Basic
Skills for Metal Riveting
written & edited by: Umesh Kumar
Meher updated: 26.08.12
A rivet gun is a very useful tool
that fastens metal parts with rivets. Working with a rivet gun can increase
productivity without degrading the quality of the finished product. There is
more to the operation of a rivet gun is more than just learning the triggering
mechanism.
·
A rivet gun is a special type of
tool that is used to drive rivets into metallic objects to bind them. This tool
is also known as a pneumatic hammer because it is a pneumatically powered tool,
i.e., it uses pressurized gas to drive the force. When a rivet is used to
fasten metal pieces, the gun produces the head of the rivet while a bucking bar
is used to tighten tail. Rivet guns that are used for fastening steel parts are
quite large while those used in aircraft assembling are comparatively small.
They differ from air hammers only by the level of driving force; the underlying
concept used in both the tools is same.
·
How the
Rivet Gun Works
There are various sizes and shapes
of rivet guns with different handles and grips. The basic parts of a rivet gun
are the regulator, throttle valve, trigger, piston, and rivet set. The
regulator is used for adjusting the amount of air entering the tool. The air,
controlled by regulator, passes through the throttle valve. A trigger present
in the handgrip controls this throttle valve. When the trigger is pressed, the
throttle valve opens immediately. The controlled air flows into the piston
through the opened valve. The piston starts moving due to this pressurized air
and opens a port from where air starts to escape. The moving piston strikes the
rivet set on the tip of the rivet gun. This force is responsible for pushing
the rivet towards the work piece against the buck. The buck then deforms the
tail of the rivet fastening it in place. A spring then returns the piston to
its original position.
·
Equipment
Required
o
Scrap piece of wood
o
Safety glasses
o
Air tool oil
o
Drill
o
Compressor
·
Riveting
Preparing Rivet Gun for the
Operation
Lubricating the inside of the rivet
gun is very important. Follow this procedure to lubricate all of the moving
parts of the gun.
o
Turn on the air compressor.
o
Air fittings are located on the
rivet gun, find them and add air tool oil to them.
o
Attach the air line to the air
fittings of the rivet gun.
o
Press the trigger so that the
O-rings present in the rivet gun are also lubricated.
Prepare the Work Pieces
Next, prepare the work pieces that
need to be fastened.
o
Decide on the type of joint you will
use. If you want to apply a lap joint then place one part over another, for a
butt joint butt the parts using other metal pieces over them on both sides.
o
Place the combined work pieces on
the table with a piece of wood beneath of them.
o
You will need to drill holes in the
metal pieces. Secure the desired size drill bit into the drill motor and drill
the required number of holes through the metal pieces. Drilling of the holes
should be done after selecting style of the riveting (for example straight or
zigzag style).
Set the Rivets into the Holes
o
Insert rivets into the holes you
drilled.
o
Precision setting of the rivet gun
is very important in this process. You have to position it onto the metal
pieces at a 90 degree angle so that maximum pressure can be applied to the
metal pieces and there is no slippage.
o
Depress the trigger when the head of
the rivet rests flush on the surface of the metal piece.
o
Check the back side of the rivet to
assure that the back side is tightened accurately.
·
Precautions
When Using Rivet Gun
o
The rivet gun should be lightly
oiled every day before use.
o
Do not press the trigger of the
rivet gun without a set secured by a retained spring.
o
When the rivet gun is not being used
disconnect it from the air source.
o
Disconnect the gun for routine
maintenance or when sets are being changed.
o
Always wear safety glasses when
operating the rivet gun.
·
Summary
The operation of a rivet gun
requires a skill set that includes more than just operational knowledge.
Maintenance of the gun and all of its moving parts is an essential component to
ensuring a clean, flush rivet. Proper placement of rivets involves predrilling
seat holes for the rivets and securing a buck to the back to give resistance to
the pneumatic thrust. This resistance creates the pleat in the back of the
rivet that secures it in place. Not following safety precautions or failing to
assure a precise alignment of the rivet gun head to the rivet can result in a
poorly secured joint or, in the worst case, a sever injury to the gun operator.
·
References
Notes On Riveting." Van's
Aircraft RV Builder Forums and News. ¯¯VAF¯¯. Web. 12 July 2011. http://www.vansairforce.net/articles/NotesOnRiveting/NotesOnRiveting.htm
"How to Operate a Rivet Gun |
Overstock.com." Overstock.com: Online Shopping - Bedding, Furniture,
Electronics, Jewelry, Clothing & More. Web. 12 July 2011. http://www.overstock.com/guides/How-to-Operate-a-Rivet-Gun
"Rivetting in Aircraft
Industry." OoCities - Geocities Archive / Geocities Mirror. Web. 12 July
2011. http://www.oocities.org/venkatej/aeronautical/rivet/rivet.htm
Instructions
ReplyDeleteo 1
Choose a rivet that's made of the same material as the items you are going to fasten. For example, if you are fastening two steel plates together, use a steel rivet. Try to find a rivet that's made from the same alloy, if possible. If you are choosing a rivet for use with a soft aluminum object, choose a similar alloy for your rivet, such as a #1100 aluminum.
o 2
Select the correct length for your rivet. According to The Sheet Metal Handbook, the length of a rivet is measured from the underside of the head to the tip of the stem. The head itself is not included in this measurement. The length of the rivet should be equal to the thickness of both objects you are fastening, plus 1.5 times the diameter of the rivet's stem. For example, a 1/2-inch diameter rivet being used to fasten two one-inch thick plates will have to be 2 3/4 inches long.
o 3
Compare blind versus solid rivets. Solid rivets are the most common, and require two people to install them. One installer stands on one side of the objects and the other installer stands on the opposite side. When only one side of the object is accessible, a single installer can use a blind rivet instead of a solid one.
o 4
Evaluate corrosion-resistance. If the rivet will be subject to moisture or chemicals, use a material that will resist rusting and corrosion. Both stainless and galvanized steel are known for their corrosion-resistance, while steel is highly subject to rust.
o 5
Consider the diameter of the rivet. Rivets must be fit exactly to the hole they are being installed in. Because these holes are typically pre-drilled, it's important to find a rivet that's the same diameter as this hole. A rivet that's too large won't fit, while one that's too small will not fasten securely.
o 6
Think about the different head designs that are available. Snap or pan heads project out from the surface of an object after they are installed. Countersunk heads will sit flush with the surface of the object, and should always be used when drag or wind resistance are a concern.
o 7
Consider using self-piercing rivets (SPR). While most rivets require holes to be pre-drilled, SPR can be installed in a single step. This can save time on larger jobs, and can reduce the number of tools needed to complete the project.