First Cut and buff job. Need some advice.

Discuss anything after that final masking comes off.



Settled In
Posts: 51
Joined: Mon Sep 14, 2020 3:30 pm

Country:
USA
PostPosted: Sun Jan 24, 2021 4:17 pm
Also what RPM do you guys recommend on the buffer for compound and polish?

User avatar

Board Moderator
Posts: 9878
Joined: Fri Oct 20, 2006 12:40 pm
Location: ARIZONA
PostPosted: Sun Jan 24, 2021 4:40 pm
Start out slow, around 600 rpm and then as the compound is spread out a bit, up it to around 2000 rpm.

You want to work an area at a time, left to right overlapping and then top to bottom. Move the buffer slowly but steadily so as not to burn through.

Make sure the buffer is rotating "off" the edges and body lines and not "into" them.
1968 Coronet R/T


ACTS 16:31



Top Contributor
Posts: 6217
Joined: Tue Sep 16, 2008 1:17 pm
Location: Pahrump NV.
Country:
USA
PostPosted: Sun Jan 24, 2021 4:48 pm
See Jim Starts slow! I generally go as fast as I can and control the pressure.
And with a DA I definitely go Fast as fast as Machine will go because it cuts slow It doesn't create the Heat a Rotary does.

Every one has a different technique; that's why there are so many different products and machines, Pads, compounds and Opinions!

It really is a Learned skill what works for one isn't gonna necessarily work for you!
You need to understand the Basic technique have the appropriate equipment and materials and Go do it! you learn by doing it trial and error make up your own way and what works for you.
Me or any one else telling you how to do it is Just how each individual does it each one of us is different each and every one of us gets to the same end result some better results than others because of a number of different factors.

I knew how to do a Basic polish on Laq. paint from decades ago and Buffing gel coat boats, then I got into painting cars while they are a Lill different the process is very much the same.

When i first started doing auto Cut and Buff I got all caught up into listening to others buying stuff and Bought into the 3M Trizact system and wasted a crap load of money on it! Only to come back to what works for me!

Sand once by hand and Polish the Turd


Its Just like Paint Guns You can put a Junk el cheapo Harbor fright gun in a Painters hands and He can lay out a quality job with it you can take a Newb with the Best gun in the world and he will still get runs, Mottle and Tiger stripes! Its not the Guns fault.

We haven't even discussed Dieback yet! That will Blow your Mind!!!!!!!!! :rotfl: :knockout:
Dennis B.
A&P Mechanic, FCC General radio Telephone Operator
Line Maintenance A&P Mechanic and MOC Tech specialist.



Settled In
Posts: 51
Joined: Mon Sep 14, 2020 3:30 pm

Country:
USA
PostPosted: Sun Jan 24, 2021 10:48 pm
Ok guys I spent 7 hours today on half of the roof and almost gave up. I tried the 1200 only grit and it didn't work for me, had even more scratches, so much that when I buffed it I had almost zero shine. I will say I figured out what works for me and it looks absolutely flawless like a show car I can't believe it.

What I did after hours of trying today is I shut off the loud radio that was blasting so I could hear the sandpaper working and if I heard a screech I would stop and start over in that area. I started over with 1200 grit and sanded and sanded and sanded in an X pattern, then I moved onto 1500 and spent another 40 minutes with that just on half the roof lol, used the squeegee and got rid of any big visible scratches which were still really hard to see, then I moved onto 2000 grit and did the same thing for about 40 minutes..

I used the wool pad with M100 and I still had scratches all over, I then used the white 3M white foam pad with the M100 and it looked the same, so I switched to the 3M compound that I had and used the white 3M pad and it looked about 40% better using that compound but still had alot of scratches. I was actually starting at 600 rpm around the edges and being careful then switching to 1200 rpm for the panel and in the end I still had f*****g scratches!! It wasn't till I turned up the RPM to about 2000/2200 that things got alot better. To be honest i was a bit scared to turn that sucker up that high but that is what did it I believe. No radio, constant sanding 1200, 1500, 2000 and turning up the RPM. I polished the roof and it looks stunning, I really didnt think I would be able to get it to look like that. Just hope I can continue to do the rest of the car the same way. Thanks fellas.
Attachments
20210124_181430.jpg
20210124_181318.jpg

User avatar

Top Contributor
Posts: 2762
Joined: Sun Dec 16, 2012 4:46 am
Location: Canberra
Country:
Australia
PostPosted: Mon Jan 25, 2021 6:36 am
Some years ago a member here, OldDupontGuy, put up a video after a similar thread. His contention was that you could sand with just one grit and then go straight to the buff and get a good result. In the video he has the buff absolutely screaming.

