Wet sand and polish / my results - input?

[SilentSeven]

Backstory: There is mild sun damage on my new-to-me 2004 Nautique 206. Mild can be described as some oxidation and fading on the black transom with some similar fading on the vapor blue waterline stripe. The waterline striping is worse in the aft and disappears as you move forward. Overall, I'd say the fading is consistent with storage on a lift with the transom facing south. Prior to my purchase, the dealer did a buff out on the boat and removed the worst of the transom fading but it wasn't a through job, more of a 'blow and go' to improve the show-ability of the boat. I never saw exactly how bad the oxidation was.

Fast forward to now. I wanted to clean up the remaining oxidation and get the boat looking tip top. The bow area was an easy call - a simple rotary polish and wax was sufficient. For the polish, I used Meguiar's fine cut cleaner and a HF variable speed rotary polisher with a wool pad. This was followed by a wax coat. Results were great...no issues.

For the transom, I used this same approach but didn't have as good of results. There was still hazing in the black with a clear visible line where some of the safety stickers had covered the fiberglass. The vapor blue line also improved but as with the black, I could also see hazing in the line. Based on this, I decided to try a light wet sand. For wet sanding, I used a 2000 grit 3m paper with a soapy water solution and then followed this up with the same rotary buffer / Mequiars polishing compound. I was pretty cautious with the sanding...it was enough to scuff the surface and material was clearly being removed. When I polished the sanded area, I had to use more polishing compound and pressure to restore the shine. All this felt pretty normal.

The initial results on the trailer looked great. The haze was gone and i didn't see any sanding marks. However, after launching the boat and wiping it down combined with getting the boat in some different light, I wasn't as happy with the results. Specifically, there was still haze in the black although it was better than before. And there were still some areas with residual standing scratches from the 2000 grit paper. For the sanding marks, I chalk that up as being due to a less than through polish out - those areas just needed more wheel time & pressure. For the remaining haze, less clear what to do.

So...now to the questions...

1) For black surfaces that have been damaged, is it realistic to expect that I will be able to get all the haze out? From my one of my past lives working as a car detailer, I'm quite aware of the special issues that black surfaces pose.

2) Would I be better serviced to use a two stage standing process? Watching youtube vids, I see people starting a 1000 then progressing to 3000 paper. To me, 2000 felt quite aggressive and I would be hesitant to start with 1000. However, is there a clear benefit of following a 2000 with the 3000? I would expect there would be less need to use the polishing wheel with the compound...

3) How do you gauge what's 'sufficient' sanding? It's tricky to tell how much material you're removing and if you have gone deep enough. I also am keenly away that sanding is a one way door and you if you over sand you really can't go back. Now I get that gelcoat is much thicker than auto paint so there's an extra margin there. Are people just making educated guesses on the amount of sanding then polishing it out and seeing if it was sufficient? And then rinse and repeat until you are happy? I'm OK with this if that's what's really needed...it's just not really time efficient.

Any other tips or tricks that might be helpful?

Thanks in advance for the input!

[Infinity]

My thoughts are you just need to add in a compounding step before the polishing. I rarely go below 2000 grit unless I am working something specific, then I go 1200, 1500, 2000 on the wetsand. Use a sanding block as that keeps gouges from happening and I make sure to wet sand in all directions. With 2000 grit, its hard to go too deep as most gel-coat is roughly the thickness of a CC (flake is a different story). After wet sand is done, then use a compound that is not too aggressive (I use the Boat Candy brand, Crystal Cut Compound...tho every brand has something similar). In my experience, you want to just do smaller 2x2 areas at a time, start start slow and also work it all directions, after I have done a slower pass in all directions, I then speed it up a bit and do it again....and then a final time a bit faster. The more you work compound and polish....the finer you break it down and the better job it does so I take my time....just dont "hold" the buffer pad in one spot, keep it moving since holding it still is what can cause a gel-coat burn. I then wipe it all down well with water and clean with a rag to look closely and make sure it looks like I got deep enough and removed the oxidation/bigger scratches, if not....I do that step a final time and then I move to the polish step using the same steps and variables in speed. Once done with the polish... clean well and inspect to make sure you are happy. I then do a final clean/wipe down making sure to remove all residue and then I wax it all.
Biggest key to it coming out perfect is spending time on it and not rushing the process no matter how badly you wanna be using the boat instead of working on it, lol. First time I did this process I compounded/polished the entire boat in a few hours.... having a black/dark blue/gunmetal flake, everything shows on my boat so I wasn't happy once I walked around looking closely since you could still see some fine scratches where I had not worked it long enough. The 2nd go-around I took my time and inspected every area carefully before moving on to the next section. It took me 30+hrs to do my entire 24ft boat including the final wax coat but the entire thing had a mirror finish and didn't have a single mark in it. Was a very rewarding feeling! That was 2yrs ago....its in the cards again for me sometime this year tho now its just minor swirls that are unavoidable when you have a mostly black hull.

