Unable to remove deep defects with Rupes + MF + 105?

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number1show

New member
Can anyone give me some suggestions as to what I might be doing wrong?

LHDbEze.jpg

Both photos are "after" with after being on the left I just couldn't get the sun quite right to split the tape line very well.
Hood was washed and clayed. All pads are the GG pads that are supplied with the G21 kit.

I started with UC and a white pad at max speed, did about 8 passes with medium pressure, nothing, then heavy pressure, nothing.

Then I kicked it up to 105 and the white pad, same thing, still not removing the deep stuff shown.
Then I kicked it up to 105 + MF pad. I felt like this must surely get it done. Full speed, medium pressure, heavy pressure, light pressure, probably 12 passes. I stopped counting, but a lot of them, and I still couldn't get those out. I hear everyone talking about being able to get wetsand marks out with a 21mm throw polisher, so what am I doing wrong?

Still a tremendous improvement and I finished it off with some 205 on a yellow and then Collinite for the photos but I am still very disappointed.

Giving answers that are more helpful than "practice" will be greatly appreciated.
 
Dont be afraid to put some pressure on the polisher and slow down your movement. I personally would be reaching for a wool pad and M101. Interested what other responses will be. Also work a small area and remember they might be too deep to safely remove.
 
Agreed they may be too deep to safely remove. If the hood is a junk hood you are just practicing on, you may consider learning some wet sanding in this case.

Also, I'd say any more than 6-7 passes with 105 is too much. From what I understand, the SMAT abrasives eventually clog up with the clear that has been removed and they stop cutting right if at all. I've heard you can most some water and keep going but you may also want to try 4-5 slow passes, wipe off, then go at it again with fresh 105.

if I was in your position I may reach for my rotary and a wool pad at this point. If that's available you could try that
 
On any machine including my Makita 9227C, you have to put downward pressure - sometimes a lot of pressure, and go slowly keeping the compound moist enough to work through its cycle of life...
With a machine that is not direct drive, I would want to run it wide open to get as much pad rotation as possible, because rotation is what breaks down the compound best, and cleans up the mess and leaves it on the pad..

You will need a lot of pads and a few small towels to wipe off the pad face at the end of the cycle before you start again..

I have never used Griot's anything so cannot speak to their pads.. I would be able to tell you much about Lake Country pads and how well they work in a Detailing Shop..

Remember to not load a lot of compound on the pad each time, and change pads frequently..

You will know when to change pads, when they do not do anymore than smear the compound all over the and start acting erratic on the panel..

Observe carefully what you are doing and never be or get distracted for a moment...

With a machine that IS direct drive, I would not want or need crazy fast speed to knock this out - probably no more than 900 - 1200 if that...

What year make model and color is that hood from ? Some paint is just harder than others and requires more work..

In my experiences Meguiars M105 can do about anything with a Rotary and wool or purple wool foam pads..
Good luck with this..
Dan F
 
What follows is the best advice I can offer, free advice is often worth what you paid for it, nonetheless....

One of the things I think you need to do is get some sandpaper and a rotary polisher if you don't already have them.

Those scratches aren't going to come out in any reasonable time frame with a random orbital machine. If the backing plate spins freely on the shaft it's a random orbital action - not forced rotation.

Get a rotary machine. My go to machine these days is the Hitachi SP18VA.

Sand the hood with wet 1200 grit sandpaper. Get a nice consistent cut - you'll be able to see the deep scratches beneath the sanding scratch. (Get as aggressive as you dare, the point here is to have the experience of cutting hard and of burning through when it doesn't matter.) Then follow that with 1500, then 2000.

Start polishing with a wool pad, the Lake Country purple foamed wool is nice and forgiving. Cut out the sandpaper scratches and leave a nice swirl mark. Then remove the swirl with your Rupes.

I'd suggest starting with Menzerna 400 on the rotary and then use the same with a foam pad on the random orbital.

If you don't know what it looks like and feels like on the way to a catastrophe there's no way to know when you're approaching one at pretty high speed. Going over the limit on a panel you don't have to pay for is good experience.

Sanding and polishing is a very good skill to have. It makes everything else easy.

Robert
 
I personally never liked m105 and microfiber pads. It almost seems like m105 drys out faster on a MF pad than a foam. Something you can try to do is prime a new MF pad with m105, then add few drops of m105 and work it into the paint for 2 slow passes on your highest speed. Then pick up your polisher and spray the pad with some water and do 2-3 more passes. Then spray the face again and do 2 more. The water helps keep the m105 activated throughout the process and won't allow it to dry out. Also, try not to do it out in the sun. It will dry out the product faster also.
 
