Rubbing compound for heavy oxidation

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TBarCYa

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I have a black boat that has pretty heavy oxidation that I'm looking to remove. I assume I need a cutting or rubbing compound but what's a good one that I can use on a buffer (not random orbit) that won't damage the gelcoat? Should I get both coarse and fine compounds or just a med/fine and make multiple passes?
 

Scott Danforth

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600 grit, followed by 800 grit, followed by aquabuff 1000, followed by aquabuff 2000 followed by 3M finessit

if you are still north of Bradenton, Fiberglass Coatings in St Pete has Aquabuff on the shelf.
 

TBarCYa

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Are you talking wet sanding or are those the compound grits?

I'm actually on the other side of the state but moving back to the gulf coast in April.
 

Scott Danforth

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Are you talking wet sanding or are those the compound grits?

I'm actually on the other side of the state but moving back to the gulf coast in April.
wet sanding with the 600 and 800. the other 3 are compounds recommended by ondarvr
 

crazy charlie

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Post a few pics.Hard to say what will be best for you without knowing how long its been oxidized,what condition the gelcoat is in,if it has ever been restored before ..etc... Charlie
 

dingbat

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Stuff I use
 

TBarCYa

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Here's a pic of the oxidation. I bought it new in 08 and it got waxed at the start of the season every year until I moved to Florida and the season never ends. So it hasn't been waxed since 2015 and hasn't seen the water since 2018 when the engine died. She's finally almost ready to splash and I'd like her to look nice when she does.View attachment 20220204_083914.jpg
 

TBarCYa

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If the rain lets up I'm going to get started on the sanding. I tested with 400 and 800 by hand and it got to a consistent, smooth dull finish. I didn't see any black coming off, the water was always white. I'm obviously being careful not to cut into the black but that's the question... If I'm not getting down to the color am I going deep enough to remove the oxidation?
 

TBarCYa

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Ok so I went back to my test spot and I don't think I went deep enough with the 400 because it's still hazy. I then started a new test patch with 800, 1000,1500 and 2000 on the machine and it's not hazy but also not shiny. I know it still needs compound, polish and wax before it really shines but I expected more from the 2000.

So the first grit is what should be removing the oxidation and the rest smoothing out the scratches left by the previous sanding so how do I know when to stop the first grit? With the machine I was still getting greyish water when I moved from 800 to 1000.

The port side closest to the drive is the first test and the starboard side closest to the drive is today's.

This is the untouched section
View attachment 20220206_090853.jpg

First test
View attachment 20220206_090903.jpg

Machine test done today
View attachment 20220206_090925.jpg

The test is to the left and the untouched has more gloss with the oxidation
 

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Grub54891

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I had to go up to 3000 grit, then polish from there. Don't have pics but it turned out well. Just hope you don't burn through the gel.
 

Scott06

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Ok so I went back to my test spot and I don't think I went deep enough with the 400 because it's still hazy. I then started a new test patch with 800, 1000,1500 and 2000 on the machine and it's not hazy but also not shiny. I know it still needs compound, polish and wax before it really shines but I expected more from the 2000.

So the first grit is what should be removing the oxidation and the rest smoothing out the scratches left by the previous sanding so how do I know when to stop the first grit? With the machine I was still getting greyish water when I moved from 800 to 1000.

The port side closest to the drive is the first test and the starboard side closest to the drive is today's.

This is the untouched section
View attachment 355503

First test
View attachment 355504

Machine test done today
View attachment 355506

The test is to the left and the untouched has more gloss with the oxidation
After wet sanding it will be dull. Take a small area and compound it , it will be dull after cutting compound as well, shine will start to come out after polish, and really come out after finishing compound .
every time i do this i do a small section start to finish to see how it comes out , sometimes you have to back and do more cutting compound.
 

TBarCYa

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After wet sanding it will be dull. Take a small area and compound it , it will be dull after cutting compound as well, shine will start to come out after polish, and really come out after finishing compound .
every time i do this i do a small section start to finish to see how it comes out , sometimes you have to back and do more cutting compound.
I'm gonna spend this rainy day shopping for compound and wax and buffer pads... If I'm lucky I'll get a day or two this week to try it.

I took a better overall look at the boat and I've come up with a plan... The bow below the rail is in good shape so I'm just going to polish and wax from the bow back until I don't get shine then add compound until that no longer cuts it then wet sand... My hope is that I don't sand more than is absolutely necessary.
 

Scott Danforth

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If you use the aquabuff 1000 and 2000, you only need to sand to 800
 

TBarCYa

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If you use the aquabuff 1000 and 2000, you only need to sand to 800
That's the plan but I can't find it local so I'll have to see how long it takes to get here.

I dug some meguiars compound, polish and wax (stuff I've used on the car) out and gave it a try to make sure I didn't damage the gel coat and it came out amazing on the test section that was sanded with the machine. It's gonna be a ton of work but it'll be worth it in the end.

Question about the bottom... I have to sand it to remove some barnacle remnants but how smooth does it need to be? Would 320 be good or should I go up to 800? Do I have to worry about compound and wax? I've watched a ton of boat detailing videos and nobody seems to bother with the bottom.
 

Scott Danforth

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That's the plan but I can't find it local so I'll have to see how long it takes to get here.

I dug some meguiars compound, polish and wax (stuff I've used on the car) out and gave it a try to make sure I didn't damage the gel coat and it came out amazing on the test section that was sanded with the machine. It's gonna be a ton of work but it'll be worth it in the end.

Question about the bottom... I have to sand it to remove some barnacle remnants but how smooth does it need to be? Would 320 be good or should I go up to 800? Do I have to worry about compound and wax? I've watched a ton of boat detailing videos and nobody seems to bother with the bottom.
the mequiars cleaner wax is something I have used before

regarding teh bottom, mine is as-sprayed which is a far-cry better than it was with the rolled-on anti-fouling paint.
 

TBarCYa

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A quick update.... I spent most of the day yesterday sanding barnacle remnants from below the water line and was able to get one side compounded, polished and waxed. I probably could / should have sanded the rearmost corners where the black is typically in the water but was able to get a good gloss without it. If it ever warms up a bit I'll head out today to power wash the other side and do the same process before moving to the topsides which are white and chalky and very dull.
 

wheller

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I used a variable speed buffer with foam pads and it was the easiest compounding job I have ever done. I bought two 3M Marine rubbing compound bottles but really only needed one for a 28 foot cabin cruiser. After polishing it no longer stains and cleans with ease.
 

aspeck

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I used a variable speed buffer with foam pads and it was the easiest compounding job I have ever done. I bought two 3M Marine rubbing compound bottles but really only needed one for a 28 foot cabin cruiser. After polishing it no longer stains and cleans with ease.
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