buffing gelcoat |
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Online Points: 21186 |
Posted: November-07-2006 at 11:48am |
I would think that using an electric sander would be a bigger risk of removing excessive gel coat. Then again, if you know what youre doing maybe youre ok. I hadnt done this before so going by hand was a safer bet. Youre wrong about the shine in my case though, Chris. My deck had yellowed a bit over the years- I removed an original warning sticker and found bright white get coat. I worked on that area only until I got the surrounding gel to match- and only the 320 grit was able to get it close. Polish, compound and the finer grits couldnt. Like I said before, wet sanding is not needed to bring back shine. Its only needed if there is a serious amount of oxidation or fading, like in my case. I would think most people dont need to go that route. |
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David F
Platinum Member Joined: June-11-2004 Location: United States Status: Offline Points: 1770 |
Posted: November-07-2006 at 1:10pm |
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).
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
Posted: November-07-2006 at 3:30pm |
A DA isn't an electrical device it is phnuematic, meaning it runs off of compressed air. Dual Action mean it rotates and vibrates at the same time so there isn't any directional markings.
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Online Points: 21186 |
Posted: November-07-2006 at 3:53pm |
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. |
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
Posted: November-07-2006 at 4:13pm |
I'm sure glade you know what the f**k a DA is because what you have isn't a DA they're both polishers d*ckhead I've never seen an electric version of one to start with. You don't use a DA for polishing it is for sanding only dumb a$$. |
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
Posted: November-07-2006 at 4:20pm |
TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Online Points: 21186 |
Posted: November-07-2006 at 4:30pm |
Sorry to confuse you Chris.
The PC 7424 is an electric "random" orbital polisher. Its commonly referred to as a "DA" because its backing plate spindle is free spinning. You can read more about it on Autopia. Its not to be confused with DA sanders. Like I said, the Dewalt 849 is a rotary polisher. I cant wait to meet you in person- you seem like a real friendly dude. |
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David F
Platinum Member Joined: June-11-2004 Location: United States Status: Offline Points: 1770 |
Posted: November-07-2006 at 4:41pm |
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. |
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88 Nautique
Senior Member Joined: September-20-2006 Location: United States Status: Offline Points: 221 |
Posted: November-07-2006 at 4:56pm |
Does everyone agree that 3M auto compounds and polishers are pretty much the same as marine stuff? I have a plethora of 3M stuff for my cars. I just hate to go out and spend more $$ for a bottle of the same stuff that has the word "marine" on the label.
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
Posted: November-07-2006 at 6:11pm |
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. |
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
Posted: November-07-2006 at 6:21pm |
Far from confused I'm extremely sure you don't know what the f**k your talking about and I've never seen a body man ever confuse a DA for a polisher. porter cable DA |
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boat dr
Grand Poobah Joined: June-27-2004 Location: United States Status: Offline Points: 4245 |
Posted: November-07-2006 at 7:56pm |
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$$.........
A DA works at the courthouse and sends crooks to jail........... boat dr |
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
Posted: November-07-2006 at 8:28pm |
Doc that's right if it is used in a different context or sentence related to a civil or criminal court proceeding or a court of law. But in reference to a sanding application it would refer to Dual Action and then someone makes the foolish statement that they say they know what they are talking about and own said item and then go on to give an erroneous example of a DA and confuse it with a polisher deserves a smart a$$ starcastic remark.
It's realy hard to discripe facial expression or tone of voice on the computer and your a$$umption that I'm raging mad and screaming is also erroneous as well. Since It was done as a general starcastic responce with a normal tone of voice as I was talking to my best friend or a group of my buddies. |
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05 210
Platinum Member Joined: February-17-2006 Location: Southern Maine Status: Offline Points: 1481 |
Posted: November-07-2006 at 10:15pm |
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 |
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Online Points: 21186 |
Posted: November-08-2006 at 7:10am |
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.
