How to read a sealant technical data sheet

Match the product name and variant to the cartridge in your hand, then note the revision number and issue date.

Variants can differ more than you'd expect. Pereseal N clear and N in black, white and grey have separate data sheets. The coloured version is about 42 Shore A with about 250% elongation. The clear is much softer, at about 15 Shore A. If a sheet has no revision or date, ask the supplier for the current one.

The uses list tells you where a product works. The "not recommended for" list tells you where it fails, and that's the quicker way to rule something out. From our own sheets:

• Pereseal 802: not for marble, quartzite or natural stone, and not for structural glazing.
• Pereseal MP: not for uPVC. Copper and lead may be attacked.
• Pereseal AF: not for aquariums, paint coatings, copper, or polycarbonate and acrylic sheet under tension.
• Pereseal 702: not for joints that are constantly submerged.

• Movement capability: how far the sealant can stretch and compress, as a percentage of joint width. 802 and MP are ±25%, AF and N ±30%, 702 ±15% and FR ±12.5%. This decides how wide the joint must be.
• Skin or tack-free time: how long you have to tool, and when dust stops sticking. AF, N and 802 are tack-free in about 15 minutes; tool within 5.
• Cure rate: how fast it cures through. AF, N and 802 cure about 10 mm deep in 7 days.
• Application temperature: the range you can gun it in. AF, N and 802: −20°C to +50°C. 702 and MP: +1°C to +30°C.
• Service temperature: the range the cured bead handles. AF, N and 802: −50°C to +150°C.
• Joint size: minimum and maximum. Our silicones take up to 30 mm wide; 702 and FR take 5–50 mm.
• Hardness and elongation: softer, stretchier sealants move more easily and put less stress on the bond.

These are typical values measured in a lab. A deep bead or dry air will be slower than the printed cure rate. See how long does sealant take to cure.

A standard on a TDS tells you what the product was tested against. "ASTM C920 Class 25" on 802 means it passed the American specification for elastomeric joint sealants at ±25% movement. ISO 11600 classifies sealants the same way, which is where FR's ±12.5% figure comes from.

Fire ratings need more than the TDS. Pereseal FR is rated up to 4 hours to BS 476 Part 20, backed by a Warrington Fire test report and a TÜV SÜD PSB certificate of conformity. For fire-stopping submissions, you need the test report, because it shows the exact construction that was tested. See fire-rated sealant systems.

Hazards, protective equipment, first aid, spills and disposal are on the safety data sheet (SDS), not the TDS. Read the SDS before you open the product, especially for acetoxy silicones in a small, closed room.