How to Paint a Wooden Boat

By: Terry Buddell

One of the great increasing mysteries of today’s modern boatbuilding is the amount of hi-tech gobble-de-gook that the average home boat builder is expected to wade through when the time comes to paint the boat after the horrendous amount of sanding, fairing and hard work is (mostly) over and the fruits of your labour now require a shiny deep lustre that the painting now promises to bring. This part, to my mind at least, is one of the best parts of boatbuilding, the finish! (Well, at least the start of the finish!)

Painting a boat used to be a reasonably simple task. All one needed was a fine dry day, one of Dad’s paintbrushes, some turps, a roll of masking tape, a bit of pink primer left over from the decorating and a half gallon of shiny blue enamel paint from the local hardware store…they were the days!

Not so today, my friends! The unsuspecting boat builder who toddles off to the local chandlery or superstore best be prepared for the very worst- not only will he (or she) face a huge financial onslaught on their wallet but a mind boggling array of hi-tech whiz wow balderdash that the (generally) uninformed shop assistant will proceed to throw in their general direction in the faint hope that you will give in under the stress and buy several litres of the latest polurethanicalslitheryaminomolecular goop that’s just come in. For example, you’ll be faced with trade names like ‘Interlux Interthane coating’. I mean, come on, it sounds like a new space invaders game! This is bloody paint! There are many others but I’m sure you get the gist of what I’m saying.

Another example of the kind of thing that drives me nuts is that you can expect to buy several litres of a iso-cyanate two pack marine polyurethane paint only to be cheerfully told its illegal to spray it unless you have a proper licenced premises to do so, drone drone!! I suppose they have to make up new names to go with the new paint company policies of charging up to $150 a litre for some of these new fangled paints! What the hell have they discovered that’s so expensive to put in this stuff? I was under the impression that paint was a few litres of linseed oil, turps, some drying agents and a few ounces of pigments for colour…can I really be so out of touch?

BACK TO BASICS

So, why do we paint wooden boats? Or any other boat for that matter? The first part of that question is easy. Boats look much smarter and better if they shine and gleam a bit… it’s only human nature after all. The second part to that question is: We want to protect it. Ok, from what? Well, wood rots if you don’t paint it, right? - wrong! Wood left to its own devices does not rot. Wood only rots as a result of its environment. There are multiple cases of how, plain untreated wood can last for centuries as long as it is in the correct environment. There are basically only a few elements that start wood rotting. Biological attack from spores, fungi, temperature, high humidity or total absorption, physical attack from marine borers and crustaceans that allow ingress to all the other elements aforementioned.

Don’t let’s forget that polluted waters can degrade timber to the point where it will rot….we’ll add chemical attack to that list too. So, in view of all these very compelling reasons we protect our boat by painting it to coat it fully against these assaults.

PREPARATION OF TIMBER

The actual preparation of timber can cover a range of differing requirements. If your boat is a new build you won’t have to go through many of the preparatory stages that an older boat may have to go through. With some forms of boatbuilding where a boat has been built by a different method such as strip planking or cold moulding, we paint the boat as if it were a fibreglass boat, due to the fact that either layers of fibreglass cover the timber or that the timber has been coated with epoxy that does not allow conventional paints to adhere to it properly. However, if we wish to protect bare timber then we use a different tack. Timber in its bare natural state has millions of thin hollow tubes running through it, constructed of cellulose in its natural form. We have to seal these tubes to prevent the ingress of water into them. Therefore we seal and coat the timber first of all.

The first thing we do is to clean and remove any loose and flaking or damaged paint plus any dirt that remains on the hull – sounds easy if you say it quick but it must be done! If necessary (and most times it is) degrease the hull using a proprietary paint degreaser after removing all dust preferably with a vacuum cleaner. Don’t forget it won’t be absolutely necessary to get all the hull back to bare wood just dry, clean, grease and dust free.

