Types of Marking Media, Uses, Marking Methods

Hello friends, Today I am going to discuss about marking media in which we will know that what is marking media and how many types of marking media.

Marking media is especially used for marking or layout of guide lines before machining or cutting by hand tools in a machine party and also in fitting operations.

Machining operation mostly done by lathe machine, shaper machine, milling machine, planer machine etc. Which are produces flat surfaces.

The main purposes of using marking media is that ensuring the correct amount of metal is cut from different places to form the correct shape.

Metal cutting is done by cutting tools like drilling bits, milling cutter, grinder etc.

If we talk about the types of marking media, Prussian blue, layout dye, copper sulfate, white wash are some of the commonly used marking media which will know further in details.

So, without wasting of time let's begin to know types of marking media and it's uses.


What is Marking Media?

Marking media, as metal is a hard material, so the drawn lines are not clearly visible hence marking media is used.

In this way, the marking media is a material that is applied on the surface on which marking has to be done by marking tools so that the lines of marking can be seen clearly. 


Types of Marking Media

Marking media can be divided into four categories

  • White Wash
  • Prussian Blue
  • Copper Sulphate
  • Cellulose Lacquer

Types of marking media
Types of Marking Media


White Wash

White wash is  a mixture of chalk and water  which is used on rough structures such as castings or forgings.

It is also made by mixing white glass powder with turpentine oil.

White wash is generally used for marking on ferrous material.

The main advantage of this marking media is  If a any type of mistake is made it can be easily erased .

However, its major disadvantage is that it will be erased or washed away due to water,  So it is used where temporary lines are required.

White wash also used in chalk string line, A chalk string line is a tool filled with chalk, as soon as it is pulled from the container, it coats the string with chalk dust. It is used for marking large jobs.

To use it, pull the required length of a lanyard from its container and it is ready to use.  Ask an assistant to hold one end on the required marking position and pull it tightly over the marking position.  Then with your other hand lift the thread straight up and release.  A straight chalk dust line from the chord will transfer to the job.  It is used to make a long line for marking.

 

Prussian Blue

Prussian blue is a color used for marking on machining surfaces.

It is used to paint on a piece of metal with a very thin layer of dye that can be scratched by a scriber or a sharp instrument to make it appear shiny. 

However, under this color, a very narrow line is formed on the metal.  The advantage of this is that the dye covers the existing scratches and there is a back grid showing the variation in the new lines.

Apart from this, the drawn lines are clearly visible. 

Its main disadvantage is that it taking long time for drying and also may be erased during working.

 

Copper Sulphate

Copper Sulphate is a mixture of distilled water and A few drops of nitric acid or sulphuric acid solution is used.

This thin copper coating greatly resists the action of rough handling and cutting fluid or coolant.

It is widely used in refined surfaces because it sticks very well on finished surfaces.

Copper Sulphate is also known as blue vitriol because when it mixed with nitric or sulphuric acid a blue colour solution is found.

This type of marking media is used where to required a very accurate marking.

 

Cellulose Lacquer

Cellulose lacquer is found in many colors in the market and is the best marking media. This marking media dries up very quickly and always used in refined surfaces.

It is also called layout die.

 

Methods of Marking 

The following methods are often used for marking

1. Datum Line Method

2. Center Line Method

3. Marking by Template

4. Marking of Center on Round Rod End


1. Datum Line Method

In this method, first a base line is applied which is called a datum line and all further lines are preceded by the preceding line. 

This method is used where the attached arms of the job are finished in right angles.


 2. Center Line Method

This method of marking is used on odd-shaped jobs.  Firstly, a center line is drawn and other joint lines of marking are attached with reference to this center line. 

 

3. Marking by Template

In this method, a template is used for marking which is made of a thin metal sheet in proportion to the size.

Identical sized jobs are done by this method of marking.

 

4. Marking of Center on Round Rod End

There are following methods are used during marking of  center on round rod end

(A) By Jenny Caliper

(B) By Surface Gauge or Vernier Height Gauge

(C) By Center Head of the Combination Set

 

(A) By Jenny Caliper 

Open a little more or less than the radius of a round job and rotate from different four places and then center find out.

 

(B) By Surface Gauge or Vernier Height Gauge

Place the job on the V-block and Square the surface gauge or Vernier height gauge by drawing lines from the four different positions of the job.  Put the hypotenuse lines, that means join opposite corners of the square. Set the cutting location of these lines, slightly more or less than the center.

The intersection of these  lines is the center of the end of the round rod.

 

(C) By Center Head of the Combination Set

Put the center head on the job and draw a line.  Rotate the center head and put the second line in the right angle of the first line.

The intersection of these two lines is the center of the end of the round rod.

 

Hints to Be Noted While Marking

1. Carefully study the drawing of the workpiece. 

2. Determine the datum surfaces from which all marks are to be marked. 

3. Calculate all the dimensions and allowances of the workpiece.

4. Check the correct use of marking media on the surface of the workpiece.

5. First put straight horizontal, vertical and slant lines and then apply lines of circles, arcs, rounding etc. 

6. After the marking is complete, clean the job and the tools used.

 

FAQ Related to Types of Marking Media

People have many questions regarding types of marking media, so here we will  know step by step all questions answered.


Q 1. Which marking media is poisonous?

Ans. Copper Sulphate is a poisonous marking media because it's mix with nitric or sulphuric acid which are poisonous.

 

Q 2. Which marking media is used for casting and forging surfaces?

Ans. Generally white wash marking media is used for casting and forging surfaces.

 

Q 3. Which marking media provide clear line on machine finished surfaces?

Ans. Prussian blue media provide clear line on machine finished surfaces.

However, its main disadvantage is that it may be erased during working.

 

Q 4. Which marking media is used on the rough surfaces?

Ans. White wash marking media is used on the rough surfaces because it sticks easily.

 

Q 5. Which type of marking media found in different colour and also dry very quickly?

Ans. Cellulose lacquer type of marking media found in different colour and also dry very quickly.


So friends, I hope you all know the types of marking meadia and its uses very well.

If you have any doubt then you can ask me through comment.


Thank You

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