One of the methods I use for restoring dented plastic bumper bars is leave the bar on the car, and make a dent tool to suit for plastic dent.
Please note, some dents can be repaired on the car, and other dents or damage on or in a plastic bar may require you to remove the plastic cover, due to limited access or excess damage, or you are just repairing the bar to paint it at the same time ,
In this Kia situation, 1 screw /clip had been torn out allowing me to be able key hole dent restore this plastic bumper bar, (mostly from inside and behind the dent, ) please note, you can restore a lot of plastic bumper dents, using this easy and quick method, but with more serious damage, you might need to remove the bar, depending on the type of bar, type of car and type and extent of the damage,
1026 before picture.
Above picture, red arrows shows most of the paint has fallen off, and a milky colour indicating server creasing and stretching damage to the plastic at a molecular level, the red orange colour is the reflection from a orange safety cone,
1325,
Top view shows the size of the dent, pretty deep ,
1324,
Above picture shows large dent in the side of the plastic painted bumper bar, Early Kia people mover., the paint is falling off most of the bumper,
Please note, the dent was caused in a collision with another car of the same colour, plastic to plastic only, no gouging or scraping,
Two blue arrows shows the main 2 dents I will heat and massage with little pressure from behind, first,
Red arrows show the outside of the dent with the front crease line at almost right angles, ( some white milky stress line showing to my eye, but not so much seen in this picture, ),
Green arrow on right shows plastic clip with metal screw has been ripped out of the guard and is misaligned, new guys please note, a point to remember is if plastic clip has been ripped out of the HOLE in a metal guard as above, the hole in the metal guard is likely to be opened up or deformed, please note, the metal hole in the guard should be repaired before reassembly, or the plastic clip will not tighten up, just spin,
1326,
Left red arrow shows a length of flat bar bent around to form a quick handle shape, so I can rest my knee and apply pressure on the dent tool ,
( please note this type of dent tool is just quickly bent flat bar, to suit the position of the dent, and still maintaining best points of leverage, ect,)
So the dent tools I refer to in this method are just quickly hand bent dent tools of flat bar, please note I often change or bend the dent tool flat bar to suit a different dent positions, and pre - angle the tool head to suit the angle of the rear of the plastic bumper, while still maintaining the same pivot points on the wheel,
Small yellow arrow shows and please note the length of flat bar between the handle and pivot point bend against the tyre, (the edge of the front tyre is a great adjustable pivot point, just turn the steering wheel to place the tyre in correct position.)
Longer yellow arrow shows flat bar then extends up in between the inner and outer guard up to and behind the yellow circle area, from the pivot point on the tyre.
( white arrow shows point between main dent, and pivot point on tyre, I find using a measuring tape gets the length of the tool very close to right, most of the time, so I measure up the outside dent to the tyre, then measure the dent to handle, and a length for a suitable handle, then mark it on the bar, then bend it into a tool., )
The head is positioned approximately behind the dent and pressure is applied by my knee, ( please note, the flat bar is a bit flexible under my knee, and usually flexes too much to bend cold plastic,at this point.
Two red arrows on left show the nozzle tip of a hot air gun, which is set at high, to simulate me or,
Anyone using a good hot air / hair dryer, with no temperature control at all. Just pretty hot,
New guys please note, If I were to use my variable temperature heat gun at a much lower temperature, actually set well below plastic melting temps, the whole job would take a lot longer to warm up, but the plastic could not over heat and burnt or melt,
Blue arrow shows distance between gun and plastic, and directed at the deepest part of the dent, (yellow circle), this is warming up or keeping the whole area warm,
I will keep heating the plastic, (around the yellow ring area, )until the plastic is hot enough to feel soft under the slight pressure used by either 1 handed, or one knee leverage pivoted off the tyre or 2 handed free hand ( without leverage ),, the focus is waiting to see a slightly bulging impression of the dent tool protruding out ( and from behind ) small areas of soft warm/hot plastic,
I apply pressure from behind the plastic bumper., then the tool can be slid a few inches across and on the side or against the tyre, back and forth, still maintaining some pressure, resulting in small areas of plastic being massaged back into shape, , from behind, then I moved a few inches forward to the dent crease just in front of the first one, and most of %60-70 of the dent popped out, at which point I re bent the dent tool, to reach up to the front creases or fracture lines, ( joined red arrows) and massaged and heated , with some slight pressure on the tool and good control of the heat, I always keep the heat quickly moving around the area I am working , and as soon as the hole dent area is soft, and the dent is %90 popped, then I let the area cool while still massaging from behind with the tool, using 2 hands on the dent tool, ( and no pivot point leverage on the tyre ) I can see the tool face impression pressing out of the still warm/hot plastic dent area surface with only a little pressure, and
I finish by raking or dragging ( massaging )the head face against the hot plastic using 2 hands from the front of the dent to the rear, my line of thought is I am massaging and ironing out the soft plastic, (( so that the plastic will remember and take the clean lines and shape it was pressed or injected new in the factory,))) please note, I try to gently massage the soft plastic into roughly the right shape, and let it cool right down with a free standing fan blowing max cold air over it, , at which time it returns to the original factory shape on its own, while the area is cooling, I usually have to reheat and massage small areas like low or high spots, or a straight lines with a low spot a few times,
My observations and line of thought is like metal in panel beating ect, plastic can be heated and cooled to cause it to shrink back to it original injection moulded shape, and using the dent tool makes it much quicker,
1332, dent removal tools.
