BASIC SEAM
FILLING & SANDING
(Page Two)
5. Bondo Glazing & Spot Putty
(Automotive)
Advantages:
·
Easy to apply. Due to its “sticky” nature, applies better
to surfaces than contour putty.
·
Also, since it is not quite as
“sticky” as Squadron’s, its application is not as messy.
·
Goes on more uniformly than
Testors contour or Squadron Glazing putty.
·
Sands down very smoothly and
uniformly.
·
Cures fast.
Disadvantages:
·
Also difficult to apply due to
large tube opening. (A toothpick or plastic syringe can also be used for a more
precise application).
·
According to its Warning, can
cause a person MORE problems than the Testors and Squadron putties. (Its
vapors may affect the brain or nervous system, etc., along with it causing
kidney and liver damage if absorbed through the skin)
·
Related to the previous
characteristic, quite a bit of dust is created while sanding, unless “wet-sanding.
6. Cyanoacylate (Super) glue –
(Zap-a-Gap)
Advantages:
·
Easy to apply, (by putting some
on a sheet of glass or a piece of aluminum foil, and using either a needle,
straight pin, or toothpick to apply directly to gap area)
·
If applied carefully, is not
“messy.”
·
In addition to filling, also
bonds.
·
When used with an accelerator,
bonds in seconds.
·
Baking Soda can be used as an
accelerator, along with giving the super glue some “meat” to it.
Disadvantages:
·
Be careful when applying. Due to its
nature, it’s quite easy to glue things together that shouldn’t be, (like
fingers, hands, etc.).
·
Since the cured area becomes
harder than the softer surrounding plastic areas, care must be taken when
sanding down.
·
The vapors given off can cause
eye irritation.
7. Elmer’s White Glue
Advantages:
·
Easy to apply, (with a
toothpick).
·
Easy to correct mistakes. With it
being water based, a wet Q-tip or paper towel will remove any excess.
·
In addition to filling, it also
bonds.
·
Since it will not craze clear
plastic, it is great for attaching clear parts, (like aircraft canopies and
windscreens).
·
Also, it can sometimes be applied
to a gap having a large amount of surrounding surface detail, (which might
otherwise be destroyed by sanding).
Disadvantages:
·
Not a very good gap filler:
·
It shrinks a lot when it dries.
·
It does not fill a gap uniformly;
(i.e., there will be higher and lower areas with the filled gap). With this,
repeat applications may be necessary.
V VARIOUS TECHNIQUES & SOME FILLING AND
SANDING SHORT CUTS
·
Filling
1.
A plastic syringe can be used to
more precisely apply putty from a tube which have a large opening.
2.
Use two pieces of masking tape to
surround the gap area. This will help keep putty only in the gap. Be sure to remove
the tape after the putty has been applied, but before the putty starts to
harden. (Some of the putty will cake off with the tape otherwise).
3.
Use a toothpick or a sewing
needle to apply the lacquer-thinned putty more directly to the gap area.
4.
Use a piece of aluminum foil and
a sewing needle or straight pin for applying super glue. Squeeze some of the
glue onto the aluminum foil sheet, put the needle or pin into the super glue
puddle, and touch the side of the needle or pin to the gap area.
5.
An accelerator can be used to
speed up the chemical bonding process with super glue. In addition, Baking Soda
can be used as an accelerator, along with giving the super glue some “meat” to
it. When using it, however, realize that the more the super glue has cured, the
harder the excess will be to remove, and hence, the longer the sanding process
will be.
·
Sanding
1.
If a large amount of putty or
super glue has been applied, metal files can be used to remove much of the
excess, before moving over to sanding paper.
2.
In addition, a sharp #10 X-acto
blade (curved) can first be used to remove excessive amounts of contour or
glazing putty, before going to sand paper. This can only be done once the putty
has hardened. Excess putty is very
carefully chiseled away.
3.
Transition to a “relatively”
coarse piece of sanding paper. (I usually start with a 320 or 400 grit paper).
4.
Work down to finer grades of sand
paper. (I usually end up with 600 or 720 grit).
5.
An emery board, cut to shape, can
be used to sand down “hard to get to” spots.
6.
You can use water to wet/sand the
area. This prevents much of the putty from building up in the sand paper, along
with acting as a lubricant, giving you a smoother sand. Since not all sandpaper
is wet/dry, check its type before using it with water.
7.
Masking tape can also be used
during the sanding process to protect surface detail surrounding the gap.
Sandwich the gap with two pieces of tape. Then, sand as normal. Remove the tape
when finished.
·
Priming
(& repeated filling, sanding and priming)
1.
This very important step is often
overlooked during a kit’s construction. What’s involved here is the painting of
a light color of paint, concentrating on the newly puttied and sanded areas.
This procedure will help to uncover problem areas, allowing you to refill and re-sand
the gap areas, before applying your final coats of paint.
2.
It may be necessary to repeat
this priming step multiple times, until a smooth surface results.
Copyright © 2007 by Anthony I. Wootson. No material may be
reproduced without permission of Anthony I. Wootson. Unauthorized duplication is
prohibited.