Hello friends, Today I am going to discuss marking
media in which we will know what is marking media and how many types of marking media.
Marking media is especially used for marking or layout of guidelines before machining or cutting by hand tools in a machine part and also in fitting operations.
The main purpose of using marking media is that ensure 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 detail.
So, without wasting time let's begin to know types of marking media and their 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
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| 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 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 is also used in chalk string lines, 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 takes a 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 is mixed with nitric or sulphuric acid a blue color 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 is always
used on 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 baseline 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 at 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.
Identically sized jobs are done by this method of marking.
4. Marking of Center on Round Rod End
There are following methods are used during the marking of the center on the 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, which means joining 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 at 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 media and their uses very well.
If you have any doubt then you can ask me through a comment.
Thank You
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