how do you wet sand?

[beagleboy]

How and what do you use to wet sand a boat? I want to remove some swirl marks, scrathes, and dull areas on the cuddy cabin

 

[Amigo]

Have you tried a polish with an electric buffer? 3M makes some good compounding/polish products. Something like 3M High Gloss Gelcoat Compound?

 

[Brad1]

I've wet sanded gel coat repairs to the point that you can't tell where the repair is. Now I forget the exact name of the type of sand paper, but it's the black stuff they sell in either auto parts stores or even home centers that says wet or dry sand on the back of the paper. Anyway, dip the paper in a bucket of water, and start sanding. Occaisionally change the water in the bucket. When I do a gel coat repair, I start with 300 grit, but only to remove the excess gel coat. Then I switch to 600, then to 800, then to 1000. After the 1000, go over it with 3m wax.

 

[blackdiamond296]

Wet sanding is pretty much self explanatory. Brad explained the process correctly- the best thing about it is that you really cant to any serious damage. as long as you keep the water flowin' you'll never accidently over-sand an area- i guess you could say its also the PITA part of wet sanding too bc to get a gel coat repair to factory quality takes a while!

...but as far as your repair is concerned- going over the area with compound and wax might end up being enough to get the job done

 

[jehines3]

600 to 800 wet. Use dishsoap as a lubricant as you are getting close to finishing sanding. Make sure you use a block or keep your finger very tight together and a very flat hand. Don't use your finger tips. If you are mostly after swirl marks, then sanding is not required. Some 3-M finesse-it on a fam pad should get you the results you want. jh

 

[TBone]

600 to 800 wet. Use dishsoap as a lubricant as you are getting close to finishing sanding. Make sure you use a block or keep your finger very tight together and a very flat hand. Don't use your finger tips. If you are mostly after swirl marks, then sanding is not required. Some 3-M finesse-it on a fam pad should get you the results you want. jh

Yes, all that, also I found it helpful (a trick i've used wet sanding cars) to

take an old windex bottle and fill it with the water/dish soap mix, as you're

sanding spray the area with it to help keep it flowing and remove residue.

But you don't need to much soap so just use a squirt or so. Also used the

"spray" nozzle on the bottle as opposed to "stream".

If the swirls are'nt deep go easy with the 600, maybe even start with 800,

go to 1000, then finish with 1200. Then a quick buff with 3M Finnesse It

it will look like glass!

 

[CJBROWN]

3M is the most common wet-sanding paper, and yes, it's black, the finer grits are gray. I have always just used a bucket or tray and keep dipping the paper in the water. You want to be sanding on a water film, it lubricates the surface and keeps the dust from plugging up the paper. I have never heard of soap, but I imagine that would also cut the viscosity and make the water flow better.

400-600 grit is normal for taking a lot of material off, like for orange-peeled spray, or to take down a repair that's considerably higher than the surrounding surface. However, it is relatively easy to sand right through your gel coat so watch out there.

Thousand grit or 1200 is used for final sanding before polishing. I use a wool wheel, but state of the art is now with the new foam polishing pads.

As mentioned, for swirl marks, polishing compound may be in order, then a swirl-mark remover polish - not wet-sanding! I have seen surfaces ruined from inexperienced finishers, paint burned off edges, and paint and gel coat gone right thru. The gel coat is only a few mils thick, albiet Grady's are considerable thicker than other brands.

If you burn through the gel coat you'll have a whole lot bigger project on your hands!

 

[jehines3]

I've also used soft scrub or cleanser to "sand" out stubborn stuff in a pinch when detailing. It will require a deep cut (3-M heavy oxidize remover) pass and a finesse-it pass with the polisher when complete. It is slightly more aggressive than a polisher. These are good to switch to before you hit the machine since they minimize your chances of a burn through. Curved or hard edges do by hand if you have not done this and have allot of practice. Finesse-it works by grit/and heat to get out swirl marks so foam is almost a must for that deep mirror finish.

Make sure if you go to an auto place (much cheaper) to buy finesse-it you buy for light colored finishes unless you have a dark boat 8)

 

[Heavy Duty]

Don't know if this will help...but since corvettes are fiberglass and gelcoat I use a clay bar to get swirls out. Last thing you want to use is sand-paper unless you have to. Last vet i had painted was $5,000. You use the clay bar just like the fine-grit sandpaper and yes the spray bottle with soap water or auto detailer (what I use) works great. As you use the clay bar you will need to nead out a clean spot.

I'd show you some of the results but I don't know how to post pics here.

HD

 

[beagleboy]

Thanks for input. Will try finesse first wet sand later

 

[gradyfish22]

finesse it 2 will work in most cases, if that does not then resort to wetsanding. If you are waxing and upkeeping the boat properly you should not need to get to the point where you need to wetsand, but unfortunetley it can happen. Unless the hull is cloudy and the swirls really set in, finesse it 2 will remove the swirls, do not forget to wax after, after either wet sanding or using finesse it, you leave the gelcoat vulnerable to quick deterioration without wax. My boat is in the water for 6 months, I usually wax my topside twice, once before it goes in and once on a cool overcast day about half way through the summer. My hull gets waxed 1-2 time, it gets a coat before launching, and then one if I need to come out for some service or otherwise I try and use a side dock which is not always an option at my marina.