black marks

[G0ri11@]

I know this is a question that has been asked and answered 1000 times, but all of the solutions I've read in the archives have failed for me.

My boat was freshly painted about a year ago, but then sat in the previous owner's slip for a couple months before I moved it to mine. While it was there, it received 3 nasty scuff marks from old fenders on both sides. To remove these, so far I've tried:

1. Mr. Clean magic eraser
2. Denatured alcohol
3. 3M compound wax on a powered polisher

The scuffs have improved some, but I really want to get them completely gone before I apply lettering to the boat. Any other suggestions?

I haven't tried acetone, but the PO warned me against using it for a reason I don't really remember. There is no gelcoat, so that is not the issue.

 

[jssailem]

I haven't tried acetone, but the PO warned me against using it for a reason I don't really remember.

Acetone is a strong solvent. You are considering using it on paint. It will likely dissolve the paint and remove any gloss that may still be left.
Perhaps you are no looking at painting again.

You might look at BoatworksToday on Youtube. Andy has a lot of "How To Fix" projects.

 

[SailingLoto]

If acetone dissolves your paint, you've got bigger problems, like who painted my boat with tractor paint?


Any clue what it was painted with? my guess is it's a urethane. you've tried 3 very gentle methods, my next try would be a real compound, 3m super cut, McGuires diamond cut or speed cut. if that fails I would wetsand with 1500 and polish it back.

 

[Head Sail]

Try Goof Off. I think it's mostly ether.

 

[dlochner]

If acetone dissolves your paint, you've got bigger problems, like who painted my boat with tractor paint?


Any clue what it was painted with? my guess is it's a urethane. you've tried 3 very gentle methods, my next try would be a real compound, 3m super cut, McGuires diamond cut or speed cut. if that fails I would wetsand with 1500 and polish it back.

Be very careful with abrasives on painted surfaces. There is a huge difference between one part polyurethane and two part polyurethane paints. The one part paints are softer and will dissolve with solvents. Hit the one part with abrasives and you'll be back to gelcoat.

Check the Boatworks Today Youtube channel, Andy has several videos on fixing painted areas that have been scratched.

 

[jssailem]

Check the Boatworks Today Youtube channel, Andy has several videos

 

[Project_Mayhem]

I use acetone on marks that wont come clean with other chemicals. It usually evaporates before I'm done with it and far before it damages the gelcoat. It seems to get fender scuffs off better than anything else I've tried

 

[Tedd]

It usually evaporates before I'm done with it and far before it damages the gelcoat.

I was surprised to find that it's also quite water soluble, so you can flush it off right after you finish cleaning, to be sure nothing is left behind.

 

[Project_Mayhem]

Try Goof Off. I think it's mostly ether.

@Tedd's comment reminded me that Goo Gone can leave behind some residue that can easily be removed with rubbing alcohol. This was useful for removing butyl from window frames. I'm never using butyl for those again!

 

[Joe]

Use acetone. Don't use an abrasive cleaner. The acetone will remove the rubbery skid marks immediately. Works well with shoe sole scuffs also. Do not be afraid. Dab a small amount of acetone directly from its can to a shop towel or rag. Then use the soaked portion of the rag to apply the acetone to the work area. A gentle circular motion will remove the mark....it will also will remove any wax... so you may want to re apply new wax to the work area when finished. Anyway... rinse with fresh water to remove any solvent that hasn't evaporated. Job done!

If you're still hesitant... try a test run in a concealed area... but I'm sure your fears will disappear with the first try. Remember, dab the acetone on a rag, then work small areas, rinsing as you go. You'll be annoyed that the PO scared you about using it.

 

[berner73]

On gelcoat, both of these have worked well for us in the past. Surprised the 3M cmpd wax didn't do the trick. Good luck.

Starbrite
3M

 

[dlochner]

When recommending chemical like acetone and alcohol, the boat has been painted. It is important to use a cleaner that is compatible with paint. Gelcoat is more impervious to solvents than some paints.

Single part polyurethanes, like Interlux Brightside, will soften and dissolve if some solvents are applied to the paint. This is why it is not possible to apply 2 part polyurethanes, like Interlux Perfection, on top of 1 part polyurethanes.

lt would be best for the OP to find out what kind of paint was applied and then ask the manufacturer for suggestions.

Both Starbrite and 3M make black streak removers.

While it was there, it received 3 nasty scuff marks from old fenders on both sides. To remove these, so far I've tried:

If these scuff marks are actually scratches in the paint and not dirt and grime, then repairing the painted surface will be only good option. Andy on Boatworks Today has some videos about this.

 

[Kings Gambit]

What Joe said above is the ticket. No hard rubbing needed. After I use the acetone, I rinse the area with fresh water from the dock hose.

 

[rgranger]

I was surprised to find that it's also quite water soluble, so you can flush it off right after you finish cleaning, to be sure nothing is left behind.

Acetone or Ethyl Acetate are the two solvents commonly found in fingernail polish remover.

Acetone is also (relatively speaking) environmentally safe in small quantities.

 

[rgranger]

Try Goof Off. I think it's mostly ether.

Mineral spirits!

OTOH: Starter fluid (in the spray can) is almost pure diethylether.

 

[Head Sail]

Mineral spirits!

OTOH: Starter fluid (in the spray can) is almost pure diethylether.

Actually mine say's it contains Xylene.

 

[rgranger]

Actually mine say's it contains Xylene.

Right... -ish

Xylene is a name given to a group of compounds that are dimethyl substituted benzene. Mineral spirits are petroleum distillates and they add zylene and also trimethyl substituted benzene and naptha compounds (naptha are fused benzene rings.)

 

[Stu Jackson]

When recommending chemical like acetone and alcohol, the boat has been painted. >>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

lt would be best for the OP to find out what kind of paint was applied and then ask the manufacturer for suggestions.

Thank you, Dave, for getting those with reading comprehension skills up to date.

 

[dlochner]

Right... -ish

Xylene is a name given to a group of compounds that are dimethyl substituted benzene. Mineral spirits are petroleum distillates and they add zylene and also trimethyl substituted benzene and naptha compounds (naptha are fused benzene rings.)

Oh great. Reading this before heading to bed will no doubt bring about nightmares of organic chemistry from 49 years ago. Can you get PTSD from organic chem?

 

[jssailem]

Dave I believe you can. It is one of those protein molecular links that invades the chemical bonds.....

There will be a pop quiz first thing tomorrow.