Above picture shows dent tools, again red arrow is the handle end seen in above picture, and at the first bend , black arrows show I re bent the flat bar to get more length to reach the plastic creases in the front of the dent,
Black arrow on right shows the tool face , that actually rubs and massages the hot soft plastic dents from behind, ( the metal head surface is sanded smooth with no sharp edges that might cut through the soft hot plastic from behind, )and the tool is used to determine when the plastic is hot enough,
Yellow and purple arrows show another tool I made for other dents, flat bar is flat bar, ready to bend into a tool. ?.
1327,
Above picture shows white arrow points at a slight low spot in or on the outstanding bumper line, highlighted by the kink in the red line, within the circle, and blue lines show uneven surface where the main crease and stretch damage lines were,
1331,
Above picture shows small white circle above middle blue arrow, the white circle is the inside of a metal pipe, sketched in the picture in gray colour,, which I used to massage and roll over the lumpy uneven surface, I started rolling cold and got a friend to wave the hot air gun over this area, until I could feel the plastic go soft under the thin 1 pipe, and stopped the heat, and keep rolling and massaging the area until it cooled, the plastic is hot/ warm enough to stay soft enough to roll the pipe around and over the lumpy uneven surface, 4-6 times,with very little pressure, the lumps ironed or rolled out smooth, and waited for it to cool. remembering the plastic cover is only thin,
Blue arrows show straight line,
(Please note, to be clear, I lever the bulk of the dented area, as I heat around those areas, until the dent has popped out and I have a good basic bumper shape in the dent area, at which point I stop heating the plastic, and using the tool face free hand, that is with 2 hands, ( and not using pivot point or touching the tyre.) I can see the tool face impression protruding out of the hot soft plastic ( 1/8) moving over a small hand size heated dent area, and I iron out / massage out all dent creases and or stretch lines, (milky colour), ).and leaving it to cool and contact.
1330
Above picture shows the 5% left to fix, my line of thought is I hate bog on plastic because if there is future damage in this area of the bumper, the bog will cracked or ripped open or off, to me that looks bad, especially when most dents of this type are common, my line of thought is concerning easy repairs like this, no bog should be used at all,
Yellow circle shows the area where most of the creasing and stretching and microscopic cracking damaged occurred, please note the milky colour has turned black, most of the blue paint fell off in the impact, also show the outstanding edge parallel with the white line inside the yellow circle is not quite right yet, and area in lower half of yellow circle still requires a few minutes more heating and shrinking work, perhaps 15 minutes in total,
Please note and see the only area of bumper I actually massaged the heated plastic on or from the outside of the bar, is within the circle, the rest of the dent was massaged from behind with the dent tool, and no flaking blue paint fell off, and not enough heat was applied to burn any paint off,
Red arrows show the top of the bar and headlights need some more work and realignment, Heating and rolling,
The rest of the white line show the leading edge of the bar is almost perfectly straight along the previous dent area, also showing I was able to heat and cool / shrink plastic back to the original injection moulded shape,
1329,
Above picture shows nearly ready for sanding and paint, no bog,
Points I remember,
1, never hold any heat source directly on plastic, for any time, keep it moving around the area which is being worked, or you will melt a hole in the bumper, quickly,
2, keep feeling how soft the plastic is with the dent tool and once the plastic is or has become just slightly soft and workable, remove the heat source and massage the area with the dent tool until it takes shape and cools shrinks / contracts down,
Please note, I reheated this main bumper dent once, and massaged it into shape until cooled, and then reheated small areas with slight imperfections another 4 times, please note, once the or as the soft plastic cools it hardens too much to massage, I usually use a fan on a stand to cool the all the bar down quickly, only when it is cold or cool can you see the true imperfections or low or high spots.
