PDA

View Full Version : Sometimes I just prefer to sand by hand...



Nick Chapman
Jun 5th, 2008, 08:53 AM
Working on a red Viper right now. Started sanding by air, and I can not see what I'm doing. You just can't tell what you're removing. Go to buff, and the oragne peel is still there :(

Hand sanding, I can see all of the imperfections while I'm sanding.


Any tips on this thing? I'm using the Mirka sander with the Abralon disks

Nick

Nick Chapman
Jun 5th, 2008, 09:03 AM
Guess I should explain a little better.

Air sanding, sand with the Abralon system(1000 then 2000), wipe dry. Everything seems to be all level. Go to buff, orange peel is still there :(

Hand sanding, Sand with 1500 gritt, wipe dry, you can still see the orange peel and know to keep going.

Never really had this problem before. Dont know if it's this red, or the paint itself. Real pain to have to go back and sand some more after you've already buffed :(

Mike Phillips
Jun 5th, 2008, 09:12 AM
Usually you sand an area and then wipe dry and compare it to the surrounding area and see where the orange peel is and where the paint is flat?

This is what you're seeing but then when you buff out the paint the orange peel is still there?

Is this factory paint?

Mike Phillips
Jun 5th, 2008, 09:14 AM
Will send the link to this thread to Mike Pennington and Jason Rose, maybe they have some insight or tips...

:)

Mike Pennington
Jun 5th, 2008, 09:33 AM
Hi Nick,

2 things to consider...

1) 1000 DA is not like 1000 hand....1000 DA is more like 1500 or even a tick finer hand sanding.

2) A "foam back" disc like Abralon will not flatten like hand sanding or a "film disc". The foam discs tend to follow the contour of the paint, therefore making it appear there is no orange peel. However, a film disc will actually cut through the orange peel.

If you want more flattening with a DA, we recommend trying a film disc w/ no interface pad for intial cut and then switch to a foam disc to refine the scratch.

Mike

Nick Chapman
Jun 5th, 2008, 09:50 AM
Thanks Mike!
That explains a lot. Guess I'll do the initall cut by hand, then fine tune it with the air sander. All I have is the Abralon system for my air sander.

Renny Doyle
Jun 5th, 2008, 10:01 AM
Hey guys...we you are DA sanding, are you taking measurements? If so on average how much does DA sanding remove clear coat wise?

Also, in your opinions, how safe is DA sanding on factory finishes?

Why Do I Ask? When I DA Sand, it does not take long to remove .2-.5 of a mil and that is what many conceder a safe yet approaching danger zone for factory finishes.

Also, we are really getting into 105 and I want to make certain we as an organization are acting/ providing services within safe zones. In addition, we have 25 detailers from across the country gathering at our main shop later this month and Joe Fernandez and myself are performing some demo work using 105...it would be of great interest to all there that we provide some guideline right from the Meguiar's team on their suggestion for tolerances when wet sanding or performing advance polishing services.

Very curious to see/hear what you guys think.

Thanks a ton,

Nick Chapman
Jun 5th, 2008, 10:16 AM
Hey Renny,

This is a Viper. So I have no way to measure. It's an aftermarket paint job, and I have spoken with the painter personally. He assured me that there was more than enough clear to sand the orange peel plus some.
Normally I would pass on a job like this because I would have no real way of knowing. But, knowing the painters reputaion, I trust him to not lead me wrong or lie to me.

How come I never get invites to your functions :(

Nick

the other pc
Jun 5th, 2008, 10:42 AM
Nick,

One of the features of the Mirka system (http://www.mirka-usa.com/applications/productapp/autoclear.htm) is that you can match orange peel on a repaired area to non-repaired panels. The Abralon discs are intended to remove coarser sanding scratch while leaving the texture (orange peel) intact.

Mirka’s Royal Micro discs work great for cutting orange peel. You can use Royal Micro dry so you’re not constantly wiping and waiting for water to flash off to see how you’re doing. It’s a real time saver.

The processes is controllable and easy to inspect so you can cut as much or as little texture as you want. Then you use the Abralon to reduce scratch for easier buffing.


PC.

Kooz
Jun 5th, 2008, 10:46 AM
Nick, I know I'm not helping in any way but can you post some pics when you are done with this car? Seeing a shined-up red Viper would be a nice treat! I'm drooling just thinking about it. :drool1

Renny Doyle
Jun 5th, 2008, 11:20 AM
Once again I get ahead of myself and DON'T READ THE POST completely. Thx

Nick Chapman
Jun 5th, 2008, 12:27 PM
Nick, I know I'm not helping in any way but can you post some pics when you are done with this car? Seeing a shined-up red Viper would be a nice treat! I'm drooling just thinking about it. :drool1



We'll see how it turns out ;) :D

Nick Chapman
Jun 5th, 2008, 12:28 PM
Nick,

One of the features of the Mirka system (http://www.mirka-usa.com/applications/productapp/autoclear.htm) is that you can match orange peel on a repaired area to non-repaired panels. The Abralon discs are intended to remove coarser sanding scratch while leaving the texture (orange peel) intact.

