cement into the
joint (and nowhere else) with a thin brush
- Hold the parts tightly together, until all liquid glue has evaporated
- Sand the joint and/or apply putty if required
Also good types of adhesive are cyanoacrylate glue and 5-min. epoxy (any
strong glue will do, providing you keep the parts together until completely
cured) I myself have junked the tube glue long, long ago.
Hope this helped.
(Tuomas Viljanen)
Lahderanta 20 A 19
SF-02720 Espoo 72 FINLAND
358-0-592175 or c34657b@saha.hut.fi
[A] bruceb@mpd.tandem.com (Bruce Burden)
For plastic (polystyrene), I use Tenax and Faller. The Tenax in
Creations Unlimited applicator is good for large applications, Faller
for small areas (the applicator is too difficult to attach two small
parts).
You should keep white (PVA) glue around for attaching the canopy.
Super glues and plastic cement can glaze or craze the canopy.
[A] schmitz@transarc.com (Don Schmitz)
Hot-melt glue - the stuff you put on with an electrically heated gun,
has its uses. In particular, its great for gluing seats in an auto.
Hot-melt dries to a rubbery consistancy, so don't use it where you need
real strength. I haven't had any problems with the heat warping the
plastic, but my glue gun has a low-temp setting and I've always used that.
[Q] What do I use to glue on clear parts?
[A] arsenaul@emc.com (Brian Arsenault)
[A] schmitz@transarc.com (Don Schmitz)
Attaching clear parts, eg. aircraft canopies and windows, can be a problem
as many glues will form ugly smears or fog the plastic (the fumes from a tiny
drop of cyanoacrylate can fog a big area). A few glues that are safe
for this are:
- watch cement. Used by jewelers for attaching watch crystals. Some
folks claim this is the same thing as "Micro Crystal Klear" - a glue
sold via hobby sources for the same purpose.
- Good old Elmers white glue.
- Clear enamel paint. Just brush some on the mating surfaces, wait a few
minutes for it to get tacky, and then stick the two parts together.
This has also been recomended for attaching photoetched trim.
Note that none of these glues give really strong bonds with plastic, so you
don't want to use these as general purpose glues.
[Q] What are the basics of masking?
[A] cdt@sw.stratus.com (C. D. Tavares)
Try to find a low-tack tape, and use as little tape as possible.
Aluminium foil and small plastic bags which you just tape around
the edges are good ways to cover large surfaces.
Before you apply tape, stick it to your table, or a piece of glass
once or twice to make it less sticky. Remove any tape promptly
(30 min) after painting, as they set harder the longer you wait.
When removing the tape, pull back over the _______ =>
tape that still sticks, and keep the angle /___________
as small as possible. ------------------
....
A good point. I often read how you are supposed /
to pull tape off at "a 45-degree angle" and I / tape
always thought they meant this: /______________
It doesn't work! -------------------------
painted surface (from side)
painted surface (from above)
__________________
Then I discovered that they meant something tape /\
entirely different: make a 45-degree angle ________________/ \
in the FLAT plane. This works much better! / /
/ /
\ /
- \/
cdt@pdp.sw.stratus.com --If you believe that I speak for my company,
OR cdt@vos.stratus.com write today for my special Investors' Packet...
------------------------------
[Q] What are the basic techniques for applying decals?
[A] urf@icl.se (Urban Fredriksson)
For Tricky Decals - Decals that seem to not to want to lay down can be coaxed
into doing so with the following technique. WARNING - this is tricky - if you
aren't careful you can make a big mess. Lift up the decal and apply a small
amount of liquid cement to the model's surface with an old brush. Blow the
decal down with your breath or use a light single stroke with a brush.
DO NOT TOUCH THE DECAL AGAIN! The glue will melt the decal thus adhering it
to the model. If you are careful this coes out great. If you touch the decal
while the glue is setting it will smear like paint - the decal at this point
it melted and until it dries is very susceptable to damage. Once it dries it
will be fine. I've used this on old decals (from 1960's kits) and those tricky
German losenge patterns.
