Celvaseal® Leak Sealant

Celvaseal® leak sealant is compounded especially for sealing leaks in the high and ultra-high vacuum systems. It will repair leaks as large as 2 micron liters per second with the system under vacuum. This high vacuum sealant can also be used to repair larger leaks when the system is at atmosphere.


Celvaseal SealantCelvaseal® Advantages

– Seals vacuum leaks with just a spray
– Reformulated to contain no Class1 Ozone depleting materials
– Low vapor pressure sealant for use in ultra high vacuum
– Steady state weight loss of 1.6 x 10-8 grams/CM2/hr which is less than most epoxy molding compounds
– Withstands repeated temperature cycling, from -200º to 400º C
– Excellent electrical resistivity
– Good adhesion at cryogenic temperatures
– Reduces reflectivity of metals
– Storage stability at 25º C is greater than 1 year


Some typical uses for Celvaseal® for suspect leak areas

  • Glass tube sensor pin feed troughs. Occasionally the glass to metal seal becomes suspect due to movement of the pins when plugging on or changing the tube cable socket. Be sure to keep the sealant off of the electrical contact points.
  • Glass-Kovar joints sometimes start to leak in the Kovar due to crystallization.
    Some UHV systems with metal gaskets and/or high penetration welds “open up”. The sealant fluid carrier will draw into the suspect area and can be cured with the system conditioning schedule.
  • Glass systems where fusing of glass joints is not thoroughly annealed and “pin prick holes” have developed.
  • External exposed gasketed flanges where aging of gasket has caused small stress cracks. This would be a temporary fix until the gasket could be replaced.
  • Welded steel where crystallization of the weld has occurred and a small hairline crack appears. The surface tension of the fluid will flow into the crack by capillary action before it starts to cure.
  • Brazed connections of copper tubing to brass valve housings.
  • Apply to pipe threads for mounting of sensors and other components to vacuum system.

Celvaseal® may be used at temperatures up to 300ºC continuously, and up to 400ºC for short periods.

Average Curing Temperature Schedule

400ºC – 20-30 minutes
250ºC – 60-70 minutes
230ºC – 75-90 minutes
Room Temperature – Days

Celvaseal® 2 oz. Bottle Brush-On: Part Number 271375
Click here to download MSDS/SDS in PDF Format 

Celvaseal® 6 oz. Aerosol Spray Can: Part Number 271373-6
Storage stability at 25º C one year
Click here to download MSDS/SDS in PDF Format 

Celvaseal® is a registered trademark of Myers Vacuum Repair Services Inc., Kittanning, PA. 16201.

The information contained here is believed to be accurate and reliable, however it is the responsibility of the user to determine the suitability of use.

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