Question About Polishing Hull

shank

.
Apr 20, 2016
124
Catalina 27 5231 Lake Champlain
Hello, I'm polishing the hull on a 87 C-22 for the first time that I purchased last year. I went over the hull with 220 sandpaper and very lightly wet sanded the more visible scratches and oxidized areas. Now I'm going over the boat with an electric polisher and a wool buffer pad using TotalBoat's rubbing compound. Unfortunately, the scratches aren't really buffing out and it's almost like the sanding made it worse.

A few things come to mind that maybe I'm doing wrong:
1) I'm using the wrong kind of buffing pad. Maybe it's not strong/abrasive enough
2) I need to wet sand the hull again with a finer paper
3) I've never used rubbing compound or an electric buffer before. TotalBoat's product gets good reviews online but maybe it's not that great.
4) Maybe it's just me and I don't know what I'm doing.

Any suggestions are appreciated. Thanks
 

Slartibartfass

Capri 22 Mod
Dec 13, 2015
499
Catalina Capri 22 1139 Mamaroneck, NY
Not much experience myself other than this year with some gelcoat repair and I started with 400 grit going to 600/800/1000/1500 and 2000 grit....

Based on a lot of reading 220 grit is too coarse for polishing. I would not start with anything less than 400 grit depending on the condition and you need to go up to 2000 to get a mirror finish.
 
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shank

.
Apr 20, 2016
124
Catalina 27 5231 Lake Champlain
Thanks for the response. So if I go back over it with the finer papers will that address the scratches or did I do some permanent damage using the 220?
 
Feb 6, 1998
11,669
Canadian Sailcraft 36T Casco Bay, ME
220 is way too aggressive you'll need follow it up with successively finer grit until you get to 1000-1200 before switching to a compound. The lowest I usually recommend is 600 but even this is very aggressive..
 
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Slartibartfass

Capri 22 Mod
Dec 13, 2015
499
Catalina Capri 22 1139 Mamaroneck, NY
Thanks for the response. So if I go back over it with the finer papers will that address the scratches or did I do some permanent damage using the 220?
You should be ok going to finer grit unless you took too much off the gelcoat and the fiberglass shines thru....
 
Aug 2, 2009
641
Catalina 315 Muskegon
Ditto on this set of instructions.
https://forums.sailboatowners.com/index.php?threads/tips-for-a-great-buff-wax.117266/

It was put together by MaineSail, who has responded to your posting, noting that 220 was way too aggressive. The instructions are extensive, and require a bit of study, but are well written. I've used them on a couple of boats, on the topsides and on the deck in the areas without non-skid. FABULOUS RESULTS. I just got home from the marina (Michigan) where folks are getting their boats ready to launch. I mentioned to my wife when I walked in the house, I doubt there is a better looking twenty year old boat in the marina.

If you read MaineSail's instructions and decide to follow them, I strongly advise you to follow them to the letter. Use the type of grinder polisher he recommends, use the pads he recommends, and so on. If you do what he says, you'll have excellent results. If you take shortcuts or think you know better, you will have to be happy with the inferior results.

On a 1987, you could have gone as aggressive a 600 or likely 800, and increased from there...600-800-1000, etc.. All wetsanding by hand, not machine. If you try to sand out deep scratches, you're very likely to end up with lumpy looking topsides. Either fill the big scratches with matching gelcoat or leave them alone.

By starting with 220, you'll want to follow up by wet sanding with 400-600-800, etc.. If you skip a grit you will fail. I followed MS's instruction closely, starting with 600 and working my way through the sandpapers and into the compound and polish, and when I was done, the shine was so deep that applying wax didn't make it shiner (just protects the gelcoat).
 

shank

.
Apr 20, 2016
124
Catalina 27 5231 Lake Champlain
This polishing guide from MaineSail is excellent. Thanks for pointing that out. I'm definitely not into taking shortcuts and will follow this guide precisely. I was just concerned that if I kept sanding after going too aggressive with the 220 that I would make the problem worse.
 