Wait 2-3 days before dullcoating - Always wait at least two days after applying
decals before applying a dull or gloss laquer coat. The moisture in the decals
will react badly to the laquer if you coat too soon and the decals will wrinkle.
...
* Cut away all decal film you can do easily. Use a very sharp
knife, don't press hard as you don't have to cut the paper.
* Put a few drops of Micro Set into the water before you wet
the decals.
* Wet the decal, but don't let it stay in the water.
* Apply Micro Set to the surface you want the decal.
* Slide it there.
* Press down with a soft brush, blot off excess water.
* Brush on Micro Sol, press down gently.
* Place the kit so the decal lies horizontally (if possible).
* Let dry slightly, apply more Micro Sol, press down. Don't
worry about small wrinkles, but try to smooth down large
ones. The decal will contract again when it dries.
Repeat about twice.
No guarantees, but this is what works best for me.
[A] Tuomas Viljanen
Decal film
The decal film is cellulose acetate by chemical composition, and all of the
so-called "decal setting solutions", such as Micro (nowadays Super) Set/Sol,
Humbrol Decal Cote, Testors etc are based on acetic acid and some detergent.
The detergent lowers the surface tension of water and acetic acid saturates
and softens the decal film. As it is amorphous by composition, it does not
dissolve, but softens; while the acetic acid evaporates away, the decal film
sets to conform the surface beneath it.
I have worked with glacial acetic acid (straight from the lab of Organic
Chemistry in HUT) and made an aqueous solution of 2:5. It tames most of the
commercial and kit decals (the brand I have had most difficulties with is
the "Cartograf" used by Italeri and Esci). Even some stronger brands of
household vinegar might be suitable !
One of my friends has gone even longer and he uses a solution of CH3COOH,
MEK, water and dish-washing detergent as a decal-setting solution. He has
not revealed the exact composition, though !
Tuomas Viljanen
Lahderanta 20 A 19
SF-02720 Espoo 72 FINLAND
358-0-592175 or c34657b@saha.hut.fi
[Q] I would like to tint the windows of the model I am building,
how can this be done?
[A] urf@icl.se (Urban Fredriksson)
Try using food colours mixed into future floor wax (or some other
acrylic clear coat). This can be brushed onto the clear part.
In "The Verlinden Way III", tinted windows on a S-3A Viking were
produced similarly. However, here gloss clear lacquer tinted with
India Ink was used
Some paints are manufactured that are transparent. For example,
Tamiya has a Clear Yellow which could be used for tinting.
[Q] The F-117 that I am building has gold tinted windows. How can
such a metallic tint be produced?
[A] urf@icl.se (Urban Fredriksson)
There are several possible ways to accomplish this. Here are several
suggestions.
1) One possibility is to use some of the carrier fluid for the
metallic paint, and a very small portion of the metallic
particles. Airbrush this mixture on the inside surface of the
part.
2) Another possibility is the use of thin Mylar Film, sometimes
called "space blanket". It can be applied to the inside of the
canopy using Microscale foil adhesive. Practice. If you get a
wrinkle while applying it, and remove the film, the adhesive glue
residue is very difficult to remove.
3) Another solution is to use metalised mylar for tinting house
windows. Available at most hardware stores, this material comes in
silver, gold, bronze and smoky, and has the advantage over a
space blanket in that it is designed to be transparent. To
attaching it, it is apparently adhesive backed with a peel-off
protective layer on the back.
4) Yet another possible solution are the metallic polishing powders,
such as those that come with SnJ Spray Metal products may be used
like a dry pastel. Apply it to the inside of the canopy with a Q-
tip.
For a more permanent coating of the powder, apply a clear coat,
such as Future Floor Wax first. Once dry, apply the powder, and
rub it into the coating.
[Q] How do I attach canopies to my model?
[A] urf@icl.se (Urban Fredriksson)
As with everything in modeling, there is no absolute answer, although
I would hazard to say that everyone has their own absolute answer.
