Buff out oxidized hull..

What you want to do is sand the surface with 1000 grit.
Get yourself some 3M Imperial compound, a wool pad, and a high speed buffer.
Then get some glaze (polish).
I personally use 3M's Perfect It line.
Use number 2 then number 3.
For number 2 you want to use the 3M black glazing foam pad.
Then for number 3 you need the 3M blue glazing pad.
The glaze/polish seals in the compound.
Without it, the compound would just haze up and fade out.
You want the machine spinning at around 2-3 (speed) and move the buffer slowly for best results.
Do an area of 2 square feet at a time.
A lot of people make the mistake thinking that you're supposed to put the buffer speed at full or just under full speed.
But that has a higher risk of burning the gel coat, and it doesn't really allow the compound to get up in there.

When buffing edges, make sure you're making the pad spin off or away from the edges.
Do not have the wheel spinning into the edges, you will burn them.
It's really not hard at all.
If doing outdoors, wear a pair of polarized glasses while doing so.
If not, the glare while buffing will make you see things. lol


For wetsanding the hull, you can use a block and do it by hand.
Or you can use a wetsanding d/a.
Or, you can use a porter cable multispeed sander and dry sand it.
If you want to be sure that you have gotten all the oxidation off, prior to sanding, make sure you mask off everything and mist some "guide coat" or flat black spray paint on the surface.
Allow to dry.
Once it's removed, you know you've sanded enough.

For buffing clear coat, I stick to the Perfect It line. 1,2, and 3.
But for gelcoat, I like the 3M Imperial compound.
It really digs in there and brings it back to life.

I highly suggest using a 3M Hook It pad on the sander, and using Hook It sand paper.
It's much easier and better to work with than Stick It.
And 3M sells some foam pads for the sander for the Hook It system.
It gives it a soft touch so that the sander edge cannot dig into the surface.

Once done, it'll look as good as new, if not better.

Here's another "extended", start-to-finish bit of info I found while searching the 'net:

Tips For Compound, Polish & Wax

Buff Polish & Wax

Try these products (for Gel-Coat only not intended for Awlgrip)

The Cliff Note Version:
Steps:
#1-Clean the hull with an acid base cleaner like FSR, oxalic acid or On & Off to remove rust & tannin staining.
#2-Wet Sand by hand 600 (if real bad) then move up the grits to P1000+ (only if severely oxidized other wise you can start at #3)
#3-3M Marine Rubbing Compound or Presta Gel Coat Compound (use a wool 3M super buff COMPOUND grade pad or Presta black wool pad)
#4-3M Finesse It or Presta Ultra Cutting Creme (Use a foam 3M #05725 pad)
#5-(OPTIONAL STEP) Presta Chroma 1500 - Use 3M #05725 pad)
#6-Collinite #885 Fleet Wax Paste Version- or 3M Performance Paste Wax. For a polymer coating I like AwlCare or Nu-Finish

The Full Detailed Version:

Tools & Supplies:
To be successful in completing this project you'll need a few items first. Don’t be bashful in pulling out the wallet for these supplies, and while you do, think about how much money you’re saving over a new AwlGrip Paint Job. The tools for this project can be used, and will last, for years and years and with each use they cost you less.

#1) Buffer- A good Buffer is an absolute necessity. Unfortunately, one of the cheapies from Wal*Mart or Auto Zone doesn’t count as quality and will yield rather poor results. If you’re buffing the soft paint of a Yugo these buffers might work but not on a 30+ foot sail boat. The “cheapies” ultimately can’t handle the loads & run either too fast or too slow for the material & pad combination you are using. They also cant usually accept quality polishing and buffing grade pads.

A machine with a thumb controlled speed dial will be the best money you spend on an orbital buffer. I use a Makita model 9227C and it’s proven itself to be a reliable and top quality machine. Most of boat yards around here also use the 9227C for buffing and also with 7 & 9" sanding discs. The 9227C comes equipped with a thumb dial for easy access and instantaneous speed control and turns speeds from 600 rpm to 3000 rpm. The difference between my Makita and my brothers old Sears Craftsman is like night and day.

There are many manufacturers of speed-controlled circular buffers but Makita, Milwaukee, Flex (German company) & DeWalt build about the best and most reliable units. When buying a buffer it’s important to buy a unit with a “no load” motor. “No load” means that no matter how much pressure you put on the buffer it will still spin at the speed you set it at. While some boaters have found a cheapy Makita knock off buffer that will work they rarely last or can handle the loads. For a one time job or a small boat a Chinese Makita knock off might be fine. If you want one of these Harbor Freight has one for about $40.00..

Buffer features that matter: 1) No load speed. 2) Weight (lighter is better when working overhead). 3)Thumb control speed dial. 4) Low speeds 600 rpm is a very useful speed but many circular buffers have a slow speed of 1000 rpm. 5) Soft start this helps prevent sling upon start up. A power cord and handle design that makes cord replacement easy.