Please note, some dents can be repaired on the car, and other dents or damage on or in a plastic bar may require you to remove the plastic cover, due to limited access or excess damage, or you are just repairing the bar to paint it at the same time ,
In this Kia situation, 1 screw /clip had been torn out allowing me to be able key hole dent restore this plastic bumper bar, (mostly from inside and behind the dent, ) please note, you can restore a lot of plastic bumper dents, using this easy and quick method, but with more serious damage, you might need to remove the bar, depending on the type of bar, type of car and type and extent of the damage,
1026 before picture.
Above picture, red arrows shows most of the paint has fallen off, and a milky colour indicating server creasing and stretching damage to the plastic at a molecular level, the red orange colour is the reflection from a orange safety cone,
1325,
Top view shows the size of the dent, pretty deep ,
1324,
Above picture shows large dent in the side of the plastic painted bumper bar, Early Kia people mover., the paint is falling off most of the bumper,
Please note, the dent was caused in a collision with another car of the same colour, plastic to plastic only, no gouging or scraping,
Two blue arrows shows the main 2 dents I will heat and massage with little pressure from behind, first,
Red arrows show the outside of the dent with the front crease line at almost right angles, ( some white milky stress line showing to my eye, but not so much seen in this picture, ),
Green arrow on right shows plastic clip with metal screw has been ripped out of the guard and is misaligned, new guys please note, a point to remember is if plastic clip has been ripped out of the HOLE in a metal guard as above, the hole in the metal guard is likely to be opened up or deformed, please note, the metal hole in the guard should be repaired before reassembly, or the plastic clip will not tighten up, just spin,
1326,
Left red arrow shows a length of flat bar bent around to form a quick handle shape, so I can rest my knee and apply pressure on the dent tool ,
( please note this type of dent tool is just quickly bent flat bar, to suit the position of the dent, and still maintaining best points of leverage, ect,)
So the dent tools I refer to in this method are just quickly hand bent dent tools of flat bar, please note I often change or bend the dent tool flat bar to suit a different dent positions, and pre - angle the tool head to suit the angle of the rear of the plastic bumper, while still maintaining the same pivot points on the wheel,
Small yellow arrow shows and please note the length of flat bar between the handle and pivot point bend against the tyre, (the edge of the front tyre is a great adjustable pivot point, just turn the steering wheel to place the tyre in correct position.)
Longer yellow arrow shows flat bar then extends up in between the inner and outer guard up to and behind the yellow circle area, from the pivot point on the tyre.
( white arrow shows point between main dent, and pivot point on tyre, I find using a measuring tape gets the length of the tool very close to right, most of the time, so I measure up the outside dent to the tyre, then measure the dent to handle, and a length for a suitable handle, then mark it on the bar, then bend it into a tool., )
The head is positioned approximately behind the dent and pressure is applied by my knee, ( please note, the flat bar is a bit flexible under my knee, and usually flexes too much to bend cold plastic,at this point.
Two red arrows on left show the nozzle tip of a hot air gun, which is set at high, to simulate me or,
Anyone using a good hot air / hair dryer, with no temperature control at all. Just pretty hot,
New guys please note, If I were to use my variable temperature heat gun at a much lower temperature, actually set well below plastic melting temps, the whole job would take a lot longer to warm up, but the plastic could not over heat and burnt or melt,
Blue arrow shows distance between gun and plastic, and directed at the deepest part of the dent, (yellow circle), this is warming up or keeping the whole area warm,
I will keep heating the plastic, (around the yellow ring area, )until the plastic is hot enough to feel soft under the slight pressure used by either 1 handed, or one knee leverage pivoted off the tyre or 2 handed free hand ( without leverage ),, the focus is waiting to see a slightly bulging impression of the dent tool protruding out ( and from behind ) small areas of soft warm/hot plastic,
I apply pressure from behind the plastic bumper., then the tool can be slid a few inches across and on the side or against the tyre, back and forth, still maintaining some pressure, resulting in small areas of plastic being massaged back into shape, , from behind, then I moved a few inches forward to the dent crease just in front of the first one, and most of %60-70 of the dent popped out, at which point I re bent the dent tool, to reach up to the front creases or fracture lines, ( joined red arrows) and massaged and heated , with some slight pressure on the tool and good control of the heat, I always keep the heat quickly moving around the area I am working , and as soon as the hole dent area is soft, and the dent is %90 popped, then I let the area cool while still massaging from behind with the tool, using 2 hands on the dent tool, ( and no pivot point leverage on the tyre ) I can see the tool face impression pressing out of the still warm/hot plastic dent area surface with only a little pressure, and
I finish by raking or dragging ( massaging )the head face against the hot plastic using 2 hands from the front of the dent to the rear, my line of thought is I am massaging and ironing out the soft plastic, (( so that the plastic will remember and take the clean lines and shape it was pressed or injected new in the factory,))) please note, I try to gently massage the soft plastic into roughly the right shape, and let it cool right down with a free standing fan blowing max cold air over it, , at which time it returns to the original factory shape on its own, while the area is cooling, I usually have to reheat and massage small areas like low or high spots, or a straight lines with a low spot a few times,
My observations and line of thought is like metal in panel beating ect, plastic can be heated and cooled to cause it to shrink back to it original injection moulded shape, and using the dent tool makes it much quicker,
1332, dent removal tools.
