Monday, April 27, 2015

A Perfect Match

A couple of posts back I talked about getting some color-matched gelcoat from Fiberlay.  And I promised I would tell you about the results.  Well here they are:

Filling some screw holes and chips on the edge of a cockpit seat
Looks pretty good, doesn't it?  I must say that managing the gelcoat as you are applying it is difficult.  Just like working with polysulphide, it seems to get on everything, including my hands, my pants, and my feet.  You will want to keep a can of acetone and a rag handy. 

Before I applied it to the problem areas, I used my Dremel tool to clean them up.  Some were just small screw holes or chips as in the picture above, but one area needed severe remedial work.  I mixed the gelcoat in a plastic cup with a tongue depressor and then used the tongue depressor to apply it.  On the next batch I think I will try a paint brush for the larger areas - the stuff is pretty runny.

After it goes off, it needs to be sanded, a process I am way too familiar with from doing automotive body work.  I used 220 grit wet/dry paper, wet, and I applied blue tape around the area to be sanded so that I wouldn't accidentally sand thru the gelcoat on adjacent areas.  Once I had the patch down to about the thickness of the tape I switched to 400 grit, removed the tape, and sanded it flat.  Then a touch of polishing with some compound, and...

Poof!  Gone!
Yes, there is a little bit of white showing on the edge chip where I failed to remove enough of the Previous Owner's MarineTex patch.  I will grind it out and apply more gelcoat.  Again, a process I am way too familiar with...

But the color match is absolutely perfect!  Huge kudos to Fiberlay for a match well made!


Monday, April 20, 2015

Galley Work

Back in October, I re-designed the curtain tracks on two of our aft ports in order to allow them to open more completely.  The results were so nice and professional looking that the remaining six ports just begged to be upgraded too.  So I ordered more curtain track from Sailrite.

This last weekend I got around to making the installations.  But because there were six to do, a little manufacturing engineering came into play. 

First, at home I cut and trimmed the track with my trusty hacksaw and vice. Then I set up a work station at the galley sink for drilling - the sink traps the drill swarf and keeps it off the floor where it would damage the finish. Above, you can see that I have marked where the holes go on the tracks and am busy drilling them with a 5/32" bit.

After finishing the manufacture of the tracks, the work fell naturally (that is, unplanned...) into four workstations, each with its own dedicated tools:
  • Station 1:  At the current port.  Tools here were a #2 Phillips screwdriver, a 3/8" box wrench, a small flat blade screwdriver, and a small #1 Phillips screwdriver.
  • Station 2:  The galley sink. Tools here were the drill, water and a sponge
  • Station 3:  The saloon table.  Tools here were Meguires plastic cleaner, Meguires plastic polish, and some rags
  • Station 4:  The saloon settee.  Tools here were a #2 Phillips screwdriver and a 5/16" nut driver.
And so the work went like this...
  • At Station 1:
    • Remove the existing curtain track and curtains from the rusty spring clips and set aside
    • Using the #2 Phillips and the 3/8" wrench, remove the nuts and screws holding the port hinges together.
    • Remove the port lens.
  • At Station 2:
    • Carefully wash the port lens using water and the sponge.
    • Transfer the hole locations from the track to the port lens and mark with a Sharpie.
    • Drill two 5/32" holes.
  • At Station 3:
    • Apply polish to the inside of the lens and turn it over
    • Apply cleaner to the outside and rub vigorously to remove the oxidized lexan.
    • Remove the cleaner with a rag and apply polish to the outside of the lens
    • Buff the outside of the lens.
    • Buff the inside of the lens.
  • At Station 4:
    • Now that the lens is clean, it won't dirty the settee cushion, and it needs protection.  Working on the settee is perfect.  Install the track to the lens with two 6-32 screws and nylock nuts, using the #2 Phillips and the nut driver.
  • Back at Station 1:
    • Insert the lens hinge plates into the hinge plates on the port frame.  
    • Use the small Phillips screwdriver to align the holes.  It is perfect for this - the shaft is exactly the right diameter and the tapered tip allows easier alignment.  I struggled mightily with this step before I stumbled across the use of the screwdriver.
    • Insert the screws into the hinges and add the nuts.
    • Using the small flat blade screwdriver, remove the stop screws from the ends of the old track.
    • Remove the curtains from the old track.
    • Install the curtains into the new track.
    • Install the stop screws in the ends of the new track.

And then move on to the next port...