Mirka’s Royal Micro discs work great for cutting orange peel. You can use Royal Micro dry so you’re not constantly wiping and waiting for water to flash off to see how you’re doing. It’s a real time saver.

The processes is controllable and easy to inspect so you can cut as much or as little texture as you want. Then you use the Abralon to reduce scratch for easier buffing.


PC.

Thanks Paul!
I'll have to check into that in the future. Lucky for me, the paint on this car is sanding very easy. So hand sanding won't be too bad.

Mike Pennington
Jun 5th, 2008, 12:33 PM
Mirka’s Royal Micro discs


Good example of a "Film Disc"

:D

RaskyR1
Jun 5th, 2008, 12:33 PM
I know my father is old school but he says wet-sanding by hand produces better results anyway....:huh1

the other pc
Jun 5th, 2008, 01:06 PM
Well, everybody’s entitled to their own opinion. All I can say is try it for yourself.

My bet is you’ll be blown away by how much better your results are with a DA compared to hand sanding. I sure was.

It makes sense if you think about it. The critical thing for high quality sanding is consistency. The more consistently you can do something, the more easily you can adjust your process for maximum performance. And once you’ve tuned it to a very high level you can maintain it there.

A DA can perform exactly the same motion, precisely the same way, over and over and over again, thousands of times a minute. A human being simply can’t come close.


PC.

RaskyR1
Jun 5th, 2008, 02:25 PM
Well, everybody’s entitled to their own opinion. All I can say is try it for yourself.

My bet is you’ll be blown away by how much better your results are with a DA compared to hand sanding. I sure was.

It makes sense if you think about it. The critical thing for high quality sanding is consistency. The more consistently you can do something, the more easily you can adjust your process for maximum performance. And once you’ve tuned it to a very high level you can maintain it there.

A DA can perform exactly the same motion, precisely the same way, over and over and over again, thousands of times a minute. A human being simply can’t come close.


PC.

Yeah, I've wet-sanded hundreds of cars over the years helping my old man in his shop. I think his thinking behind it is similar to that of blocking the car during the sanding stages, prior to paint, to obtain the straightest possible panel. Wet sanding by hand you don't sand with a motion like a DA, you use similar motion like when you're blocking the car. Either way I prefer to do it by DA.

I was just curious if there has ever been any studies/test to show which is better. :D

the other pc
Jun 6th, 2008, 08:22 AM
.... Wet sanding by hand you don't sand with a motion like a DA...Yes, you use straight strokes for hand sanding vs. the tiny round ones a DA makes. But A human can’t be as consistent as a machine no matter what kind of motion they’re doing. And even though the motions are completely different the end results can be compared directly for uniformity of material removal, ease of buffing out and quality of final finish.



...I was just curious if there has ever been any studies/test to show which is better. :DI don’t know about any formal studies. But the simplest test, hand sanding and DA sanding the same panel in the same session, inspecting the results and then buffing out the scratch from both at the same time is easy enough for anybody to try. When I’ve done it the difference was night and day.


PC.

RaskyR1
Jun 6th, 2008, 08:33 AM
Yes, you use straight strokes for hand sanding vs. the tiny round ones a DA makes. But A human can’t be as consistent as a machine no matter what kind of motion they’re doing. And even though the motions are completely different the end results can be compared directly for uniformity of material removal, ease of buffing out and quality of final finish.


I don’t know about any formal studies. But the simplest test, hand sanding and DA sanding the same panel in the same session, inspecting the results and then buffing out the scratch from both at the same time is easy enough for anybody to try. When I’ve done it the difference was night and day.


PC.


Thanks!

I've never done a side by side either but I have always found it easier to remove the sanding scratches from a DA then the scratches from sanding by hand. By hand it seems that some of the scratches can groove down a little deeper.

While I think my old man had good intentions in his thinkning I would agree that DA is the way to go. FWIW he does use the DA at work and it's been some time since I've asked him if he still feels the same way.

Thanks for your input. :wavey

Rasky

Nick Chapman
Jun 6th, 2008, 08:36 AM
DA sanding is definately better! No question about that!

I am hand sanding this Viper for the initial cut. Then doing the final sanding with the DA and the Abralon 2000 grit. I know it's not the perfect procedure, but it's all I have available to me right now. It's going to look a ton better when it's finished :D

RaskyR1
Jun 6th, 2008, 11:03 AM
DA sanding is definately better! No question about that!

I am hand sanding this Viper for the initial cut. Then doing the final sanding with the DA and the Abralon 2000 grit. I know it's not the perfect procedure, but it's all I have available to me right now. It's going to look a ton better when it's finished :D

Waiting to see pics! :dp:

Mike Pennington
Jun 6th, 2008, 11:06 AM
I know my father is old school but he says wet-sanding by hand produces better results anyway....:huh1

As with many topics on this and other forums....We all have to ask ourselves....What does "better" mean ?

Regarding this thread...What does better sanding mean ?

:D

Nick Chapman
Jun 7th, 2008, 05:51 AM
Regarding this thread...What does better sanding mean ?

Easier! :D:D:D

asim_296
Dec 7th, 2008, 05:40 AM
Mr. Chapman ;) any pics? Viper? process? anything..