Physical/Chemical Characteristics of Microseal in Alphabetical Order :

  • Boiling Point : 180 degrees F (82 degrees C)
  • Chemical Composition: Microseal’s composition is based on bakelite-type resins. Ketone-type solvents are used.
  • Chemical Resistance (of hardened Microseal): within normal temperature ranges the seal resists:1) water, hot water and most aqueous solutions; 2) weak and strong acids, including aqua regia and hydrofluoric acid; 3) weak and strong alkalies; 4) alcohols; 5) greases, mineral oils, animal oils vegetable oils; 6) many organic solvents, such as petroleum naphtas; 7) most inorganic materials.
  • Consumption Range*: 500-2000 square feet per gallon, depending on roughness of surface.
  • Durability(of hardened seal): The effectiveness of the hardened seal does not deteriorate with time.
  • Elasticity: the modulus of elasticity of Microseal is considerably lower than that of any metal or in other words the allowable bend before breaking is greater for Microseal than for metal.
  • Evaporation Rate*:5.7 (Butyl Acetate = 1).
  • Flashpoint*: 23 degrees F Tag closed cup.
  • Hardening*: At room temperature ideally three days. However, usually one day is enough. Hardening can be speeded by air-drying for at least one hour and then heating at 150 degrees F for one hour.
  • Penetration*: Microseal has an unusual penetrating power. Interconnected pores are penetrated all the way to any depth. Penetration is practically instantaneous if the pores are clean. When pores are contaminated, Microseal has to dissolve the contaminant first, which takes more time.
  • Pore Size Sealable: The size of opening that can be expected to be sealed by Microseal depends upon the geometry of the pore and the wall thickness. Generally, the pore size can go up to about 1/4 mm (0.01 inch).
  • Temperature Resistance: We do not recommend prolonged exposure of the hardened Microseal to temperatures above 350 degrees F. There is no low temperature limit.
  • Vapor Pressure*: at 20 degrees C 70mm Hg.
  • Viscosity*: Saybolt Universal 45.8 sec at 100 degrees F.

* Applies to Microseal before hardening.

Miniseal is a nonflammable alkaline liquid. Like with most chemicals, protect eyes and avoid prolonged or repeated contact with skin or breathing of mists. In case of contact with the eye, immediately and repeatedly flush with water, then see a physician.

  • Physical/Chemical Characteristics of Miniseal in Alphabetical Order:
  • Boiling Point: 212 deg F (100 deg C)
  • Chemical Composition: Miniseal is an aqueous solution of sodium salt of silicic acid and a penetrating agent (inorganic materials).
  • Chemical Resistance (of hardened Miniseal): After air drying, Miniseal resists all organic materials, including gasoline and other fuels. Improved water resistance can be obtained by air drying for one day and then gradually heating to 180-200 deg F (hold at this temperature for two hours) and then heating slowly to 300-400 deg F (holding at this temperature for one hour).
  • Consumption Range*: 500-2,000 square feet per gallon (depending on the roughness of the surface).
  • Durability (of the hardened seal): The effectiveness of the hardened seal does not deteriorate with time. If a not quite hardened seal is exposed to sudden higher temperatures, drying time may not be gradual enough and therefore, sudden water loss may result in shrinking of the seal, which makes a second treatment necessary.
  • Evaporation Rate*: Like water
  • Hardening: At room temperature ideally three days. Enclosed areas may even take longer; but, ordinarily, one day may be enough. Faster hardening can be made possible by air-drying at least one day, followed by heating at 180-200 deg F.
  • pH: Rather constant. 11.3 (buffering capacity)
  • Penetration*: Interconnected pores are penetrated all the way to any
    depth. Penetration takes only about five minutes if the pores are clean.
  • Pore Size Sealable: The size of opening that can be expected to be sealed by Miniseal depends upon the geometry of the pore and the wall thickness. Generally, the maximum pore size sealable is 1/4 mm. (.01 inch) in diameter.
  • Temperature Resistance: We do not recommend prolonged exposures of hardened Miniseal to temperatures above 1000 deg F. There is no low temperature limit. Fluid Miniseal will freeze and requires thorough stirring before use once it is thawed. (Coming from up-state New York, it is safe to assume that Miniseal has been frozen at some time and therefore, always needs shaking and stirring before use.)
  • Viscosity*: Centipoise 6 at 20 deg C.

