Meguiar's #4 or #84 for extreme fiberglass oxidation

G

gofastman

New member
my friend wants me to clean his boat up a bit, it has been very neglected and the exterior feels like chalk, Im thinking its gonna take some muscle to cut through this stuff, should I start out with one of these (#4 or #84) and a LC purple foam or orange pad on a rotary? I have never done a boat so I really dont know what to expect :scared:



also, once its cleaned up should I hit it with a paint sealant or something like 303?
 
I had the same problem on a recent detail I have done.



Go to your local west marine and pick up 3M Rubbing Compound. Will have green letters. Its sand in a bottle. Also, pick up a wool compound pad, it will cut through the oxidation perfectly.
 
I like to use 105 and wool. If you need something more agressive than 105, I go straight towards wet sanding! Got pics of the job at hand?



GREG
 
Go get this kit and don't even bother with a foam pad on chaulky gel coated fiberglass... get big wool pads and lots of them. You'll be going through a ton of them in a poor condition boat.



product_image.ashx




I can show you some of my boat before and afters if needed but trust me you're in a for loooooooong few days to get it all right.
 
Jakerooni said:
Go get this kit and don't even bother with a foam pad on chaulky gel coated fiberglass... get big wool pads and lots of them. You'll be going through a ton of them in a poor condition boat.



product_image.ashx




I can show you some of my boat before and afters if needed but trust me you're in a for loooooooong few days to get it all right.
Click to expand...



Im using that kit on a 1973 MFG that is orange that has never been buffed. The boat is pretty much all white from being oxidized for so long. With the oxidization remover the gelcoat is coming out shiny orange again.
 
I strongly sugggest that if the boat is very bad (chalky) that you use agressive sanding working your way down to say 1500grit then break out the polish. Compounding a boat that is bad takes more time than, wet sanding it............every experience I have had, its faster.



Cheers,

GREG
 
+1 for the 3M with the green letters, worked amazing on bringing back the hull (white) of my 1996 SeaDoo GTX, took 2/3 passes though.

I recently just did my 21' Crownline that has some black and some white. I used purple wool pad with M105 on my G110, worked wonders, never thought I'd see the black that black, however, it didn't work wonders on the white...evened it out but didn't get an amazing shine. Good Luck
 
I hate wet sanding found a compund from Presta called Super Cut i cant find it on their site but they have it here Super Cut



or you can try this.......Gel Coat Compound



ive used Presta with good results they also say not to use either of these on cars, ive never tried espesscially after you feel the grit in this stuff....
 
Jakerooni said:
Go get this kit and don't even bother with a foam pad on chaulky gel coated fiberglass... get big wool pads and lots of them. You'll be going through a ton of them in a poor condition boat.



product_image.ashx




I can show you some of my boat before and afters if needed but trust me you're in a for loooooooong few days to get it all right.
Click to expand...



The kit/advice mentioned above will be your best bet. The only thing I would ad,Wash the thing with A.P.C. you will not believe all the white crap that comes off doing this.This will surely save you a Pad or 3.:woohoo:Wet sanding should not be nescecary
 
For heavy oxidation on a gel coat, you need to get somewhat mideval.



Twisted wool, rotary, and a heavy cut marine compound are a must. Most likely wet sanding too.



Need to get way more agressive than you would ever dare on auto paint.
 
smprince1 said:
For heavy oxidation on a gel coat, you need to get somewhat mideval.



Twisted wool, rotary, and a heavy cut marine compound are a must. Most likely wet sanding too.



Need to get way more agressive than you would ever dare on auto paint.
Click to expand...



Yes, Medeval is called for from time to time
 
+1 on the 3M compound, wool pads, rotary buffer, and lots of pressure. I few years ago I had a crew of 4 guys and a girl buffing out a 50' Sea Ray Sundancer that had never been waxed. It was chalky white and filthy. Make sure you wash it extremely well with the strongest cleaner you have at your disposal. Then tear into it with the 3M Marine Compound and LOTS of twisted wool pads. Run the buffer at medium/high speed and put a lot of pressure on it (but keep it moving). It took us all 5 days to finish it, but got it looking brand new in the end.



If there's a stripe or any colors on the boat, make sure you're using separate pads for the fiberglass and the vinyl decals (you can actually burn some of the color into the white fiberglass if you use the same pad).