A problem I've seen with some very nice models is that some people
seem to be scared of treating the transparency as another piece of
plastic, or treat it as an afterthought to the entire model. A little
more care needs to be exercised. So lets look at several methods of
attachment, and what situations hint at one method.
1) Sometimes we are fortunate and the clear part to be attached has
wide border areas that will be painted. For these types of parts,
I typically use ordinary liquid cement. This allows a firm bond,
and if the parts fit well can be sanded and faired into the
surrounding areas. Some filler can be used to fill any gaps
between the transparency and the model. Many people seem to
forget that you can sand a clear part, and polish it back, and
many times after polishing it looks better than before you
started, because of inconsistencies in the molding process itself.
Polishing is specifically discussed a little later in this FAQ. I
personally think it is important to make the transparency look
like part of the model, like the real thing, and not something
simply attached as an afterthought. Being a model aircraft
builder primarily, this is important. Canopy windscreens are
integral parts of the plane, and there aren't big gaps between the
canopy frame and the rest of the aircraft (generally). The clear
part then can be masked when it comes time to paint.
2) Now say that you have a part that there isn't much free attachment
space between the clear and where it joins to the model. If the
parts mate well (and for some reason, it always seems that model
companies don't make clear parts mate as well as other parts)
again ordinarily model cement can be used, very carefully. Use a
very fine paint brush, like a 000 for instance, and carefully
touch some liquid cement to the joint, allowing capillary action
to pull the cement in. Don't use too much, just enough to pull
into the joint. If too much is used, the clear part will craze
near the cement. Again, this works well for parts that can be
attached before painting.
3) Some discourage superglue for clear parts because it can fog the
plastic, but superglue can be used, if used very carefully. If
too much superglue is used, it will fog the clear parts and
usually does this on the inside of a canopy where it is hard to
clean or polish out. I use thin superglue quite often with no
problem with fogging. The trick is to use only enough to join the
parts and no more. Use a sharp #11 blade as the applicator. Put
some superglue on a piece of scrap plastic, touch the blade to the
glue to get some on the point, and run the point along the joint,
allowing capillary action to pull some superglue in. I use this
exclusively to attach open canopies, like the canopy hood on an
open Messerschmitt Bf109. This is also useful for attaching the
brass and steel canopy detail sets available for aircraft these
days. It is also, in my humble opinion, the best for attaching
vacuum formed acetate canopies like those from Falcon. Again, the
key is BE CAREFUL and don't use too much.
4) For those not up to wanting to risk superglue, there are
alternatives. One of the most used is white glue. Several brands
exist, Elmer's for one. Similar to white glue, there are some
other similar products. Some use Kristal Kleer. My favourite
among these types of products is a decoupage material called Mod
Podge. It is like white glue, but I think dries even more
transparent (it is intended of decoupage, to be applied over
plaques, etc.)
5) As an alternate to white glues, some use 2-part epoxies. It's
odourless, cures slowly, is sandable, easy to apply, doesn't attack
styrene, bonds all type of materials, and is cheaper than
superglue.
[Q] My model aircraft is tail heavy, what do I use for ballast to keep
the nose down, and where should I put it?
There are many things that you can use, and many places in the model
that the ballast can be placed. Lets look at where to put the
ballast first.
1) The radar nose radome is a good place to start. It is in general
the point most forward from the wheels, so the lever arm is
longer and less weight is needed.
2) Engine nacelles. These are forward of the wheels on many
aircraft. The major drawback is that since they are in general
not as far forward, more weight is needed, and if too much is
used, the landing gear could bend or even collapse.
3) You can place weight in the ejection seat. And for many 1/72
aircraft, there are actually white metal seats that are weighty.
This can help.
4) Remove weight from the rear of the model. Sometimes, in some
older kits, there is structural overkill in the rear section of
the aircraft. Some of the inner supports can be removed if they
are deemed unnecessary.
Next, what materials work well as ballast? There are many materials
that can be used, each with advantages and disadvantages.
