On Board with Mark Corke

Cheap and effective spray booth

I have recently been working on some upgrades for the boat's headliner. A full video will be coming soon but in the meantime I thought that I would share the process that I have been using to spray the wooden strips.

The original headliner for the Grand Banks series of classic yachts was a sort of perforated vinyl material of the sort that might be found on a 1950's vintage Chevvy. Over the years this had suffered from rips and discoloration and I decided that it was well due for replacement. Apart from the general wear and tear I also wanted to upgrade the lights and add speakers for the stereo, neither of which would be possible without changing out the headliner. In short, I have gone for a painted wooden headliner which allows easy installation of the new lights and speakers. 

I wanted to paint the tongue and groove strips I had machined up before I installed them as painting them in place would be next to impossible. I could have painted them with a brush I suppose but spraying gives a far better finish and is faster once the necessary spray equipment is set up. Initially I did think about setting up some sort of poly tent in the garage but then by chance came across an 8 man tent for $100 in Walmart, far easier and almost cheaper than any home made contraption. The end farthest from the opening door has a ready made mesh winder which is perfect for a box fan. A  furnace filter stops the overspray from going everywhere and in all the tent works better than I could have hoped. The strips are more that 12 feet long and they fit easily inside the tent, plus once the job is complete I can pack up the tent into its bag and save it for next time. The pictures and video below give a flavor of just how capable the whole system is. For the actual spraying I'm using a Groco airless sprayer which, when correctly set up, produces almost perfect results.

 

 

 

 

 

 

 

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.

Boat winterization checklist

Shrink wrapping is popular for boats stored outside. But do make sure that the boat is dry and properly prepared for the coming winter months before wrapping. Also ensure that the boat is properly ventilated. If the boat is painted then only wrap to the rub rail. A boat wrapped to the waterline like this one may have problems with the paint lifting off.

For many of us fall marks the end of the boating season and time for us to start thinking about putting our boats away until the next spring. Although it may seem tempting to just haul the boat from the water park it in the yard or some other place and forget all about it until the next season this is not a very smart thing to do.

Properly preparing your boat for the coming winter months is essential if the boat is not to be damaged and additionally proper prep work now will enable you to get on the water sooner when the warm sping weather finally does come around.

What you actually need to do will depend to some extent on your boat, but below is my list of those things that think you absolutely must do.

Pressure wash the outside of the boat as soon as it comes out of the water. If you wait too long the small critters and crustaceans set like concrete and will be harder to remove if you wait. Dry fully and apply a good wax.

Clean the prop shaft and apply a light grease coating.

Remove and replace worn anodes.

Dry the bilges and add a little non toxic antifreeze to prevent any water that does find a way below from freezing.

Empty water tanks and water heater and add antifreeze.

Run the engine until warm then drain the oil and replace with fresh. 

Run some anti freeze through raw water systems until it starts to be blown out of the exhaust, then shut down engine(s).

Change the oil filters.

Change fuel filters

Remove the raw water pump impeller.

Fill diesel tanks to the top and add biocide.

Remove plugs from outboards and spray in some fogging oil. replace plugs.

Change oil in lower units on outboards.

Completely drain gasoline tanks.

Remove batteries and place on charge.

Clean the boat thoroughly inside and remove all soft furnishings

Cover boat if left outside and if possible install a dehumidifier.

Check the boat regularly throughout the off season.

Now is also a good time to do repairs and upgrades that you made a note of during the boating season. You may also want to anti foul the boat ready for the new year to save doing it in the spring. If the boat is indoors then you can also attend to any bright work and other routine maintenance tasks.