[SilentSeven]

Thanks for the insight. Really appreciated! Your outline lines up with I'm observing...but a few questions please.

Is this the cutting compound you are using? https://www.amazon.com/Boat-Candy-Cr...B00K6Y4VSM This looks more aggressive than the Mequires product I am using.

You mention polish...are you doing a two stage buff out? Meaning starting with the cutting compound then moving to finer polish? I'm thinking I may switch to two stage buff out. Start with a more aggressive compound after the initial sand followed by a finer polishing / swirl remover type compound.

The working a 2x2 section is good advise and your suggestion to work / check / do again is inline what what I am seeing. One problem I was running into was that the surface looked good after initial sand / polish but after I ran the boat and did a wipedown, it seems like I could now see residual sanding scuffs that weren't initially there. I suspect this may be due to having to really wash the surface to see the final result; dry wiping after a polish may leave compounding product on the hull that hides the flaws? Did you experience anything like this?

And thanks for warning to not burn the gelcoat. From my car detailer days (many moons ago) I'm quite familiar with the benefits - and risks - of a high speed rotary polisher. Can be your best friend or worst enemy depending on how you use it.

[Infinity]

Hey,
Sorry for the delayed response.

I actually have all 3 stages of the Boat Candy cutting compound...starts really aggressive with the "Extreme" and works down. Personally tho I have only ever used the least aggressive cutting compound and have never used the extreme since if something was that bad, I would work it with wetsanding first, then the compound, then polish. Yes, I use the Boat Candy polish after the cutting compound is done. So essentially I do the 2 stage process with the variable speed rotary like you said
Yes, I have run into seeing lite scratches after the fact, black shows everything... so I typically check it really well (a good flashlight helps during inspections) and many times will do the polish process 2 separate times so its as perfect as possible. Before waxing I also do a good wipe down of the gelcoat with something to remove any residual compound (I also do that before I start the sanding/compound process to have a nice clean surface). The coat of wax at the end is really what makes things pop.
One thing that I do that helps the polishing...is I have a spray bottle with distilled water and a small amount of dawn dish soap and I "lightly mist" the polishing pad before putting my 5) pea size drops of the compound on the pad, I have found that seems to help my end finish some. FYI....If you put too much water on the pad it will want to sling the polish around once you get the rpm's up toward the end.

For maintenance....I really like the Hot Sauce since it easily removes water spots and also puts a light coat of wax on the finish. I typically wipe down the boat with microfiber cloths and the Hot Sauce after taking the boat out.

[SilentSeven]

No worries at all....lots of distracting stuff these days. Appreciate the feedback. I think I'll stick with the 2k sandpaper in the tough areas but move to a two stage polishing process. I like the wipe / flashlight suggestion...that should help prevent surprises later on....

Next time I get at it, I'll post an update on how it works.

[SilentSeven]

Update / been working out faded areas on the boat (vapor blue waterline) and have had good luck with the following setup.

1 - 2000 wet/dry paper sand
2 - Polish with Harbor Freight variable speed rotary polisher with wool pad - use the lowest speed - "15"

Have tried a few compounds and am really liking the Griots Complete Compound Liquid. Quickly removes the sand scratches but also seems to break down and buff out nicely without swirls. Griots used to be hard find and $$ ...but am now seeing in on the shelf at Autozone and O' Reilly's - picked some up on a $13 whim. This stuff is getting 2 thumbs up from me right now - better than 3M Marine and several Mequires products I have tried.

https://www.griotsgarage.com/product...ks&from=Search

Still up for consideration - deep sand the stern and try to fully recover the black. It's pretty good right now so I may just call it good.