Presand the hull before I apply VC17?

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Richard

Was wondering if I should sand the hull with 400-600 grit to get the hull smooth and bump free before we apply the annual coating of VC17? I look at some other boats and their hulls are extra slick and ours has a finish that is not as nice as theirs. Comments...
 

RichH

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Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
Not necessary ......

VC17 goes on 'pimply' due to the very fast dry times because the acetone solvent used 'flashes' so quickly. For my racing boat when applying VC17 I simply take 'stiff' newspaper wadded up into a 'bunch' and burnish the VC17 so it becomes smooth after it 'dries'. The burnishing will 'move' the pimples and actually 'smear' the surface smooth ... the burnishing 'transfers' the VC17 high spots into the 'low spots' ...... then you can wetsand with 400, etc. A better way of application but takes at least two to apply is to apply one coat with a foam roller and let dry. Then use a foam roller to apply the second coat and the second person ***quickly*** draws a large polyethylene trowel with a very flat edge across the wet paint to flatten it into the valleys ..... then flat sand with 400 W&D when all is thoroughly dried. The 'ultimate' way is to use a high pressure (pressure pot) spray gun and build up several coats .... then flat sand. The two person method can almost accomplish the same results as spraying .... but the person with the clean trowel has to work **very** fast. Spraying with an acetone solvent is potentially 'explosive' so ultimate caution must be observed - inotherwords dont spray unless you KNOW how to spray explosive mixtures. (hint: the aircompressor needs an 'explosion proof' motor, etc.
 
D

Dave

Sand VC-17

I have used VC-17, VC-17m for over 15 years. It was always my practice to use a orbital sander every spring to smooth out the surface before applying a new coat of paint. This is my first step in the spring commisioning because of the dust, remember always wear a mask when sanding. VC-17 goes on so thin, it would take years to get any kind of heavy build up if you were using a conventional bottom paint.
 
May 22, 2004
130
Other CS27 Toronto
Do you know what's under the VC 17?

Richard, just a thought, but could the problem be something like the barrier coat under the VC 17. I have seen boats with 2000/2001 under the VC 17 and the "orange peel" finish is quite visible through the thin coat of VC 17. Sanding into the barrier coat may reduce it's thickness. The instructions for VC 17 say to just wash and apply the new coat. No sanding is required. I have seen racers sanding VC 17 but us cruiser types just put on a new coat. Kevin
 
Mar 31, 2004
244
Catalina 380 T Holland
But NO soft Bottom Paint is allowed

VC-17 can go over some hard bottom paints and / or epoxy bottom coats. However, NO soft bottom paint is allowed under VC-17. VC-17 is incompatible with soft ablative bottom paints, adn will probably fall off (I say another boater who had just slapped some VC-17 on the scaly, rough, multicoated bottom of his older boat for the third season in a row really uipset for the third season in a row that there was no VC-17 left on teh bottom of his boat at the end of the season. If you don't know what type of bottom paint you already have on your boat, you should sand the bottom down to either barrier coat or gelcoat (if you don't have a barrier coat) and then apply the VC-17. If you are don't have a barrier coat, you should probably apply one at thsi time. I did this on my first two boats, and it was a royal pain in the but. However, every year after that, I just washed the bottom with soap and water (and, if I was feeling ambitious, a quick wipedown with acetone), let the bottom dry for a few minutes, and then painted with a small foam roller. (actually a standard epoxy roller cut in half). In Lake Michigan, I can't say enough good about this VC-17. Steve Alchemist C-320 #909
 
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