#2)Buffing Pads- You will need two or three grades of buffing pads or discs. I only recommend 3M pads because they are easy to find and most Napa Auto Parts stores stock them. The 3M heavy wool Hookit Superbuff pads are great for the compounding phase the part number is - 05711. For polishing the yellow wool Hookit polishing grade pad #05713 is anotehr favorite. You can also use the 3M foam polishing grade pads liek the #05725. They are wonderful for adding the finishing touch.

Use a heavy wool compounding grade pad for the compounding, and a polishing grade wool #05713 or the #05725 for the polishing stage and the same #05725 foam pad for the finishing or glazing stage.

I’ll use 3M professional grade foam pads #05725 for the polish & glaze stage but I also use some Lake Country CCS pads. When buffing a gelcoat hull it’s important to match the aggressiveness of the pad to the phase of the buffing though you can experiment too and have great results. You will just not get a good final shine using a heavy compounding grade pad even if you’re using Finesse It or Chroma 1500 with it as the wool itself is too course.

#3) Microfiber Rags- Honestly these are the best invention for buffing & waxing since the buffing machine. I’ve been using microfibers for years and years on antique cars and trust me they have come way, way down in price since their introduction.

A pack of three microfiber rags used to cost me in the vicinity of $40.00 but now you can buy a pack of three at an auto parts store or, gulp, even Wal*Mart, for about $3.00-$4.00. Occasionally Sam’s Club will have them in 18 or 24 packs for about $12.00. When buying microfiber rags be very wary & conscious of the quality. A good rag will look more like a good quality terry cloth towel, with thick full loops. In short, it will be nice and robust and the quality will be visible to the naked eye. Even the worst quality microfiber rags will still outperform the best quality terry cloth so don’t worry too much. Again, these rags are amazing and they will save you time! Trying to compare terry cloth or cotton rags to microfiber rags, for this job, is like pairing Michael Moore & Bode Miller in a ski race. There is NO comparison..

#4) Wet Sand Paper- Usually any good quality wet-sand paper like 3M is fine and grits of 600-1000+ are what will be necessary. If your hull does not need a wet sanding don’t bother buying it. You can actually wet sand the entire project then after 2000+ simply do a polish phase but this can be a LOT of work.

#5) Compounds- All compounds & polishes are not created equally. Avoid buying any compound that uses terms like “essential oils” or has the word “silicone” in the label. Compounds with these additives are intended for novices. Unfortunately, these products, like 95% of the “one step” products will give a false & premature shine. This premature shine is caused by the “essential oils” or “silicone” & will cause you to stop polishing before you’ve actually polished anything due to this false shine. They add these lubricants to the product to make the wheel spin easier and to make you think you are getting a great shine. Sadly the shine is fake, premature and caused by "essential oils or silicones"

Perhaps the best, of the easily available compounds, is 3M Marine Rubbing Compound. I’ve used it with very good success over the years and it works. Is it the best compound? No not at all. Do I regularly use it when compounding? No, but I still do on occasion. 3M Marine Super Duty Rubbing Compound is a good product and it would be considered “paint shop safe” meaning it contains no “cheater oils” like silicone.

If you want very, very good products look up Presta Products on-line. Presta Gelcoat Compound is a GREAT compound that leaves a surprisingly high level of shine before you begin to polish. Presta is generally sold only through body shop distributors and are water based (zero oils), but also worth every penny. For the average guy who just wants his boat shiny 3M is decent. If you’re part of the anal-retentive crowd, who will settle for nothing but the best, do yourself a favor and look into Presta Products it's basically all I use these days and it performs well above the 3M stuff.

#6) Polish- After the compounding phase you’ll need to polish. 3M Finesse It II is a good choice for a polish. I’ve used many bottles of Finesse It II and it’s readily available and “paint shop safe”. Unfortunately, Finesse It II does have some chemical binders or carriers in it that give a minimal pre-mature shine. A quick wipe down with a spray bottle of denatured alcohol and a rag gets rid of this so you can see the real shine you’ve created.

Again, for the next level Presta Ultra Cuttting Creme with the yellow wool #05713 pad is a great step to follow the Gelcoat Compound with. It is my #1 choice for both light compounding and polishing. This unique product, like all the Presta compounds and polishes, uses a very high quality diminishing grit media that starts out more aggressive than Finesse It II but finishes finer than it thus avoiding another full step.


The Process:

Buffing and waxing a boat the right way takes time and is a commitment. On a gelcoat hull of 36 feet I would plan on about 5 hours for doing a two step polish, & wax or about 6-8 hours for a two-step glaze & wax. This is once you get caught up, after your first re-condition, including a wet sanding or compounding, it's usually only a two step process each spring. Unfortunately, the first season of re-conditioning may take you up to 20 hours if your hull is heavily oxidized. It's a commitment but gives a beautiful finish.