1) BB's, for BB guns make good ballast. They are small and fill
space pretty well. They can be held in place in the nose,
nacelles, or around the cockpit tub with epoxy or gap filling
superglue.
2) Lead fishing weights work very well. They come in different
sizes, and being lead, their density is high, so not much is
needed to add a lot of mass.
3) You can literally put your money into your models. Pennies can
be used to supply weight.
4) Modeling clay can be used. It fits into difficult places, and
can be used to hold BB's and lead in place. However, there can
be a problem. Some commercial modeling clay begins to separate
after a number of years, and the oil component can migrate out
and damage the finish.
5) Glazing putty can be used like modeling clay, with the
advantage that it is denser.
6) Flux-free solder works very well. It is dense, and can be
easily coiled and made to fit into areas. Superglue can be used
to fix it into place.
7) Lead foil from wine bottles is very good also. It can be
crushed and made to fill unusual shapes.
8) If you are really in need of a lot of mass, you can mold a
weight that fills the entire area. Use aluminium foil or wax to
fill the area to get the shape. Remove this shape and make a
temporary heat resistant mold. Nothing fancy, maybe clay or
sand. Then melt solder into the cavity. Once hardened remove
it from the mold and you have a custom weight that fills most of
the available space. As in the other weights, superglue, epoxy,
or even white glue can be used to hold the weight in place.
[Q] What tools do I need for modeling?
[A] From: urf@icl.se (Urban Fredriksson)
I have found some specialized tools that I need for model building that I
did not have for miniatures. I started out by trying to do without some of
these but finally I have broken down and purchased them and I don't know what
I was ever thinking trying to do without them. All should be available at
stores like Eric Fukes.
Sprue Cutters - Specially made cutting pliers that snip models off of the
mold sprues. These make a big difference over just breaking the parts off the
sprues. The specially made cutters leave no sprue and cut clean enough that
you don't have to go back with a knife to remove the last little bit of sprue.
In a pinch, you can use a pair of nail clippers and a knife to do a similar
job.
Liquid model cement - Model Master makes liquid cement in a black bottle with
a syringe like applicator. This is morth ten times the $3.00 price. The cement
acts much faster than normal cement and the applicator is great.
Clothes Pins - The ones with the springs in them - make excellent clamps for
fuselages and other parts - get about six to eight on your workbench. Also
use some heavy objects for weights in glue-up. I use Dullcoat bottles.
Super Glue Accelrator - Spray accelerator for super glues is a must for
tricky set ups. This stuff really works great! Well worth the expense.
Many models have metal parts that must be attached with super glue. I also
sometimes use super glue when minimal set up time is desired.
Decal Set - made by testors. This stuff is really magic. Follow the
instructions on the bottle and your decals will come out great. I swear
by this stuff.
[Q] How do you transfer paint from the bottle when mixing, thinning, etc?
[A] <law10031@leonis.nus.sg> TOH YUNG CHEONG
You mention offhand that you used droppers... I would also like to suggest
disposable plastic pipettes. Testors sells them.. but you can buy them
cheaply by the box at a Scientific supplies store.
[Q] What are the basic techniques of painting?
[A] ???
Here are a couple of neat tricks I have learned.
Glue small parts to toothpicks - Glue parts like pilots, propellers, engines
and etc. to toothpicks with gap filling super glue. Paint them using the
toothpick for a handle and then remove the toothpick and glue the painted part
to the model after the paint has dried. I use a lump of clay or a box with
holes in it to hold all the toothpicks upright so the parts don't lay on the
workbench.
Don't let parts move - propellors and wheels that were intended to move by
the manufacturer should be glued in place. If they move they will invariably
be broken by people trying to make them move. I've often found that moving
parts have an unrealistic amount of slop in them anyways.
Follow the instructions carefully - there is a lot of sound advice in many
kits instructions including, dry-fit parts first, paint small parts before
assembling, etc.
Washes
[Q] I have heard of giving models a wash to bring out surface details.
How do you go about this?