Jun 14, 2010
2,096
Robertson & Caine 2017 Leopard 40 CT
When it comes to sanding, polishing and waxing this is the most detailed instructions I have ever found and its from this forum. Looks like you'll just need to increase the grit of the sanding. Or you can always go the poly-glow route but you'll have many opinions on that route as well.

https://forums.sailboatowners.com/index.php?threads/tips-for-a-great-buff-wax.117266/
Poli Glo is garbage. I used it 4 years before I gave up and stripped it (a difficult job) then compounded and waxed several more years using Mainesail's methods, but the boat would still be chalking again by mid August. I finally gave up and painted it.... Painting is the best move if you have a dark gelcoat.
 
Nov 19, 2008
2,129
Catalina C-22 MK-II Parrish, FL
I've had just the opposite experience with Poly-Glo that Larry evidently had. The preparation is the hardest part. I followed their directions and first used their wax stripper, followed by their oxidation and stain remover. That took a lot of scrubbing with their plastic scrubbing pad. Then the easiest part is wiping on the final Poy-Glo. Probably applied 5-6 coats and gives a beautiful shine that lasts a year or longer. Then I strip it, fairly easy job with their stripper, touch up any stubborn stains, and reapply the Poly-Glo application. I only use it on the hull, does GREAT on those nasty looking gelcoat waterlines. I prefer Meguiar's in the cockpit and on the cabin.

Don
 

AaronD

.
Aug 10, 2014
723
Catalina 22 9874 Newberg, OR / Olympia, WA
Ditto on this set of instructions.
https://forums.sailboatowners.com/index.php?threads/tips-for-a-great-buff-wax.117266/

It was put together by MaineSail, who has responded to your posting, noting that 220 was way too aggressive. The instructions are extensive, and require a bit of study, but are well written. I've used them on a couple of boats, on the topsides and on the deck in the areas without non-skid.
...
Any recommendations on the areas of deck and topsides that are too small for a full 7" or 9" polishing pad? Try to edge in the polisher? (sounds risky). Polish by hand? With the same compounds? Hand-holding the same recommended pads? Or are there other pads better for hand use in those areas? If it's detailed in @Maine Sail's polishing thread, I missed it.
 
Feb 11, 2015
212
Catalina 22 Lake Jacomo
There are many opinions on this, and I'm not saying that any of them are wrong, but I do disagree with some of what has been said. I have owned over 20 boats over the past 30 years. Most of them required some degree of restoration, so I have tried just about every polishing regime known to man. I am not a flipper, I actually kept and used each of them long term, so I got to see how each method held up over time.

The first thing I disagree with is 220 grit being too aggressive. You don't always need to start that aggressive, but if you have deep scratches or gouges to work out then you certainly do. If you have heavy oxidation, starting at 600 as others have suggested will be a complete waste of your time. Sure, you might eventually get where you want to be but you'll burn up a lot of sandpaper and elbow grease in the process. Start more aggressive and work your way down.

The next thing I disagree with is the need to go all the way to 1000 - 2000 grit. Although 220 is not too aggressive to start, it is definitely too course to stop at because you can see the sanding marks. IMO, there is no need to sand beyond 600 - 800 grit, especially if you are following up with a compounding and polishing process. The TotalBoat compound you are using (I'm assuming Total Buff ) is roughly 1000 grit by the way, so it will not get out all of the 220 grit marks, but also would be a step backwards if you had wet sanded all the way to 2000 grit. I suggest wet sanding again with 400, then 600, followed by the rubbing compound. Then move to the polish to remove swirl marks left by the compound, and finish with the wax.

