Plastics repair with ABS cement: Difference between revisions

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===Theory===

The theory behind the plastic repair is simple. A crack or a break in the ABS bodywork can be bonded back together by welding the plastic together. This can be done chemically, or by heat. Heat is used to make the primary bond, and then the surface imperfections are filled in with the ABS cement. This takes place in several steps.

The theory behind the plastic repair is simple. A crack or a break in the ABS bodywork can be bonded back together by welding the plastic together. This can be done chemically or by heat. Heat is used to make the primary bond, and then the surface imperfections are filled in with the ABS cement. This takes place in several steps.

The first figure shows the cross section of a break in the plastic. The top surface has a paint layer, and a relatively thick plastic layer.

The first figure shows the cross section of a break in the plastic. The top surface has a paint layer and a relatively thick plastic layer.

[[Image:theory01.gif]]

Start by sanding the paint off, to clear out the surface. This makes repainting REQUIRED. You can skip this step and only weld the break from the back. This makes a nice looking, but weaker, repair. If the paint gets into the ABS, it contaminates the bond, and you'll have to sand anyway.

Start by sanding the paint off, to clear out the surface. This makes repainting REQUIRED. You can skip this step and only weld the break from the back. This makes a nice-looking, but weaker, repair. If the paint gets into the ABS, it contaminates the bond, and you'll have to sand anyway.

[[Image:theory02.gif]]

A hot soldering iron melts together the two sides. Run the hot iron down the length of the fracture from the rear (unpainted side), with your finger on the painted side, moving gingerly up and down the surface. The idea is to keep the feeler fingertip from getting too hot. This is especially important if ~~one is~~ only welding one side. If your finger can't take the heat, neither can the paint. In this picture, both sides are welded.

A hot soldering iron melts together the two sides. Run the hot iron down the length of the fracture from the rear (unpainted side), with your finger on the painted side, moving gingerly up and down the surface. The idea is to keep the feeler fingertip from getting too hot. This is especially important if you are only welding one side. If your finger can't take the heat, neither can the paint. In this picture, both sides are welded.

[[Image:theory03.gif]]

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 ===Theory===
-The theory behind the plastic repair is simple. A crack or a break in the ABS bodywork can be bonded back together by welding the plastic together. This can be done chemically, or by heat. Heat is used to make the primary bond, and then the surface imperfections are filled in with the ABS cement. This takes place in several steps.
+The theory behind the plastic repair is simple. A crack or a break in the ABS bodywork can be bonded back together by welding the plastic together. This can be done chemically or by heat. Heat is used to make the primary bond, and then the surface imperfections are filled in with the ABS cement. This takes place in several steps.
-The first figure shows the cross section of a break in the plastic. The top surface has a paint layer, and a relatively thick plastic layer.
+The first figure shows the cross section of a break in the plastic. The top surface has a paint layer and a relatively thick plastic layer.
 [[Image:theory01.gif]]
-Start by sanding the paint off, to clear out the surface. This makes repainting REQUIRED. You can skip this step and only weld the break from the back. This makes a nice looking, but weaker, repair. If the paint gets into the ABS, it contaminates the bond, and you'll have to sand anyway.
+Start by sanding the paint off, to clear out the surface. This makes repainting REQUIRED. You can skip this step and only weld the break from the back. This makes a nice-looking, but weaker, repair. If the paint gets into the ABS, it contaminates the bond, and you'll have to sand anyway.
 [[Image:theory02.gif]]
-A hot soldering iron melts together the two sides. Run the hot iron down the length of the fracture from the rear (unpainted side), with your finger on the painted side, moving gingerly up and down the surface. The idea is to keep the feeler fingertip from getting too hot. This is especially important if one is only welding one side. If your finger can't take the heat, neither can the paint. In this picture, both sides are welded.
+A hot soldering iron melts together the two sides. Run the hot iron down the length of the fracture from the rear (unpainted side), with your finger on the painted side, moving gingerly up and down the surface. The idea is to keep the feeler fingertip from getting too hot. This is especially important if you are only welding one side. If your finger can't take the heat, neither can the paint. In this picture, both sides are welded.
 [[Image:theory03.gif]]