Sand, Buff or Just Leave Alone?

Trueke

New Member
Looked around this and other forums and cannot find a definitive answer for this questions. I am in the final steps of painting my SF, and don't know what should I do after the final coat (third one) is applied. I am using Interlux Brightside and have wet-sanded (320 grid)in between coats. Should I:

1. Wet-sand the final coat of paint then buff? 320-left the previous coats looking not so shinny and I am worried that even with buffing will not bring the shine out. Should I use another grid?

2. Just buff the paint? Although with not a "mirror-like" finish, the previous two coats have dried pretty well and looked good from s distance (not perfect up close). Will buffing cure this? What should I use to buff other than my orbital buffer and the wool?

3. Will the third coat be enough and leave it as it is? Like I said before, the previous two coats have come out looking good, but not sure if this is as good as it gets. Will it be enough or should I do something else?

I will like to add that the Interlux manual and website are not too specific on how to paint. And that I did not primed the hull nor thinned the paint. I am tipping and rolling.

Suggestions???
 
I would like to also hear an answer since I'm about to paint my boat with Interlux Topside paint. Also, how many quarts of paint have you used on your boat? Thanks.
 
...since we're at it. Any one knows what is the "thickness" of the deck stripe that runs through the middle of the SF (front to back) of later models? I am planning in painting one and want to get it right.

Some'm like so:

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http://www.inland-sailing.com/New_Boats/Vanguard/images/sunfish_12.jpg
 
I would like to also hear an answer since I'm about to paint my boat with Interlux Topside paint. Also, how many quarts of paint have you used on your boat? Thanks.

chau, I so far have used about half of a quart in two coats just on the deck and sides. I am not painting the footwell (thought I leave something original + it was not in bad shape) and the sides look good enough to leave with only two coats. I can kind of still see the old orange stripes through the new paint, therefore a third will be added. I am applying it kind of "light" in order to have no run-offs, and as I mentioned I am not thinning it nor priming the hull. Although I now think priming would have been a good idea since it will save you in number of coats and ensures a better prep and coverage. All in all I think (or hope) that what I have left will be enough for a third coat on the top, and two maybe three(crossed fingers) on the bottom only giving the sides two.

Another thing is that I read people who advised to stay away from the very bright withes interlux offers since the reflection apparently is strong enough to make you go blind:cool:. I am using one of their off-whites and I have to say is really off-white. Does not looks bad, but I think off-white is not a color well suited for a small dinghy. Still it looks waaaaay better than the faded-scratched-patched-up-dirty white and orange it came with.
 
I am using Interlux Brightside and have wet-sanded (320 grit) in between coats.
I would think paint over 320 grit swirls would come out without seeing the underlying effects of sanding. Usually roll & tip comes out with faint ripples hardly noticible even a few feet away. What sort of roughness are you getting? Can you post a picture?

If it’s just a haze you can buff with a polishing compound ... not to be confused with heavier grades of rubbing compound.

Polishing%20Compound.jpg


Are you sure each coat is completely "dry" ... sometimes it can take several days for each coat depending on temperature and humidity.

Did you get the same problem on your practice board when you were testing how light or thick a coat to apply?

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I am painting my top side fire red and the bottom/sides white. The cab area will also probably be white.

Cool, then I guess you will end up getting a quart of each which I think will be more than enough for several coats.
 
Cool, then I guess you will end up getting a quart of each which I think will be more than enough for several coats.


Yea, I already bought the paint, a quart of red, quart of white, and a quart of primer. I was worried I wouldn't have enough primer, but after what you told me, I feel more comfortable now.
 
I would think paint over 320 grit swirls would come out without seeing the underlying effects of sanding. Usually roll & tip comes out with faint ripples hardly noticible even a few feet away. What sort of roughness are you getting? Can you post a picture?

If it’s just a haze you can buff with a polishing compound ... not to be confused with heavier grades of rubbing compound.

Polishing%20Compound.jpg


Are you sure each coat is completely "dry" ... sometimes it can take several days for each coat depending on temperature and humidity.

