Sticky On Bare Metal Prep

rushorwell

rushorwell

New Member
Where can I find a detailed post about bare metal prep?

For example, I used aircraft remover to bare metal. Now what? Oil and grease remover? I'd like to know a sequence.

Thank you for any assistance.
 
jtfx6552 said:
Hmm, I haven't used any chemical paint stripper yet, I didn't realize neutralizing while wet was a thing?

I knew about it for Ospho, but not stripper...
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You also need to neutralize acetone applied to bare metal.
 
Pure acetone leaves no residue, so unless it's contaminated, there is nothing to neutralize. But that's academic, since acetone has no place in cleaning large surfaces like we find in the automotive world, it dries way too fast. If something similarly strong as acetone is needed, there's always MEK.
 
Not trying to pile on but I think it's important to note that acetone is a solvent and does not require neutralizing.

OJ86 said:
Did you nuetralize the paint stripper while it was still wet?
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jtfx6552 said:
Hmm, I haven't used any chemical paint stripper yet, I didn't realize neutralizing while wet was a thing?

I knew about it for Ospho, but not stripper...
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It's not like using an acid product. Ideally you would wash any surfaces where chem paint stripper was used with Dawn. Barring that I have used waterborne W&G remover successfully. SPI 700 would work well. Do it 2X. Apply, wipe off, apply, wipe off.Going over it once with 700 and scrubbing with a scotchbrite pad then wiping down with 700 2X should be fine.
 
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Ya I've always just applied a coat of stripper after everything was all clean and washed it off with soap and water. Never had any issues. I guess I read people having delam issues with it before when it wasn't clean so I never wanted to experiment.
 
crashtech said:
Pure acetone leaves no residue, so unless it's contaminated, there is nothing to neutralize. But that's academic, since acetone has no place in cleaning large surfaces like we find in the automotive world, it dries way too fast. If something similarly strong as acetone is needed, there's always MEK.
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www.slateslice.com

How To Remove Acetone Residue?

Acetone, a colorless liquid also known as propanone, is a solvent used in the manufacture ... Read more
www.slateslice.com www.slateslice.com
 
Acetone is a major component of many cheap W&G removers as well as being in many reducers in varying quantities. It does not need any sort of neutralizing. It also doesn't leave a residue. I don't know what that article is talking about removing as it is not very clear. It seems to be referring to the leftover residue when using acetone to remove something else. That's not acetone residue in the specific sense. Because it's a solvent it dissolves other substances. That would be what that article is talking about removing. The leftover residue from the dissolution.

Acetone itself does not leave residue and most certainly does not need to be "neutralized"
2nd link contains test data for the acetone that company sells. Scroll down to see."residue upon evaporation" data.
www.solventsandpetroleum.com

Solvents, Thinners, and Cleaners for Automotive Use

SPS is a national chemical supplier of solvents, thinners, and cleaners for the automotive industry. Solvent supplies are available in bulk, mini-bulk, 55-gallon drums, totes, and pails.
www.solventsandpetroleum.com

 
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The reason acetone isn't suitable for large surfaces is because it evaporates too fast for the second dry wipe to capture contaminants before the solvent evaporates. Acetone is also strong enough to partially dissolve some substrates that are better left in place, such as the basecoat components of OEM featheredges. This is becoming an unfortunate digression, imo, and serves little purpose other than to say don't use acetone.
 
crashtech said:
The reason acetone isn't suitable for large surfaces is because it evaporates too fast for the second dry wipe to capture contaminants before the solvent evaporates. Acetone is also strong enough to partially dissolve some substrates that are better left in place, such as the basecoat components of OEM featheredges. This is becoming an unfortunate digression, imo, and serves little purpose other than to say don't use acetone.
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I wouldn't say it's a digression. Acetone has many purposes and I used it in an automotive painting prep application. I used it on panels that had been painted and had a layer of contact cement on top of that painted surface. Sure other methods could have been used to remove those two materials. I used acetone for its quick, instant cleaning. It did however leave a residue. That residue is a byproduct of the material that it removed.

When acetone is used and a residue is left from the byproduct that it removed, that residue presents itself as a white film layer. That white film layer is a combination of dried acetone and the byproduct of the material it removed. To completely remove the residue requires wiping it again (reactivating) with acetone, then wiping with a mixture of dishwashing soap,1 teaspoon to 1 cup of water before the acetone dries.

My personal opinion is using the acetone was a faster and cheaper method than media blasting, paint stripper, or sanding off.

Here is a panel that was prepped using acetone with the method listed above.

Removing paint and contact cement with acetone.
IMG_20240302_153801_166.jpg


White residue after cleaning with acetone.
IMG_20240308_132807_023.jpg


I didn't take a picture of the panel after reactivating acetone and cleaning with dish soap and water. Here is the panel after 80 grit on a da before wiping down with SPI 700
IMG_20240310_164737_462.jpg


IMG_20240310_164710_735.jpg
 
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Acetone evaporates extremely fast which doesn't leave enough time to remove the contaminants that it's lifted and dissolved. Thats why acetone by itself is a poor choice for any sort of cleaning. The residue you mention is what is left of what you were trying to remove. What is leftover after the acetone dissolves the contaminant and evaporates before all of it can be removed. Again, pure acetone on a perfectly clean surface evaporates and leaves no residue.

It's no different than using one of the SPI W&G removers and cleaning something and they evaporate before you can get it all off the surface. You would then reapply it. I get what you mean by saying reactivate it but it's not really correct to use it in that context. The film you are speaking of or making a comparison to the acid film left by an acid treatment type product is not a result of the acetone but what's on the surface already that you are cleaning. With acid treatments it is a result of the chemical reaction of the acid reacting with the rust. Similar but not the same. Again I get the point you are making but I didn't want people that are new to this misunderstanding what you were saying and unnecessarily complicating what they were trying to work on. Only reason I'm replying.
 
MEK is a better choice if a very strong solvent is required. From the MEK wiki:
It (MEK) has similar solvent properties to acetone but boils at a higher temperature and has a significantly slower evaporation rate.
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Chris_Hamilton said:
Acetone evaporates extremely fast which doesn't leave enough time to remove the contaminants that it's lifted and dissolved. Thats why acetone by itself is a poor choice for any sort of cleaning. The residue you mention is what is left of what you were trying to remove. What is leftover after the acetone dissolves the contaminant and evaporates before all of it can be removed. Again, pure acetone on a perfectly clean surface evaporates and leaves no residue.

It's no different than using one of the SPI W&G removers and cleaning something and they evaporate before you can get it all off the surface. You would then reapply it. I get what you mean by saying reactivate it but it's not really correct to use it in that context. The film you are speaking of or making a comparison to the acid film left by an acid treatment type product is not a result of the acetone but what's on the surface already that you are cleaning. With acid treatments it is a result of the chemical reaction of the acid reacting with the rust. Similar but not the same. Again I get the point you are making but I didn't want people that are new to this misunderstanding what you were saying and unnecessarily complicating what they were trying to work on. Only reason I'm replying.
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I'll pass your thoughts on the subject to the scientist who wrote the article about incorrect context since that's how he explained it, using the word "reactivate" to remove the dried left over material. Acetone is a interesting chemical. In humans, our body makes a small amount of acetone, which is a natural byproduct for the breakdown of fat.

I didn't even think about trying MEK, probably due to not having any in the garage. I'll have to look up the properties of MEK and see if it would be safe to use as a cleaner before applying paint. Another member here suggested using toluene. For my application, and where the application was being used after reading up on the product, I felt comfortable using acetone.
 
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