Smooth Bottom

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L

Leo

My bottom is not smooth...my boat that is... Our boatis up on the cradle for the winter and so are others. I have noticed just how smooth these race boats bottoms are. What do I have to do to make it slick like them?
 
Aug 9, 2005
772
Hunter 28.5 Palm Coast, FL
a lot of hand sanding and burnishing....

I repeat, a lot of hand sanding and burnishing!
 
W

William

smooth bottoms abound

I redid the bottom on my C&C last year and it really wasn't that bad. The two biggest tricks...take your time and keep the sander flat against the hull. I sanded all the old bottom paint off with a large body sander (cheap at Harbour Freight). Next I filled in any rough spots and sanded them all smooth. Once that was done I applied several coats of sandable primer and sanded anything that needed it then I applied interprotect 2000. I used 6 or 7 coats and sanded to help smooth out the bottom a little more. After that I used 4 couts of VC17. It was very easy to do, I will admit that I have a great bunch of guys with eions of knowledge in my boat yard and they gave me all the guidence I needed to do it right but it saved me a lot of money and I do enjoy working on my boat. Check out the interlux web site as it has a lot of info that will help you out.
 
Jun 4, 2004
844
Hunter 28.5 Tolchester, MD
BOttom Prep and Wet Sanding

First hand scrape and/or hand sand the hull, keel, and rudder to remove any existing paint that is not compatible with the racing paint you intend to use. Do not be tempted to use a disc sander! Smooth and fair in the entire hull and keel using west systems epoxy mixed with microbaloons to a paste consistency and applied with a rubber squeegee. When you are satisfied with the fairing, smoothness and shape of the hull and keel, scratch sand with 80 grit paper and apply any barrier coat(s) you might want, such as Interlux 2000. Smooth out the roller print orange peel texture or brush marks by wet sanding with 220 grit paper on rubber sanding blocks . Apply at least two coats of your hard finish racing bottom paint with west system foam rollers and wet sand the final surface to remove any orange peel roller texture. Wet sand with 320 to 400 grit wet-or-dry paper, with the final sanding strokes only in the direction of water flow. Obviously you need to be able to move the jack stands supporting the boat to get uniform applications of primer and paint as you do each coat. This is a real test of just how hard you want to work to perfect your boat's bottom finish. You will still need to address all the other usual factors such as decent sails, folding prop, decent crew work and all the usual 'go-faster'equipment you might need to be competitive.
 
R

Rick

Question for William

How are you planning on preparing the bottom for repainting this spring. I also did the same as you you and when I hauled last fall I was pleased with how clean the bottom was. I v'e heard that all you have to do is clean the botom and apply the new paint, but if this is true could you ask your "guys" to define "clean" or how they would recomend repainting VC17 Thanks only 3 months till launch
 
May 18, 2004
259
J-boat 42 conn. river
a lot of good advice here

one way to cut a lot of the elbow work is to apply your new racing paint with an -___AIRLESS___ sprayer. you don't have to deal with all the orange peel and roughness associated with rolling it on. needless to say you can't do this on a windy day unless you would like to clean other boats in the yard. i find that early in the morn or late in the day works well on the chesie. the other beauty is that your not sanding away all that very expensive paint. i noticed that you are in Md. i would not recommend vc17. there's not enough copper in it to be a good antifoulent on the chesie. I've used vc offshore for about 20 yrs on the chesie with good results. its an ablative paint that doesn't have the hassles of build up that baltoplate has and then has to be periodically removed. i started with one color then switched to a different color on top. this lets you know where it might be getting thin. after putting it on with the airless i only have to kiss wet sand with 220, then go to 400, then final burnish with 600.takes me about 4 hours to do the entire bottom on a 30'o'day. one last note. make sure all the previous paint is off. vc paints and balto are not compatable with almost any other bottom paints. it akin to trying to over coat enamal paints with laquer. it just won't work. you'll have orange peel out the wazoooo. capn jim s/v "Que Pasa" Havre De Grace
 

RichH

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Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
A 'close' alternative to a flat racing bottom ....

If you use an ablative paint and have previously put it on with (horrors) a roller you can quickly get a fair flat bottom with the following technique: 1. with a power sander - sand off the tops of the old roller 'pimples' and roughness of the previous paint coat. This will leave approximately 50% of the old paint unsanded and 50% sanded. 2. with a fine thin foam roller apply a single 'stripe' of paint from the waterline all the way down 3. Immediately take a plastic (polyethylene) trowel (used for fairing epoxy or polyester) and quickly 'brush' the painted surface - the paint will be removed from the surface of the sanded 'flats' and will begin to 'fill' the valleys. 4. leave a ~1 foot 'space' between the previously painted 'stripe' and the next 'stripe' ... and continue for the entire hull. When these stripes are fully dry/cured go back and fill-in those areas not painted, slightly 'blending' them into the previously applied new paint. 5. Let fully dry/cure and then repeat. This is the same technique as when 'fairing' epoxy or polyester with a trowel. It usually takes two (total) applications to get a FLAT surface. Leaving a dry stripe between wet stripes will promete less 'mess' when troweling. Next applictation apply horizontal or diagonal stripes when fairing the paint. The flatter and more 'fair' the bottom paint becomes the longer the paint will last. Thinner coats will adhere better than thick coats (and less chance of 'wrinkling'). Once the hull bottom paint eventually becomes FLAT, each successive appliication becomes faster and easier to apply. If you later feel the need to 'flat sand' and 'burnish' (for racing) with wet and dry paper ... it will be much easier if the above techique is applied beforehand. The above technique will produce an 'almost' as flat and smooth bottom as a laborious 'spray then flat sand job' .... and will require much much less work. If you later desire a full 'racing bottom' then such a produced surface is easy to 'finish'.
 

RichH

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Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
Rick ----

The acetone thinner in VC17 dissolves the previously painted VC17. No need to sand VC17 when 'top coating'. If you dont want to apply a sprayed coat, go to my previous post of using a polyethylene trowel. If there is a 'heavy' coat of VC17 still on the boat I simply roll on acetone with a roller to soften the surface then very quickly use a plastic trowel to flatten it. On my racing boat, I apply and trowel, then flat sand with wet and dry then "burnish" the surface with clay-filled newspaper (the 'shiney stiff type of newspaper). The 'burnishing' will physically 'move' some of the VC17 from the 'peaks' and will fill-in some shallow 'valleys'.
 
W

William S/V Liberty Belle

RICK

Rick I Will Just apply another coat to it that is the bennifit of using the VC17. I love the stuff and will never use anything else...the bottom was spotless when we haul it in Dec for the winter (sad Day).
 
Aug 9, 2005
772
Hunter 28.5 Palm Coast, FL
the simplest way to improve the bottom....

without all the work. Try flaring in your thru hulls and bottom fittings. Use micro/lightweight filler applied with a plastic spreader, sand smooth and paint. This is the easiest way to improve the bottom shape and drag coefficient for the least amout of time spent.
 
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