Did you get the same problem on your practice board when you were testing how light or thick a coat to apply?

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Not much roughness really, just not a mirror smooth finish...:rolleyes:...I guess then that I will be polishing-buffing it...although I got a killer finish on the sides.... Thanks for clearing the difference between polishing and rubbing compounds. I am used to the rubbing but never have touched the polish compound:). I'll be getting some this weekend. And yes, I am pretty sure the paint was quite dry. It has taken me over a week to do these two coats due to the changing weather here in the Northeast. Plenty of time in between coats. Forecast calls for an awesome weekend for painting, sanding, polish, and sailing too:mad:

Practice board:p:p:p...Man you are funny! Where do you get this stuff?:D:D:D

Will post pics hopefully tomorrow.
 
Thanks for clearing the difference between polishing and rubbing compounds. I am used to the rubbing but never have touched the polish compound:)
If you look around, 3M and Maguires both have really fine grit polishing compounds ... they list the grit level on the label ..., like 800 grit and 1000 grit, for example.

The finest grit is what's known as mold polish. It's what's used to polish a fiberglass mold before the gelcoat is sprayed in.

At retail look for this stuff or an equivalent...

1982_2.jpg

Finishing Material is designed for topside paint systems
to remove micro-fine sanding scratches or compound swirl marks.





Practice board:p:p:p...Man you are funny! Where do you get this stuff?:D:D:D

NEVER use your boat for practice ... help someone else fix theirs first, then bring the learning home. :rolleyes:

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NEVER use your boat for practice ... help someone else fix theirs first, then bring the learning home. :rolleyes:


I guess I skipped that part of the lesson.....:p I don't really have anything to practice on either. But I've done body work before, so I'll try to use that to help me.
 
I guess I skipped that part of the lesson.....:p I don't really have anything to practice on either. But I've done body work before, so I'll try to use that to help me.
Well, if you've done body work you probably already know it's laughable right up to the day you slide down the back side of the learning curve..., get a bad batch of paint, or miss a crucial step in the instructions. Then an extra day spent re-sanding and double the expense becomes sobering. But, I'm probably the only one who'd ever do that. :rolleyes:

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Any big difference between the No.7 polishing compound and the 3M fancy-name stuff you posted other than the 20 dollar difference? I know that you get what you pay for, but it never hurts to ask. Another question. If some of these polishing compounds are graded by grit numbers, would it be the same as using the equivalent in paper? Lets say, wet-sand with a 1000 grit sand-paper? Which number should I use for this? Fell free to treat me like an idiot in this topic because I AM really clueless when it come to this. Remember, a few posts ago I had no idea what was the difference between polishing and rubbing compound.;)

Again, anyone out there knows how wide is the middle color line that cross from front to back on newer Sunfish? :confused:
 
Any big difference between the No.7 polishing compound and the 3M fancy-name stuff you posted other than the 20 dollar difference?
I've mostly used the No.7 or Maguires. The important thing is the grade. Most No.7 you find is medium and heavy rubbing compound ... and that's not a finishing polish. Check their web site and see how they distinguish grades. There must be a dozen polish manufacturers too, from Turtle Wax to DuPont.


Another question. If some of these polishing compounds are graded by grit numbers, would it be the same as using the equivalent in paper? Lets say, wet-sand with a 1000 grit sand-paper? Which number should I use for this?
Even when a polish is rated the same as a wet sandpaper the suspension of particles in the compound seems to leave a more swirl pattern free polishing job.


Sorry, don't have a measurement on the GT stripe


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Update:
Called Interlux this morning and the young fella' on the other side of the line told me that once the final coat is applied you are pretty much done:rolleyes:. I should not sand, buff, polish or any of that. Now I will try to follow their advise, but that just seems wrong to me:p.
 
Update:
Called Interlux this morning and the young fella' on the other side of the line told me that once the final coat is applied you are pretty much done:rolleyes:. I should not sand, buff, polish or any of that. Now I will try to follow their advise, but that just seems wrong to me:p.
It may need to cure for a couple of months before it would get any further polishing (SWAG).
 

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