05/31/2026
COMIC BOOK CPR TIP: DON'T NEGLECT YOUR SPRAY BOTTLES
Recently, I discovered something that many comic book pressers and restoration hobbyists may never think about: contamination inside continuous fine-mist spray bottles.
I happen to be extremely sensitive to mildew and mold odors. Even when I can't see mold, I can often smell it immediately. Over time, I noticed that some of my fine-mist sprayers would develop a musty odor after sitting unused for days or weeks between pressing sessions.
Interestingly, I noticed this issue almost exclusively in sprayers containing bottled water or tap water. My hydrogen peroxide and calcium hydroxide sprayers did not appear to develop the same odor.
After investigating further, I learned that the problem may not be visible mold at all. Instead, moisture trapped inside the pump chamber, pickup tube, and nozzle assembly can allow bacteria, mold spores, and biofilm to develop over time. The water inside the reservoir may look perfectly clean while contamination is actually hiding inside the spray mechanism itself.
A few things I've learned:
• Plain water is far more susceptible to contamination than hydrogen peroxide or calcium hydroxide solutions.
• Continuous mist sprayers can retain moisture inside the pump assembly long after the bottle appears empty.
• If a sprayer develops a musty odor, contamination may already be present even if nothing is visible.
• For those of us who are sensitive to mold and mildew odors, the smell itself can serve as an early warning sign.
I also discovered something important regarding spray performance.
When the reservoir level drops below approximately 50%, many continuous mist sprayers begin producing larger droplets and less consistent atomization. For applications such as BLED-M stain removal, HOP overlays, and preparing copy paper overlays, I have found that keeping the reservoir nearly full produces a much finer and more uniform mist pattern.
For those who only perform pressing or stain removal occasionally, consider the following maintenance routine:
✓ Empty the bottle after use.
✓ Flush with distilled water.
✓ Spray until the pickup tube runs dry.
✓ Allow the bottle and nozzle assembly to air dry completely.
✓ Store the bottle empty until needed again.
✓ Replace inexpensive sprayers periodically.
For cleaning, I prefer flushing with fresh hydrogen peroxide rather than bleach or heavily scented cleaners. Hydrogen peroxide helps sanitize the internal components without introducing harsh chemical residues that could potentially contaminate work surfaces, overlays, or comic book paper.
There is also a health component to consider. Mold spores, mildew, bacteria, and biofilm contamination can trigger allergies, sinus irritation, headaches, respiratory symptoms, and unpleasant odors in workspaces. Keeping your spray equipment clean protects not only your books, but also your work area and your health.
Sometimes the smallest tool on the workbench can become the biggest source of contamination.
Have any of you experienced musty-smelling spray bottles or inconsistent mist patterns during pressing or stain removal work?
