Celvaseal™ leak sealant is a compound specially engineered for sealing leaks in high vacuum systems. It can repair leaks as large as 2 micro liters/second, even with the system under vacuum. Larger leaks can be repaired when the vacuum system is at atmosphere. 

It is available in two forms: Spray (ozone safe) and fluid in a brush-on bottle. It has a low vapor pressure which makes it suitable for use in ultra high vacuum systems and withstands repeated temperature cycling from -200°C to 400°C. (-328°F to 752°F) Steady weight loss of 1.6 x 10-8 gr/cm2/hr, which is lower than most epoxy based systems. Can be used at temperatures up to 300°C (572°F) continuously, and up to 400°C (752°F) for short periods. It has good adhesion to cryogenic temperatures and excellent electrical resistivity. Can be stored longer than 1 yr at 25°C (77°F). Density is 1.14 gr/cm3 and viscosity is 250-1000 cPs.

Typical applications for Celvaseal™ include:

• Glass to metal seals, such as sensor pin feedthroughs
• Glass-Kovar joints
• UHV systems with small leaks on metal gaskets or high penetration welds
• Small leaks in glass vacuum systems
• Temporary repairs of small cracks in exposed gaskets
• Sealing hairline cracks in welds and brazed joints
• Thread sealant of fine pipe threads for mounting sensors and components to vacuum systems

Average curing temperature time:

• 400°C (752°F) 20-30 minutes
• 250°C (482°F) 60-70 minutes
• 230°C (446°F) 75-90 minutes
• Room temperature - Days