buffing gelcoat

It is a known fact that gelcoat oxidizes and fades. Sanding is the only way to remove the oxidized and faded surface of the gelcoat. Even Correct Craft recognizes this fact and thus applies gelcoat thicker than most boat buildiers for precisely this reason (to allow restoring color and shine by sanding or other means of surface removal).

Chris, I know what a DA is- Ive got a PC 7424 DA polisher on my xmas list. I didnt realize that most DA sanders were pneumatic.

The 7424 will be for the car- I bought a Dewalt 849 (rotary) last spring for the boat, and I love it.

PC 7424



dewalt 849

Against my better judgement, I will give my advice on sanding polishing gelcoat (since I have done large areas). IMHO, it is a mistake to use power (or air) tools to sand gelcoat. You run a significant risk of creating flat spots in areas with compound curves. Best to sand by hand. 800 or 1000 grit will take off the surface oxidation a bit if it is not too bad. If you are trying to remove a scratch that you can catch your fingernail on, then forget it and start with 320.

The gelcoat on CC boats is very thick and even with a 4.5" grinder is hard to penetrate (don't try it

So, sand by hand, polish with a 7" grinder with a wool pad (sans the grinding pad). Due to the hardness of gelcoat, polish with a course compound. The course compound will take care of the haziness left after 1000 grit.

with the polishes compounds and such they are pretty much the same but the wax's aren't they are a little different and a marine grade will hold up better over the long haul.

As far as the hand vs. power issue it all goes back to who's hands are operating the power tools as they can get you into trouble pretty quick if you don't know what your doing so bb hand is the safer bet but you won't get as good as a result with power tools in skill hands.

the boat doctor prescribes a bottle of Valium and three cheeseburgers for the bear.those long Fla. days are having a negative effect on his normal laid back attitude,79 lighten up . This is not history cla$$.........

A DA works at the courthouse and sends crooks to jail........... boat dr

   This is too much fun.I believe the proper term for the polisher Tim is referencing is "Random Orbital".Good for bringing out the shine(low speed).Rotary-good for removing refinish scratches(high speed).

Tim,DA sanders aren't agressive unless you want them to be.You honestly could have saved a bunch of time with a finer grit DA disc,and cut the wet sanding in half(at least).If you have deep scratches,DA's are excellent for feathering the edges and eliminating the heavy handwork.Wetsanding bites.

Reguardless,your boat looks great.

   Mike

TRBenj wrote: Mike, I figured I would only do this once, so by hand was my method of choice. No one I spoke to suggested using a DA sander- they all said by hand with a rigid block on the agressive grits was the best way to go, and switching to a rubber block was OK at 600 or 800 grit. I agree, wetsanding bites. Im happy with the results though. <snip>

You chose the best and safest method. I might add that it is ok to sand using the palm of your hand when you get to 600. Rubber sanding blocks should be thrown in the trash.

Regardless of what you call a tool, if it is what you need and suits your needs, you can call it a widget for all I care. IMHO, polishers and grinders are the most confusing of all tools when it comes to names for the many different types of tools available.

79

is that a new type or strain of bees that have moved in on ya'll???? maybe simular to the Killer Bees from Mexico..If possible please give more info so we can be on the lookout for them in La.I have my radar pointed east, looking and hoping they dont come here.BTW the meds must be working i only see 2 bleep bleeps in your post...........boat dr

I am going to go out on a limb here and say that I consider myself fairly skilled in paint or gelcoat finish work (I have done both, more paint than gelcoat). Definately not a pro as I do not do it for a living every day. What I do know is that for the majority of members on this site, if you attempt to use power or air sanders on the compound and concave curves on the boat (i.e. the sides of the hull near the bow), then you run a very high risk of F'ing up your boat.

When I was re-gelcoating this area of my boat, I attempted to use my pneumatic DA sander (huge air hog) and was not happy with the results. The problem is that you cannot get enough of the surface of the pad on the gelcoat and you end up segmenting the surface (i.e. creating flat spots), or taking off too much material too quickly, or problems at the end of your stroke, etc. I ended up respraying the area. The best method was block sanding with the block position in such a manner as to get the best surface area contact. The block size of choice was about 1" wide by about 4" long.

DA sanders on the deck or other convex simple curves work fine.

Go ahead, just try to use that DA at the base of the windsheild where it curves down into the deck...good luck.

You wouldn't, just an example of the many such places on the hull of a boat...like the sides of the hull.

I used a combination of hand sanding, DA, pneumatic file (in-line sander), grinder, palm sanders, you name it to repair my boat. Man, those pneumatic sanders really taxed by air compressor to the point I had to let the compressor rest before I had to rest...what air hogs!

When it was down to the making it look pretty, hand sanding produced the best results, by far.

Now, with that said, if you really watch the automotive pros, they do most of the finish sanding by hand, by far.

Almost forgot this little tidbit. When I was gathering information on materials and methods to repair my boat, I talked in length to a local fibergla$$ boat repair pro who has been in business in my area for dozens of years. I asked him the best way to sand out the orange peel from spraying gelcoat. He said only way to do it right was by hand. He was right! I will say that I used the palm sander in the flater areas to get most of the orange peel sanded down, then switched to hand sanding to get good control when switching to the finer grits.

I will have to agree with 79 on 1 point. It is depending on the skill level. I am sure there are people that can do it with a power sander (whatever type), but I felt more comfortable doing mine by hand which did take longer & it was harder, but I felt like I had more control on how much I sanded by hand. I would probably consider most people on here like me, the weekend warrior that can & will tackle about anything we need to do to our boats, but not considered a pro at any of it. I sure would not respond to anyone asking how to go about bringing back a shine to grab a power sander & have at it. My advise would have to error on the side of caution.

Well if your going to grab a DA and load it with 320 grit paper all your going to do is f**k it up, That's why I said use 1000 grit and 1500, different strokes for different fokes I guess. I don't like spending that much time on something that can be done in a fraction of the time and have the same results. I tryed the hand sanding deal when I had to remove the lettering on the stern spent about a 30-40 mintues and said f**k this called my buddy asked if I could borrow his DA went and got it and was done in 5 minutes using 1000 grit paper. Where with hand sanding it for 30 plus minutes didn't even remove one letter guess I should have used a lower grit paper to realy scratch it up instead of doing what I know was right.

I don't know how this thread got away from me all this time- great entertainment.

TRBenj wrote: A fool with a tool is still a fool.

That's right your still a tool that is a fool.