Cat Refinishing--What's your take?

If you go to a painted hull, doesn't that mean you need to strip ALL of the gelcoat off?

No.

How did the results not last, and why?

Thought about a wrap?

Hey Collin,
I dont know if you saw the 18square that I painted over the winter, but it turned out pretty good for just rolling and tipping it. I used awlgrip and am very happy with it. It is very forgiving. Just like any paint jon its all about the prep work.

In a nutshell, there are a lot of variables. Cure temperatures and catylist ratio, quality of the gelcoat, thinners, additives, etc. will affect porosity. Gelcoats are porous inside with a non-porous skin on the outside and they are really intended to be applied in a female mold. When it's done this way, the outer surface (in contact with the smooth and fair mold that won't require refinishing) is non porous and last a long time. Once the sun and environment finally gets through that outer layer of gelcoat, the boat becomes harder to keep shiny as the porosity makes the gelcoat more susceptible to breaking down and it will not hold a finish as long.

When we gelcoat on an exterior surface, you have to sand through the outside layer and polish to remove the orange peel to achieve a smooth surface. Once you do that, you remove the durable solid layer and expose the more porous layer that won't hold a finish as long.

That explains much of the struggles I have had with some repairs.

There are good quality Gelcoats that last longer than two years. The place I buy my stuff from have 2 or 3 different types. While I'm not using it anymore adding Duratec additive will make your Gelcoat better.

Another cause of early failure is not finishing the surface properly to begin with. Any sanding or buffing scratches left will accelerate the degradation. I wet sand to #800 or 1000 then use a product called Aqua Buff 2000.

A couple options, Sand without going through the color and coat the existing surface with Duratec Clear Coat (different than the additive) which is a high quality polyester product or sand and coat with a quality urethane (car clear coat). The only issue with clear coating is, are you doing repairs and is the color on the boat consistent?

If your just going to paint look at Awlcraft 2000. Whatever you do get something that can be sanded and buffed. I would stay away from polyurethanes.

What is the particular issue? Is it coming off entirely? Fading?

Here's some things to think about regarding cat refinishing:

New Shine for an Old Hull

(This article was originally published on SailNet in October, 1999, authored by Don Casey.)

http://www.sailnet.com/collections/articles/index.cfm?articleid=caseyd008

There comes a time in the life of every aging sailboat when the hull finally loses all its gloss. No amount of scrubbing or waxing or compounding will restore it. The gelcoat is dead, period. R.I.P.

A stroll through any marina will reveal that the apparent response of many boat owners to this eventuality is little more than a shrug. And why not? Boats sail just as well sans gloss. But the pleasures of a sailboat are not limited to a cracking reach or a smooth tack, and as the surface of the gelcoat erodes, it can take with it a good portion of the joy of boat ownership. If you don't enjoy your boat as much as you once did, maybe it's because it no longer evokes the same sense of pride. This typically has less to do with how a boat sails than how it looks.

You can restore that new-boat gloss—better than new, really—with an application of linear polyurethane paint. If your boat is valuable and your pockets are deep, you may want to have the paint applied professionally, but when you own a $10,000 boat, a $10,000 paint job can be hard to justify. Fortunately there is an alternative that reduces the cost of painting the hull to about $10 per foot of boat length, excluding haulout fees.

Is it really possible to get a great looking finish from paint applied by the

roll-and-tip

method? That is the question I am asked more often than any other, and the answer is an unequivocal yes.

Here is a true story: In the aftermath of Hurricane Andrew, I found myself in the boatyard repairing some abrasions to the hull of our old Seawind, and this necessitated repainting the hull. There was a lot of repainting going on around me, most of it funded by insurance payments. The pros were spraying; I rolled. Three times before I splashed, other boat owners dragged the yard manager over to our boat to ask why their hull didn't look as good as ours.

What they were seeing was not superior skill but higher gloss. Spraying polyurethane requires an aggressive (and dangerous) solvent that flashes off quickly, taking gloss with it. The slower solvent for roller application doesn't have this effect. These sailors saw only the gloss; none noticed that the paint had been applied by a roller.

There is nothing particularly difficult about applying polyurethane to the uninterrupted expanses of hull topsides, but getting perfect results takes a little practice. You can get that productively by painting your dinghy first. If you don't have a hard dinghy, a few inquiries will usually turn up one that the owner would be happy to see refinished. The worse condition it is in, the better. If you can't, scrounge up a dinghy, paint a dock box, a discarded hatch cover, or even plastic laminate (Formica).