Amine blush

ammonium carbamate which in extreme cases appears as a visible white coating. Blushing is most prevalent when the temperature drops as after the curing process has started. Blushing if left on the surface willl effect subsequent coats of epoxy and paint and varnish if you try to coat over them without removing it. Specifically the varnish or paint will not set nor adhere to the substrate correctly. The best method for getting rid of the blush is to wet sand I find. This accomplishes two things in one, it both smoothes down the roughened surface thus preparing it for further coatings and washes off any blush at the same time, because you are sanding the surface you can tell which bits you have missed as the surface willl still be rough. You may think that sanding with an electric sander would be the way to go but I must caution you that dry sanding forces the wax deeper into the surface and clogs up the abrasive paper is short order. If you have a large area to sand and need to use a sander then you willl have to wash the surface down first in which case use plenty of clean water and some ammonia cleaner such as Comet to de wax the surface.

I should add as a final note that amine blush does not always happen especially if the ambient air temperature is warm, not too humid and stays at a stable level until the cure process in complete. Additionally some epoxies such as those sold by MAS do not blush and so they may be worth investigating before you go out and buy your next batch.

Anti fouling safety

       One of the most unpleasant jobs for many boat owners is anti fouling the boat. The paint is smelly, expensive and on top of that the shape of the boat means that you spend a good part of your time on your back getting splashed with paint. For this reason it is essential to keep the paint out of your eyes (I am not wearing them here as I was trying to operate the camera and pose all at the same time) and the vapors are not good to breathe either so now I wear a good organic respirator when applying the paint. By the way if the respirator is doing it's job you can't smell the paint at all, forget those disposable type masks they are ineffectual and allow the fumes straight through. I suspect that applying the paint in the open air is less hazardous than working in an enclosed space, like say a garage or workshop where the vapor do build up. Nevertheless I think it best to wear a respirator even outside.

Incidentally a far greater health risk is presented if sanding anti fouling, the boat should be tented over and a slight positive pressure should be achieved within the tent via means of a small fan, neither the EPA or your next door boat owner will thank you if you sand in the open air. The dust is very insidious and unless contained goes everywhere. It is also illegal to allow the dust onto the ground, it should be captured and disposed of as hazardous waste.

Actually removing all of the old bottom paint is something that I think I will have to do next year. Although I use Micron extra, an ablative paint there is still a build up on the underside of the boat which I would like to remove entirely, inspect and fair the boat and then reapply. That's going to be a big job but I think that it would be worth it and give me a little extra speed.

One of the best machines is the Festool dustless system, expensive perhaps but it does capture the majority of the dust. I might just have to invest in one.

Satin Finish

 I must confess that the last few times that I have painted a boat interior I have used oil based house paint and it has worked out just fine. Many of the interiors that I have done still look good after 10 years. This is due in part to the interior of the boat's cabin not being exposed to salt water and the harmful effects of the direct sun and it's damaging UV rays. I would never use house paint on the outside of the boat, for that my preferred choice is the Interlux 2 part Perfection which to my mind, perhaps because I am familiar with it one of the best finishes that it is possible to get with the roller and tip method. I've been using Interlux paints for 35 years all told and during that time I must have tried almost every product that they have made except their flattening agent, until now.

I spent some time on an old but beautiful MacKenzie recently and I much admired the interior paintwork which had a silky smooth finish which apparently was Interlux brightside single pack paint to which flattening agent had been added and wanted to get that same effect on my latest interior powerboat project. A satin finish I find is easy on the eye as it is not so glaring and especially if using white, a popular color for boat interiors that won't blind you as soon as the sun comes out.

 

Flattening agent can be mixed in different ratios with the paint depending on the level of sheen one is after, one to one gives a semi gloss, two to one an eggshell and so on down to dead flat matt finish. It works great but because there is no pigment in the flattening agent it does not cover as well as paint would on it's own. The best approach and the one as recommended by the makers is to use the paint neat for the first few coats and only add the agent for the final coat. The flattening agent readily mixes in with the paint and has a similar viscosity so application requires no special technique save for the surface preparation which you would have to do in any event.

My project is well underway and I hopefully will have some pictures to post here by the end of the week so you can see how everything worked out. Most of what I am painting are doors and other trim which I have in the workshop so I will try to get a shot of a couple of the doors, one with and one without flattening agent so you can see for yourself.

