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Isopac is a ready to use refractory paste composed
of specially compounded materials that give it the consistency of putty-making it easy to apply and remove. It will neither
crack nor shrink in temperatures up to 2000 F. Isopac will improve your heat treat operations - by saving time and material.
When
dies have holes drilled near the edge or close to a thin section, many times cracks will occur in this area during severe
water quenching operations - and the part is either scrapped or subjected to expensive repairs.
The application of
Isopac before heat treatment prevents decarburization and eliminates cracked dies. To prevent cracks in dies, simply apply
Isopac as follows:
1. Be sure the part is thoroughly clean.
2. Slip looped end of a tag wire fully in the die
hole.
3. Pack in on top of the wire 1/2" or more of steel wool.
4. Then fill up the hole with at least 1/2" of Isopac.
Be sure to pack in tightly and proceed to heat treat.
5. After the entire heat treatment or after quenching, draw wire
out of hole to aid in removing the Isopac and steel wool packing.
NOTE: Follow this same procedure to prevent cracking
in thin wall sections or any parts with holes near the edge (gears, axles with lubricating holes, etc.)
Isopac is the
IDEAL STOP-OFF PASTE
When properly applied, Isopac effectively prevents the penetration of carbon and loss of carbon.
It slows the cooling of protected sections in the quench so that no change or hardness is obtained even if the part is of
high carbon steel (except self-hardening alloys). The protective layer of Isopac also prevents scaling and corrosion.
For
best results, follow these general instructions:
1. Clean part thoroughly.
2. Cover the areas to be protected
with a layer of Isopac approximately 1/2" thick, making sure the paste is pressed on tightly, to be certain there are no air
pockets between the paste and the metal surface.
3. ONLY after the part has been heat treated and quenched is the Isopac
to be removed. The coating is now brittle and is quickly removed by knocking it off or be wire brushing.
Caution:
The area covered by Isopac may still be hot even though the rest of the part is cooled off.
Isopac is equally effective
in a gas or a box furnace or when the parts are packed in a carburizing compound. It is also used with induction hardening
and other methods on all types of steel except self-hardening alloys. It is not recommended for use in a salt bath.
For
uniform quality results it is important to keep the quenchant, oil or water, free from contaminants. Since Isopac after heat
treatment will not dissolve in either oil or water, the quenchant medium remains clean.
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