On Board with Mark Corke

SIA abrasives

The very nice folks at SIA recently sent me some abrasive paper to try and I have to say I am very impressed. To my knowledge I have never used them before always tending towards 3M the undeniable giants in the abrasives market. I have been using  a variety of SIA products most notably the PSA discs, velcro backed disks for the random orbit sander and strips for long board sanders. All the products cut well, don't load up and appear to be manufactured to a high specifications. I especially like the 320 grit discs folded in half and used for sanding down varnish between coats, they were used for inter coat sanding on the hatch boards and tiller that Ihave used as a back drop for the picture. Further details and a video are promised later in the week so you can see them in action but for now if you want further details you can go to the SIA website by clicking here, which if I have one complaint with is that picking the right product for a particular sanding application is next to impossible without recourse to the help line, so many products do they have!

Copper Anti fouling

 
Washington state has become the first state in the union to ban the use of copper based anti fouling paints and it looks as though California will not be far behind. After January 1st 2018 it will be illegal in Washington to sell  boats with copper based anti fouling paints and paints with no more than 0.5 % copper cannot be used after  January 1st 2020. It seems likely that other states will follow suit. What bothers me about this is that boats over 65 feet are exempt as are all  government vessels, research vessels and commercial vessels. So basically the one people that it is going to affect is the small recreational boater. So that means that in Port Townsend, WA I cannot paint the bottom of my Boston Whaler with a copper based paint but right next to me in the ship yard they can be spraying on copper based paint to a 370 foot bulk carrier! Now the surface area of that Boston Whaler boat that is contact with the water is but a minor pimple compared with the bulk carrier. Then when we factor in that the Whaler is dry sailed off the trailer and may only go into the water a few weeks a year but the bulk carrier sits at the dock for days leeching copper into the surrounding water. Something does not add up here.

Copper is one of the best anti fouling treatments out there. The British admiralty knew it hundreds of years ago and started nailing sheets of cooper onto the bottom of their warships to prevent infestation from ship-worm and other pests. Anti fouling works because it is toxic if you make anti fouling less toxic then the boat become more susceptible to fouling. Come on, does the average recreational boater make that much difference, I don't think so. The other problem for paint manufacturers is that they now have to come up with alternatives. We had this same problem some years ago when TBT (tri butyl tin) was banned which again was only for recreational craft, commercial vessels were exempt. If congress and individual states are really worried about our oceans then worry about the billions of oil that were spilled into the Gulf last year of which no one seems to have been held accountable.

Red Lead

 

One of the great things about old boat shops is the smell. As soon as you walk through the door, the floorboards creak and you get hit by that smell of pine tar and varnish. OK so maybe I am romanticizing just a bit and those kind of boat shops are few and far between now and you are most likely to get hit by the smell of styrene of the latest Sundecker 42 being built as you walk through the door of an industrial unit that just happens to make boats. But the fact remains that there are boat builders out there that continue to use traditional materials. There are good reasons for this; on a traditional wooden boat the whole structure continues to move and 'work' as it travels through the water. Modern materials such as epoxy, fiberglass and two part paints are marvelous materials but they do not hold up when applied to something like a lapstrake or carvel cruiser. What is needed is something better suited to the substrate that can expand and contract with the changing seasons and the natural movement of the boat.

Years ago when I started building boats all the frames, planking lands and just about everything else that was sure to get wet was liberally coated with red lead paint. This coating was and still is the best defense against the ravishes of time and weather and for all those areas that would be impossible to gain access to once the boat was constructed. Environmental and other concerns have made many of these old time paints and compounds hard to come by but they are available I am happy to report from Kirby paints in New Bedford, Massachusetts. Red lead primer at $225 a gallon is far from cheap but the chances are that in many cases it will only be applied once after which it will be left to do it's job for years to come. Red lead can be used for all sorts of things, of course you need to be aware of the health hazards but it is unsurpassed for protection and as an undercoater on both wood and metal. It is perfect for steel keels and centerboards and the timbers in the bilge.

I need to add that I am not being paid to write this I am just enthusiastic about the products which come from a small firm that has been in the same family for the last 150 years or so and is today I understand run by George Kirby the forth. In addition to the red lead they make white lead paste and traditional boat enamels. Their website is basic by many standards but they do publish prices and have an on-line color chart so  you can see what they do offer. You can buy direct or you can order their products from Jamestown Distributors  who seem to be about the only other stockist of their products.

