The Seagull Part VI: Painting

Why paint an engine?

Painting helps prevent rust and makes an engine look brand new.

Above:  The 1958 Johnson Seahorse.

After sandblasting the next step in restoring the Seagull was to paint it. Before sandblasting the metal surface was smooth, but without any paint it was now a little more coarse, like emery paper. Dirt could easily stick to the metal, and if this happened I would have to sandblast it all over again to get the dirt off. Paint won’t bond to metal if there is any dirt in the way. I had to handle the parts with clean grease free hands to ensure that dirt wouldn’t get into the tiny grooves on the metal.

Painting can be tricky. If too much is applied it will run or drip and the finished result will not look very professional. When I painted the Viking (a past outboard project), I gave it one coat, and when I saw that some places didn’t have enough paint I sprayed it again before the paint had dried. This resulted in large globs of paint in various places and didn’t look very good at all. I had to resand it and repaint it which was very time consuming and quite frustrating. The proper way is to give the object several light coats instead of one thick coating.

Before painting, remove all the old paint. With a small engine, the best tool for the job is a sandblaster. Once the old paint is gone, prime the metal before painting or use rust paint (no primer necessary). Primer helps the paint stick to the metal. It is best to paint on a warm dry day; this will help the paint dry and bond to the metal. If there is too much humidity in the air you run the risk of the paint looking “sticky” or taking ages to dry. I like to use cans of spray paint because you avoid brush marks with spray paint. Make sure you have a large drop sheet or piece of plywood under your project before painting.

Above: Painting the float bowl.

Here’s website that offers some useful advice:
<http://www.oldengine.org/members/murphy/painting.htm&gt;

After painting it’s best to leave the paint to dry for at least a week. Once I left a motor to dry only for one day and the next day I tried to reassemble it. The paint scratched off almost immediately; when I tightened the nuts and bolts, the underside of the bolt would scrape paint off the surface. It was incredibly frustrating. If I had left it to dry for longer it wouldn’t have done this. The paint eventually dried but the finished result was (sadly) amateur looking.

Painting bolts and nuts can look nice, but I find that when they are being removed the ratchet bit can scrape paint off the nut or bolt. One solution is to buy new bolts and bypass painting them altogether. This also avoids the issue of having old nuts crack during reassembly.

Above: Don’t forget to clean the cap off when you’re done painting! Old paint will dry up and block the small opening on the nozzle.

To clear the cap of paint you turn the can downside and spray for a few seconds, until the paint no longer sprays out.

After painting I used PlastiKote engine enamel to seal the surface. This adds gloss and prevents dirt from sticking to the paint. It looks especially nice on gas tanks and flywheels. It also handy if you’re replacing engine decals as it will keep the gasoline from dissolving the decal.

 

The Seagull Part IV: New Gaskets

Obtaining new gaskets to replace old ones, whether it’s buying a brand new set or making your own, is an important part of restoring a motor. Gaskets seal the space between the components of an engine – increasing the amount of compression necessary for an engine to perform well. Poor gasket = poor compression. The types of gaskets vary: some are thick while some are made with thin metal. It is very important to know which type of gaskets to use on your motor. On the Seagull all gaskets were the same thickness, except for a fat copper gasket which fit between the head and the block. I never replaced this one because it was in good condition. Gaskets generally decay because the heat from the block will ‘melt’ the gasket, causing it to fuse and bond to the block. When you’re removing them you’ll notice that they will often need to be ‘peeled’ off their seating.

I had some leftover gasket material from an outboard I restored a couple of years ago which would work. You can get this sort of material at most automotive shop. Fortunately it was very similar to the Seagull’s original gaskets.

I started by tracing the shape of the object onto the gasket material. There is no right or wrong side with this material (be careful though – this might not be the case with all gasket material). Use a pencil so you can erase it if you make a mistake.  I included screw holes that were on the original gasket.

Above: tracing the lower half of the gearbox.

Above: This tracing job isn’t very good – what line should I follow? I decided to redo and make it more accurate.