Chris, obviously Im no body man. But Im not making this stuff up either. The 7224 and 7336 (same machine with a different counterweight and backing plate) are referred to as "DA's" by detailers. From the article I referenced before: "Some people have defined the Porter Cable 7424’s tool action as “jiggling”, but this is not the case. The head freely rotates on a bearing and orbits around the centerline driveshaft. Rotation is a free-wheeling action of the backing plate spindle caused by the orbiting head. This “dual-action” is where the Porter Cable 7424 gets its “DA” nickname." I didnt mean to mislead anyone- Im just repeating information that Ive gotten from people who know more than me. To add fuel to the fire, Porter Cable calls their 7336SP a random orbit sander with a polishing pad. Maybe its not a true DA like you speak of, but Ive heard it reffered to as such and it is electric. |
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David F
Platinum Member Joined: June-11-2004 Location: United States Status: Offline Points: 1770 |
Posted: November-08-2006 at 8:58am |
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. |
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
Posted: November-08-2006 at 9:12am |
Walk up to a tool truck and ask for a DA and I'll guaranty he's not going to hand you anything with a cord on it made from porter cable, dewalt or any other power tool company that spins less than 6,000 rpm. He's going to hand you a pnuematic sander that spins over 10,000 rpm so If that's what a bunch of other yahoo's are telling you in another chat room keep getting your info there becuase they don't know d*ck about anything either. Scott what are you going to wetsand with your hand or a DA? again it goes back to the skill and knowledge of the end user. Every car that I've ssen painted is wet sanded then polished and they don't use the same piece of equipment to do both, f**king wanta bees.
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boat dr
Grand Poobah Joined: June-27-2004 Location: United States Status: Offline Points: 4245 |
Posted: November-08-2006 at 9:38am |
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 |
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Online Points: 21186 |
Posted: November-08-2006 at 9:47am |
Autopia is one of the largest detailing forums on the net and theres a lot of good info there, so I dont know if I would say they "dont know d*ck about anything." Perhaps the term DA is mis-used when referencing the PC polishers, though. From now on ill refer to them strictly as "random orbital" polishers just for you Chris!
If youre skilled and knowledgeable about using a DA sander, Im sure you could save a bunch of time going that route. However, great results can be had wetsanding by hand for those without those skills or equipment. |
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David F
Platinum Member Joined: June-11-2004 Location: United States Status: Offline Points: 1770 |
Posted: November-08-2006 at 10:03am |
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. |
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
Posted: November-08-2006 at 10:17am |
Again it's back to the skill and knowledge and why you would try and use a 6" pad on a 2" radius bets the hell out of me, Know one ever said that you can do the whole thing with a DA, you don't on a car and sure wouldn't on a boat either, might use a smaller diameter pad to get into the smallr areas but sometimes it's still too big to work.
looked at the autopia site far from authority on detailing, good info but more of a self promotion for the manufacturer of a line a polishes and waxes but you can call it what you want. |
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David F
Platinum Member Joined: June-11-2004 Location: United States Status: Offline Points: 1770 |
Posted: November-08-2006 at 10:29am |
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. |
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Online Points: 21186 |
Posted: November-08-2006 at 10:47am |
If you looked at the forums then you would have realized its all individual contributors sharing their knowledge (just like here). Autopia does have a store, but I rarely find it mentioned in the forums. I dont post there (just search) and have found it a good resource. Of course, you have to weed out the people who dont know what theyre talking about, but you have to do that on any public forum, dont you Chris? |
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skicat
Platinum Member Joined: May-18-2006 Location: Duluth, GA Status: Offline Points: 1129 |
Posted: November-08-2006 at 11:10am |
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.
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Hollywood
Moderator Group Joined: February-04-2004 Location: Twin Lakes, WI Status: Offline Points: 13515 |
Posted: November-08-2006 at 11:22am |
Alright, so I'm a little confused. I got this angle grinder off Ebay for $8 and I want to buff my deck. What pad do I need???
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
Posted: November-08-2006 at 11:26am |
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.
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
Posted: November-08-2006 at 11:29am |
this is what you do throw it in the tool box hook up the trailer to the car and take it to someone that has the right tools and knows what the f**k their doing. |
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M3Fan
Grand Poobah Joined: October-22-2005 Location: United States Status: Offline Points: 3185 |
Posted: November-08-2006 at 11:35am |
I don't know how this thread got away from me all this time- great entertainment.
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Online Points: 21186 |
Posted: November-08-2006 at 11:49am |
A fool with a tool is still a fool. Just kidding, Chris! |
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79nautique
Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872 |
Posted: November-08-2006 at 12:00pm |
That's right your still a tool that is a fool. |
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