FILLING AND IMPERFECTIONS

Obviously, not many timber craft are perfect on the outside. There are many blemishes, cracks, imperfections and splits both large and small to deal with by filling them and sanding them flush before priming the boat. It’s a bit of a chore but time spent here will reward you with a boat that will certainly look better plus have a longer life. Some folks fill these holes and imperfections in timber with epoxy filler but it is not a good idea. Sometime later, for example, when the boat has to undergo a repair, it will be the very devil of a job to remove the epoxy from a fastening hole. It’s best to use some kind of proper timber filler that dries hard and fast but is never that hard that it can’t be removed later on. For example, painter’s glazing compound is a fairly hard setting soft paste that can be quickly applied then sanded and painted satisfactorily. Carvel boats usually have their seams filled fair with a special seam compound AFTER the boat has been primed. Once the boat has been filled and faired smooth and all dust removed we are ready to put some actual paint on. Remember, the difference between a professional paint job and an amateur is the PREPARATION!

WOOD PRESERVATIVE

There are two schools of thought about treating bare timber with wood preservatives. I’ve heard stories that primers and paints don’t adhere to many of them. In my case, I have never personally had that happen to me, so I am generally in favour of using them. Nevertheless, I am convinced that in many cases where the paint refuses to stick to timber is because the wood has not properly dried out after application. There is a definite percentage of humidity level that every timber has (and most of them differ slightly) where paint of any description simply won’t stick. It can be up to fifteen per cent in some timbers. Above all, ensure that your timber is dry enough to allow any paint or filler to adhere to it. Remember too that salt deposits on timber will readily contain water and keep it damp…. if your boat was in salty water wash it off in fresh before commencing painting. When and only when, your timber preservative is dry the next stage is:

PRIMER

The first coat of primer to go onto your hull is metallic grey primer. It is a good primer to use because it is made up of millions of microscopic flat metal (aluminium) plates that lie on top of each other giving water a very hard time to pass though it…Pink primer for example, has circular molecules of substances therefore allowing water to ingress a lot quicker…fact! Grey primers also contain certain oils and most have anti-mould agents contained within (biocides to you and I) We put two coats of grey primer above the waterline and three, no less, below it.

SOME OTHER OBSERVATIONS ABOUT PRIMERS

There are a whole world of paint primers out there and confusion about their qualities are very common. For basic dry timbers, the grey metallic primers are good as previously explained. Also many oil–based primers from well-known companies are also very good and will do the job perfectly well. Hi–build primers however must be approached with caution and I must say that I have never personally got on too well with them. Most of them contain Titanium Dioxide (that’s talcum powder to us lot) and even when it is fully cured can absorb copious amounts of moisture that can prevent really good paint adhesion. To avoid this only paint hi–build primers on good clear dry days and avoid excessive atmospheric humidity levels. Then, as soon as is possible apply the topcoats to seal them in. Note too, that hi-build primers are a soft type of paint and can suffer badly from scuffing over stony or shingly beaches and even when launching from boat trailers. When sanding these primers remember that huge clouds of white dust are released so be aware of where you sand and wear appropriate safety masks.

TOPCOATS

Once again, there are many types to choose from. Let’s get the two- packs out of the way first. TWO-PACK POLYURETHANES have to be applied over a two-pack epoxy undercoat first of all. They have a fantastic finish and that’s fine but you must be absolutely sure that the timber underneath is not going to move because the paint cures so hard that it can and will crack (strip plankers and cold moulded boats are your best bet here…apart of course from glass boats). The primary reason is that timber constructed boats move or ‘work’ as it is known. You may well get away with it if your timber boat has been glassed from new….not glassed over later as a preventative method to stop leaks. Rarely boats treated thus dry out properly and are still susceptible to movement as the timber inside the glass either rots because it was wet or it dries out too much and shrinks. Also boats that have been chined properly, that is, strips of timber glued in between the planks instead of being caulked, stand a reasonable chance of not moving.