After tracing, I cut out the gaskets using a very sharp knife. The gasket material is like cardboard and just as hard to cut. The first time I made gaskets I was a bit hasty and my knife got stuck, then it would slide out of control if I pushed too hard. A definite learning curve and I wasted a lot of material. This time round I took more time and got a better result:

Above: Punching holes for the screws (using a plain old hole punch). I left a space around the trace to account for the lip in the gear box cover (the gray circular object at the top of the photo)

This way it would fit around the lip and not be too small.

The Seagull Part II: Taking it Apart

A few months after last year’s final 4-H fair I got to work on restoring the Seagull. I began at the beginning: taking it apart. There was a lot of rust, dirt, and the gearbox behind the propeller was full of an ominous looking sludge. I looked like a drop of seawater had gotten in at some point, it’s a good thing there was oil in there or the corrosive salt water would have rusted the gears.

Above: The gear box after I drained most of the sludge.

After dismantling the gearbox, I removed the flywheel. The flywheel was stuck tight and it took a lot of hammering (and patience!) to get it out. I spend a five hours hammering, tapping, prying and levering on it, and eventually it gave way. Why the hammer? On small motors the flywheel is bolted onto the crankshaft, which is usually tapered. Hammering gently on the flywheel while a helper pulls up will loosen it from the tapered end.

Above: A hammer is a useful for removing flywheels. Don’t get rough!

Above: One end of the crankshaft. Note the taper.

Many of the bolts were stuck and rusted which made it difficult to take them out. When this problem comes up, be very careful. The last thing you want to do is break a bolt. On British Seagulls the bolts are all Whitworth sizes – somewhere in between metric and imperial – but not quite a perfect fit on either of these sizes. Whitworth wrenches aren’t something you can find at your local Canadian Tire store and buying replacement bolts is difficult too; regular hardware stores don’t carry anything that fits. It’s best to go to a specialist.

Now I had an awkward combination of problems: jammed bolts and tools the wrong size. Eventually, by combing through my grandfather’s tool room I found a bit which fit quite well onto the desired bolt. I carefully loosened the bolt by slowly pushing the rachet back and forth. This can break the corrosion holding a bolt in. I levered the ratchet back and forth, gently, loosening all the rust and dirt around the head of the bolt. Whether it takes one minute or one hour, take your time with this process. You don’t want to break anything!

British Seagulls are water cooled: Water from the ocean is drawn in and forced up a pipe by an impeller to the block, where it fills a chamber that encircles the piston. On my Seagull this water chamber was heavily clogged with rust and it was obvious no water was going anywhere. In the photo below the engine head is removed to reveal the four inlets from which you can access the water chamber. This is handy because through these inlets you can see and clean inside the water chamber. The rusty material blocking these inlets is the rust.

Above: The block, note the water chamber inlets. There are four inlets, one on each side.

Above: The inlets to the water chamber – much more visible after sandblasting.

Above: The crankcase. It splits in half, making it easier to take the cams and piston out.

Next, I’ll talk about the fun part: Sandblasting!

First Project: The Viking

My first project was a Viking outboard. I got it from the grandfather of one of the club members. This guy has lots of old machines in his yard and the Viking happened to be one of them. When I got it it was in terrible condition, and no one even knew if it worked because it had been sitting in his yard for 30 years. When I look back now I wonder what made me choose this engine, because it looked so battered and broken, but I’m glad I did, because it was a great learning experience.

Here it is after I built a sawhorse for it to sit on. This is one of the first things you should do when you get an old outboard, because it doesn’t naturally stand on its own.

Here’s the general outline of what I did when I restored the Viking:

1. Took pictures of the engine before dismantling, cleaning, and painting.

2. Took the engine apart. Sorted parts in labeled containers.

3. Cleaned the parts of the motor (removing the grease, old paint, rust, dirt).

4.  Painted the cowling, covers and other pieces (my first project, a Briggs and Stratton lawnmower, was new enough that it didn’t need paining. A spray bottle of pink solution and a cloth was enough to make it look shiny and new).

5. Finally, I put it all together.

I’m going to be discussing what I did in more detail in separate posts, so for now I’ll just introduce the project.