Several Subjects relating to Microseal (alphabetical)

Coloring Sealant:

Microseal is a clear liquid material. Its composition is based on bakelite-type resins which have been dissolved in ketone-type solvents.

Anyone wishing for color should use organic dyes, preferably non-alkaline, that are soluble in ketones. Dyes are available in all colors of the rainbow, but we doubt that they come in white.

For white, you may have to use a pigment. Antimony oxide is advisable in that case.

Dyes are easier to use because they dissolve in the ketones. Pigments always stay as particles in the liquid requiring frequent stirring and shaking.

Some suppliers of dyes and pigments:
CLARIANT Corp., Pigments & Additives:
BASF Coatings, Paints and Coatings:

Dripmark Prevention :

Because Microseal is a thin liquid, it is not likely to cause drip marks. However, when drip marks do show, this can be prevented by pulling casting slowly from the sealant.

If drip marks are discovered afterwards while the castings are still wet, then they can be removed manually with a cloth which has been dampened in a ketone (for instance acetone or methyl ethyl ketone).

Microseal used as a glue :

If you intend to use Microseal as a glue for metals rather than as a sealant, we recommend you use Microseal-DS or Double Strength Microseal.

One should bear in mind that adhesive properties in general are influenced by temperature. Thus, if the Microseal-DS had been stored in a cold storage place, it would not start working properly as an adhesive until it reached room temperature.

Opaque or White Color of parts treated with Microseal

Normally pieces treated with Microseal will have a clear film on the surface. This film may, however, turn opaque because of high humidity or of too fast drying. This can be prevented by drying in a closed container, which slows down the drying process and lowers humidity.

Once you have an opaque film, it can me made invisible by wetting the surface slightly with Methyl Isobutyl Ketone (MIBK), for MIBK evaporates slowly.

Microseal contaminated by water may also produce a white precipitation which may be apparent on your pieces. MEK and water are miscible up to 11-12% water. After that, the water does not mix up any further but will tend to be at the bottom of the tank.

In case of just MEK contaminated with water, one can separate the MEK and water with a molecular sieve. The MEK will go through while the water stays behind. However, this will probably not work with Microseal   because of the solids in the solution.

Molecular sieves are produced by Union Carbide.

Painting over castings that have been sealed with Microseal

Minimum time recommended between spraying (or other application) of Microseal and spraying paint is one hour.

There is no particular concern about the solvents in the paint (if similar to those of Microseal) weakening the seal again, as contact is short and drying will start immediately after spray-painting again.*

Adhesion of paints to the dried Microseal is generally good. Especially recommended are textured vinyl paints, acrylic paints and methacrylic ester systems.

* We understand that epoxy paints generally have ketone-type solvents in them also.

Sealing with Microseal on castings that have previously been painted.

This can only be done if the paint used is not soluble in ketones. Ketones are the solvents used in Microseal. Similar solvents, both in the sealant and in the paint, will affect the appearance if sealing is done last.

Redipping in Microseal

Give as much time as feasible between the first and second dip, but at least one hour. The second dip should be as short as possible in order to prevent dissolving of the first deposit.

The longer the first application has had time to set up, the longer it will take to dissolve, so give it more time in between (preferably the full three days).

Removing Hardened Microseal

Hardened Microseal can be weakened by exposure to temperatures above 350 degrees F.

The solvent used in Microseal is methyl ethyl ketone. Soaking in this solvent and some scrubbing should remove the material. Any kind of ketone (acetone, methyl isobutyl ketone) can be used instead.


The modulus of Microseal and Miniseal is considerably lower* than the modulus of any metal. so vibration should not present a problem. In other words, Microseal as well as Miniseal have more give than metals.

* the smaller the modulus the bigger the allowable bend.


Microseal’s flammability is comparable to that of flammable paint thinners. Keep away from heat or open flames. Use with adequate ventilation and avoid prolonged breathing of vapors or repeated contact with skin. Protect eyes with a face shield or safety glasses, protect hands with neoprene gloves. Have adequate ventilation.

Pointers on safe handling of Microseal

  1. Do not smoke while using Microseal or in close range of it.
  2. Do not use Microseal close to an open fire. Microseal’s flammability is comparable to that of paint thinners.
  3. Have proper ventilation in the area where you use Microseal (an exhaust).
  4. If one uses Microseal regularly (for instance, a couple of hours daily), then it is advisable to wear a mask. Some very sensitive people may prefer a mask even with occasional use. (See respiratory protection – safety equipment below.)
  5. Like with all chemicals it is important to protect the eyes against accidental splattering. Wear glasses, goggles or a full face piece. Immediately rinse the eye with water for at least 10 minutes in case of splattering.
  6. Splattering on the skin can be washed away with water. Of course, regular skin contact would result in a dry skin.
  7. If swallowed accidentally, force vomiting and call physician. The solvent used in Microseal is Methyl ethyl ketone.

Respiratory Protection – Safety Equipment.

For respiratory protection, use a full face piece respirator with organic vapor cartridges. The full face piece gives a better fit and also protects the eyes that need protection anyway.

Please remember the following:

Have the proper fit (facial hair may interfere with a good fit). Masks come in small, medium and large.
Change cartridges regularly.
When done with it, put the respirator in a large zip lock-type bag to prevent unnecessary contamination of the filter.
Face masks should be personal and it’s good practice to have them marked with the users name and have him/her responsible for its proper maintenance.
It deserves remembering that filters eliminate most of the air contaminant. A residual slight smell does not necessarily mean that the exposure limits are exceeded.