UV Flashlight 395nm Battery Powered | Resin 3D Curing & Verification

395nm ultraviolet flashlight with a high-intensity 3W LED, focusable zoom, CNC-machined hard-anodized aluminum alloy body. Designed primarily for UV resin 3D printing workshops (SLA, MSLA, DLP): lets you finish curing parts that came out under-polymerized, visually inspect the cure state of any printed part, and detect invisible splashes of uncured resin on your workbench, floor, tools, or clothing. Also useful for secondary applications such as fluorescence detection, banknote authentication, invisible markers, and organic stain detection (pet urine, biological fluids on countertops). Important: battery not included — takes 1 standard AA battery or 1 rechargeable 14500 cell (neither included).

Why you need it for UV resin printing

Any maker printing with an SLA printer (Anycubic Photon Mono, Elegoo Saturn, Phrozen, Creality, and similar) works with photopolymer resins that require UV curing — both during printing and post-processing. Having a standalone, high-power UV flashlight in your workshop solves four real day-to-day problems:

Finishing the cure on sticky parts. When a part comes out of the wash & cure station but still has soft spots (because the UV light didn't fully reach certain areas due to complex geometry, support shadows, or insufficient washing), spot-lighting those areas with the flashlight for a few minutes completes polymerization in that specific zone — no need to run the whole part through the cure chamber again.

Checking the cure state of a finished part. Under 395nm UV light, uncured resin fluoresces visibly and stands out clearly from properly polymerized areas. It's the fastest way to verify whether your cure times are dialed in — especially useful when breaking in a new resin or switching machines.

Finding invisible resin splashes in your workshop. Uncured UV resin is one of the messiest hazards in an SLA setup — it splashes when rinsing parts, when peeling prints off the build plate, and during general handling. Most of these splashes are nearly invisible under normal light but glow brightly under 395nm UV. Running the flashlight over your workbench, floor, walls, and work clothes lets you locate and clean up uncured resin before it contacts skin (it's a known allergen/sensitizer) or permanently cures onto surfaces you don't want damaged.

Supplementing the cure for Gomagom 87. The Gomagom 87 UV Adhesive in our catalog includes a small curing light built into the cap, which is sufficient for small adhesive volumes. For larger repairs requiring thicker layers or full curing across wide areas, a higher-power external UV flashlight speeds up the process significantly. The 395nm flashlight we offer here is compatible with Gomagom 87's chemistry (photoinitiators active at 365–405nm).

Secondary use cases

While we designed this for 3D printing workshops, a high-power UV flashlight covers a range of scenarios that can be handy beyond the hobby:

Organic stain detection. Pet urine (dogs, cats) on carpets, sofas, and floors. Other biological fluids. Proteins fluoresce under 395nm UV.

Banknote and document authentication. UV security marks on euro, dollar, and pound banknotes; official stamps in passports; security inks on ID cards.

UV invisible markers. Invisible ink only revealed under black light — used in security, labeling, crafts, and escape rooms.

Fluorescent mineral detection. Mineral collecting, amateur mineralogy.

Scorpion hunting. In areas where scorpions are found, they fluoresce brightly under UV light — useful for nighttime outdoor use.

These are secondary uses — the primary focus of this product in our catalog is resin 3D printing workshops.

How to use it with UV resin prints

1. Insert an AA or 14500 battery. The flashlight does not include a battery. It accepts both a standard AA alkaline battery (cheaper, shorter runtime) and a rechargeable 14500 lithium battery (higher upfront cost, much longer runtime per charge).

2. Turn it on and adjust the zoom. Rotating the flashlight head controls the beam area — narrow focus for curing small areas at maximum intensity, wide beam for inspecting larger surfaces.

3. To finish curing: hold the light over the tacky area for several minutes. There is no exact time — it depends on the thickness of the uncured layer, the resin formulation, and the distance between the flashlight and the part. As a general guideline, 3–5 minutes at a distance of 5–10 cm is usually enough for small areas. For larger parts or thicker layers, do multiple passes rotating the piece so the light reaches all sides.

4. To verify curing: dim the room and inspect the part under UV. In low light, properly cured areas appear uniform; areas with uncured resin fluoresce differently (typically brighter or with a slightly different hue).

5. To detect resin splatter: dim the room and sweep surfaces with the light. Uncured resin drips and stains show up clearly against dark backgrounds.

Important notice: battery NOT included

So you are not caught off guard when you open the package: this flashlight does not include a battery. This is a manufacturer decision to reduce international shipping costs (batteries have logistics restrictions). You will need to purchase one of the following separately:

• AA alkaline battery: the budget option. Available at any supermarket or hardware store. Average runtime: 1–2 hours of continuous use.
• Rechargeable 14500 lithium battery: the more professional option. Higher initial investment but rechargeable hundreds of times, with greater output intensity and much longer runtime per charge.

If you already have AA batteries at home for a remote control or clock, the flashlight will work with them right away.