The final thing I'm gonna disagree with is Poli-Glow being garbage. As beautiful and satisfying as a quality polish and wax job can be, it's costly, time consuming, very labor intensive and ultimately leaves you disappointed. I have wasted more hours than I even want to know compounding and polishing to a beautiful finish only to see it dull and chalky 3-4 months later. I prefer to spend more time enjoying my boat than I do laboring over it. I've wanted to try Poli-Glow for 20 years, but every time I had myself talked into it, someone's negative comments on the internet would cause me to shy away. After reading about it for so many years, I have come to the conclusion that most Poli-Glow failures are a result of poor preparation and lack of maintenance. When I got my C22 in early 2015 it was heavily oxidized and chalky. After wet sanding to 600 grit I did the preparation steps and applied several coats of Poli-Glow. 6-8 coats took less time and is much easier than a single coat of wax. The results were fantastic and it has held up impeccably for two complete seasons. I just did a deep cleaning and applied several maintenance coats a few days ago. My boat is now in the water and all the people I've seen out compounding every day for the last month are still compounding.

Here are some before/after pics and video of my boat. I love Poli-Glow!
IMG_0262.JPG
IMG_0287 (2).JPG
IMG_1476.JPG
 
Sep 30, 2013
3,541
1988 Catalina 22 North Florida
That
This polishing guide from MaineSail is excellent. Thanks for pointing that out. I'm definitely not into taking shortcuts and will follow this guide precisely. I was just concerned that if I kept sanding after going too aggressive with the 220 that I would make the problem worse.
That was my concern as well, that you might run out of gelcoat thickness and begin seeing the dreaded dark shadow of fiberglass showing through. This has happened to me after using 400 grit ... a mistake I will never make again. 600 would be my absolute lowest, unless it's a major repair job and I plan to re-gelcoat the area anyway.
 
May 23, 2016
1,024
Catalina 22 #12502 BSC
MainSail's method is the way to go, no disagreement there...BUT, I thought I'd shortcut it and I didn't have 300 buks for all his supplies.

I had moderate to heavy oxidation, boat yard (one of the good ones) advised, not necessary to wet sand on mine, use medium compound (Evercoat 100023) on a buffer at low speed DRY...I was skeptical, had the yard gal (who has been doing this for 20+years) demo it, did a 3' section, dabbed the compound on the hull with a paintbrush randomly, buffed, raked the pad, buffed again, amazing results.

4 hours later, 15 buks to rent the buffer w/a new 3m wool pad, 1 container of compound and I'm done. On a 10 scale probably an 8, (by MainSail's standards) and I haven't waxed yet....plenty good enough for this year, and I need to get it in the water....YMMV...

(agree, 220 too aggressive, I'd follow Gene's and others advice)

Ron
 

dzl

.
Jun 23, 2016
159
Catalina 22 Trailer
I agree with Jacomo. 220 is heavy, not necessarily completely out of the question depending on the situation. Caution is required any way you do it. I think if there's no fiberglass showing through yet, he's probably ok, since follow up sanding is just to take the scratches out, not to go deeper than the scratches.

I do disagree with there's a certain recipe you have to follow. If you have no clue what's going on and want to just follow a grocery list, that's fine... but it's not necessary. The point is to get the surface smooth. Hand sanding with Lowe's sandpaper and buffing with a rag and automotive rubbing compound will achieve that at a minimal cost, and a ridiculous amount of work. So there's a middle of the road. No way you need $300 worth of equipment just to polish gelcoat.

I polish a lot of aluminum. Same process... I use a Black and Decker da sander and an orbital polisher from Harbor Freight. $100 there and they'll last longer than you polish job. Harbor Freight also has the foam pads for the buffer. The wheels on my truck were really bad when I bought it and I started with 60 grit on the orbital and took it up to a mirror finish. As long as you don't cut through the material any grit is fine to start with....
 
Jun 8, 2004
10,062
-na -NA Anywhere USA
Speaking from as a dealer now retired both for Catalina and Hunter, American Marine & Sail Supply, The advice on wet and dry only style sandpaper using water, I use wash the the hull first using a sponge and comet and you heard me right and then washed off with soap and water. Let dry and then did a spot using the paste Finese It by 3M using a low speed buffer only going back and forth. That would determine if 600 grit had to be used first. Using a disc it style polishing pad by 3 M I buffed that hull. sometimes it took twice. Afterwards, I used the 3M cleaner wax followed by two coats of pure Melgise wax for added protection. Yes it took some time and some money but the end result is what counts.