Condursal Stop Off Paints for the heat treating industry
Condursal Stop Off Paints for the heat treating industry

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Condursal Stop Off Paints for the heat treating industry

CONDURSAL 777 Instructions For Use:

CONDURSAL 777 II is a newly developed water base stop-off paint for all forms of gas carburizing andcarbonitriding up to temperatures of 950'C max. Based on the concept of CONDURSAL 666, it provides improved properties ip respect of minimised evaporation losses and residues in the carburlzing furnace even at high temperatures and I or in vacuum, CONDURSAL 777 II is easy to apply and provides excellent adherence to the steel surface. After heat treatment is completed, the residues of the paint can be easily removed by simply washing with hot water or alkaline. This is important for mass. production for example in the automotive and gear manufacturing industries.

Normally only one coating of CONDURSAL 777 II is necessary for effective protection against carbon pickUp up to case depths of 1,3 mm max.

Before applying, stir the contents of the CONDURSAL 777 II container well. As received, CONDURSAL 777 II is suitable for painting. Prior to applying the paste, the surfaces of the components must be cleaned thoroughly by either a vapor degreaser or a detergent washer, so that they are free of oil and grease.

Soak the brush thoroughly in CONDURSAL 777 II, then paint the areas to be protected as evenly as possible. If the steel surface can be seen through after coating, a second layer is recommended. Drying time between two coatings should be at least half an hour.

If Condursal 777 II is applied by dipping I Immersion excessive paint should be removed by from the bottom area by shaking in order to facilitate the drying process.

Spraying I Feeding
Use spraying pistols with a beaker on top, supplying the paint by gravity. Spray as evenly as possible to a thickness of approx. 0.2 to 0.3 mm (.006" to .010"). As mentioned above, normally only one coating is necessary for effective protection. .. Recommencjed pressure in the container is approx. 2 to 3 bar (29 to 43.5 psi ). Recommended diameter of the nozzles is 1.5 to 2.5 mm (.060" to .100"). If necessary for better sprayability, small amounts (less than 5%) of tap water can be added. Drying time which strongly depends on coating thickness, ambient and workpiece temperature, atmospheric humidity etc. can range from approx. 3 to 8 hours. For effective protection it is important to have the coating thoroughly dried before heat treatment is started. This can be checked by "fingernail test".

  1. The coated areas of the workpieces should not exceed 30% of the total surface of the load because otherwise the furnace atmosphere might be affected.
  2. The coated parts should be placed in the batch in such a manner that they cannot come into contact because otherwise insulation defects on the coated areas and undue insulation on noncoated areas might occur.

During use, with the container open, CONDURSAL 777 II has a tendency to thicken due to evaporation of the liquid vehicle in the paint. Normal consistency can be restored by adding small amounts of tap water. Be aware that overthinning will impair the effectiveness of the paint.

Removal of Residues after Heat Treatment
After carburizing and quenching, residues of CONDURSAL 777 II can be easily removed by just washing with hot water or alkaline.

Cleaning of Equipment
Immediately after use, CONDURSAL 777 II containers should be tightly resealed and the pistols, tubes etc. cleaned with water. If spraying is interrupted for any length of time, the pistols should be set in water to prevent drying. Deposits as well as contents of the can cannot be rejuvenated if the liquid vehicle of the paste becomes dry.

CONDURSAL 777 II should be stored in a dry cool place. Shelf life is approx. 12 months. CONDURSAL 777 II is based on water and must therefore be prevented from from freezing.

CONDURSAL 777 Trouble Shooting:

Paint runs off after applying by painting, spraying or immersion.
1. Paint has been stored at too high temperatures.
Store paint at ambient temperature.
2. Work pieces have not been de-greased thoroughly prior to coating.
Clean parts thoroughly by vapor degreasing or alkaline washing.
3. Paint has been thinned excessively.
Use paint as delivered after homogenizing the content of the bottle/bucket; add small amounts of water only if thickening has occurred.
4. Paint has been applied in too thick a coating.
Apply paint in a thin coating of uniform thickness; if necessary for deep cases, apply twice.

Paint pops off after drying.
1. Surfaces of work pieces were wet or greasy when paint was applied.
Clean parts thoroughly by vapor degreasing or alkaline washing and make sure that they are dry prior to coating.

Paint runs off in the carburizing furnace.
1. Paint has been applied in too thick layer/coating has not been allowed to dry thoroughly.
Apply paste in a thin coating of uniform thickness and let dry thoroughly.
2. The organic binder of the paint has burnt because parts have been preheated at temperatures of more than 390 degrees F. with oxygen present.
Limit preheating temperatures to 390 degrees F. max.
3. Coating has come into contact with oxygen in the carburizing furnace due to incorrect atmosphere regulation or cracking/leaking of the retort of the furnace.
Make sure by purging with nitrogen that even in the beginning of the carburizing process, furnace atmosphere does not contain oxygen/repair retort.

Residues of the paint are hard to remove after carburizing/ surface attack is noted.
1. Coated parts have been cooled down after carburizing and then reheated for quenching.
Remove residues of the paste after carburizing.
2. Paint has not been stirred thoroughly prior to use.
Stir paste thoroughly prior to use.

Protection against carbon pickup has been found to be non-uniform or non-satisfactory.
Paint has been applied in a too thin or non-uniform layer.
Apply paint in a layer of even thickness; if necessary for deeper cases, apply twice but keep in mind the first coat must be dry prior to application of a second one.