Tho having these four stations pretty much occupied the whole boat during the work, it completely eliminated all movement of tools except for the small handful used at Station 1.  For me this is a huge advantage, since otherwise I am always looking for one tool or another.

It took all afternoon, but only one beer.


Monday, April 13, 2015

I wonder if you knew

Say you have a boat, and say that the gelcoat has some flaws in it (but I repeat myself).  These might be caused by, say a dock that approached too quickly, or a wayward buoy.  Never fear... you don't have to live with those flaws.

Gelcoat is simply polyester resin with pigment and some flow modifiers added to it - there is nothing magic in it.  The magic *is*, however, in getting the right mix of pigments so that it matches the gelcoat on your boat.  You can do this (I have), but it is a truly tedious process and, for me anyway, very very challenging.  Instead, I have an alternative for you.

I wonder if you knew that Fiberlay will make up a quart (minimum size) of gelcoat to match your sample.  They scan the sample using not one, but three different light sources, take the average of those three results, and use that as a starting point for a manual match.  You even get a custom label!

(Pay no attention to the gelcoat smeared on the outside of the can, and don't let the can fall out of your car onto the pavement - the lid will probably come off)
The cost is surprisingly reasonable:  $73 tax included.  That compares to a quart of off-the-shelf Interlux Brightsides urethane paint which pushes $50 pretty hard.  Not bad at all.

Now, here's the tricky part - how do you get them a sample to scan?  If you have something that can be taken off your boat that has representative gelcoat on it (a lazarette hatch for example), then you are in good shape.  If not, then I hope you have saved all those plugs you cut out when installing instruments, etc. 

Always save those plugs
But even failing that, for an additional charge, Fiberlay will send a technician to your boat to do the scan - but I expect that the additional charge is not necessarily trivial, skilled labor being the most expensive commodity in today's world.

Next, you will have a choice to have the gelcoat mixed up with or without wax.

Wax?  Why wax?

You see, oxygen is a chain stopper for the polymerization reaction  that turns liquid polyester resin into solid polyester resin.  That means that the surface of a gelcoat application will not cure where it is exposed to air.  When you are making a boat in a female mold, this is a good thing, insuring that the next layer to be applied will bond chemically with the uncured surface of the gelcoat.  When patching this can be handy too, especially since gelcoat shrinks some while curing, and thus will likely require more than one application to a given patch.

But eventually, you will want the final layer to cure.  That's where the wax comes in.  If the gelcoat has wax mixed into it, the wax migrates to the surface as the cure progresses, sealing off the surface from the air and making a complete cure.  This is what you would want if, for example, you were spraying gelcoat onto a finished lamination on a male mold.  Or if you were willing to scrupulously dewax the surface before applying another layer of gelcoat.

I chose to have the wax left out.  And I bought a small bottle of PVA (polyvinyl alcohol).  This is a water soluble plastic that can be painted over the final layer of gelcoat to exclude air from the surface.  A simple water rinse removes it.

I will post some before/after pictures later... after the weather gets nice enough to spend time out on deck in the sun.


Monday, April 6, 2015

When Stainless Isn't

That's our right-hand sink drain. The side of the sink that the tell-tale for the refrigeration pump discharges into, discharges salt water into that is.  And that is not just staining...  it is rust.

Simplistically, stainless steel is an alloy of iron, chromium, nickel and carbon.  There are over 150 alloys called "stainless steel", each optimized for a particular set of properties.  The alloys typically found on a boat are SAE 304 (AKA "18-8", 18-20% chromium and 8-10.5% nickel), and 316 (AKA "surgical stainless", 16-18% chromium, 10-14% nickel and 2-3% molybdenum).  Between these two, 304 is the stronger and 316 is the more corrosion resistant.

But when you are buying plumbing fittings, you are not typically provided any choice of alloy (or even, usually, an alloy description).  The single exception to this is the sink, where sometimes an alloy description may be given.  All stainless alloys are somewhat attracted to a magnet, but 316 is attracted a lot less than 304.  But you would really have to have samples of both to be able to make a valid comparison.  To confuse matters more, the amount of cold work that the piece of metal has received will affect its magnetic properties - a lot.  And finally, we don't have any loose magnets aboard Eolian, for obvious reasons, so magnetic testing of the new drain fittings is not going to happen. 

It is clear that whatever the alloys of the sink and the drain fittings, the drain fittings have the least corrosion resistance.  Still, I installed those drain fittings over 15 years ago, when I replaced the original severely corroded chrome-plated brass ones.

So I guess I am good for another 15 years now.

I hope.

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