One Step Products:

Contrary to popular belief there is no such thing as a one step solution for wet sanding, compounding, polishing and waxing a fiberglass hull. The saying "you get what you pay for" is true and a $10.00 - $18.00 bottle of "one step" cleaner wax just does not cut it if you truly want your boat gelcoat fully reconditioned. Unless you're pinched by time, and are satisfied with a quickie job, and many boat owners will be, you may want to stop reading here. Using a one step cleaner wax is like going to the “touch-less” car wash and ordering the “wax” option for a Porsche. It’s just not the same as doing it the hard & old-fashioned way.

Cleaning the hull:

Before wet sanding or compounding can begin you should thoroughly clean the hull. For this process you’ll need a cheap rain suit, duck tape, rubber gloves and some ON & OFF, On & OFF Gel or FSR gel (basically acid). Duck tape where the gloves meet the raincoat so you don't get acid on your skin while reaching over-head to wash the boat. I find using On & Off, and a car wash brush, as effective, but far quicker, than applying FSR gel and they are both made of the same basic components (acids).

Buy a roll or sheet of plastic and rip it with a razor knife into 12-inch wide lengths. Tape this to your dry hull surface at the water line using 3M green film tape (seems to work) at the top but let it hang on the bottom as a “drip edge” skirt. You do this so the acid in the ON & OFF does not eat the copper bottom paint and can drip on the ground vs. the bottom paint. Wash and rinse quickly a small area at a time and do this preferably before you before you bottom paint just in case. On & Off is basically FSR without the gel. However, you can wash much faster with ON & OFF than you can with FSR. The ON & OFF will bring back the white of the hull by removing the metals or tannins. Tannins are that rusty orange discoloration you get from the ocean over time that attach to the gelcoat. You'll be amazed at the difference in the color of your hull! Even hulls that don’t look bad look amazing after a thorough washing with On & Off. This is a very good place to start before waxing if your boat is older than a few years. Be very careful not to get On & Off or FSR on aluminum rub rails, metals, stanchions, cleats etc. because it will pit them. Only apply FSR or On & Off to a gelcoat hull! Allow about 20 minutes for the skirt set up and 1/2 hour for washing the hull.

Removing the oxidation:

To do it right you must first remove all the oxidation. This will be achieved either by wet sanding, starting with 600 grit, if really bad, and working up to 1000 grit plus. Wet sanding by novices should always be done by hand. Unless you're a seasoned body shop professional do not use a machine to speed up the wet sanding process. While gel coat is very thick & most hulls can be wet sanded & compounded numerous times, compared to Linear Polyurethanes such as AwlGrip or Imron, a novice with an electric or air sander can chew through and ruin the gelcoat quickly if not fully experienced. Doing this by hand, and keeping the paper rinsed and wet, is the key to getting a good result. One trick is to add a little dish detergent to the water bucket as this lubes the paper and helps rinse the gelcoat chalk off when you dip the paper. I like to use a soft damp kitchen sponge as my backing block and it matches the hull contours nicely.

Compounding:

If the hull oxidation is minimal a good heavy duty rubbing compound, such as 3M Heavy Duty or Presta Gelcoat Compound and a 3M compounding grade wool pad #05711 or Presta black pad can and should be the starting point. You’ll know quickly after testing a spot with the compound if you’ll need to wet sand. If you need to spend more than 2-3 minutes on a 2X2 area your using the wrong machine, compound, pad or a combination of the three or you need to start at wet sanding. I can not stress enough the importance of using a compounding grade pad with a compound and a polishing grade pad with a polish. While it is fine to use a polish grade pad with a medium compound like Presta Ultra Cutting Creme you don't want to use a heavy duty pad with a polish or you won't get the desired result.

When compounding do keep in mind that a compound is like liquid wet sand paper. Therefore, you should keep your pad damp at all times. I use a misting bottle filled with water for this but don't over do it. If you are getting lots of small dot "sling" the pad is to wet. If you are a novice I do not advise attempting to use the buffer to "dry buff" or to "buff off" compounds or polishes. Running the pad dry, as in buffing until the compound is off the hull, is something best left for PROFESSIONALS or until you have the confidence and skill to go there. You can very easily damage your hull if you are not experienced at "dry" buffing. I've seen burned and permanently discolored gel coat from novices attempting this. This is part of the reason they put Silicone's in compounds and it's because most people don't understand the concept of how to use a buffer.

