Portable Fuming Chamber
 This
portable glue fuming chamber has reinforced joints. Two sets of sides
have hinged joints. When the two sets meet, they are held together by
Velcro®. This chamber has a special port on the side to allow you to insert
a fuming wand and/or to let you attach an exhaust tube to it. It comes
apart and can be stored in the optional carrying case for easy transportation
to a crime scene. It weighs less than 10 pounds. When assembled, the overall
dimension is 14" x 14" x 20 1/2"; however, the chamber body is 12" x 12"
x 19". The Cyanowand™ fuming wand, Hard Evidence™ liquid glue or Hard
Evidence™ pouches can be used inside this chamber. For more information
on the Glue Fuming process, please view our Technical Note below.
|
Code |
Name |
Price |
|
1-4676 |
Portable Fuming Chamber |
$194.85 |
|
1-4677 |
Carrying Case for Portable Fuming Chamber |
$74.95 |
Technical Note
Fuming with Cyanoacrylate (Super Glue™)
Introduction
Fumes from cyanoacrylate ester adhesives (Super Glue® and similar
products) will develop latent prints. Glue fuming techniques develop latent
prints on many surfaces previously considered unsuitable for latent fingerprints.
At a demonstration hosted by the Tokyo Metropolitan Police in 1978, forensic
scientists of the Criminal Identification Division, Japanese National
Police Agency, shared their knowledge of glue fuming with members of the
US Army Crime Lab in Japan. Soon criminalists and investigators in a number
of countries were conducting experiments and refining the techniques of
glue fuming.
Safety
As with all chemicals, always read the MSDS (material safety data sheet)
to learn about the safe handling and health hazards of each chemical.
The Home Office at New Scotland Yard indicates that fumes from cyanoacrylate
ester are irritating but nontoxic at levels encountered in most fingerprint
labs. Upon opening the lid of the chamber, arrange for the fumes to be
drawn away by a fume hood or vent fan. Remember that this is a super adhesive.
Avoid contact with skin, eyes, etc. It is very easy to glue your fingers
together, but difficult to get them apart.
Equipment
Fuming Chamber: A container to hold the glue fumes around the piece of
evidence is needed. The container can be an aquarium, a large plastic
tub, etc. The container should not be too much larger than the items being
fumed, and it must be as airtight as possible. The advantage of an aquarium
is that the progress of the fuming can be observed. Weather-stripping
can be fastened to the top edge of the chamber and a board placed on top
to seal in fumes. Covering the inside of the chamber with aluminum foil
can make cleanup faster. If the chamber is of see-through material, leave
one side uncovered so the fuming can be observed. Space the evidence so
that none touches another. Coleman Vacu-Print™: This equipment evacuates
the air from the chamber. The evidence is placed inside, a few drops of
liquid glue are added and the vacuum pump is switched on. It has been
shown that the glue fumes will penetrate folded or crumpled-up plastic
baggies of any size when under vacuum. Cyanoacrylate Glue: Loctite®
Hard Evidence™ is available in liquid form in one-ounce and one-pound
bottles. It is also available in a gel form in convenient-to-use, pull-apart
pouches.
Hot plate: This accelerates the processing with the liquid glue.
Processing Instructions
Method One- Pouches: Tape or secure the opened pouch to the lid of the
chamber. One pouch is sufficient for a five or ten gallon chamber, but
the amount of time of fuming may vary. This method may take from ten to
forty minutes, depending on the size of the chamber and the freshness
of the pouch. Method Two- Liquid Glue: This method requires the use of
heat to accelerate the process. CAUTION: Because it accelerates the process,
it is easy to overfume evidence. Place a small hot plate into the chamber.
Deposit an amount of glue about the size and volume of a nickel (5¢
piece) onto a small aluminum dish. Place this dish onto the hot plate.
Place the pieces of evidence inside the chamber and plug in the hot plate.
