Difficult sealing challenges will often succumb to Vellumoid gasket material. Vellumoid is a sealing material with an impressive ability to conform to uneven surfaces. That makes it a good choice for sealing old or uneven flanges or similar difficult surfaces.
Unlike many of the elastomeric sealing materials so often used for gaskets, like neoprene, Buna-N or even silicone and Viton, Vellumoid isn’t a polymer. It’s a combination of cellulose fiber with protein glue and a glycerin binder. Essentially, it’s paper impregnated with glue and sugar solution. It’s an older form of gasket material that performs well in challenging applications.
Temperature Range: up to 350°
Thickness: 1/16” to 1/8”
Width: 48” rolls, vellumoid sheet cut to your specifications
In addition to excellent conformability, Vellumoid gasket material is particularly good for sealing against water, gasoline, anti freeze and lubricating oils. It’s notably resistant to mold, making it useful in wet locations, by virtue of the antimicrobial properties of glycerin. The upper temperature limit on the standard or “Branded Vellumoid” composition is 250 °F but there are other formulations with higher limits.
Higher temperature capability and increased overall performance is achieved by adding rubber and/or other materials to the mix. So for example, there’s Velbuna WG-5 which includes nitrile and has a temperature limit of 300 °F, and Vellutherm 600 which includes a special blend of elastomers and is described as “A nonasbestos beater addition material [for] temperatures up to 350 °F.”
Vellumoid gasket materials are available in thicknesses from 1/16” to 1/8”. Hennig Gasket & Seals can cut it to whatever size sheet you need.