The one thing you have to keep in mind with polyurethane is that it doesn't hide anything. Nothing. The paint goes on water thin, and the high gloss accentuates every flaw in the surface. So if you want a perfect finish, you have to be willing to sand and fill and sand some more. Fortunately this is not as difficult as it sounds.

Start by washing and dewaxing the fiberglass. Even if the hull (or, in this case, the dinghy) has never been waxed, the pores in the gelcoat are still harboring mold release that will interfere with the adhesion of the paint. Use a dewaxing solvent and turn and change your rag often.

Sand the dewaxed surface lightly with 120-grit paper—a palm sander makes this go quickly—then fill any obvious gouges with epoxy filler. Sand again and apply two coats of epoxy primer, sanding between coats. The primer will normally take care of both crazing and porosity; use fairing compound between primer coats to fill larger flaws. When you have sanded (and wiped) the second primer coat to a flawless surface, you are ready to apply the polyurethane.

Mix up a small amount of paint, following the manufacturer's instructions for the proper ratio of part A to part B. Here comes the tricky part. The key to getting a perfect finish is adding just the right amount of thinner, but that can vary from day to day, depending on temperature, humidity, and wind. To get it right, you have to sneak up on it. A piece of propped-up window glass will help you get the mixture right.

Start with slightly less thinner than the manufacturer recommends, then brush a small amount of this mix onto the vertical glass. If the paint runs or sags, you already have too much thinner, but it is more likely that you will have too little thinner at this point, exhibited by brush marks in the paint. If these do not disappear entirely in a couple of minutes, add a little thinner and try again. Don't get impatient; keep thinning and testing until the stroke marks disappear.

Pour this mixture into your paint tray and use your foam roller for one final test application on the glass. Lightly drag a dry brush through the paint to smooth it and eliminate bubbles. You need a top-quality badger or an ox-hairbrush for this. Wait a minute or two and the paint should flow out mirror-smooth.

Now just do the same thing to the surface of the dinghy, always working a single wet edge and dragging your brush out through the new roller application from just behind the old wet edge. The job is easier with two people, one rolling and one tipping. Painting with polyurethane is a sprint. Work fast and never go back. You will sand out any flaws after the paint dries.

Let the first coat cure overnight, then wet sand it with 340-grit paper. You can make it easier to see where you have sanded by lightly misting the surface before you start with a contrasting color of spray lacquer. Be sure to wash off all the sanding scum.

Mix and test your paint again to get it exactly right, then apply the second coat. Two coats are normally adequate, but if you aren't satisfied, apply one more. By then you will have the hang of it, and your results are sure to be spectacular. You are ready now to put the same mirror finish on your hull.

The new shine will last into the backside of the next decade; so, too, will the satisfaction.

Six Steps Toward a New Gloss

1. Wash and de-wax the fiberglass. (I like using Naptha for de-waxing or wax remover.)

2. Sand with 120-grit paper, or use a palm sander. Fill gouges with epoxy filler and follow with sanding. Return with two coats of epoxy primer, sanding between coats.

3. Carefully following directions, mix the polyurethane paint. Do a propped-up-window-glass test. Then pour into tray and repeat propped glass test.

4. Employing the roll and tip method, apply the paint, using a foam roller, and follow up with brush.

5. Allow coat to cure overnight then wet sand with 340-grit paper.

6. Wash off sanding scum. After mixing and test paint again, apply second coat.

Fading is why I am not happy with the finish. Repairs are why I have decided to do something about it.

I thought all paints could be sanded and buffed. I know that base coat/clear coat can be sanded and buffed as long as you do not sand through the clear. I don't intend to do a base/clear for the simple reason that repairs will usually leave you with a halo effect around the repair due to fading of the clear coat. This is why bodyshops won't spot repair a body panel but instead will paint an entire panel.
Why would you stay away from polyurethanes?

cross linked polyurethanes (the one's with the 2 part additive) are very tough and extremely difficult to sand...sanding/buffing isn't recommended. You better get those right out of the gun.

[quote=Jake

cross linked polyurethanes (the one's with the 2 part additive) are very tough and extremely difficult to sand...sanding/buffing isn't recommended. You better get those right out of the gun.

Tougher than gelcoat? Don't get me wrong, I don't know everything, hence why I posted the question in the first place. I just thought Gelcoat was the hardest stuff to sand and buff in the coatings world. I was hoping this time for something that would hold a pretty good shine for a long time and would be easy to do small repairs and even relatively easy to recoat the bottom as needed.