[A] bruceb@mpd.tandem.com (Bruce Burden)
You need to wash and drybrush to bring out surface details. Washing,
and I use artists oils to tint mineral spirits, emphasises shadow
detail. Drybrushing emphasises surface detail.
Washes, therefore, are usually dark (but not necessarily black),
drybrushes are generally the surface colour with progressivly more
white mixed in. Actually, I don't like white, it looks too stark. I
prefer very light grey.
[A] <law10031@leonis.nus.sg> (TOH YUNG CHEONG)
WASHES - USING OIL PAINTS
A warning to those using oil washes over water based paints. Beware..
Paints like Tamiya may be affected by Turpentine. Make sure you spray
multiple coats of a glosscoat like Microscale and let it dry thoroughly.
A thin light coat might now be a sufficient 'barrier'.
[Q] How can I remove scratches from transparent/clear parts?
[A] <c-metz@uchicago.edu> (Charles Metz 7/98)
(1) Wet-sand the scratched portion of your clear part with
progressively finer grade of "wet-and-dry" sandpaper, beginning with
600 grade and working up to *at least* 2000 grade. Sandpapers with
grades up to 2000 or more are available at most good automobile-supply
stores (because they are used in the final stages of auto-body paint
repairs), and even finer grades (up to 12000 grade, as I recall) are
available at well-stocked hobby and craft shops. The basic idea is to
use the 600-grade sandpaper to remove the original canopy scratches,
and then to use the progressively finer grades of sandpaper to remove
the scratches produced by the previous sanding. Use a lot of water
for your wet-sanding (or even better, do the sanding under running
water) to prevent debris from re-scratching your clear part's surface
as you work. This first step is the most important and must be done
patiently. Continue wet-sanding your part's surface with very fine
wet-and-dry sandpaper until you cannot see any scratches when you dry
(2) Use a clean, soft cotton cloth (I find that an old,
freshly-washed t-shirt works best), a high-quality plastic polish
(e.g., "Bare Metal" brand) or metal polish (e.g., "Blue Magic" brand),
and a lot of "elbow grease" to bring the surface of your part to a
high shine. As you rub, periodically wipe the surface clean with an
unused portion of the cloth in order to remove debris and determine
how shiny the part's surface has become. A good-quality toothpaste
that is intended specifically for "brightening" teeth and contains a
very mild abrasive (e.g., "Ultra-Bright" brand) can be used instead of
plastic or metal polish if you wish, but I find that the "Bare Metal"
and "Blue Magic" polishes produces slightly better results.
(3) Future floor polish does a wonderful job of hiding very fine
scratches in clear parts but can't perform miracles, so to obtain
optimal results, apply Future only after you have obtained the
best-possible shine with sandpaper and polish. Wash your part with
water and mild soap; dry it with a clean, soft cloth; dip the part in
Future floor polish; collect the excess Future with the corner of a
paper towel; and then allow the part to rest on a piece of glass or
aluminum foil while it dries thoroughly. Additional advice concerning
the use of Future can be found in this FAQ at
<www.ninfinger.org/models/rms_tips/rmsfaq.17.html#q16>.
One final point. Good results in removing scratches require a lot of
rubbing in steps (1) and (2), and the twisting and flexing forces that
this involves sometimes can produce a very fine pattern of "stress
fractures" in clear parts. Unfortunately, these stress fractures ruin
the appearance of the part but become visible only in the final stages
of polishing -- a *very* frustrating and unhappy experience! Therefore,
just to be safe, it's a good idea to fill your clear part with wet
plaster (if you'll be rubbing the outside of the part) or immerse it in
a small box of wet plaster (if you'll be rubbing the part's inside) and
then let the plaster set *before* you begin sanding and polishing. The
hardened plaster is easy to remove before step (3), but it greatly
reduces the chances of stress fractures during (1) and (2) because it
prevents the part from twisting and flexing as you rub.
All this is really very simple, but (as with any modeling technique) I'd
recommend practicing on a few clear parts from old kits before you
tackle a prized model.
rec.models.scale FAQ, part 6
FAQ Table of Contents