Thursday, October 6, 2016

On the Hard Again (Part 2)

I rolled and tipped the undercoat to make it as smooth as possible for the topcoat, machine sanding between the coats with 220 grit. Some parts of the hull that were still not well faired got the treatment with West 207 filler and then sanded. The Berkerley Marine Center rents high-quality Fein sanders which helps the whole process considerably.

More undercoat

The first top coat was rolled and tipped on after wiping down with alcohol on paper wipes, and then wiped down again with Interlux 333 "Brushing liquid". The weather was pretty hot so thinned the Brightside polyurethane with the 333, and also followed the procedure of using a good brush damped with 333 for the tipping off.

To get a good finish with these expensive, hard, marine paints, it seems that you have to follow all of the procedures by-the-book, which is really hard work. For example, the weather has to be just right - not too hot and not too cold, meaning morningish. I started by painting a whole hull coat in one sitting, rolling on about 4 roller-widths, and then tipping off. But I soon found that the paint would start to thicken, and the brush would drag, so ended up painting each hull side separately. So, 4 hull sides X 4 coats = a long time. Factor in work in the real world, and it took me a month (!) to get the job finished.

First top coat.

The first topcoat was machine sanded with 320 grit, and then hand sanded all over with maroon 3M pads. This hurts because you have a nice shiny coat which you then destroy to get the matte surface required for the topcoat. The topcoats are nervy because you can't fix any foul-ups by sanding afterwards - what you roll on is what you get! Before final coating, the surface got the two-wipe-downs regimen followed up by a final wipe with a tack cloth. The two wipe downs (alcohol then 333) worked so well, that there was little or nothing on the tack cloth afterwards.

I found that the tipping went better with less 333 and some paint on the brush. Too much 333 seemed to contribute to brush lines in the finish (learned this on the first top coats).

Second top coat - looking good.

As well as the hulls, I also gave the 4-coat treatment to the underside of the center narcelle which had some flaking paint, and the glass seam repair.

After the hull paint had hardened for a few days, the next job was to tape up the waterline. I used the existing true waterline mark that I had left on, and then marked up 3-inch arcs using dividers. Three inches is a lot above the waterline, and means less shiny topside showing, but Little Cat is on an open mooring now and gets a lot of wave wash action that had put slime above the previous lower water line mark.

Taping up the water line. The blue tape is the true waterline.

Next, I rolled on the Bottomkote Aqua. Now the weather was real hot, so I thinned it a bit with water (water based paint). It went on OK, but had to work fast as it dried quickly in the heat. I did two coats over all, plus an extra coat on the waterline and edges (pretty much three coats).

Bottom paint goes on

Now it was time for Little Cat to get an actual name saying "Little Cat". I ordered the name and numbers from BoatUS and they were good quality and easy to put on.

She is now looking sharp and will no longer suffer from an identity crisis. My only regret is not getting a larger letter size. Because the hull sides are small compared to most boats, I went with 3" letters - in hind sight 4" would have looked better with this font.

OK, so now we are looking good and started the clean up to get back in the water. Some detail not mentioned here is the work that went into prepping and painting all of the steel work - what a PITA, but now all done with epoxy base coat, 3 or more coats of undercoat, and 2 topcoats. I really expect that the steel fittings will remain rust-streak free for the life of the paint. Another job I completed that I will show in a later post was bolting the center deck section to the cross beams to reduce vibration when the outboard is running.

Looking good

Then it was launch day, and she was lowered back into the water gentle as a baby. That was a lot of work and I'm expecting that she will still be looking good in two years when she comes out again for the next bottom job.

But the work is never over - right? I still have the rudders to re-glass and paint, and the entire deck and top of the boat are still waiting for the four-coat treatment - I should be done and ready for next summer. Because I took so long, the job was pretty expensive, but now everything underneath the boat is in great shape, and I can work away on the decks in my own time on the water.

Materials used:
2 quarts of  Interlux Pre-Kote primer
2 quarts of Interlux Brightside polyurethane top coat
0.75 gallon of Interlux Fiberglass Bottomkote Aqua hard bottom paint
0.5 gallon denatured alcohol (cleaner)
1 quart 333 Interlux Brushing Liquid
5 x 2" paint brushes
Too many roller covers, paint trays and containers, sanding disks, rags and paper towels to count.

1 comment:

  1. HI Little Cat and crew,
    Reading your blog over recent days has been very enjoyable. Although I don't have a Tiki (others boats include self-built Melanesia, a Hunter 19 t/s, and a Folkboat), I have been interested in Wharram cats for years and hope to cash in my my chips and buy a Tiki 21 next. I really like the way you and LC have developed through cruising, coastal trekking and racing and the way you describe fitting and trying out new gear.
    Fair winds, Terry