Secure the lid. This method may reduce the fuming time to ten to fifteen
minutes. Observe the evidence every five minutes to check its progress.
Method Three-Vacuum: This method will develop latent fingerprints
without leaving excessive residue on the surface of the evidence. Because
there is no residue buildup on the evidence, dye-staining for fluorescent
examination is more effective. Dyes such as Rhodamine 6G and Ardrox adhere
to the glue residue on the item. Items such as garbage bags do not have
to be opened up. The fumes will coat all of the surfaces. Place the items
of evidence inside the Coleman Vacu-Print™ or other vacuum chamber.
If using liquid glue, put a small volume in a small aluminum dish. Or,
if using the Hard Evidence™ pouches, cut off a half-inch strip, open
it up and attach it to the inside wall of the chamber. Turn on the vacuum
pump and evacuate the chamber to approximately 25 inches of Mercury. Turn
off the pump and leave the items in the chamber under vacuum for about
twenty minutes. If items are left longer there is no danger of overfuming.
When ready, allow air back into the chamber, open the lid and remove the
evidence. Dye-stain or powder as usual.
Examination
Most latent prints developed with glue fuming will have white ridges
and will be quite noticeable. Sometimes, however, the latent prints will
be very difficult to see; therefore, each piece of evidence must be carefully
inspected. Oblique lighting from a flashlight will be helpful. It is suggested
that these prints be photographed before other processes are used. The
latent prints can be visually enhanced by dusting with regular or magnetic
fingerprint powder contrasting with the background. Once dusted with powder,
glue-fumed latent prints can sometimes be lifted with regular lifting
tape. The latent prints are quite durable and usually can be lifted more
than once. Sometimes the second lift is clearer than the first.
Photography
Visible, contrasting prints can be photographed in the usual way. However,
photography of white, glue-developed prints on light-colored or transparent
objects may need some different lighting. If the object is transparent,
place a piece of paper of contrasting color behind it and photograph as
normal. Or, move the light source behind the object. The light will shine
through the transparent areas, but the latent prints will appear dark,
as no light will shine through. If the object is light-colored and not
transparent, it may be necessary to dust or use fluorescent dyes and powders
on the latent print to provide the needed contrast.
Helpful Hints
If you are going to use fluorescent dyes, liquid or powder, underfume
the evidence. The liquid dyes, especially, cling to the excessive glue
residue and will glow so brightly as to become one shining blur.
Placing a cup of warm water in the fuming chamber with the evidence could
make the glue residue show up whiter and be easier to photograph. It is
not necessary to put water in the Coleman Vacu-Print™.
Refrigeration of the unopened liquid glue bottle or unopened pouches can
help to extend the life of the product. Generally, however, the shelf
life is about six months to one year.
Clean the inside of a glass or metal fuming chamber with solvent when
the interior appears to be cloudy or chalky. Or if the chamber is lined
with aluminum foil, replace it frequently.
Additional Reading
Advances in Fingerprint Technology edited by Dr. Henry Lee and Dr. R.
E. Gaensslen
Manual of Fingerprint Development Techniques by the British Home Office,
second edition
Ordering Information
Catalog No. 1-4700 Coleman Vacu-Print™ Table-Top Chamber
Catalog No. 1-4701 Coleman Vacu-Print™ Long (rifle) Chamber
Catalog No. 1-4702 Vacuum Pump/Motor with hose
Catalog No. 1-4500 Locitite® Liquid Glue, 1 lb.
Catalog No. 1-4510 Hot Plate for fuming
Catalog No. 1-4620 Hard Evidence™ Pouch, 20 pack
Catalog No. 1-2101 Booklet of 50 Black Backing Cards, 2 1/4" x 4
1/4"
Catalog No. 8-5015 HOME OFFICE/Manual of Fingerprint Development Techniques,
2nd edition
Catalog No. 8-5041 LEE/Advances in Fingerprint Technology
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