Varnish tips

I like getting e mails from readers of On Board, it';s always good to hear what everyone has been up to. One of the things that it seems that plenty of you are doing right now is varnishing and paintwork. Although I have mentioned it before it seems timely to mention a few tips for getting the best possible finish.

If the surface has previously been varnished and it's time to freshen up the surface wet sand the existing finish with 400 grit wet and dry paper used wet. The water acts as a lubricant, there is no dust and the paper won't clog and best of all the surface will become silky smooth ready for additional coats of varnish. Another good reason for wet sanding is that the paper lasts ages, one sheet torn into quarters was sufficient to allow me to sand over a hundred feet of previously varnished toe rail.
On the other hand if the varnish has been let go then you will need to strip it back to bare wood and start afresh. Unless it it unavoidable do not be tempted to try and sand off all the old varnish. The far better option to my mind is to use a hot air gun and scraper, but be careful of surrounding structure and surfaces.

Dust is the enemy when it comes to spoiling your varnish. As far as practical work in a dust free atmosphere, indoors is ideal and the warmer the better. After wiping down the surface with clean rags I like to go over the surface immediately before applying the varnish's with a tack rag. These have a gummy feel to them and will pick up any residual dust left on the surface. Damp the floor down in the immediate area that you are working so that you won't kick up dust as you work. If varnishing outdoors do it in th morning on a warm windless day. I know that may be a tall order but don't try to apply varnish if rain is forecast or it is at all windy or you will end up with a non skid finish.

Use a disposable paint strainer and decant about as much varnish as you can use in 10 to 15 minutes into a paper cup. When you have used that up strain more varnish into a fresh cup and continue working. Keep the lid on the can closed while you are not using it to keep the contents clean and dust free. If you use a foam brush buy the better quality, some home stores sell bargain packs but they are too flexible I find and some are susceptible to attack from the varnish.
Think of laying on the varnish, don't over brush and if you miss a bit leave it till the next coat. Sand lightly between coats, for outdoor trim such as rub rails and toe rails I like to have about 7 to 8 coats for a deep lustrous shine that protects the wood and lasts most of the season. Nothing destroys varnish like UV and you may well find that you have to give a refresher coat during the season to keep bright work looking good.

Dolfinite bedding compound

    I've had a few e mails from one or two readers of On Board asking about bedding compounds after I wrote the post about bedding in deck fittings and so on. It seems that there is some conflicting and confusing information floating around so I will try to clear up any misunderstanding.

    Walk into almost any marine store and you will find hundreds of different tubes of mastics, sealants and other associated goop. basically there are two different types, polyurethane and polysulphide.

    Polyurethane is an adhesive compound of which 3M 5200 is perhaps the best well known and should not be used where there is a chance that you will need to dismantle the joint later. 5200 is used by many manufacturers for hull to deck joints and for this kind of application it is perfect. Polyurethanes also hold up well underwater, will bond to most materials but can attack some plastics but not Marelon so you are OK to use these for bedding in plastic underwater fittings made of this material.
    Polysulphides such as Boatlife remain permanently flexible and are my preferred choice for most jobs. They can be used above and below the water line and the joint can be disassembled later if needs be. Polysuplides should not be used for boding polycarbonates such as Lexan or PVC as they will attack them. For this reason most window frames and other components containing plastic are bonded with a silicone product. Polysulphides are available in a variety of colors, I have always found the brown a good match for teak and mahogany but for the best seal with teak use the primer first.
    Last but by no means least is the Dolfinite bedding that I have shown above. This is more of an old school product and I like it for applications where I am bedding wood to wood, it has a strong aroma which every time I pop the lid reminds me of old boatyards in much the same way that fresh varnish does. I am getting a bit off topic here but Dolfinite remains flexible for years, will not dry out and will not destroy parts should you ever have the need to take them apart at some later date. As this comes in a can  which can be resealed it will not go hard unlike those half used tubes are rather prone to do so for general bedding it could save some you some money in the long run.