Above picture shows dent tools, again red arrow is the handle end seen in above picture, and at the first bend , black arrows show I re bent the flat bar to get more length to reach the plastic creases in the front of the dent,
Black arrow on right shows the tool face , that actually rubs and massages the hot soft plastic dents from behind, ( the metal head surface is sanded smooth with no sharp edges that might cut through the soft hot plastic from behind, )and the tool is used to determine when the plastic is hot enough,
Yellow and purple arrows show another tool I made for other dents, flat bar is flat bar, ready to bend into a tool. ?.
1327,
Above picture shows white arrow points at a slight low spot in or on the outstanding bumper line, highlighted by the kink in the red line, within the circle, and blue lines show uneven surface where the main crease and stretch damage lines were,
1331,
Above picture shows small white circle above middle blue arrow, the white circle is the inside of a metal pipe, sketched in the picture in gray colour,, which I used to massage and roll over the lumpy uneven surface, I started rolling cold and got a friend to wave the hot air gun over this area, until I could feel the plastic go soft under the thin 1 pipe, and stopped the heat, and keep rolling and massaging the area until it cooled, the plastic is hot/ warm enough to stay soft enough to roll the pipe around and over the lumpy uneven surface, 4-6 times,with very little pressure, the lumps ironed or rolled out smooth, and waited for it to cool. remembering the plastic cover is only thin,
Blue arrows show straight line,
(Please note, to be clear, I lever the bulk of the dented area, as I heat around those areas, until the dent has popped out and I have a good basic bumper shape in the dent area, at which point I stop heating the plastic, and using the tool face free hand, that is with 2 hands, ( and not using pivot point or touching the tyre.) I can see the tool face impression protruding out of the hot soft plastic ( 1/8) moving over a small hand size heated dent area, and I iron out / massage out all dent creases and or stretch lines, (milky colour), ).and leaving it to cool and contact.
1330
Above picture shows the 5% left to fix, my line of thought is I hate bog on plastic because if there is future damage in this area of the bumper, the bog will cracked or ripped open or off, to me that looks bad, especially when most dents of this type are common, my line of thought is concerning easy repairs like this, no bog should be used at all,
Yellow circle shows the area where most of the creasing and stretching and microscopic cracking damaged occurred, please note the milky colour has turned black, most of the blue paint fell off in the impact, also show the outstanding edge parallel with the white line inside the yellow circle is not quite right yet, and area in lower half of yellow circle still requires a few minutes more heating and shrinking work, perhaps 15 minutes in total,
Please note and see the only area of bumper I actually massaged the heated plastic on or from the outside of the bar, is within the circle, the rest of the dent was massaged from behind with the dent tool, and no flaking blue paint fell off, and not enough heat was applied to burn any paint off,
Red arrows show the top of the bar and headlights need some more work and realignment, Heating and rolling,
The rest of the white line show the leading edge of the bar is almost perfectly straight along the previous dent area, also showing I was able to heat and cool / shrink plastic back to the original injection moulded shape,
1329,
Above picture shows nearly ready for sanding and paint, no bog,
Points I remember,
1, never hold any heat source directly on plastic, for any time, keep it moving around the area which is being worked, or you will melt a hole in the bumper, quickly,
2, keep feeling how soft the plastic is with the dent tool and once the plastic is or has become just slightly soft and workable, remove the heat source and massage the area with the dent tool until it takes shape and cools shrinks / contracts down,
Please note, I reheated this main bumper dent once, and massaged it into shape until cooled, and then reheated small areas with slight imperfections another 4 times, please note, once the or as the soft plastic cools it hardens too much to massage, I usually use a fan on a stand to cool the all the bar down quickly, only when it is cold or cool can you see the true imperfections or low or high spots.
Facebook
Twitter