Alvin Lab-metal is a fast-setting, air-hardening repair compound used to fill, resurface, and restore metal and other surfaces. No mixing, no heat, no additives required. This guide walks you through everything you need to know—from surface prep to storage—so you get a clean, lasting repair every time.
Preparing the Surface
Before you apply anything, the surface needs to be dry, clean, and free of paint, oil, and dirt. Use Lab-solvent to clean the area thoroughly. After cleaning, abrade or roughen the surface to improve adhesion. Skipping this step is one of the most common reasons repairs fail.
Also, stir Lab-metal thoroughly before use. It settles over time, and proper mixing ensures consistent application.
Ways to Apply Lab-Metal
Spreading with a Putty Knife or Spatula
This is the most common method. Apply Lab-metal using a putty knife, spatula, trowel, or flexible squeegee.
For deep holes or cavities, do not fill them in a single pass. Apply in layers no thicker than 3/8 inch, and allow each layer to fully dry before adding the next. Rushing this step leads to uneven hardening and cracking.
For vertical or overhead applications, pour the required amount into an open container and stir. As Lab-metal sits exposed to air, it becomes less fluid—this reduces the risk of sagging during application.
Brushing
To brush-apply Lab-metal, thin it with Lab-solvent to a paint-like consistency. A 1:1 ratio (one part Lab-metal to one part Lab-solvent) is a good starting point.
Pour the Lab-solvent into a wide-mouth container before adding the Lab-metal. When applying, use light brush strokes—avoid working it over like paint. Dip your brush in Lab-solvent frequently to keep the bristles clear and prevent clogging.
Spraying
For spray application, thin Lab-metal with Lab-solvent and use an external mix spray head set at approximately 65 pounds of air pressure. This helps prevent clogging. For larger jobs, an agitator tank is recommended.
Clean your spray gun thoroughly with Lab-solvent immediately after use. When spraying in enclosed spaces—such as tank interiors—ensure proper ventilation and use a NIOSH-approved self-contained breathing apparatus. Avoid any metal-on-metal contact that could cause sparks.
Drying Times to Expect
Lab-metal hardens as its diluents evaporate. There's no heat required, but thickness directly affects drying time:
- 1/16 inch application: hardens in 1–2 hours
- 1/8 inch application: hardens in 3–4 hours
- Brush and spray applications dry more quickly
If you need to speed up the process, infrared lamps can be used carefully. Other force-curing methods are not recommended.
For deep pits or holes, layering is the most effective approach. Build up successive layers no thicker than 3/8 inch, allowing each to fully harden before adding the next. This gives you the most durable, consistent result.
Special Instructions for Powder Coaters
Lab-metal repairs can be powder coated without outgassing or popping out—a common concern in finishing applications.
- Use regular Lab-metal for temperatures up to 350°F (or up to 425°F for single exposures under 20 minutes).
- Use Hi-Temp Lab-metal for baking temperatures above 425°F for more than 20 minutes, or for parts that require multiple high-temperature oven passes.
How to Store Lab-Metal Properly
Lab-metal is guaranteed for two years in factory-sealed cans. To extend the life of a partially used can, pour a small amount of Lab-solvent over the remaining product and seal tightly. This prevents premature hardening caused by air exposure.
Before your next use, mix the solvent thoroughly back into the Lab-metal. Store in a cool place away from direct heat and sunlight.
Get the Best Results, Every Time
Applying Lab-metal correctly comes down to a few key habits: prepare the surface properly, apply in appropriate layer thicknesses, and store the product correctly after each use. Follow these steps, and you'll get professional-grade repairs with minimal effort.
Have questions about the right Lab-metal product for your project? Our team is here to help—contact us for expert guidance on selecting and using the right solution for your application.