Ok, what else? One pack or single pack polyurethane paints can be a good choice for a topcoat…they are almost as glossy and as durable as the two–packs but not quite! They are however, less expensive and far easier to apply than the two–packs… there are a multitude of them out there, so a bit of research is required plus your own personal choice…I’m not going to get involved in a slanging match about which ones are the best! However, remember most major well-known paint manufacturer’s products are usually ok! It’s your call!

So next on my list are marine enamels. Once again, it pays to remember that anything with MARINE in front of it is usually expensive…a good place to avoid in this quest is the large hardware chain stores that sport one or two paints in this category and I’ve fallen for it myself before now. It’s the Name we are looking for!

Even with decent quality marine enamels some of the whites have been known to yellow with age and the way round this is to buy the off-white colours such as cream or buff. My last choice in Marine enamels proper, is a relative newcomer…a water-based enamel. I personally have never used any but I have heard some good reports and there has to be a few advantages with them, quick cleanup for one and you can even drink the thinners!

ASSORTED CHOICES

l. Each of the following paints has their different uses and attributes.

HOUSE PAINT ENAMELS

Over the years the quality of house paint enamels has been increasing dramatically to the point where many yachties I know paint their boats with it. It’s a bit softer (and definitely cheaper) than most single pack polyurethanes and some colours, mostly the darker hues, tend to fade earlier than others. However, the fact remains that they can be an excellent choice especially if you own a small boat and don’t mind repainting it every couple of years….cheap to buy, easy to apply!

WATER BASED ACRYLICS

A few years ago you wouldn’t have dreamed of painting your boat with acrylic paint….it would have peeled off in great strips. That does not apply today however. My own boat, The NICKY J has been painted using Wattyl’s Acrylic semi–gloss “CANE” and it is really amazing. I used gloss for the hull and semi–gloss for the decks over white epoxy primer single pack and it has been really good. Never once has it even looked like delaminating. I paint the boat once a year with a roller and it takes less than a day…and she’s forty two feet long! It is yet another choice!

Well there’s your main paint choices but I urge you to remember one thing…preparation is King… it will save you plenty of money in the long run, for sure.

HOW TO APPLY YOUR PAINT

There are of course, three main methods of applying your paints; Spraying, brushing and rollering. There’s another that many people use, a combination of the last two, rolling and tipping, we’ll deal with that one later.

Let’s take a look at spraying. There are several pre–requisites for a decent spray job. These usually are a decent workshop complete with suction fans and half decent ventilation using good spray gear (cheapo underpowered stuff just doesn’t cut the mustard) and most importantly, adequate and proper safety gear. There are always exceptions to the rule and there’s one chap who works in Edge’s boatyard outside in the weather and he does a fantastic job…imagine how much better he might be if he worked indoors!! You will also have to watch the weather, high humidity is not good and also where the overspray goes…not over anyone’s car as is so often the case! A good excess of paint is lost and wasted in the process. If you have a driving need for you boat to look like your car then sprayings for you! Oh yeah, it quick(ish) too!

Brushing by hand can yield incredible results if you are patient and also know what you are doing. I’ve seen boats that at first glance look like they have been sprayed only to find out that they were hand painted by brush…….Dust free atmosphere and bloody good brushes (I mean expensive) are an absolute must here.

Last of all, rollering especially the ‘roll and tip’ method. This requires two people working together as a team. One rolls the paint on thinly and the other follows closely with a decent brush and ‘tips’ out the bubbles left behind by the roller – unbelievably good finishes can be obtained by this method.

A word of warning, no matter which method you use. Don’t be tempted to retouch runs or sags in the paint or you will ruin the finish….wait until the paint has fully dried then deal with it! It’s tempting but paint always seems to gel quicker than you would think!

A SIMPLE FORMULA FOR CALCULATING HOW MUCH PAINT YOU NEED (FOR ONE COAT)

This is interesting if not exactly exact! But it gets very close indeed. This is applicable to brushing and rolling only NOT spraying. There’s a different formula for that and I don’t know it!