You need a wool pad and the right rpms with a rotary polisher. Dont polish at too high a speed perhaps 1200 to 2000 max. Use your favorite products, ones that work for you. I could suggest some, perhaps Meguires. Again use what works. Compounding with a Rotary is all about technique. There are just so many variables that effect the end product, give yourself time to learn. Everyone thinks "paint rejuvenation" is easy. Most use fillers and the car looks good until it rains. Good luck
 
For sure, with Meguiars M105, you have to nurse it through its initial "Im going to dry up really quick and mess with you" phase with some extra water from a spray bottle, experimenting with how much, and then the compound will settle down and work through its cycle.. You may need to add more moisture as you work it to the end.

I personally take it all the way down to where it polishes the paint and leaves a nice clear gloss that can be further refined if needed..

Again, you need a lot of pads to compound anything because as I use them, they load up with dead paint and crap and I also get them to clean up the surface so I always have very little to wipe off..

Yes, this means I will work it longer than the production guys who slam some compound on the panel and run the Rotary up to 3000 and use the top edge to make and leave long swirls in the finish and call it a day.. :)

If you really want to take the time and have the patience and the right equipment, M105 is an incredible product that can be used in a lot of places.. I really like how quickly it will clean up plastic tail light and headlight lenses...
Good luck !
DanF
 
Most any approach will work if you give it long enough..you know, "abrasion is abrasion" and so on. (People polished all sorts of stuff, like stone, by hand for centuries and got it smooth as glass.)

I had one rock-hard paint that took *MANY* passes with a rotary at high-RPMs with twisted wool pads and rocks-in-a-bottle compound. VERY frustrating, but it just took as much work as it took.

But yeah, if you're gonna *REALLY* hammer a trashed finish, wetsanding is not just more effective and efficient, it can actually be safer too (at least if you go about it right).

Now whether one oughta *DO* that kind of ultra-aggressive work is another matter ;) Take off a lot of clearcoat and you'd better not park the vehicle outside in the sun.
 
number1show said:
I hear everyone talking about being able to get wetsand marks out with a 21mm throw polisher, so what am I doing wrong?
Click to expand...


Common scratching and heavy swirling is often much deeper than wetsanding marks!

If you want flawless it is sometimes easiest to wetsand the panel and buff than to try and buff those on their own!
 
LeadingEdgeDetail said:
Common scratching and heavy swirling is often much deeper than wetsanding marks!

If you want flawless it is sometimes easiest to wetsand the panel and buff than to try and buff those on their own!
Click to expand...

And then, you have to wetsand the next panel, and the next panel, and the next panel, so it will all match... :)
Dan F
 
Stokdgs said:
And then, you have to wetsand the next panel, and the next panel, and the next panel, so it will all match... :)
Dan F
Click to expand...

I'm sure you know this depends on the grit of sandpaper and the stiffness of the block. Certainly, if you start with 800 grit paper and a hard block you're going to take out all the orange peel, scratches and too much of the clear but the panel would have great distinctness of image and look so much better than the rest of the car you'd have to do the whole car. As you rightly point out, that's stupid.

On the other hand, soaked 2000 grit paper with no block leaves the orange peel almost entirely intact and doesn't remove a dangerous amount of clear - if you don't go crazy - so you can use it on one panel, or on a really scratched area and not create a huge difference in the texture.

Personally, I typically won't take every scratch out of the cars I do. The reason being, even if I can do it without damaging the paint, I'm leaving a land mine for the next guy if the car gets scratched in the same area and they try to cut it out. With a rotary and wool pad, you can bring the speed down, hit the scratch from one side then the other and round the edge of the scratch off so it doesn't catch the light so much but preserves the clear.

The rotary gives you so many more options and cuts the time down so much I'm always surprised when people who call themselves pros don't know how to use one.

Robert
 
I dont know about sanding without a block for anything.. Soft, flexible, medium or the old standby 3m black hard rubber block that has to be checked for straight, I personally have had the best results with one or more of those choices.. I want straight, straight, paint to get the best light reflection and not refraction..

