Short answer: choose a thin or extra thin CA glue for tight-fitting parts and cracks, medium for general repairs, and thick or extra thick when the joint has gaps. Viscosity is the thickness of the liquid, measured in centipoise (cps); the thicker the glue, the slower it soaks into a joint and the more gap it can fill.
CECCORP CA glue viscosity chart
| Grade | Viscosity at 25 C (cps) | Setting speed | Gap to fill | Best for |
|---|---|---|---|---|
| Extra thin | 5 or less | 3-5 s | 5-35 microns | Wicking into hairline cracks and extremely close-fitting parts. Not for gap filling. |
| Thin | 30-50 | 10-20 s | 10-60 microns | Smooth, close-fitting surfaces. Not for gap filling. |
| Medium-thin | 100-120 | 10-20 s | 10-200 microns | Balanced grade with better gap filling than thin. Not for large gaps. |
| Medium | 500-600 | 10-15 s | 10-200 microns | All-around bonding that fills small gaps and suits vertical surfaces. |
| Thick | 1000-1200 | 10-20 s | 10-200 microns | Gap filling and non-sag bonding on vertical surfaces; pairs well with a CA accelerator. |
| Extra thick | 3000-3200 | 10-20 s | 10-300 microns | Maximum gap filling on rough or uneven surfaces and small voids. |
| Slow-cure thin | 30-50 | 1-3 min | 10-60 microns | Extra working time for woodturning finishes and precise positioning. |
Viscosity and setting speed are the figures in the technical chart on each product page; gap to fill is from each product's technical data sheet (TDS). Dedicated-use grades such as Wood, Metal, Plastic, Black, Platinum and Flex list their own figures on their product pages. Always check the TDS for your product.
Wicking versus gap filling
Thin glues wick: they are drawn into the joint by capillary action, so apply them after the parts are fitted together. Thick glues fill: they stay where you put them and bridge small gaps. If you can see daylight in the joint, step up a grade. If the glue runs out of the joint or onto your work, step down.
Choose by material
- Wood and woodturning: see CA glue for woodworking and woodturning and finishing.
- Plastic: CA glue for plastic bonding. Polyethylene and polypropylene need a specialty adhesive such as PO-Bond.
- Metal: aluminum and metal bonding.
- Models, RC and hobby: model making and hobby.
Viscosity and accelerators
An accelerator shortens the set time, which is most useful with thick glue in a gap. Read how and when to use CA glue accelerator.
Frequently asked questions
What viscosity is super glue?
It depends on the grade. CECCORP CA glues run from about 5 cps or less (extra thin) to 3000-3200 cps (extra thick). The range tops out at extra thick; there is no gel grade.
Is thin or thick super glue stronger?
Not by viscosity alone. In the technical data sheets, the typical lap shear strength after 24 hours at 22 C is 13-18 N/mm² (ISO 4587) for thin through extra thick, and typical tensile strength (ISO 6922) is 12-24 N/mm² for thin and 18-25 N/mm² for medium-thin, medium, thick and extra thick. What changes with viscosity is the gap the glue can fill: 10-60 microns for thin, up to 200 microns for medium-thin, medium and thick, and up to 300 microns for extra thick. A well-fitted joint with the right grade matters more than the grade number.
How should I store CA glue?
The technical data sheets say to keep the product in a cool, dry room at 10 C to 20 C, with a shelf life of 1 year in unopened packaging at +5 C to +27 C. See our CA glue safety, handling and storage guide for handling advice.