Teak treatments 14 months on

 

Regular readers may think that they have seen this board before and they would be right. It is the weathering board of teak treatments that I have been using for long term tests of various teak oils and other treatments. I initialy put these samples on this board 5 years ago and since that time the samples have been left out to weather.  I have to say that things have not changed that much since I bought you an update way back in January of last year and the findings that I came up with then still hold good. I have reapplied the treatments in accordance with the manufacturers recommendations once per year as written on the can or bottle and it has been a very interesting experience to see how they compare side by side. If you were to look at each one in isolation you can definitely see a difference from plain untreated teak but put them side by side and the difference is marked. Not only is the color different from sample to sample (I should add that the teak all came from the same log and was cut at the same time) but interestingly the grain is raised rather more on some than the others.

You can read the blog posting from a year ago by clicking here and the results as written then still hold up with no revision necessary.

Painting and varnishing tip

Now I am sure that you are fed up with hearing that a paint or varnish job is only as good as what's underneath and that means that the prep work has to be up to snuff if the paint is not going to peel off in a second and a half. One mistake that I see made time and time again is sharp edges on woodwork and other surfaces that are about to be painted. Any edge tends to attract more wear than flat surfaces but sharp edges are painful if you bang your leg into them but they also do not hold up well by comparison with the rest of the job.

 
If you look at my rather poor sketch above you can see what I mean. The black line indicates a corner of a cabin trunk or what ever and the blue line is the surface of the paint film. Because paint cannot stick will to a sharp corner the paint is very thin and will wear through quickly.

Now compare this to the drawing below.  Click on them to make them larger if you like.

 

 

 
The cabin top edge has now been rounded off slightly and the paint sticks much better to the substrate. In many cases the round over need not be huge, a little bit of time with some abrasive paper is often all that is needed but for items such as toe rails then a small round over bit in a router will turn the toes rail from the utilitarian to a thing of beauty.

Working with two part paints

   

Back in the day choosing a paint for the boat was fairly easy, you went down to the chandlery and picked out a color went home and slapped it on. Well there was little more to it that that but not much. In the past 15 years or so things have moved on at quite a rate and paint is now made by skilled chemists rather than guys in the back of the boatshed.

 One of the major advances of interest to the boat owner is the widespread introduction of 2 pack polyurethane paints. These paints manufactured by the likes of Awlgrip, Interlux, Petit and Epifanes offer the ultimate in durability and longevity. Available in an almost infinite variety of colors these paints, which were once the preserve of professional yards, are now available to the DIY boating enthusiast.

Traditionally painting glass fiber was fraught with problems the paint was generally incompatible with the substrate, which tended to flake off and not adhere well. There is still some resistance to painted hulls mostly fueled by old salts that had disappointing results years ago and still think that painting a hull is a bad thing.

Once regarded as something that was done to tart up an old tired hull there are an increasing number of high-end boat builders who now produce their hulls with clear gelcoat and then paint them to owner’s choice later. Hinckley does this and they say that this has several advantages over using a colored gelcoat, imperfections in the lay up are easier to spot, there is less chance of damaging a hull surface before the final fitting out is complete and an owner does not have to decide on a color until the boat is almost ready for delivery.

 

Two pack paints can be applied in two ways, they can either be sprayed or using the roll and tip method. Spraying is not really a DIY proposition not least because specialized equipment is required beyond the scope of all but the most affluent and determined individual. A spray booth is necessary along with expensive spray guns and respiratory protection. This leads us to the other option of the roller and tip method of application. When done correctly and with care the finished result is almost indistinguishable from spray application and is what I like to call a 15-foot finish. That is from 15 feet away no one will be able to tell the difference.

 

 

The deck of this Hinckley Bermuda 40 looks resplendent in a fresh coat of Oyster White.

