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View Full Version : Learned the importance of test spots....the hard way



Vortech5.0
04-12-2014, 12:11 AM
I was about 3/4 of the way around the car on my final polishing step and I just wasn't satisfied with the results.:doh: Let me rephrase that, I was disgusted with how it was turning out. But through out the hole process I just kept telling myself "oh it'll get better, It'll turn out good". Well, as we all know it's not gonna fix itself. I don't know what was so different tonight but my work light was hitting the paint just perfectly and it was really ticking me off what I was seeing. :bash:Letting go of my pride I finally figured I would do a decent test spot and see if it got any better. Well, surprise it did. Boy was I ticked (in a good way I guess) but I definitely learned my lesson. Now I'm back tracking a couple steps but at least It'll turn out better. But hey, on the bright side I'm getting real good with this polisher from all this wasted practice.

Before test spot

http://i1060.photobucket.com/albums/t445/truitt10/IMG_20140411_214645_109_zpsc380143b.jpg

After test spot

http://i1060.photobucket.com/albums/t445/truitt10/IMG_20140411_220217_809_zps594ee841.jpg

jamesboyy
04-12-2014, 12:32 AM
Nice before and after shots and we all sometime either forget or don't do a test spot for one reason or another and its alright but what shows your pride for detailing is when you correct your wrong and you did and for that I say job well done you should really be proud of yourself

Tato
04-12-2014, 01:18 AM
Great lesson, great results.

I believe most people will learn this the 'hard way' like you've said, test spots are time consuming, but I admit time spent in test spot will be gained at the end when everything is perfect and you won't have to go back an redo it all.

I like to tackle some roof or trunk lid parts for test spot, but nowadays I generally get 'the worst' (or some of the worst) parts I'll have to deal and test a spot there. This way I get a more complete idea of what kind of defects I'm dealing with, also, if I correct the worst imperfections, the rest will come out pretty good as well. I don't do this if there's only 1 'ugly' part, for that I'll have to do 2 test spots at least, for the spot in case, and another for the rest of the paint.

Generally, the worst part worked that needed a more abrasive product will also benefit from a second step of a finer polish being used on the rest.

Of course this is not a rule, but I tend to do this way.

Thanks for sharing this experience,

Good luck,

And keep on doing this great job, your results are awesome.

Kind Regards.

Mike@DedicatedPerfection
04-12-2014, 02:01 AM
What was your process on what wasn't working and what was?

Mike Phillips
04-12-2014, 04:41 AM
Letting go of my pride I finally figured I would do a decent test spot and see if it got any better. Well, surprise it did.

Boy was I ticked (in a good way I guess) but I definitely learned my lesson. Now I'm back tracking a couple steps but at least It'll turn out better.




I think we all learn the lesson of why it's important to do a test spot before buffing out an entire car and really dialing-in our process so there's no wasted time, product, energy, etc.

I started typing about the idea of doing a test spot on the Internet back in 1994 that I can document. I always do a test spot since before the Internet and all the way up to today.

If I've never worked on the car in front of me before then I don't know anything about the paint and how it's going to react to my proposed product, pad and process. So I always do a test spot. Always.

You'll also see us doing test spots in all our projects here at AG.

For any newbies or lurkers wondering what the heck we're talking about... here you go....


How To Do a Test Spot (http://www.autogeekonline.net/forum/how-articles/50162-how-do-test-spot.html)
(And why it's so important)



:xyxthumbs:

Paul A.
04-12-2014, 08:44 AM
I was asked in a job interview many years ago what i have learned from "good" mistakes in my career.

My answer was " not nearly as much as the bad mistakes". The bad mistakes...i mean the really profoundly bad mistakes... have taught me more in my life than any "slight mistakes". They were and continue to be the most impactful. And what you did wasn't in the category of anything really bad or profoundly wrong. So you wasted some time...you got more experience as you suggested and that is never bad! The key was to recognize exactly what you did wrong after you did it and corrected it in the future. That's exactly what you did and were wise enough to see how you may have wasted some time overlooking that all important "test spot". Plus posting it here for the rest of us to be reminded of its importance shows a genuine and humble realization that you learned something.

Well done, my friend. Well done and thank you!

Tato
04-12-2014, 09:19 AM
:goodpost:

Wheelzntoys
04-12-2014, 09:26 AM
What was your process on what wasn't working and what was?

+1

Vortech5.0
04-12-2014, 02:18 PM
Thanks for all the positive responses guys. The feedback and camaraderie of this sight continues to impress me.


What was your process on what wasn't working and what was?

Keep in mind it could easily have been more of a poor technique and lack of experience rather than the process alone. I'm a first timer for all of these steps. Dove in head first. But here WAS the process.

1-Wet sanded with 1500, 2000, 3000 grit
2-M105 with rotary and Megs 7000 foam cutting pad
3-M205 with rotary and Megs 9000 foam finishing pad
4-M205 with DA with white ccs pad.

It was on step 4 when I new it just wasn't working out. I had my doubts on step 3 as well but hoped the next steps would make it better. I have now switched to an orange ccs pad on the DA and went back to M105. Then hit it the test spot with the 205 and a white pad again. Its turning out much better.

Mike@DedicatedPerfection
04-12-2014, 02:30 PM
1-Wet sanded with 1500, 2000, 3000 grit
2-M105 with rotary and Megs 7000 foam cutting pad
3-M205 with rotary and Megs 9000 foam finishing pad
4-M205 with DA with white ccs pad.

I have done quite a bit of sanding and in this particular order that you have done. When I start my first sanding step, I get darn near to the point where the defect is removed. Then I get on the next grit and I sand double the amount of time I did for the first grit. This not only ensures that I am left with 2000 grit marks but I will also completely eliminate the defect on this round. When I get to the final sanding step I am doubling the sanding time from the 2000 grit. This ensures that I finish with nothing more than 3000 grit marks.

So if I sand for 20 seconds on 1500, I am going 40 seconds for 2000. When I get to 3000 I will be at the 60-80 second mark. When I go to polish this out all that is needed is M105 on a yellow W8207 pad and I follow that with M205 on a black W9207 pad for sure fire results.

Hope this helps,

Mike

oldmodman
04-12-2014, 04:04 PM
Undercorrecting. No big deal. Just some time down the drain.

Overcorrecting. Like right through the super thin previously sanded clear. Bad. Car repaint coming our of your pocket.

Always start out gentle on an unfamiliar car. If need be you can always break out the gravel in a bottle later.

Vortech5.0
04-12-2014, 05:59 PM
So if I sand for 20 seconds on 1500, I am going 40 seconds for 2000. When I get to 3000 I will be at the 60-80 second mark. When I go to polish this out all that is needed is M105 on a yellow W8207 pad and I follow that with M205 on a black W9207 pad for sure fire results.

Mike

Very good advice there, wish I had heard of this a month ago. My process of sanding was probably reverse that, I definitely spent the most time on 1500 and the least amount of time on 3000. Doesn't even make sense now that I'm thinking about it. Hind sight is 20/20.


Undercorrecting. No big deal. Just some time down the drain.

Overcorrecting. Like right through the super thin previously sanded clear. Bad. Car repaint coming our of your pocket.

Always start out gentle on an unfamiliar car. If need be you can always break out the gravel in a bottle later.

Good point. Better I made this post than one saying "help, I burned through my paint".