Tried to damage a car today with rotary

DSVWGLI

New member
Well not really. Today I detailed my neighbor's old car, so I thought I would be a little more aggressive with the rotary. Some areas of the car the clear is flaking right off so he wasn't to worried about it. I used a 7.5" LC CE cutting pad with OHC @ 1700 rpms slow passes, no problem here. The paint got a little warm but not overly hot. So I thought I would try that on the edges and guess what, no problem there either. Now I went a little quicker on the edges because I would never go slow on edges any way. The one thing that did happen was the pin striping melted away when I turned the pad on edge over the pin striping and worked that area for about 5 seconds :bolt . I found that as long as you keep the buffer moving over pin striping you won't have a problem as I was using the cutting pad and OHC @ 1700 rpms on it with out incident. So I learned that you would really have to try to burn an edge to succeed. The paint on this car was almost 20 years old so the clear should be thinner and more susceptable to damage than newer paint.
 
thats good to know, thanks for the update on your hitachi adventures . . . .gonna be detailing a black 330 convertable tomorrow . . . cant wait to demolish some defects . . .
 
I think your findings only pertain to this vehicle. I don't think it's a safe assumption to make that it isn't easy to burn paint with a rotary.
 
Yes, agree. On some paints just a light touch is enough and a fine white line appears on the edge...



When I tried to burn some beater doors, I was surprised that the large flat areas could withstand the serious heat and the abrasion of HTEC @ 2200 with HEAVY, panel bending pressure, yet the edges were very sensitive and got burned in no time, with negligible pressure.
 
EDGES ARE VERY DANGEROUS! I have seen burned paint from cars that were previously detailed by someone else. The edges on certain paints are VERY THIN and would not recommend hitting those edges with the rotary. Like others have mentioned it depends on the paint and vehicle. Otherwise you burn the edges on a vehicle you may have one unhappy customer and a paint shop repair bill in front of you.
 
Thanks for the input on this as I have not done to many cars yet. On my VW I used a polishing pad @ 1100 with OP over edges with no problem and that paint is very soft. I guess if your working on an older vehicle with soft paint you could run into a problem, as you don't know how much clear is left. But to burn an edge don't you have to create heat to burn through the paint :nixweiss ? Because I never let the heat build up to much on the edges to do that, I kept a steady speed going to gaurd against that. More advice please.
 
Paint can be so thin that you get a burn mark (white line) in a fraction of a second, with the slightest touch of the rotary. It will happen more likely with an aggressive pad, but we've seen damages with finishing pads too.
 
When I use EC/OP with a yellow, orange or even a white LC VC pad I always tape edges and seams. When I use 106ff with a green P2 pad I remove the tape first, the green P2 is soft enough.
 
Bence said:
Paint can be so thin that you get a burn mark (white line) in a fraction of a second, with the slightest touch of the rotary. It will happen more likely with an aggressive pad, but we've seen damages with finishing pads too.



So in these incidences are the edges that are being "burned" getting hot or is it the friction of the pad against the edge with out heat that is taking the paint off. If it is happening with out heat then it is not a burn then. If paint is so thin on an edge that just touching it with the rotary takes the paint off, then a PC on speed 6 with pressure and slow passes would as well don't you think? On the hundreds of cars I've done I've never burned an edge with the PC compounding @ speed 6 using slow passes. Your thoughts.
 
If my math is correct, at the outer edge of the pad (the one that will cause damage), a 6" pad has 1.5ft of distance per revolution, which @ 1000rpm travels at 17.04mph. Now, anything going 17mph that is touching the paint can EASILY do a lot of damage of concentrated on anything less than a few square inches.... An edge can easily be 1/8th of an inch area...



Heat can burn paint, friction can soften and smudge paint, or it can melt the foam pad onto the paint (thank god paint wasn't hurt!)
 
StumpyDetailing said:
If my math is correct, at the outer edge of the pad (the one that will cause damage), a 6" pad has 1.5ft of distance per revolution, which @ 1000rpm travels at 17.04mph. Now, anything going 17mph that is touching the paint can EASILY do a lot of damage of concentrated on anything less than a few square inches.... An edge can easily be 1/8th of an inch area...



Heat can burn paint, friction can soften and smudge paint, or it can melt the foam pad onto the paint (thank god paint wasn't hurt!)



So you also believe heat is the damaging factor here?
 
this whole edge concept is freaking me out. I am afarid to get near the edges of panals now . . . I just did the above mentioned BMW, and yellow lc 6'' pad with OHC @1700 rpm had a tough time removing defects, I had to make multiple passes with the Hitachi . . . . .(grnated its a BMW and the clear is hard- expected varible)



by edge of panal do we mean the actual edge of the body panal itself . . . or the 1/2 to inch of painted surface near the actual edge of the panal . . . .



should i increase my speed (movement of buffer, not RPM) and lower my buffer speed near edges ?



i have yet to have a burning incident so far, at least where edges are concerned . . . i want to monimize my risk . .



sorry to thread jack GLI. . . .
 
fdizzle said:
this whole edge concept is freaking me out. I am afarid to get near the edges of panals now . . . I just did the above mentioned BMW, and yellow lc 6'' pad with OHC @1700 rpm had a tough time removing defects, I had to make multiple passes with the Hitachi . . . . .(grnated its a BMW and the clear is hard- expected varible)



by edge of panal do we mean the actual edge of the body panal itself . . . or the 1/2 to inch of painted surface near the actual edge of the panal . . . .



should i increase my speed (movement of buffer, not RPM) and lower my buffer speed near edges ?



i have yet to have a burning incident so far, at least where edges are concerned . . . i want to monimize my risk . .



sorry to thread jack GLI. . . .



No problem, it's all related. An edge is the actual edge where the flat surface rounds off becomming an edge. When buffing, the paint should be toasty warm not hot. If it isn't then you could slow your movement down or add a little pressure but you shouldn't have to go higher than 1700 rpm. It's probably a good idea to trigger the speed down at edges if the paint is really warm.
 
dude . . . it was cold, @ 1700 rpm and slow passes, it was cold . . . barely had any warmth to it at all and I was working in the sun. Now, when I used the rotary on the mini and burned the paint (rotary disaster...almost thread) the paint was scorching . . . but taht was not oem paint. . . .
 
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