And FWIW, I have been professionally detailing boats for over 10 years. I have used every compound you can ever imagine. And I have NEVER burned through gelcoat; not one single time. Gelcoat is a LOT thicker than most automotive guys think, and it's very forgiving. Lay into that sucker!!!
 
AndrewOSU said:
+1 on the 3M compound, wool pads, rotary buffer, and lots of pressure. I few years ago I had a crew of 4 guys and a girl buffing out a 50' Sea Ray Sundancer that had never been waxed. It was chalky white and filthy. Make sure you wash it extremely well with the strongest cleaner you have at your disposal. Then tear into it with the 3M Marine Compound and LOTS of twisted wool pads. Run the buffer at medium/high speed and put a lot of pressure on it (but keep it moving). It took us all 5 days to finish it, but got it looking brand new in the end.



If there's a stripe or any colors on the boat, make sure you're using separate pads for the fiberglass and the vinyl decals (you can actually burn some of the color into the white fiberglass if you use the same pad).



And FWIW, I have been professionally detailing boats for over 10 years. I have used every compound you can ever imagine. And I have NEVER burned through gelcoat; not one single time. Gelcoat is a LOT thicker than most automotive guys think, and it's very forgiving. Lay into that sucker!!!
Click to expand...



I was really hoping someone would say that! :clap:



also, when you say strong cleaner, do you mean go crazy? I have some stuff with sodium hydroxide that will melt skin off.
 
Has anyone compaired Meguiars 91 power cut compound to 3m marine compound? which cuts faster and works better overall for this type of work?



lastly, I take it 3m's super duty compound is even more agessive then the one with green letters on the bottle. :confused:



3m09004.jpg




vs



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My shop is next door to a marina so I do tons of boats.. love them. In my opinion easier than a car and more money. My process:



Wash with toilet bowl cleaner using a sponge

Buff with Rotary with 105 on a wool pad (if I don't get the results I want I use the Meguiars Boat Resto Kit) About 1800RPM

Buff with 205 on a Meguiars Yellow polishing pad About 1200 RPM

Wax with Meguiars boat wax with Da



Works every time. I can do the outside of a 20' boat in about 3-4 hours. Don't worry about burning through that gel coat!!!!!



I do not do the bottom's of boats for customers. I will get from about the trailer bunks/rollers forward but do not crawl underneath.



I have used Ultimate Compound a few times with great success too.
 
Ok I picked up some LC twisted wool cutting pads and some M105, I still would like to try M04 or M84 first as I rarly use them and I wanna use them up because their getting old. Anybody have any insight as to which compound would be more effective on gellcoat?



yanks_178, you said scrub tha outside with toilet bowl cleaner, should I use the stongest stuff I can find or do you use a perticular brand? Im woried about doing damage to the finish if I use an industrial strienth acid cleaner on the outside.
 
I use the Meguiar's Velocity Mold Release products for heavy oxidation on boats.





Meguiar's Velocity MV80 has the cutting power almost equivalent of about 800grit sand paper.

Meguiar's Velocity MV81 is like the cutting power of 1500 grit, that breaks down to a fine polish as it's used.





It's used in the fiberglass mold productions, to make a glass-smooth finish.



I use MV80 with a W4000 wool pad, for severe oxidation.

MV81 with a W4000 wool pad for heavy oxidation.

MV81 with a W8000 foam polishing pad for mild oxidation/general polishing. I'll usually use this after the MV80/W4000 combo.





It is aggressive stuff. And it will eat through the paint stripes if you're not careful. But to make a gelcoat look brand new, I haven't found anything better. Not that there isn't something better out there, but I've used a lot of different compounds, and those are the best I've found.



Here's a link for the MV80:

Meguiar's Velocity 80 Speed Cut Mold Compound Gallon - SKU# MV8001



And the MV81:

Meguiar's Velocity 81 Mold Compound Gallon - SKU# MV8101





They only come in gallon sizes, though.



Here's a before of some severe oxidation I had on a 65' Novatec yacht:

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Here's an after, from the MV81 and wool pad:

n1535958037_76250_9682.jpg




And here's the profile shot, from using MV81 and a wool pad:

n1535958037_76254_757.jpg
 
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