You can use 2 pack paints almost anywhere but they are probably of most interest to boat owners who use them on their topsides. They are not suitable however for all applications however. Unlike more traditional alkyd paints which have a degree of flexibility, 2 part polyurethanes once cured are very hard and do not have any give and thus are unsuitable for substrates such as wood which move in concert with changes in the atmosphere. Below is an outline of how to go about using 2 part paints for topside painting but also note that they are not suitable for surfaces that will be constantly immersed in water so should not be used below the boot top. However the paints are expensive cost up to 60% than more traditional coatings so you might find it useful to have a go at a smaller project before committing to a full-scale refurb of the boat. A small dinghy could be a good project, as it will give you useful experience with working with the paint before you go on to tackling a larger and more costly project.

 

For the best results aim to apply 2 pack polyurethanes when the air is still and the temperature is between 50 and 85 degrees. Any hotter and the surface is liable to skin up too fast and any cooler and it will drag, both will result is a poor finish. Avoid applying towards the end of the day when the temperature is falling as this can often result in a loss of gloss retention. At 65 degrees the surface will be tack free within about 3 hours and after 24 will be ready for the next coat. Finally if you are one of the increasing amount of owners that shrink wraps their boat during the winter get the yard to only go as far as the toe rail. You might think that it offers better protection for the paint by going down to the waterline but you would be wrong. Moisture inevitably gets trapped between the wrap and the paint and this will cause bubbling so is best avoided.

 

How to apply

 

 Two part paints are very expensive so it is important to avoid costly mistakes. The only time that I really got into trouble was when I thought I knew better than the manufacturer and used less thinner then they suggested but the less said about that escapade the better.

Before you go anywhere near your project the first thing to do is read understand and digest the information supplied by the manufacturer. Much information is contained on the can but it is also worth reading the safety data sheets which can be often found at the location where you bought the paint or downloaded from the manufacturers web site.

There will be slight dissimilarities between each of the paint products but in general terms the application and use techniques are common to all two pack paints.

As with any painting the finish will only be as good as the preparation. Get the surface as smooth as possible and you are half way to a great looking paint job. Assuming that you are going to paint the topsides start by washing the boat down with good boat soap, check that it does not contain any silicone, which will react with any paint coatings and prevent them from adhering. I have had good results with Latitude 43 organic boat soap, spray on leave to soak for 15 minutes then rinse off. The other option is to use some of the soft scrub type bathroom cleaners. What we are trying to do at this stage is to clean all contamination from the surface. Whatever product you ultimately use rinse thoroughly and completely with lots of clean water. Any beading up on the surface of the hull means that wax or other contaminants are present.

 

With the hull clean the boat can be sanded to provide a key for subsequent coatings. I like to use 80 grit paper in a random orbit sander, keep the sander moving to avoid sanding off too much or you could go through the gel coat or at the very least make it very thin unnecessarily. Work methodically and completely making sure that the hull or other surface is universally dull. This process is very dusty so wear old clothes, a suitable dust mask and eye protection. I like to run my fingers lightly over the sanded surface as you can feel imperfection far better than you can see them. Dust off the topsides and as you do put pencil mark circles around any imperfections, dings or gouges that need attention. If major fairing and filling work is required in any area now is the time to mix up some epoxy and micro balloons and trowel this onto the surface with a wide plastic squeegee. If the repairs are minor I like to use Bondo type filler. Filling an d fairing is definitely an acquired art on the one hand you need to apply enough to fill the imperfection but on the other hand not so much that you have a lot of extra sanding to do later. With the filler applied I like to leave the surface for at least 24 hours to allow any filler to cure I then come back to the boat and sand down the surface to feather in the filled areas. Although it can be tempting to use the random orbit sander it is all to easy to take off too much in which case you will have to reapply additional filler. Buy or make up a long sanding board to which you can stick abrasive paper and use this to sand down any filler, it can be hard work but the end result will be far better.

With the surface now hopefully silky smooth we can start to apply paint but first mask off all areas that you don’t wont paint to touch which for most yachts will be along the underside of the toe rail and along the top of the boot top. Dust the boat off thoroughly then wipe the whole area to be coated with the thinners or solvent recommended by the manufacturer changing rags often to avoid moving dirt from one area to another. While min some cases it is possible to proceed directly to topcoats better results will be obtained by applying an epoxy primer. This is mixed following the instructions on the can to the letter. Generally these are two part products a hardener is added to a base, mixed solvent added, mixed again then left to stand or ‘induct’ for 20 minutes to half an hour before application.