Tougher than gelcoat? Don't get me wrong, I don't know everything, hence why I posted the question in the first place. I just thought Gelcoat was the hardest stuff to sand and buff in the coatings world. I was hoping this time for something that would hold a pretty good shine for a long time and would be easy to do small repairs and even relatively easy to recoat the bottom as needed.

Yes...harder than gelcoat. When guys are refinishing boats already painted with the stuff, they try all sorts of things - even sandblasting, to remove it.

would a light coat of some of those shiny/slippery bottom paints work? Pretty pricey, but maybe they offer similar finishes without the anti-fouling compounds?

There was a good article regarding polyurethanes ,I can't find it but the jest is as the poly's cure the good stuff rises to the surface in a very thin, very hard layer. If you sand through this (and you will) you open the softer undercoat to the elements. Like Jake said if you get it right then it's fine as long as you don't plan on doing spot repairs. I remember when we built Kialoa IV the painter orange peeled a good portion of the hull using Awlgrip. The only way to fix was sand it smooth and spray it again. A lot of work and a lot of money on an 80ft hull. So in the future if you want to do small repairs to a poly paint you'll have to re coat the whole boat or at least the side to have a perfect finish.

I used to do small paint repair for car dealerships. I would say most of the cars I did spot work on wouldn't halo. Almost always you would see it on darker colors without flake or pearl like Black or Jaguar British Racing Green. The halo would appear when using the clear coat thinner to blend the edges. I believe since I did most of my work outside in the Florida sun part of the cause was the amount of thinner I would spray trying to blend the edge because the heat was curing the paint so fast. I can't remember ever seeing it happen on a white car. Now a days there are blending solvents that will not halo.

The advantage of Gelcoat is, it's so easy to repair.

There are single stage (no clear coat) urethanes you might want to check out. Never use anything without a catalyst.

Gel coat is on the other end of the spectrum,(pretty soft) which is a good thing seeing how you have to sand orange peel unless you're very good at cyphering,mixing,and applying it and also use duratec. Llook at Awlgrip, Alexseal or Interlux-perfection for hard non-workable coatings.

Collin, you saw my boat now. It looks literally brand new. I had it done with PPG.

Lee, can you elaborate on what you did?

I'm weighting options about giving Undecided a face lift.

I had a local marine paint shop repaint it with PPG. They redid the no-skid and decks as well. It looks like it just came from the factory. The color came in just a tad lighter than I had hoped for but it looks awesome. I also had them lay up the rear beam beds with carbon since this was a common failure point for these boats with a lot of distance racing on them. They then bedded the beams, let it set, removed them, then painted it.

If you plan on doing your own repairs, gel coat is easier if you don't know how to shoot paint. I just re-did an A cat that had a bad paint job ,long board faired, primed and had a buddy shoot it.I had some issues with the paint and some with my driving ,so learned how to shoot the repairs myself. Take my word for it , when it is all said and done gelcoat is easier to apply but requires maintenance. Paint is a pain but holds up longer without as much maintenance.

I had gelcoat work done to it a while ago... its not exactly great looking these days.

I'm just trying to get options together for costs. Not likely that the wife will let me sell her so I got to do something about her looks. She's beyond what a good rubbing compound and buffing can accomplish.

Not likely that the wife will let me sell her so I got to do something about her looks.

You might want to rewrite that... jus' sayin'.

Why?

Its the truth.

edit: I see what you're saying.

Its not likely that the wife will let me sell the boat....

Have you tried Newglass2? If you just have old dull gelcoat this stuff really works. I scrub the boat well with comet cleanser(gets rid of stains and removes oxidation). Rinse, dry, and apply about 5 coats. Just wipe it on. I do this at the beginning of each year and the boat looks like new. This stuff will seal the gelcoat to help prevent further stains. It is about 40 dollars a bottle and I can redo the boat about 4 times with each bottle. If you have repairs to cover this will not work but if it is just old looking gelcoat give it a try.
http://www.newglass2.com/cgi-bin/cp-app.cgi

Yeah I had a bottom job done about 4 years ago where the gelcoat never really kicked.

Plus some patches that are just ugly... some nonskid stains that I can't get out...

Nose repair gelcoat is flaking off... I'm just at wits end with it and want to get it taken care of so I can just forget about it.

great product for adding shine and luster to old gelcoat but does not hold up to fl sun and saltwater. I have used the product for the past 2 years and it requires semi frequent re-coating. not that hard to do, but if adding 4-6 layers of product every 4 months gets old too.

I decided that the N20 was and still is such a fantastic boat and knew I'd regret selling it, so that's why I dumped some money into it to make me happier about keeping it. Whatever my next boat ends up being...I'm going to sand down the gel coat and have it painted.