As a beginner your buffer should be considered just that a buffer and not a "remover". Work a 2 foot by 2 foot area first going at a slow speed 600 then slowly up to 1000 for 30-45 seconds then turn the dial up to 2k+ but below 3k and stop before it is dry. Next wipe the residue off while it's still in the "damp haze" mode. Don't let it dry or it will be a bear to remove unless you wet it again.. This will show you how much more you need to do or if you can move onto the next 2X2 area. ALWAYS, ALWAYS keep the pad and machine moving!!!

Apply compound in a criss-cross not a circle (note the mist bottle of water):

Edging the pad is for pro's or after you get comfortable with the process & machine !!

Right Way - keep it FLAT..


After compounding phase only using Presta Ultra Cutting Creme (no sanding was done here 30 year old gelcoat):

Pre-compounding Phase:

The polishing phase:

This is perhaps the most important because it gives that deep wet look to the hull even before you wax it. Skipping the very important polishing phase, and using an aggressive compound only, will leave very small, barely visible, scratches or “swirl marks” in the gel coat that will absorb more UV light. It may look very shiny after this step but the sun & UV see the swirls. These micro ridges and valleys or micro scratches, if you will, actually create more exposed surface area, and thus oxidize the hull more rapidly. This is why you should polish the hull as the second phase or third phase depending on your level of oxidation.

So phase 1 is wet sand (if needed), phase 2 compound, phase three polish.

Contrary to popular myths & beliefs you should not be dependent on the wax for the shine of your hull. The wax is a protection layer only and a final sealer to keep the elements at bay and to minimize pollution and dirt from binding to the hull. Unfortunately, most DIYer's actually skip the polishing step thinking compounding is polishing. It's not. Once the hull is polished I do a phase called glazing step (overkill for most unless you’re totally OCD) and then two coats of Collinite Fleet Wax. Most often one coat will suffice but for a really long lasting finish two coats is best. I normally do three at the waterline because this is where the wax sees the most abuse.

The same techniques apply to polishing as do compounding.

After polishing but before wax:


Glazing Phase (optional):

The fourth step, or glazing phase, would be considered over kill by many but this is the step where you literally make the hull surface as smooth as glass removing any traces of “swirl marks”. By using products like Meguiars #9 Swirl Remover or Presta Chroma 1500 you eliminate micro scratches and slow the oxidizing by creating even less surface area for the sun’s UV rays to degrade.

Don’t worry though, if you stop at 3M Finesse It II you’re 90% of the way there and this level of polish is plenty good for most boaters and will last a long time if done right and with patience.

Understanding Grit Levels:

What is grit level? If you were to rate various products on a 1-10 scale of grit (1 being least aggressive & 10 being most) wet sanding at 600 would be a 10 or most aggressive, compounding with a heavy duty compound would be a 6-7, Finesse It a 3-4.5, #9 or Chroma 1500 a 1-3 and wax a Zero.

Using the above scale as a guide you can see why you would not want to jump the compounding phase to a wax. Stopping at the compounding phase will leave swirl marks or micro scratches, which creates more surface area, to absorb UV rays. Stopping at the Finesse It phase will leave considerably less aggressive swirl marks but they will still be there all be it very, very minimally. Going all the way to a glazing phase will leave virtually zero swirls and prolong the time between oxidation's re-appearance.


One Step Products / Liquids:
Don't be fooled by the "easy application liquid carnuba waxes" I've yet to find one that lasts and I've tried many of them! Trust me I did this for a living when I was younger and no one wants to wax a mega yacht every three months! I used to work on and detail "shiny boats" (mega yachts) and found Collinite Fleet Wax #885 paste version to be the longest lasting and hardest of the Carnuba's. Practial Sailor, not once, but twice now has backed up my own personal finding crowning Collinite #885 the king of paste waxes. There are others but Collinte is truly a great product.

One way to test if your wax will pass the test of time is to watch your waterline. If it becomes yellow the wax is dead and gone! With Collinite #885 you can get 6-8 full months without any yellowing at the waterline. No other wax I've tried has even come close.

There are literally hundreds of waxes out there and any one of them is better than none. I only recommend the above waxes because I have used them and found them to be very durable. I have also used many of the “marine” waxes including some of the “teflon” based products, but again, none worked as well as the old-school paste Carnuba’s.

More Process Tips:
When buffing & waxing a boat, out of the water, a good trick is to cover the bottom paint with at least 2" blue tape so you don't accidentally buff and wax the bottom paint. It's important to tape neatly so you get wax as close to the bottom paint as you can without actually getting it on the bottom paint. I usually do a 3/4-inch width tape followed by a 2-inch width giving me plenty of tape to save my buffing pads. Fouling of your buffing pad, with bottom paint, is the end of that pad until you can wash it in a commercial washing machine. To keep "sling", what happens when you use a rotary buffer, and it throws white dots of compound up onto your deck, off the decks, I bring old card board boxes to the boat yard. Lay them on the deck directly above the area you're working protruding about 12" over the edge of the deck. The cardboard overhang will catch any "sl