The document summarizes observations and suggestions from a visit to CSL's foundry facilities. It was found that testing procedures for green sand were incorrect and new standard procedures were suggested. Modifications were also suggested to improve melting, pouring, molding, patterns, tooling, and other processes. Key recommendations included using different sized tubes for different tests, improving treatment and pouring methods, converting hand ladles to tee-pot ladles, venting cope molds, avoiding water repairs, improving gating systems, and outsourcing pattern repair work.

1. Observations/Suggestions during my Visit to CSL on January 6th
through 9th
of 2015
SAND LAB: Observed the existing testing procedure of “Green Sand”.
Green sand (144gms) is filled in a specimen tube of 97mm height and 50mm inside diameter. Green
sand is rammed three times by the rammer and the sand specimen is used to test Compactability,
Permeability and GCS.
The above procedure is totally wrong.
Suggested / Standard Procedure: CSL has bought new sand testing equipment. Two specimen tubes of
100mm and 120mm heights are given along with the testing equipment.
100mm height tube should be used to test Compactability and 120mm tube should be used to test
Permeability and GCS.
Compactability: Fill the 100mm specimen tube with green sand and level it. Ram it with three blows of
standard rammer. Measure the Compactability
For Green Compression Strength and Permeability AFS Standard sand specimen of 5.08 cm (2 inches)
diameter and 5.08 cm in height is prepared by ramming the required quantity of sand (140gms) in a
smooth surface tube with three blows of standard rammer.
The weight of 140gms was standardized to achieve the sand specimen of 5.08 cm (2 inches) diameter
and 5.08 cm in height.
Note: The weight of 140gms will not be consistent all along as the specimen size depends on the AFS
and Granular size of sand. Therefore every day first sample of standard specimen is to be checked to
ensure the size. To achieve the standard specimen size the weight of sand to be adjusted.
To determine permeability the AFS Standard sand specimen of 5.08 cm (2 inches) diameter
and 5.08 cm in height is prepared by ramming the required quantity of sand in a smooth
surface tube with three blows of standard rammer. This sand specimen is placed in the
mercury cup of the permeability meter. The air drum is raised to take 2000 cm3 of air in to
the air drum which will be indicated by the graduation on it. The whole air is then allowed
to escape through the sand specimen.
Madhu/Vinay to get in touch with Versatile and call them for a demonstration of permeability as the
air drum when raised is not at “Zero”.
For green compression strength test, the AFS Standard sand specimen is prepared. The test
is performed on the sand specimen by using Universal sand strength machine.
Find below are the sand properties after correcting the procedures:

2. SAND TEST PARAMETERS(100mm tube for Compactability & 120mm
tube for Permeability & GCS, sand weight - 140gm)
Compactability
(%)
Cake
length
(mm)
Weight of
cake (gm)
Permeability
number
GCS
(g/cm2)
1 49 51 140 226 1040
2 50 50 139.9 212 1130
3 50 50 139.7 205 1200
Note: Procedures for sand testing are given to Madhu.
MELTING / POURING: Charge Mix is OK.
Tapping temperature 1580 to 1600 Deg Cent is on the higher side.
Magnesium of 2.5kgs for 900kgs metal is high. There is scope for reduction of Magnesium.
Magnesium requirement calculation is given to Madhu.
Also there is scope of reducing the Carbon & Silicon. Madhu to look into this.
Gray Fracture: Madhu / Yogesh showed me some micros and told me that they noticed Gray fracture in
middle of the pouring. First, third and fifth poured molds are found to be OK and second & fourth are
having Gray fracture.
Observed the treatment and pouring and noticed metal in the treatment ladle is not being poured into
hand ladles and transferred back to treatment ladle to make homogeneous mixture.
Explained to the team that the top metal will not be properly treated with magnesium and the mixture
will not be homogeneous.
Suggested to pour the metal to at least 2 hand ladles and transfer the metal back to the treatment ladle
to ensure homogeneity of the mixture.
Hand Ladle: There is plenty of scope for the slag to enter inside the mold as the top metal enters first

3. which will have lot of slag.
Suggested to have Tee-pot ladles. Madhu will make one Tee-pot ladle to conduct trials and
subsequently convert all the hand ladles to Tee-pot.
In fact the Tee-pot ladle was introduced in 1999/2000 by me at CSL. I am not sure why it was
discontinued.
In the hand molding area the top side of the cope mold is not vented and the parting of the cope and
drag is closed with clay which prevents gases escaping.
Two molds are made with top venting and leaving the cope and drag partition uncovered with clay and
showed the team the difference of gases burning between vented & uncovered with clay Vs Non-vented
& Covered with Clay. Pl refer to the above picture.
Suggested to vent the cope mold and avoid using clay at the partition.
MOLDING: Broken Molds are being repaired with water, especially hand mold items. After repairing the
mold is torched at the repair area.
Breakage of the mold is because of bad tooling and not because of improper stripping. Repairing of the
mold with water to be avoided.
Suggested to instruct the molder not to accept the tooling if it is bad.

4. PATTERN SHOP: Majority of the tooling is in a very bad shape. Improper gating system in majority of the
tooling. Manufacturing of the tooling is bad.
For example DFT2424 - The Flange thickness as per AWWA C110 Standard is 1.88” (47.7mm) whereas
the flange thickness in the tooling is maintained at 55.0mm. There are many patterns like that.
Without changing the gating system one sample of DFT2424 was made for which the results are yet to
come.
Detailed Gating System calculations were given to Madhu/Pattern shop supervisor. Also briefly
explained how to calculate the gating system.
DMK8/DMK6: Trials were made with new gating system (by removing the riser) and the yield has
increased by 10%. Further trials to be conducted before finalizing the gating system.
Tooling: Had a talk with Mr. Vinay in presence of Madhu and explained the condition of the tooling and
serious attention to be given. Vinay was kind enough to arrange the out sourcing pattern maker.
Had a detailed discussion with the pattern maker and explained the condition of the tooling and what to
be done. Madhu to send a set of tooling and drawings by Wednesday January 14th
2015 to start the
repairing work.