|Super glue fuming is widely used in the process of evidence both in the lab and at the scene. In the lab, we use fuming chambers, such as a commercially purchased fuming chamber, aquariums of various sizes, old refrigerators and handmade Plexiglas chambers but these are not practical to use at the crime scene because of their size and portability. The reason some evidence needs to be processed at the scene is to preserve the latent print on the evidence using super glue so the latent prints are not destroyed or damaged before they are delivered to the lab. To have a fuming chamber that can be used at the crime scene, it must be compact, easy to assembly and cost effective.
It is quite easy to make your own fuming chamber. To do this, the framework is built out of ½” PVC pipe and the cover is a trash bag. The completed overall dimensions of the chamber when assembled are 14.75” wide x 19” long x 18” high. Unassembled size is 14.75” x 19” x 2.75”. The trash bag used for this size of chamber is a 39 gallon bag which is 2’9” x 3’8” in size. The size of the chamber can be changed by making the ½” PVC pipe sections longer or shorter to fit your needs. The PVC pipe, cleaner and cement can be purchased at your local hardware store.
- 1- ½” PVC pipe 10’ $ 0.18 per foot
- 1- ½” PVC pipe 5’ $ 0.18 per foot
- 8- ½” PVC “T” connectors $ 0.20 ea.
- 8- ½” PVC 90° elbows $ 0.20 ea.
- PVC Pipe Cleaner $ 2.29 ea.
- PVC Pipe Cement $ 2.89 ea.
Total investment: $ 11.08 less trash bag
Cut the PVC pipe with either a fine bladed saw or PVC pipe cutter.
1. From the 10’ section of PVC pipe cut the following:
- Cut four (4) pieces at 16” Uprights
- Cut four (4) pieces at 13.5” Side section
2. From the 5’ section of PVC pipe cut the following:
- Cut four (4) pieces at 12.25” End section
- Cut four (4) pieces at 5/8” (nipples)
Step 1 - To build one end for the frame the following pieces are required:
- 2 pieces - 13.5”
- 2 pieces 12.25”
- 4 - ½” PVC “T” connectors
- 4 - ½” PVC 90° elbows
- 4 - ½” PVC 5/8” nipples
Note: If you do not want to glue the end sections together do not use the PVC cleaner or cement to put the end sections together, this way they can be completely taken apart.
Use the PVC cleaner to clean the ends of each section of ½” PVC pipe, ½” PVC, 5/8” nipples, inside the ½” PVC “T” connectors and ½” PVC 90° elbows. Use small brush to apply cleaner with clean, dry rag wipe clean.
Step 2 - Pre-assemble all pieces before applying the PVC adhesive.
- Place one end of a ½” PVC 5/8” nipple into one end of a ½” PVC 90° elbow. Insert the other end of the ½” PVC 5/8” nipple into the ½” PVC “T” connector. Line up the nipple and the “T” connector (see figure 1).
- Repeat this step with the remaining three corners.
- Insert the two end sections into the “T” connector (see figure 2).
- Insert the two side sections into the “T” connector (see figure 2).
- When completed, it should look like figure 3.
Step 3 - Repeat Steps 1 and 2 to make the other end frame.
Step 4 - Now that you know what it is supposed to look like, it is time to apply the PVC cement to the joints to hold the end together.
- Apply a small amount of the PVC cement to the joint then insert the pipe section and align up the connectors.
Note: When the PVC cement is applied and the two joints are put together, make sure you have put it together correctly because the setup time is very fast.
Step 5 - Once the end frames have been cemented together and allowed to dry, you are basically ready to use it.
To use chamber:
- Insert the four (4) upright section into one of the end frames (see figure 4).
- Place the other assembled end frame onto the four upright sections (see figure 5).
- Place the portable PVC frame into the trash bag and lay on its side (see figure 6).
- Insert evidence to be processed into the chamber (see figure 7).
- Place the super processing method you choose (Hot Shot, Sodium Hydroxide treated cotton, warming plate, etc.) into the chamber.
- Seal chamber by closing the end of the trash bag and secure with a wire tie (see figure 8).
- Remember not to over fume the item being processed. (See superglue techniques for proper use.)