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Old 07-08-2014, 16:39   #16
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Re: Sandpaper Marks Visible in Endproduct?

Full disclosure:

It's not professional, but not because of sandpaper scratching. See link to pic below.

http://www.cruisersforum.com/forums/...cture20911.jpg
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Old 09-08-2014, 18:10   #17
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Re: Sandpaper Marks Visible in Endproduct?

Use guide coat every time you change grits. This allows you to sand until the scratches from the previous grit are totally gone, and no more. Huge time saver. Plus, you won't miss scratches in corners and hard to reach places that you might otherwise. Much more thorough.
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Old 09-08-2014, 19:11   #18
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Re: Sandpaper marks visible in end product?

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Originally Posted by Orchidius View Post
...parts of it had to be sanded by hand with 60 grit sandpaper....
I'm not at all sure and sanding the whole thing again with 220grit as recommended by the paintcompany is a ****ton of work...

Watcha reckon'?...
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...experience also teaches me that I tend to be overly perfectionistic, and in this case that would cost me the remainder of my summer holiday with half the refit still to do...
I reckon that too many DIY-ers try to find excuses to do a Mickey Mouse job.

I would fair it with epoxy and microballoons, sanding through the grits, then 2-part priming it and finishing with 220G, until you get it prepared the way the paint manufacturer recommends.
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Old 09-08-2014, 19:38   #19
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pirate Re: Sandpaper marks visible in end product?

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... I would fair it with epoxy and microballoons, sanding through the grits, then 2-part priming it and finishing with 220G, until you get it prepared the way the paint manufacturer recommends.




Orchidus: Call me. I know how to do this stuff. Am ready for a European adventure. How about a sailboat charter in Greece? Got pals to see.
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Old 10-08-2014, 10:01   #20
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Re: Sandpaper Marks Visible in Endproduct?

Hey guys,

A thank you is in place! I sanded a section with fine grit and put a layer of primer on, smooth as a babies ass!

I have noticed though that the brushstrokes and roller pattern leaves a not-so-smooth surface... How does one go about this? Sand it smooth again between layers (sanding away half the paint you just put on) or leave it as is, just sanding before the last layer?

Cheers!
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Old 10-08-2014, 10:09   #21
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Re: Sandpaper Marks Visible in Endproduct?

Two coats of primer and a light sanding between coats with 150 to 220 I think would work. The base is too hard to sand out the marks from the 60 grit. The primer is a little softer than the base and therefore easier to sand down smooth.

The only way to get a mirror finish is to spray.....I have seen plenty of rolled on or brushed on applications where the guy who did it thought it looked as good as a spray finish...it wasn't. We don't see rolled on car finishes do we? Rolled on is still going to look amateurish regardless of how good you are.
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Old 10-08-2014, 10:13   #22
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Re: Sandpaper Marks Visible in Endproduct?

It's not hard to sand smooth again, it's just that in a paint-system with 2-3 coats primer and 3-6 coats finish you'll end up sanding away half the paint you put on if you sand it smooth between every layer...

Giving it a quick sand between layers to help the paint stick to the previous layer is another matter of course, but then again, that won't help you achieve a slick result either.
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Old 10-08-2014, 13:12   #23
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Re: Sandpaper Marks Visible in Endproduct?

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...The only way to get a mirror finish is to spray...Rolled on is still going to look amateurish regardless of how good you are.
Not true, David.

In fact some professional brush jobs are much better than sprayed as there is not even the slightest hint of orange peel, and no sags or runs. This does require skill and proper technique.
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Old 13-08-2014, 13:57   #24
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Re: Sandpaper Marks Visible in Endproduct?

1. if you dont have at least 100 hours of prep time in you will not be happy with result (especially relative to the cost of the awlgrip).

2. you can get great results with roll and tip but will need to sand between multiple coats.

Note: while i am not convinced spraying is 'easier' then r&t but i roll high build primer and spray top.

3. if you sand thru the primer, it will show thru in the end

4. balloon balloon balloon.

5. the darker the paint the more prep is required

did i say 100 hours of prep... i meant 200.
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Old 13-08-2014, 14:01   #25
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Re: Sandpaper Marks Visible in Endproduct?

That boat needed some more fairing prior to coating.
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Old 13-08-2014, 14:18   #26
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Re: Sandpaper Marks Visible in Endproduct?

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That boat needed some more fairing prior to coating.
u can not possibly be suggesting that more fairing was required b4 she was sprayed...

i put in over well over 500 hours and every inch was board sanded to 220 resulting in a single quarter sized blemish where i removed, filled and faired a mid hull thru hull and the primer was too thin.

-steve
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Old 13-08-2014, 15:01   #27
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pirate Re: Sandpaper Marks Visible in Endproduct?

Wish I could recall the author of something like, "prep and polish the boat til it reflects the true image of wealth and power."
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