Description
Selleys Autofix Instant Gasket High Temperature Sealant is a red, 100% silicone gasket maker for engine and exhaust jobs where ordinary gasket sealants would give up, supplied here as a 100ml squeeze tube. It lets you form a custom gasket straight from the tube on almost any flange, and it is built to cope with intermittent heat spikes up to 343°C.
About the formula
An acetoxy (acetic cure) silicone that cures to a tough, flexible red rubber seal. It flows into uneven surfaces and small gaps between mating parts to make a high-pressure seal, and it is described by Selleys as sensor safe and suited to high torque and vibration use. Continuous service temperature is rated from -40°C to 260°C, with intermittent exposure up to 343°C.
Where to use it
Indoors: gaskets and flanges in dishwashers, refrigerators, oven doors, plumbing, and heating and air conditioning equipment.
Outdoors and under the bonnet: oil pans, valve covers, water pumps, exhaust manifolds, mufflers, tail pipes and exhaust pipe connectors.
Intended for metal flanges and similar mating parts in engines, exhausts and appliances. Check the part and the service conditions suit a silicone seal before you start.
How to use it
- Remove all old gasket material, then clean the surfaces with mineral turpentine and let them dry. If you do not want the gasket to adhere (for easier disassembly), wipe the mating surfaces with an oily cloth instead.
- Take off the cap, remove the foil seal, refit the nozzle and cut it at a 45° angle.
- Squeeze the tube with steady pressure to lay a bead about 1.5 to 3mm thick on one of the surfaces, running around the bolt holes.
- Join the parts within 10 minutes. Hand-tighten the bolts until sealant just starts to squeeze out, then leave for 30 minutes.
- Tighten the bolts to the required torque. If you need a thicker gasket, assemble the parts but leave the bolts loose for 24 hours.
- Allow 90 minutes before filling with liquid. The sealant fully cures in about 24 hours.
- Clean up uncured sealant with mineral turpentine. Cured sealant has to be cut and scraped away.
- Replace the cap after use. Let the sealant cure in the nozzle and pull it out before the next use.
Important notes
Apply in conditions between -20°C and 50°C. A skin forms in about 5 minutes, so work promptly and assemble within 10 minutes of applying the bead. Where a cork gasket is being replaced, make sure parts such as rocker covers still have enough clearance and do not fully tighten until the sealant has cured. If you need to separate the flanges later, pry them apart and clear off the old sealant before reassembling. Store below 30°C and use within 24 months of the production date.
Specifications
| Brand |
Selleys |
| Product |
Autofix Instant Gasket High Temperature Sealant |
| Size |
100ml tube |
| Colour |
Red |
| Base |
100% acetoxy silicone |
| Application |
Squeeze tube with cut nozzle |
| Skin time |
About 5 minutes |
| Set time |
About 30 minutes |
| Full cure |
About 24 hours |
| Service temperature |
-40°C to 260°C |
| Intermittent temperature |
Up to 343°C |
| Application temperature |
-20°C to 50°C |
| Density |
1.02 g/ml |
| Movement capability |
25% |
| Hardness (Shore A) |
18 or higher |
| Use |
Interior and exterior |
Safety
Avoid skin and eye contact, work in a well-ventilated area and wear suitable gloves and eye protection. Store in a cool, dry, well-ventilated place out of direct sunlight, away from foodstuffs and incompatible materials. Refer to the Safety Data Sheet (SDS) for full details.