The undercoats are applied in the same way as the final topcoats so perfect your technique on this initial coat and the topcoats will go like a breeze. Starting at one end of the boat one painter rolls on a coat of paint while a second painter immediately follows up with a dry brush and ‘tips’ off the surface to relax the orange peel effect left by the roller and further smooth out the paint. The brush should not be dragged through the paint only the lightest of touches are necessary. The work will move quickly but once you stop don’t stop, the last time I did this on a 38 footer two of us got round the boat in a couple of hours fairly easily.

The colored topcoats are applied in exactly the same way and using the same technique but you will notice that they can be noticeably thinner and therefore faster to apply but to achieve full coverage you may need 3 coats sanding between each coat with 400-grit paper.

 

 

Safety

 

Working with 2 part paints does not pose a health hazard providing a few simple common sense rules are followed.

1

Always ready and adhere to manufacturers recommendations for application techniques.

2

Keep a clean work area and do not smoke, drink or eat until you are well away from the painting area and you have washed your hands.

3

Wear protective face and eye protection. Tyvek suits and latex or nitrile gloves will keep paints and solvents off your skin.

4

Don’t spray 2 pack paints unless you have specialist knowledge and the correct equipment.

5

Dispose of unused paint properly allow it to cure before throwing into the trash and never under any circumstances tip it down drains or into watercourses.

 

How much do I need?

 

As a rough guide one pint of correctly thinned paint will cover about 75 square feet so from this you should be able to work out the amount of paint that you need. I found that I needed one undercoat and three top coats for the best coverage last time that I used 2 pack paints so work out the square footage to paint multiply by four and that will give you the total surface area that you will eventually have to cover with paint.

 

The paints are all available either directly from the suppliers or from local stockists such as West Marine. Color charts are available on line but every computer monitor is different and shows color in a differing way so pick from a color card if at all possible to avoid disappointment.

 

Resources

 

 

Paint

Epifanes

www.epifanes.com

800-269-0961

 

Interlux

www.yachtpaint.com

800-468-7589

 

Pettit

www.pettitpaint.com

800-221-4466

 

Brushes and rollers

 

Corona

www.coronabrushes.com

800-458-3483  

 

 

 

 

The roll and tip method when done correctly produces results to rival spraying. One operator rolls on the paint and another helper follows immediately behind with a dry brush tipping off the paint. This relaxes the paint makes roller marks disappear and smoothes the surface.

 

Cheap dust control

 

With the colder weather comes times when I will be locked away in the workshop sanding some part or scraping some varnish or paint. Almost every project seems to generate at least some dust which can be both annoying and at times dangerous to your health. Keeping dust under control is a major concern to me not least because I don't want to breath it in and I don't want airborne dust to settle on every shelf in sight.

There are a ton of fairly expensive electrostatic air cleaners on the market which do a pretty good job - at a price. My solution is to use a cheap $25 box fan from Walmart and tape a suitable furnace filter to one side of the fan as shown above. Note however that the filter should be attached to the 'suck' side of the fan. The filters last a fairly long time if you vacuum them once a day with the shop vac. Because the fan is light weight you can move it close to the work area but remember they you may still need to use a face mask to protect yourself. 

Sandpaper types

Even though it has not been available for many years we all still use the term sandpaper when referring to any sort of abrasive paper that we will use for rubbing down wood or other materials. In fact this may well have something to do with the general term of 'sanding'.

These days 'sandpaper' and I will continue to use that term as we all know what I am talking about, is a paper or sometimes a cloth onto which abrasive particles has been stuck. There are many different types of sandpaper and the abrasive may be aluminum oxide, glass, silicone carbide or even industrial diamonds. Each of these grits have different properties which make one more suitable than another depending on whet we are asking it to do. I now routinely only use a couple of types of paper in my shop and around the boat. For most of my dry sanding operations I use aluminum oxide paper which is available in a wide variety of grit sizes as well as in sheets, rolls or cloth backing. I find the most economical way to buy this paper is in rolls which I can then cut off as I need them. Aluminum oxide is suitable for use either by hand or for sanding machines but for many of the random orbit machines you have to buy paper with a velcro back to attach it to the pad.

