El Camino Central Forum banner

1 - 8 of 8 Posts

·
Premium Member
Joined
·
4,020 Posts
Discussion Starter #1 (Edited)
Yes, I know. The title really is "Removing stucco from paint".

One of my good nephew's new wife's 2 year old car somehow got many stucco globs all over it. It was there for more than 90 days before he asked for my thoughts.

He "hesitantly" shared that he had tried to use ScotchBrite pads to remove the globs and damaged the clear coat. In case you are considering doing the same thing. Stop considering it. I asked two friends who teach automotive paint detailing if they have heard of using ScothBrite before and both replied, "More times than you can imagine." One replied, "Yep, Satan's Detailing Tool"

It has good useful purposes in our hobby. Surface prep prior to painting used parts is one of them. Surface scuffing of clear coat is rarely a good application.
 

Attachments

·
Premium Member
Joined
·
4,020 Posts
Discussion Starter #2 (Edited)
I sent Nephew this link to a video showing how a mix of white vinegar and water could work to help break down the old stucco gobs.

I asked him to spray a little on, cover with a paper towel then saturate the towel. Let it sit and then use a spoon, plastic if possible and not the edge.

I explained that rolling on the glob was like pushing small sharp rocks into the paint and to go lightly. It did work for him, without much spoon pressure. Much of the time he did not need to use the plastic spoon. It dissolved as it went.
Since vinegar is acidic, he did rinse and not leave it on long.

 

·
Premium Member
Joined
·
4,020 Posts
Discussion Starter #3 (Edited)
So here is our goal for Sunday.

Goal: Diminish the damage and effectively achieve some paint correction.

I will be using tools I have, with a few small things added.

The Plan
Set up
Move pickup so we have flattest part of drive way, access power and detailing cart

Evaluate
Take before images
Wash or clean if needed.
Test for above paint contaminants (Baggy test)
Clay if needed (Meguiar's white mild clay, go to red medium clay if needed)
Clean with 50/50 isopropyl alcohol
Identify and tape areas that need protection

Machine sand as gently as possibly
Meguiar's MT300 dual action polisher with 3” backing plate, plus 3 inch interface foam, plus 3” foam 3,000 sanding disc
At speed 4
Ten seconds max.
Clean with 50/50 isopropyl alcohol and check with flash light
Repeat machine sand until below most paint scratches (10 seconds or less each time)

Compound
Meguiar's MT300 dual action polisher with 5” backing plate and 5” microfiber cutting disk and M100 compound, speed 4.
4 section passes, more if test panel shows it needs it. Did it? How many passes?
Clean with microfiber towel
Test with light. Any sanding scratches remain?
Clean the pad between sections with brush

Polish
Meguiar's MT300 dual action polisher with 5” backing plate and 5” yellow foam polishing pad and Meguiar's M205 Polish, speed 4.
4 faster arm passes, more if test panel shows it needs it. Did it? How many passes?
Clean with microfiber towel
Test with light. Any sanding scratches remain?
Clean the pad between sections with brush

Protect
Meguiar's Ultimate Paste Wax
Buff residue
Check with light
 

·
Premium Member
Joined
·
4,020 Posts
Discussion Starter #4 (Edited)
The plan will need to adapt, based on our test panels.
This same plan might help in a situation on your 2 stage paint one day.

Wish us luck.
 

·
Premium Member
Joined
·
4,020 Posts
Discussion Starter #5
Tools and materials now staged by the garage door near the flattest part of the driveway and electric power.

Will also need a spray bottle of water to help keep the 3000 grit sandpaper clean and just damp. And of course lots of microfiber towels.

Detailing cart is near by with stuff for when the plans change.
 

Attachments

·
Premium Member
Joined
·
4,020 Posts
Discussion Starter #6
A couple of posts to share with you some degree of success and one failure.

The areas where nephew used the vinegar/water short soak resulted in far less damage to the paint

I will show some before and after images.
The plan above worked OK, except, I did not sand where deep scratches had been put near ridges or in the two inch wide concave section near the base of the windshield. These did get compound and polish, which minimized but did not remove the ScotchBrite scratches. The compound in the concave section was applied by hand.

Before images below
 

Attachments

·
Premium Member
Joined
·
4,020 Posts
Discussion Starter #7
Note: Each cars' paint is different. Even if the same brand.

In the plan above, I had to reduce the ten seconds to about 5 to 7 seconds moving the sanding disk over an area and then check. Repeat if needed, but no more than 3 times.

We could remove the 3,000 sanding marks with the M100 compound and the polish.
However the deepest of the ScotchBrite scratches remained.

We used MT100 over the full hood and then M205 polish over the full hood.
There were some other deep RIDS (Random Isolated Deep Scratches) in the hood that we did not sand out. We did compound away many of the less deep scratches.

The scratches inside the 2 inch concave, are too deep to safely remove.

Here is our overall results.
 

Attachments

·
Premium Member
Joined
·
4,020 Posts
Discussion Starter #8 (Edited)
I really feel a need to talk about this process and my one failure. It is important to set realistic expectations and not lead anyone into think sanding on paint is easy.

This is my failure. I understand you might not have had this failure. However I want to tell you where I used poor judgement and technique to keep you from repeating my errors.

In addition to the RIDS, and inflicted scratches, there were four very nasty bird poop damaged areas.

I should have inspected them more thouroughly. Even in this image below, you can see that these went below the clear coat. Why (mistake 1) I did not determine that when working is unknown.

These four were OK in the 3,000 sanding and I went very lightly. When compounded, we hoped we could do better.

I stepped up to 1,500 (mistake 2) and cut the time to under 5 seconds.

When the sanding started, it had some rotation (torque) My nerve damaged hands responded by clamping on to the motor head, which put some downward force (Mistake 3).

The result is the damaged clearcoat paint in the bird poop area disintegrated and we went below clearcoat in one place. I wish I then new that this damaged area would sand that much quicker (mistake 4).

Obviously, we did not use the 1.500 on the other three bird poop damaged areas of the hood (now that was not a mistake).

Due to other previous damage, this car will need to have body work and repaint on the passenger rear door, rear fender, rear bumper and hatch. With my mistake and the 4 hood bird spots, the hood will need to be resprayed when the other work gets done.

My thoughts include:
No more 1,500 grit with my damaged hands.
Practice on junkyard hoods, even with the 3,000 grit.
Use as close to zero pressure as you can when sanding.
Recognize that some stuff is not going to be fixable without a repaint and use minimum work on those spots.

I should have recognized this damage went through the clearcoat.
 

Attachments

1 - 8 of 8 Posts
Top