* Applies to Miniseal before hardening.

Properties of hardened Miniseal:

  • On castings which have to be electroplated, anodized or painted the nonmetallic film left by Miniseal has to be removed mechanically.
  • Therefore, sealing after electroplating, anodizing or painting is preferred.
  • Hardened Miniseal is nontoxic and odorless and can be used in contact with food (FDA Approved).
  • Pressure resistance depends on many factors such as wall thickness and size of pores, etc., therefore it is not possible to give an exact figure.
  • Temperature resistance also depends on many factors. The maximum temperature resistance is 1000 degrees F.
  • After air drying, Miniseal resists all organic materials including gasoline and other fuels.
  • Unless it is baked after air-drying, Miniseal’s resistance to water is not as that of Microseal-AC or Microseal-MEK.

Chemical Resistance of Microseal

In General:

Within normal temperature ranges (below 350 degrees F) hardened Microseal resists:

  1. Water, hot water, steam and most aqueous solutions
  2. Weak and strong acids including aqua regia and hydrofluoric acid.
  3. Weak and strong alkalies
  4. Alcohols
  5. Greases, mineral oils, animal oils and vegetable oils.
  6. Many organic solvents, such as petroleum naphtas.
  7. Most inorganic materials.

Resistance of Microseal Sealant To Some Common Chemicals:

R = Resists; D = Dissolves; S = Swells

Acetic Acid, Conc. R 
Acetone D
Alcohols R 
Ammonia 50% R
Ammonium Hydroxide R 
Aqua Regia R
Benzene R 
Carbon Tetracloride R 
Caustic Soda 70% R 
Chromic Acid R 
Diesel Oil R 
Ethanol (Ethylalcohol)95% R 
Ethylene Glycol R
Formic Acid, Conc. R 
Freon R 
Glycol R 
Hydrocloric Acid Conc. R 
Hydrogen Peroxide R
Isopropyl Alcohol R 
Lactic Acid, Conc. R
Machine Oil R 

Methanol(Methyl Alcohol, Carbinol, Wood Alc) R 
Methyl Chloride R 
Methyl Ethyl Ketone D 
Nitric Acid, Conc. R 
Paraffin Oil R 
Phenol Solution 10% R 
Phosphoric Acid, Conc. R 
Potassium Cyanide R 
Potassium Hydroxide R 
Saline Solution 10% R 
Seawater R 
Sodium Hydroxide 40% (soap, lye) R 
Sulfuric Acid, Conc. R 
Xylene D, S
2-Propanol (Isopropyl Alcohol) R

Hardened Microseal is not resistant to:

1. Ketones
2. Aromatic Hydrocarbons (Toluene, Xylene)
3. Esters

Comparison – Microseal vs. Miniseal

As compared to Microseal the advantages of Miniseal are:

  1. Higher allowable temperature (1000 degrees F vs. 350 degrees F)
  2. Resistance to all organic materials, including those to which Microseal has limited resistance (ketones).

Disadvantages of Miniseal are:

  1. Slower drying time.
  2. Unlike Microseal it interferes with paint adhesion.
  3. Unless it is specially treated (baked) its resistance to prolonged contact with water and steam is not as perfect as Microseal-AC or Microseal-MEK.

The method of application is the same for both products.


Our sealants are used because of the following reasons:

  • Easy application
  • Saves time
  • Saves money
  • It’s an uncomplicated, one-step solution
  • Does not require expensive equipment
  • It can be applied in-house, so it saves shipping pieces back and forth
  • They seal all metals and also ceramics
  • Once set, the seal lasts practically indefinitely
  • Once set, the seal resists heat (to 350 deg F and 1000 deg F) depending on sealant
  • Once set, the seal resists most chemicals
  • Economic in use because a little sealant goes a long way

The information contained herein is based on data obtained by research or from information furnished by users. The information is considered to be accurate, but no warranty is expressed or implied regarding the accuracy of these data or the results to be obtained from the use thereof. This information is furnished upon the condition that the person receiving Microseal, Modified Microseals, and/or Miniseal shall make his own tests to determine the suitability thereof for his/her particular purpose.