Wednesday, June 30, 2010

Bottom Job drags on

Since the last update I've continued focusing on the bottom job, and I am only a few days away from finishing the main grinding of the port side. I usually work Monday through Thursday after work until dark. Weekends have been on hold until I am fully settled in here in St. Augustine. I couldn't work all last week due to travelling for work, my first week without getting anything done.

I had some technical difficulties with my grinder two weeks ago so I spent that week sanding the previously ground starboard side down smooth with a 5" random orbit sander using 40 grit pads. This smoothed out the grinding marks and faired the hull somewhat. I am about 2/3 done grinding the port side. Once grinding is finished, then I'll give it a good sanding and I'll be done with the hull for a while.

Starboard side after grinding down to bare glass and sanded smooth

Port side grinding progress:

Space man at work

Thursday, June 10, 2010

Project - Bottom Job con't.

I finished grinding the starboard side today

Took approximately 40 hours, mostly 3 hour shifts after work till dark. Hopefully I can finish the other side quicker with what I learned on this one. Opened up about 40 blisters as well. It is difficult and boring work. Holding the grinder above the head and away from the body is hell on the shoulders and back, but my endurance is getting better. This is probably the worst job of the whole rebuild, glad it is over halfway done.

Wednesday, June 9, 2010

Project: Bottom Job

Since hauling Windsong out of the water I have been focusing most of my energy on her hull below the waterline. My goal was to get the hull to the point where it could dry out for the rest of the time on land. This would mean removing paint and the gel coat (if necessary) and then leave the hull alone while I worked on the rest of the boat. Fiberglass boats do in fact absorb water through osmosis (what creates blisters). The hull needs to be completely dry before I apply the planned epoxy barrier coat (protects against water absorption) and then paint.

I had researched many different ways to remove paint from the bottom. The most common choices are to sandblast, grind, use a chemical peeler, or just old fashioned muscle and scraper. I opted for the simple method of scraping with a cheap paint scraper from Home Depot. The bottom paint was loose enough where the majority of it came off with the scraper. I would scrape a section of hull then go back and sand away the remaining paint down to the gel coat. I started at the bow on the starboard side and worked my way back.

Here is the hull after the first weeks work:

Removing the old paint to the gel coat revealed quite a few small spots where fairing compound was used in some sort of repair. It also revealed the blisters I feared would be present. The worst case scenario in my mind were thousands of small blisters all over the hull. But what I discovered were isolated, larger blisters averaging about 3-4" in diameter (some larger some smaller). When I found a big blister I would drill into it with a countersink bit to release the fluid inside. The fluid is some sort of gross acidic chemical that smells very distinct and shoots out at high pressure. It is always fun to pop them, but I always seem to get the stuff all over me. I would drill a pattern of holes all around the area of the blister so they would drain completely, and could be flushed out with ease. Cleaning and flushing the blisters with fresh water removes salts, chemicals and other nasty stuff that slows drying time.

Drilled out blisters. You can also see all of the old repairs/fairings:

Small blister completely ground out:

Another small blister, and even smaller ones showing the poor condition of the gel coat

I determined that the blisters needed to be ground out completely until I reach undamaged glass. Since these are deep and large, I will need to build the leftover hole up with layers of glass before fairing compound.

Ground out blisters below. I have yet to bevel and shape the ground out blisters completely for repair, only ground out to dry:

After scraping and sanding for a week or so, someone at the boat yard saw me struggling with my scraper and going slow as molasses. He recommended that I use a pressure washer with a special nozzle attached to really blast off the loose paint. I did so and was able to get all loose paint off (most of it!) with only an hours work with the hose. This was fantastic compared to the slow slow work of the scraper.

Unfortunately the blasting revealed many areas where the gel coat was in such bad shape it just chipped away. Some areas where it chipped away revealed more blisters and hydrolysis (water damage) in the first layer of glass. After wasting a week working on sanding down to the gel coat, I know accepted the fact that the gel coat needed to be removed completely so that the glass underneath it can dry out.

Here are some pictures of the hull after the pressure blast:

So I re-tooled and began to grind away the paint and the gel coat underneath it down to bare glass, grinding out any blisters or evidence of hydrolysis I came across in my path. I've been experimenting with many different pads for the grinder and have settled on using a 4 1/2" rubber backing pad and 36 grit disks. Most of the time it comes out pretty even, but I'll have to go back over the entire hull with my random orbit or palm sander to get it nice and flush.

Here is the hull after a week or so of grinding. I started the port side when I came to work on the boat early on a Sunday, the sun was on the other side so I switched to the shady one :)

By the end of this week I should be over half way done. Once fully ground off, I'll leave the hull to dry out while I turn my focus above the waterline, the deck, and the interior.

Once most of the projects above the waterline are out of the way I'll follow this procedure to finish the bottom job:

-Sand entire hull smooth
-Repair deep blisters and any other major damage (keel) with layers of glass
-Fill and fair small blisters and gouges until smooth
-Apply epoxy barrier coat
-Apply anti-fouling paint

Wednesday, June 2, 2010

The Haul Out

he Monday after we sailed Windsong into St. Augustine we finally hauled her out to begin the massive rebuild. I had been anticipating this moment since I bought the boat about a year ago. I had never seen the hull below the waterline but knew a little bit of what to expect. I dove down to check the bottom once, but it was too murky to see anything. I could feel blisters however near the waterline so I figured I would have a few of them. Windsong was kept in warm Florida fresh water for a long time without a bottom job, ripe conditions for blister problems. I feared that she may have a case of full blown pox - a condition of thousands of tiny gel coat blisters covering the entire hull. This was the worst case scenario and I wanted to be prepared for it. I didn't expect any other major problems with the hull, though I anticipated some damage on the keel from when we ran hard aground. During the past year I have been studying all that I will need to do to the hull depending on its condition.

It was a gross morning with a ton of rain. We hauled her out in the downpour and I got a first look at the bottom

Proud owner :)

After the haul they gave her a good pressure wash. There wasn't much growth on the bottom, just some slime. She had only been in salt water for about two months and the water was pretty cold the whole time, so barnacles didn't get time to grow. The pressure wash was taking off chunks of old paint that had begun to deteriorate over time. It turns out, the gel coat blisters I thought I felt were actually just paint blisters and chipped off with the pressurewash.

I had to leave to work half way through the pressure wash, but thankfully the weather cleared up later on for me to check her out on the stands.

Decades of old anti-fouling paint chipping away.

Depth sounding transducer, paint blisters

keel damage

thru hulls

Rudder and prop

The prop was in surprisingly good shape. I thought the cutlass bearing would be shot since there was a ton of vibration when motoring at cruising RPMs. It turns out there is some sort of shim that slides under the prop and into the bearing tube. This shim somehow broke, making the prop loose and explaining many strange noises and vibration.

I am concerned about this area that the rudder attaches to. Lots of cracking and whatnot

The zinc. This appears to be the only zinc, with all thru hulls wired to it. I anticipated bad problems with electrolysis since it had been so long since a zinc was replaced, but somehow it is still there.

Port side paint

I discovered many things about the hull as I began to remove the many layers of paint. I'll detail the first two weeks of work in the next post. I am having computer problems at home so I cannot upload any new pictures that were taken after the haul out. As soon as I get them up I'll post and keep a more frequent progress report going.