Prep work for repainting hull of my boat?

[HillbillyWanderer]

Lots on this but really did not see answer I was looking for. I am planning on painting the entire hull of my Cat22 this winter. My main goal is a smoother faster bottom since I am mainly interested in racing and my boat is always stored on the trailer. The gelcoat has several stress cracks from aft to stern at various places for what I can only imagine. The bottom coat barrier, I have no idea what it is but you rub it with your hand your hand is covered in black. My plan is to sand off the entire barrier coat to gelcoat. As for the stress cracks sand that area down to fiberglass "make sure no damage to structure" and primer. As for final paint not sure about that yet. As i said no need for antifouling paint because the boat will be on trailer. Not sure about the method of painting yet either. Roll/Tip vs. Spray. I have a shop and equipment to spray but seems the Roll/Tip method takes less paint, less messy, and is easier to do with almost the same results. Looking for experienced advice please. Thank you in advance for your time.

 

[Joe]

All your technical questions can be answered by researching the paint manufacturer's resource. Interlux makes two popular topsides paints... a one part epoxy called "Brightside" and the more durable two part "Perfection". That's a start. http://www.yachtpaint.com/usa/diy/products/finishes/search.aspx

When you decide which paint you want to use, and method of application... the specific preparation and application instructions will be attached. You'll want to purchase the recommended additives and thinners recommended also.

There are also many YouTube features on using these products.

I have rolled and tipped with pretty good success. Never tried spraying.. lots of restrictions on that around here.

 

[Charlie Jones s/v Tehani]

Brightsides is not an epoxy paint- it's a single part polyurethane.

 

[tommays]

From a racing standpoint you want to use Durepox "The World's fastest Bottom Paint.

How much it inproves your speed compared to fairly clean gecoat is the sublect of much debate about fluid dymanics and boundary layers

 

[Crazy Dave Condon]

Hillbillywander;

Contact Cave Run via the forum email. He can help you what is best on paints for your lake. Not exactly what you have but the black stuff probably is bottom paint. You may want to power wash off first. If sanding, wear protective clothing, gloves, boots and respirator or you can get sick. Make sure sanding is not around other boats, cars, near buildings, etc as that dust gets into everthing and wash off your boat every time you sand only if sanding off bottom paint. We use to power wash as mentioned and if not, used a scaper. I have removed a lot of bottom paint over my time as a dealer on Catalina 22 sailboats. I am out of town but feel free to contact me via the forum email and I will call and discuss this with you if you want me to.

 

[HillbillyWanderer]

Thanks to all for the info! I will read up on the advised material and just may send you a questions along the way.

 

[Barnacle Bill]

I am a bit confused if you are looking to just apply paint to your underwater surface or from the keel to the gunwales (sides of the boat above the waterline too - the freeboard).
Two different types of paint would have to be used.
Below the waterline I recommend a VC Product that is epoxy and also has teflon in it (but because of copy write problems the word Teflon cannot be used by VC - now an Interlux product). It is called VC Performance Epoxy and is perfect for trailerable boats. It is a very hard epoxy finish and you can spray it on and get a very smooth racing bottom. It has no antifouling properties, so not designed for boats that sit in the water all season. You can also roll it on, but you will have to sand it to obtain a smooth racing surface. Spraying will provide a much smoother surface.

 

[HillbillyWanderer]

I am planning on painting the entire boat starting with everything below the rub rail. I took a pressure washer to the bottom paint and believe I was too close with too much pressure as the paint came off pretty good but also chips of gel coat came off in a feel places as well. You could see the fiberglass mat. Do I need to sand all the way down to the gel coat?

 

[Chris Patterson]

Yes. You'll really need to get bottom paint out of the way in order to effect a repair on the bad spots. Barrier coat on top of that wouldn't hurt.....then..your bottom paint.

 

[Crazy Dave Condon]

I received a personal email from him via forum and will help him with this. I use to sell the Catalina 22 and introduced the new boats for Catalina at Annapolis. I will keep you all advised of what I see and discuss. However, never use a power washer above the water line and with low pressures on the bottom. It does wonder to wood decks as well with high pressure as it will tear up the wood and of course not recommended either. I use to repair bottoms after some used high pressure and did not know what they were doing. Only use the low pressure of bottom paint and if it does not come off, take it off with other means.

 

[HillbillyWanderer]

Finally getting around to prepping the bottom. I used an 5" orbital sander the other day with pretty good results. However, it did not take long to figure out this process will be much easier if I flip the hull. Hoping to get this done in next couple of weeks. Dropping keel and doing some work on it as well. I want the boat to have a good smooth bottom for racing but I am a long way from being where I need to be. What I am saying is I don't want to spend a ton of money on some special type of racing paint if it's not going to really increase the speed of my boat. It's a cost/reward thing. I am thinking barrier coat with another coat of chosen paint scheme I want. Is that the right way to go?