Having learned the painting trade from the beginning, wet sanding down zillions of primed panels with a guide coat, to help insure I would get them straight, I just cant figure out how any part of the human body would be able to do better than a good block whatever hardness, in a trained hand..
But that's just me.. :)

Totally on board - It is never going to be a good idea to take out every defect especially on daily drivers, who will be back next year, full of tree sap, and marks from the Brown Bear Car Wash in Bellevue, WA.., the Quick Quack Car Wash in Sacramento, CA. etc.., I cant agree more with you on that..

I measure everything I correct before, during, and after to help insure I dont remove even a part of a micron...

Having learned how to use a Rotary at a young age and continued through my life, I cant think of anything better than direct drive, and I never use nutty high speeds because I dont need them..
Would rather work the compound or polish into the pad and paint slower, to allow it all to work through the cycle that will be determined as its being done, along with a little moisture at times, to keep it from drying and dusting, which creates yet another step to clean..

Only use Lake Country Purple Foam Wool on really bad scratches with M105 on a smaller backing plate and pad to quickly bring down the measured area/s just as much as I can to get the look we all want to see, and that's it..
Yeah, I'm going to use the Rotary forever on everything because it IS fast in trained, experienced, hands, and flat does the job..
And on top of that, its a great work out for the upper body when you haul it around all day for a few decades.. :) And look Ma - no vibration.. :)
Dan F
 
Dan,

You and I are pretty much on the same page, but just to be clear, for others reading this exchange. The point of using soaked paper without a block is to not take out the orange peel and create a difference between areas.

All the best,
Robert
 
WhyteWizard said:
Dan,

You and I are pretty much on the same page, but just to be clear, for others reading this exchange. The point of using soaked paper without a block is to not take out the orange peel and create a difference between areas.

All the best,
Robert
Click to expand...

Robert,
I get what you mean precisely and understand how the process can work in hands that are trained to sand for this result..
Thanks for the clarification to the Board..
Dan F
 
LeadingEdgeDetail said:
Common scratching and heavy swirling is often much deeper than wetsanding marks!
Click to expand...

Hey, that's a great point! The typical RIDS (if there is such a thing!) would be quite a coarse-grit sanding scratch, it's just that there's only one of them..like a single piece of abrasive from the paper.

WhyteWizard said:
Personally, I typically won't take every scratch out of the cars I do. The reason being, even if I can do it without damaging the paint, I'm leaving a land mine for the next guy...
Click to expand...

That's another great point, and one that even non-Pro Autopians should pay attention to. Get the car all perfect with a "whatever it takes!" mindset and then some kind of Real World Event mars it...
 
Thanks for all the feedback, everyone. Wetsanding is beyond the scope of what I'm willing to learn, and since it's just a practice hood I didn't care too much.


I went at it with a wool pad, the G21 and M105. After a *lot* of passes, I managed to get about 1/3 of those deep suckers out. It didn't get a ton better but did improve it.

The good news is, I've learned that it is virtually impossible to burn through paint. :D

Toward the end I was actively trying to see how long it would take to get to bare metal, or even through the clear and I got tired of pushing so hard and waiting for the hood to cool down.
 
number1show said:
Thanks for all the feedback, everyone. Wetsanding is beyond the scope of what I'm willing to learn, and since it's just a practice hood I didn't care too much.


I went at it with a wool pad, the G21 and M105. After a *lot* of passes, I managed to get about 1/3 of those deep suckers out. It didn't get a ton better but did improve it.

The good news is, I've learned that it is virtually impossible to burn through paint. :D

Toward the end I was actively trying to see how long it would take to get to bare metal, or even through the clear and I got tired of pushing so hard and waiting for the hood to cool down.
Click to expand...


As I've said, I can't imagine a professional - someone who's asking to be paid for their work - not using a rotary for deep scratches, color sanding, etc. unless of course, the charge isn't connected to the amount of time spent. If the charge is connected to time spent and someone is using a technique that's slower than a readily available alternative then the question becomes, "Are we asking our clients to subsidize our incompetence?" Still, there's so much effort going into making pads and polishes to work with random orbitals that they are getting somewhat faster, but I don't see any way they'll ever be as fast as the rotary. The same principle would apply if someone refused to use a random orbital and insisted on doing everything by hand with soft cloth and fine, fine abrasive.

Anyway, good luck.

Robert
 
Try 205 ;)

Personally, if you can catch the scratches with a nail you most likely need to sand or even worse it's not 100% fixable but maybe be semi blend-able.
 
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