THE FORMULA

ONE COAT = The boat’s length overall x the beam x 0.85

Divided by square feet covered per litre listed on the paint can instructions.

If you can’t work it out the paint manufacturer will tell you if you ring the company hotline.Good Luck!

Terry Buddell is a freelance writer, boat builder and marine surveyor who lives on board his own yacht the "Nicky J Miller" in Gladstone, Queensland Australia. Terry has designed a series of boats that he sells from his website on the net and also built his own 42' yacht which he refers endearingly to as "his filthy old lugger'. Terry writes for several boating magazines and specializes in the " How to do it " kind of article using practical ideas and basic common sense! Terry is only too happy to help people who wish to build their own boat from a dinghy to a yacht and his contact details can be found on his website http://www.dolphinboatplans.com

If you liked this article there are more in a similar vein to be seen on http://www.dolphinboatplans.com

Original article can be found here...

Latex Paint for Boats

By David Carnell - Dave is a retired chemical engineer who has been messing about in boats for well over 50 years.

WARNING:  Warning this article contains material that may be offensive if  you think painting is more fun than boating. 

When I bought my first yacht (27’ auxiliary sloop) for $300 in 1951 I quickly learned that if its for a boat, the same material costs several times as much as if it is for your house.  Oakum was $1/lb. at the marine supply store; five pounds for a dollar at the plumbing supply store.  Marine paint cost several times as much as house paint of similar composition.  I worked for a major chemical company that also made paint and knew that their paint that made the most money and on which they spent the most on research was house paint.  Houses are out in the weather all year-no winter cover or inside storage.  Their owners expect to repaint them infrequently, such as every ten years or so.  They also expect a good paint job will require little preparation before repainting.   Back then the only house paints were oil paints, so my yacht was painted with top quality oil-based house paint.

All paints consist of binders or resins, pigments, solvents, and additives.  The binder forms the film that sticks to the boat and holds the pigment there.  The pigments color the paint, make it opaque and have a good deal to do with UV resistance.  Solvents keep the binder dispersed or dissolved and the pigments dispersed in an easy to apply state.  They allow the paint to be applied in the correct thickness and then evaporate from the paint film as it
dries.  Mineral spirits, a petroleum distillate fraction, is the most common solvent in oil-based paints.  In latex paints, water is the major fluid.  It does not dissolve the latex particles, but disperses them in suspension.  Small amounts of special solvents are present to control the coalescence of the latex particles into a tough, tenacious film and to slow down the drying of the latex paint.

Through the years latex paints have developed to the point where 100% acrylic latex paints are better than oil paints on all counts.  They are more durable and tougher.  They resist chalking and fading, retaining their color especially well when exposed to bright sun.  They are easier to apply, going on more smoothly and with less brush drag.  They have less tendency to grow mildew.  They have almost no odor and no fire hazard.  Cleanup is with water.  They can be recoated in as little as one hour.

The 100% acrylic latex is the key to the outstanding latex primers and paints now available.  The weather resistance of these polymers parallels that of the acrylic molding powders that make red automobile taillight and stoplight lenses that last forever without fading.  I checked out all the top quality exterior primers, paints, and porch and deck paints at both Lowe’s and Home Depot-they are all 100% acrylic latex products (the Glidden latex exterior primer at Home Depot used an organic nomenclature I hadn’t worked with for 50 years, but my Handbook of Chemistry and Physics translated it to 100% acrylic copolymer latex).  All of the products are available as custom colors mixed to your desire.

Your new boat went together pretty fast-instant boat or tack and tape construction.  What kind of a paint schedule can you use to get it in the water next weekend.  Let’s say the inside will be all one color and the outside all one color, not necessarily the same as the inside.  You can do the outside in one day, the inside the next, and give it a couple of days before you launch it.