Silicon carbide is very hard, often black in color, and when stuck to water proof paper with a suitable adhesive can be used wet and this is my paper of choice when sanding varnish or paint ready for over coating. The water acts as a cutting lubricant and helps the paper from clogging or loading with particulates.

Abrasive is denoted by it's grit size, the bigger the number the smaller or finer the grit.

Thus a 40 grit will be very coarse and 400 grit very fine. These number hold true for every paper no matter who makes them as the grit or grain size is measured by it's ability to pass through a sieve of a certain size. The size will often nearly always be marked on the back of the paper.

One thing I would advise against and that is buying paper from the local DIY store. Often they will have a very limited range and as most folks shop on price they tend to only have the old fashioned glass paper. Buying this stuff is in my humble opinion a total waste of money. Cheap it may be but the grit falls off almost as you look at it and it does not last long at all before it fails to cut as it should. Either buy on line or go to somewhere like woodworkers warehouse or Jamestown Distributors who advertise on this site and get your paper there. It will be three time as expensive but the aluminum oxide paper, which is often red in color will last 10 times as long.

You will often see paper as being open or closed coat. This refers to how closely packed the grit is on the paper. An open coat paper is often better for mechanical sanding or on softwoods such as pine and a closed coat will work well on hardwoods or when hand sanding.

There are a number of additional resources on the internet and you can log on to mirka or 3M  both of which offer help when choosing the right abrasive, just don't call it 'sandpaper'

 

Liquid Gold or not- Schooner varnish

I've always liked varnish. I might not always like the upkeep on keeping varnish looking in tip top condition but I do like the look of it when done right and applied properly. During the last 30 years or so I must have tried almost every varnish on the market from the so called no sanding between coats varieties to the more traditional. Two of my personal favorites have got to be Epifanes gloss and the product made by Interlux specifically Schooner varnish.

Epifanes is a high solids varnish which whilst great for large flat surfaces can be a devil on vertical surfaces or areas requiring careful cutting in with a brush, a cabin top hand rail for instance. Imagine my dismay then when I found out that Interlux were discontinuing Schooner and replacing it.  The new product is called Schooner Gold and my first impressions of it are that it is a completely different product to the old Schooner. It has a higher solids content it would seem and thus, at least from my use to date does not seem to flow out as well as the older product. While the higher solid content allows the varnish to 'body up' quicker it does not seem to flow out as well. The varnish needs to be thinned with Interlux 333 solvent to make it flow but then this to some extent defeats the object of having a varnish with a high solids content and although I have not used this product on a very hot day yet I could see that the solvent would tend to evaporate off quickly causing the brush to drag more than I would like. I shall continue to  use the Schooner Gold as it does take time, practice and patience to achieve the best results and I'll bring you a further update in dues course. In the meantime I would be interested to hear what other On Board readers have found if they have had the chance to try Schooner Gold for them selves.

Teak treatments- the results

The board above was part of a survey that I started when I was with Boatworks magazine and is series of test samples of teak treatments. All of the teak decking sections were all machined from the same teak board and as such were all the same color at the start of the trial some two and half years ago. Since that time I have weathered the board and applied the treatments following the manufacturers recommendations both with regard to the initial treatments and subsequent applications.

The results are interesting, some of the samples look good while others look like they have had virtually no treatments at all. You can click on the picture to make it larger and although it is not the same as actually seeing it in real life you can see the color variation.

From left to right they are as follows; Teaqua, Starbrite, Mequiars, West Marine, Interlux and finally Amazon Gold.

Of course results are very subjective but to my mind the Teaqua is by far the best of the bunch with the Amazon Gold a close second. What you cannot tell from the picture however is the feel of the samples. The Teaqua feels very smooth, while the Meguiars and the West Marine feel rough to the touch. As these last two also have the most washed out appearance it would appear that the treatment has had the least effect both in terms of protecting the wood and maintaining the appearance. Of course teak requires no treatment and can be left to weather to a silver grey color if the owner prefers and it would appear that this is exactly what is happening to the West Marine and Meguiars samples albeit more slowly than would be the case had no treatment at all been applied. Interestingly the Interlux sample has quite pleasing color but the surface is somewhat rough.

So my final recommendations would be that if you want to keep the just laid teak deck look then a regular treatment of the Teaqua would be the way to go with the Amazon Gold not far behind.