 

[finding41]

I was about 5.5 hours on my back sanding one of my Mac 26D's while it was on the trailer. I used interlux 2000 and rolled it on twice. Afterward I put 2 coats of Aquaguard anti fouling paint on. I don't know if the roller texture helps or hinders the speed of the boat. I would think that it would lengthen the water line by a few mm due to the gentle rise and fall of the texture. (Just like the painted walls in your house.) A longer water line means faster boat. Right...?
That said: If you have the equipment and space to spray, I would spray. I have the equipment to do it to mine... Just not the space to do it.
For those that think spraying uses more paint... It uses less if you do it properly. Do it in a space with no wind at all. Tape and tarp off areas that you don't want over spray on. Wear a respirator.

 

[Jumpstart]

Uh, this guy is on a freshwater lake. Only bottom paint he should consider is Interlux VC 17 or its clone Petit SR21. Remove all previous bottom paint, fair with something like 3M vinylester fairing compound. Interprotect epoxy barrier coat before VC. For freshwater, VC is great with no buildup. Next season clean and roll a coat of VC again. A Catalina 22 should only need one can if you apply it with a west systems foam roller.

 

[HillbillyWanderer]

Hey thanks Wednightracer! Read little bit about the paint sounds like it might fit the bill. The boat will be staying on trailer most all the time except for racing or maybe a few week cruises to the coast a year if I am lucky. Not sure I need any antifouling paint at all.

 

[hawk232]

if you are truly only worried about racing, you don't need any paint at all. paint will add weight and the shiney surface will cause the boat to "stick" to the water more. if you want the paint for looks I would paint it then sand it down with 400 grit to get it dull and leave it at that.

you should also be checking the shape of the bottom. a 36" flexible sanding board will be your friend (but your muscles worst nightmare). to really do it right you would want to hit the whole bottom with a marker paint of some type (just lightly misting it, not an actual coat of paint) the areas that sand clean right away are high, the ones that gradually sand away are just right and the spots that never go away are low and should be faired out. after fairing, mark and sand again until the entire bottom is shaped just right. you should also work to sharpen all of the trailing edges (of the keel and the hull) so that the water will "shear" off rather than "rolling" up and around causing friction.

doing the above on my speedboat took me from 87 to 91mph. a sailboat is a different game but the principles are all the same... you don't want the water to "stick"

 

[CloudDiver]

I just ordered the bulk of the paint I will be using on my C22 hull (all from SBO). Interlux Interprotect for the bottom, Interkote to prime topsides, 3 quarts of Brightsides in Steel Grey for sides, one gallon Brightsides in white for deck, cockpit. I will order the non-skid and bigekote later.
I am using 2 engine hoists (cherry pickers) to flip my hull. I'm actually planning to flip it tonight after work with some friends coming over to lend a hand. I have a dust control system attached to my shop vac which plugs into my orbital sander and 3 inch belt sander. This tool is amazing for keeping airborne dust under control while not clogging up the shop vac's filter. All this is in my resto thread on the C22 page.
I know the hull had been painted before as it is not the original color as far as I can tell. I don't expect to find too many blisters on the bottom, but I do expect to possibly find evidence of previous blister repair. Anyway, I went over this entire paint plan with my local Interlux rep prior to purchasing and hashed out the correct products to use for each application. I won't be racing (yet), so I will chose a bottom paint at a later date, for now it will sit on the stands with the Interprotect after it cures and flip the hull back upright to paint the topsides.
BTW, the paint bill was $430 for this order. Have yet to buy Interdeck (2 quarts hopefully will cover it), 1 gallon Bilgekote (not a requirement but I may as well get it all done while in 'drydock'), and bottom paint. I imagine I will have a total of $850 into paint and disposable paint supplies, but if done right it should last another 20 years.

 

[HillbillyWanderer]

Thanks for the info guys. The InterProtect is something I am seriously considering as a barrier coat. I may just stop there. Thinking I might use a 2 part poxy topside paint after that to get the color I want. Or Could use something like the VC17 if I remember correct its a antifouling, barrier coat and hard racing finish. I have read several threads where guys use this. Also looking at a product called Pettit Vivid. Hawk Thanks for info on flexible sanding board and other tips. Watched a couple youtube clips on it. Hoping to do that as well.

 

[Richard Bryer]

Interprotect is fine without anything on top of it except anti fouling- which is all that VC17 is. It does not have any barrier properties.

 

[CloudDiver]

That some redneck engineering right there son, I tell you whut!

 

[CloudDiver]

BTW, what is better de-waxer for gelcoat after you sand, acetone or denatured alcohol? I have plenty of both. Not really interested in buying the expensive Interlux products when I've heard the above chemicals do the same thing.