Here is the schedule.  Sand it all over with 60 grit and clean up the dust.  Put on a coat of latex primer.  That will raise some hairy fuzz, so after drying a couple of hours give it a once over with 60 grit to defuzz it.  Put on a coat of your exterior latex paint.  Gloss is the toughest and most durable, but also shows surface imperfections best.  Semigloss is almost as tough, durable, and easy to clean as gloss while not showing surface imperfections.  For me, it is the usual pick.  I have stayed away from flat paint.

You won’t have to sand after the first coat of finish paint and you can easily recoat in the afternoon.  That finishes half of the boat.  The next morning turn it over and repeat the schedule for the other half of the boat. 

If you use two colors on the outside of the boat, you will add another day to the painting.  If you use different colors for the bottom and the side on the inside and have a steady enough hand to cut it in at the chine you can do it in one day.

While it is best to wait a week for the paint to dry hard, don’t let it keep you from getting in the water before next weekend.

A posting on the rec.boats.building newsgroup on the Internet asked if latex paint was good below the waterline, as if it was going to wash off.  Look around your neighborhood.  All those houses painted with latex paint sit out in the weather all the time.   My boats live in the water with their latex paint jobs.  Platt Monfort recommends for waterproofing the Dacron® skins of his Geodesic Airolite boats “...the simplest method being a good quality
exterior latex house paint.”

How long is the latex paint job going to last?  My sailing skiff that lives in the water was three years old this spring.  The inside, especially the bottom, was scroungy from bilge water and having been through two hurricanes, so I gave it a one coat repaint job this spring.  It looked great until Hurricane Bonnie messed it up this year.

The 16-year old Uncle Gabe’s Flattie Skiff (Sam Rabl) built of ¼” fir plywood was painted when new and then about 9 years ago.  It looks pretty scroungy, but the interesting thing is that while the paint on the wood has been scoured off by hurricane winds and general wear the paint on the epoxy-fiberglass joints in the sides is perfectly intact and looks great.

A fellow who was donating a boat to our local museum told me he had the real secret to boat painting.  He had painted a production plywood boat with latex primer and latex paint.  He was sanding the paint off and found it was almost impossible to remove the last traces of the latex primer because it had penetrated the wood to some degree.  Well, nothing soaks into wood like water and some of the pigment particles are bound to be carried along with the water vehicle of the latex paint.

When I rebuilt my 1964 Simmons Sea-Skiff 20 I used a heat gun and a wide chisel to remove about a dozen layers of old oil paint.  To repaint I used latex primer and then two coats of Lowe’s “Severe Weather” 15-year guarantee semigloss latex exterior paint custom colored to match the “Simmons blue” that was next to the wood.  It
has been three years and three hurricanes ridden out on the mooring since the boat was launched.  Except where the boat has rubbed fenders or the edge of the float and on the cockpit floorboards the paint is in first class shape.  I do need to repaint the floorboards.  In my survey I found that Lowe’s has an exterior 100% acrylic latex skid resistant paint (Skid-Not®) that can be custom colored.  I believe I will try it.

I am not alone in appreciating the outstanding performance of 100% acrylic latex paints for boats.  Thomas Firth Jones, boat designer, boatbuilder, and author of Boats To Go wrote in Boatbuilder several years ago that he preferred latex paint over oil paint for boats for all of the reasons cited above.  He did comment that he paints his tiller with oil-based paint because the latex paint stains there.

I was talking with “Dynamite” Payson one May weekend a couple of years ago and he told me he was going to repaint his skiff with latex paint that weekend.

Jim Michalak, boat designer and builder, uses latex paint on his boats.

Phil Bolger reported in Messing About in BOATS that his personal outboard boat is painted with semigloss latex house paint.

Boatbuilders are traditionalists and it has been a hard sell to get them to accept plywood, stitch-and-glue construction, epoxy adhesives, and other similar innovations.  Don’t let tradition keep you from benefitting from the ease of application and outstanding performance of 100% acrylic latex paints.

(You can find more articles by David Carnell by clicking here).