UV light safety

395nm UV light is low-intensity UV-A — the same part of the spectrum as the UV in sunlight that is filtered by the atmosphere before it reaches us. It is not comparable to a germicidal UV-C lamp (which is genuinely hazardous to eyes and skin). That said, basic precautions are still recommended:

• Do not stare directly at the LED while it is on for extended periods
• Do not deliberately shine it into the eyes of pets or children
• For long sessions (more than 30 minutes of continuous use), consider wearing UV-protective eyewear

For typical workshop use (spot-curing for a few minutes at a time, checking for resin splatter during cleanup), no special protective equipment is required.

Technical Specifications

• Type: Zoomable UV LED flashlight/torch
• Wavelength: 395 nm (UV-A)
• LED Power: 3 W
• Body Material: CNC-machined aluminum alloy with hard anodized finish
• Body Color: Black
• Dimensions: 92 mm length × 26 mm head × 22 mm tail
• Weight: 58 g (without battery)
• Power: 1× AA alkaline battery or 1× 14500 rechargeable lithium battery (NOT included)
• Light Modes: 1 mode (on/off)
• Zoom: Focusable by rotating the head
• Primary Applications: Curing and inspection of UV resin 3D printed parts (SLA, MSLA, DLP), detecting uncured resin spills in the workshop, supplemental curing of Gomagom 87 UV adhesive
• Secondary Applications: Banknote authentication, organic stain detection, fluorescent minerals, invisible ink markers, scorpion detection
• Brand: Alonefire (model SK68UV)

Why Buy It from Mr Resin

If you work with UV resin 3D printing (Anycubic, Elegoo, and other brands), a powerful UV flashlight is one of those workshop tools that once you have it, you use it all the time — from the moment you pull a part out of your wash & cure station and want to check it's fully cured, to the final cleanup of your work surface. As a store specializing in 3D printing, we carry it specifically because we know how useful it is for our customers.

Ships from our warehouse in Spain: delivered in 24–48h (no waiting 2–4 weeks like with direct purchases from Asian suppliers). If you're already placing an order for resin, filament, or accessories, adding the UV flashlight ships in the same package at no extra cost. Free shipping on orders over €79 to mainland Spain.

Mr Resin has been serving over 5,000 makers across Spain, Portugal, and France for years. Our catalog is built around what the community actually asks for: printers and materials as the backbone, and the workshop tools that become part of everyday use.

Frequently Asked Questions

Can it fully cure UV resin 3D printed parts?
For small parts or spot-curing tacky areas, absolutely — it works great. For curing large parts in full or very thick layers of resin, a dedicated wash & cure station with an enclosed curing chamber is the more efficient solution (Anycubic Wash & Cure, Elegoo Mercury, Phrozen Cure). The UV flashlight is a handy spot-curing and inspection tool, not a replacement for your primary curing setup.

Is the wavelength right for 3D printing resin?
Yes. Photopolymer resins used in 3D printing (Anycubic, Elegoo, Phrozen, Siraya Tech, and most others on the market) are formulated to cure in the 365–405 nm range. At 395 nm, this flashlight falls squarely within that range and is the most universally compatible option. Some dental or specialized resins may require 365 nm exclusively — check your resin's technical datasheet if you're unsure.

How do I check whether a part is fully cured?
In a darkened room, shine the UV flashlight over the part. Properly cured areas will look uniform and matte. Any uncured or undercured resin will fluoresce differently — typically showing a distinct glow or color shift compared to the rest of the surface. If you spot undercured areas, apply focused UV light directly to those spots for 3–5 minutes.

Are resin splashes really invisible under normal light?
Yes, especially small droplets. When washing parts or removing them from the build plate, tiny uncured resin microdroplets scatter everywhere — and they're practically invisible on your workbench, floor, or clothing until they dry or accidentally cure in sunlight. Under 395nm UV light, all those droplets glow clearly and can be wiped away with a paper towel and isopropyl alcohol before they cause problems. This is one of the most important safety habits in any SLA printing workspace.

Why doesn't it include a battery?
This is a manufacturer's decision to avoid international shipping restrictions (batteries are subject to specific transport regulations). It's standard practice for this type of product. You'll need to purchase a regular AA battery separately (available at any supermarket for $1–2) or a rechargeable 14500 lithium battery. If you already have AA batteries at home, it works right out of the box.

Is UV light dangerous to your eyes?
395nm UV-A light is low energy — it falls in the same range of the spectrum as the everyday UV in sunlight that doesn't cause immediate burns. It's not comparable to a UV-C germicidal lamp, which is genuinely hazardous. That said, avoid staring directly at the LED while it's on for extended periods, and don't deliberately shine it into the eyes of pets or children. For normal workshop use — a few minutes at a time — no special protective equipment is required.

Does it also work for checking banknotes or detecting fluorescence?
Yes, those are secondary uses covered by any 395nm UV flashlight. Euro banknote security markings fluoresce visibly under this light, as do invisible inks, organic stains (urine, blood), fluorescent minerals, and scorpions. If one of these is your primary use case, this flashlight has you covered — our catalog focuses on 3D printing workshops, but all the secondary uses are just as valid.