Reading a Resin Label: Viscosity, Bottle Size, and Test Standards

Resin is the part of a windshield repair that stays in the glass. It deserves more attention than it usually gets. This article explains what to look for on a resin label and product page, using Ultra Bond's resin line as an example. It is general information for professional technicians. Confirm details with the manufacturer and follow their instructions.

What Viscosity Tells You

Viscosity, measured in centipoise or cps, describes how thick a resin is. Thin resins flow into fine cracks. Thicker resins can fill larger breaks. Ultra Bond lists chip repair resins at 100, 70, 50, 40, and 20 cps, and says many chip repairs by other tools use resins around 18 to 20 cps.

Different Resins for Different Damage

The company's resin line includes chip repair, crack repair, long crack, and edge crack resins, plus a pit filler, a waterproof rain resin, adhesive promoters, primers, and additives. Using the right resin for the type of damage is part of a good repair.

Bottle Sizes

The page says resin comes in three sizes: 13 ml, 15 ml, and one quarter liter. Smaller bottles suit occasional use. Larger bottles suit busy shops, but check the shelf life so resin does not age before you use it.

Look for Test Information

Ultra Bond says its resins are tested to a customized version of ASTM D790, the standard test method for strength of glass by flexure, and to the ANSI approved ROLAGS laboratory tests. It also says tests for new windshields under FMVSS 205 were run for long cracks. The company says scores are shown on the bottle. Ask any resin maker the same questions and compare.

Appearance Matters Too

The page says its crack resins passed the visual tests in ROLAGS and FMVSS 205, which include luminous transmittance, light stability, and distortion. A repair that holds but looks poor is a problem for customers.

Questions for Any Resin Supplier

Which viscosities are offered for chips, cracks, and edges?
What test methods were used, and are results available?
What is the shelf life and storage guidance?
Is a new formula compatible with the tools you own?

Where to Read More

Technicians researching Windshield repair resin can read the resin category at Ultra Bond, which lists the resin types, the sizes, the cited tests, and newer products such as a crystal quartz chip resin announced for 2026. The company lists 1-800-398-2663.