Paint Question

Any suggestions/comments on using good quality house paint (probably semi-gloss) for the interior of my daysailer?  It is a partially open boat.  I work for a hardware store where I can get a discount on house paints and with finances the way they are, the price of house paint versus topside marine paint makes it an attractive alternative...

 

 I will also check with the sporting goods manager to see what kind of marine paint they could purchase for me.  Problem is we normally have to order whole cases, which could either be 2 or 4 gallons or 4 or 6 quarts...

 

Which ever way I end up going, I will probably apply it with a sprayer...

 

Andy

 

 

Prime and Paint Question

I am building with a modified stitch and glue, I have used PL Premium polyurethane construction adhesive for my seams, stuff is strong, waterproof and I found once fully cured the plywood will fail way before the glue. It will take paint according to manufacture.

 

now the question, all the "stitch and glue" techniques call for fiberglass tape and resin at the seems inside and outside, (more expensive than I want) and all I have found built this way are left clear coated with the resin.

 

I plan to apply two coats of exterior wood primer and paint inside and outside, do I have to apply fiberglass and resin to my plywood, this boat will be used maybe 10 times a year during camping trips and stored inside a climate controlled shop.

 

 

Priming...

Yipppeee!  all of the interior priming is done!!!  We have a couple of days of warmer weather and maybe I can take advantage of it and get the interior paint coats on....

primer coat peeling a bit...

Now that I have my sailboat hull in a dry garage.  I have noticed that the primer coat I put on last summer is peeling in spots.  Also, the fiberglass strips I placed on a couple of the scarf joints are loosening.

 

What do I do now.  Sand the whole hull down and reprime?  Totally strip all of the priming off and reprime?  I will replace the fiberglass no matter what.  I originally went with the fg strips because I couldn't afford to glass the entire hull...  Now I am thinking about "biting the bullet" and glass the whole hull.  Can I go over the primer coat or should I sand down to bare wood to get the best adhesion of epoxy to wood?

 

Any suggestions are welcome.

 

I am just about done fileting the entire hull interior - thank God!  Then I can prime and paint the interior and get busy on decking, seats, etc.

 

Andy

How should I paint on name

Hi fellow builder's Thinking off using the router to lightly dig into the plywood the chosen name of the boat, but do I then varnish and paint the name then varnish again or just paint or paint then varnish ,any tips boaties

bogdolics.

Paint scratches

Can anyone tell me how to keep the bottom side of my boat from getting all scratched up from rocks.  Seem's like I am always touching up the sides and bottom of the boat. Is this just the nature of wooden boats?  I am very new at boat building and could use some help in this area.  Is there some kind of hardener that could be applied over the paint?  I have tried Oil base and Latex paints and still seems like the paint doesnt adhere to the fiberglass resin verey well.

Help on painting

Thank you for accepting my membership request.

I am NEW in the wooden boat world. I purchased a 23 foot Clippercraft 2 weeks ago. She was built in 1983 out of mahogany plywood. The owner of the boat painted her, I am not sure what kind of paint it is. The oringinal paint is still the only layer she has on. It has been stored in a garage all of its life 21 years. The paint at plywood ends at the transome has worn away the topside has small blisters on it.

 

The construction on the side gunnels are plywood strips screwed and epoxyed to a 1.5 inch strips creating a lapped plank look.

 

My big questions are. Do I need to strip all of the paint off the hull before I repaint her or can I sand the good paint and reapply a new layer? If I need to strip all the paint off will a heat gun distroy the epoxy bond between the plywood and 1.5 inch strips? Should I use an epoxy penitrator to seal the ends of the plywood. The boat will be on a trailer all the time with a week being the longest it will remain in the water can I use top paint for the bottom or is it recomended to use bottom paint? I plan to spend many hours on the Pacific ocean chasing salom and halibut.

 

attached is a picture of a simular boat. Unfortunitly I do not have a digital camera.

 

Thank you for any input you might have.

 

Steve

Attachment: Clippercraft.jpg