One of the compound brands have a demo where they scratch up a painted surface with P240 and then take the scratches out with just their compound and a wool pad on a rotary buff at 1200-1500rpm. I've seen it and I still have the car that they did the demo on - the scratches have never come back.
Chris



Top Contributor
Posts: 6217
Joined: Tue Sep 16, 2008 1:17 pm
Location: Pahrump NV.
Country:
USA
PostPosted: Mon Jan 25, 2021 8:09 am
:goodjob:
NFT5 wrote:Some years ago a member here, OldDupontGuy, put up a video after a similar thread. His contention was that you could sand with just one grit and then go straight to the buff and get a good result. In the video he has the buff absolutely screaming.

One of the compound brands have a demo where they scratch up a painted surface with P240 and then take the scratches out with just their compound and a wool pad on a rotary buff at 1200-1500rpm. I've seen it and I still have the car that they did the demo on - the scratches have never come back.

:goodjob: :goodjob: :goodjob:

ODG knew what he was talking about No Nonsense or BS just what worked!
Dennis B.
A&P Mechanic, FCC General radio Telephone Operator
Line Maintenance A&P Mechanic and MOC Tech specialist.

User avatar

Board Moderator
Posts: 9878
Joined: Fri Oct 20, 2006 12:40 pm
Location: ARIZONA
PostPosted: Mon Jan 25, 2021 3:27 pm
In order for any of the advice you have received to work, you must follow it. Even though we all use different methods and materials, if you picked one and followed it to a "T" it would work for you as well.

I have a hard time believing you followed the directions I gave you - exactly. I can post many pictures of the work I have done using the exact steps I gave you.

Dennis posted pictures of his process and it works as well.
1968 Coronet R/T


ACTS 16:31



Settled In
Posts: 51
Joined: Mon Sep 14, 2020 3:30 pm

Country:
USA
PostPosted: Tue Jan 26, 2021 4:28 pm
I have a hard time believing you followed the directions I gave you - exactly. I can post many pictures of the work I have done using the exact steps I gave you


I actually tried it all step by step and it, but got the RPM settings screwed up. As posted above I believe I have found what works for me on this car. The white paint made it hard to see any scratches, I also had probably alot more orange peel then you pros get so I had to bring that way down. There was alot of variables.

The entire car is sanded to 2000 grit. From 1000, 1500, to 2000 to get rid of orange peel, I didnt take the time to fine tune and remove small scratches in the beginning only concentrated on removing orange peel. Now as I go back on each panel for the cut and buff i carefully hit it with 1200, 1500, and 2000 again concentrating on a small section at a time. Then buff with a wool pad with 3m compound, then a 3m foam pad with 3m compound at around 2200 RPM, then a black foam polish pad with 3M machine polish and I seem to get a good result. Maybe alittle over kill but seems to work for me. I DEFINITELY took alot of advice from this post. Much appreciated.

User avatar

Board Moderator
Posts: 9878
Joined: Fri Oct 20, 2006 12:40 pm
Location: ARIZONA
PostPosted: Wed Jan 27, 2021 12:06 pm
Glad you found something that works.
As time goes on you will perfect your process and find it isn't so daunting. Still a lot of work to produce a mirror finish but most cars don't even come close to that, unless they are for show.
1968 Coronet R/T


ACTS 16:31



Settled In
Posts: 51
Joined: Mon Sep 14, 2020 3:30 pm

Country:
USA
PostPosted: Fri Jan 29, 2021 6:58 pm
most cars don't even come close to that, unless they are for show.


Funny you should say that, after jumping head first into the cut and buff game for the first time, now I'm starting to notice things more, like my newer Chevy ZR2 Colorado that wasn't cheap has more orange peel than an actual orange haha. I can really appreciate what goes into making cars paint look good now. I think when a shop charges you alot to do this that it's worth every penny. I cant imagine doing this everyday to someone else's car and not my own car, hats off to you pros.

I finished the entire roof now and it looks amazing. I found that I had to buff it a few times not just once and expect the scratches to be completely gone. The second time around I would squirt alittle compound on any scratches that remained so I knew where they were located, then i buffed that area carefully without leaving the buffer in one spot too long, but the scratches went away completely. Off to the next panel right now..
PreviousNext

Return to Cut, Buff, Polish & Detail

Who is online

Users browsing this forum: No registered users and 51 guests