Shields Prep Week Update 2

Got another big day in yesterday. Dave and I spent about 6hrs sanding and prepping the boat. Here are a couple photos from the last 3 days.

Niki sanded off the rest of the deck's non skid, and I just think this is a neat photo.


This is the inside of the hull deck joint, located in the (dust cave) front air tank. The tabbing on the left has come loose, and you can see the crack on the right.



Removing the tabbing was generally no fun, but it was made a lot easier by our new Fein Multimaster tool. This tool gives you a very thin saw blade and thin sanders, which made it (relatively) easy to separate the tabbing from the hull. This took about 4 hrs, and would have taken much longer if I had to grind it all off, which would also have been quite clumsy working upside down in the bow.



Once we retabbed and reglued the deck joint, we clamped it using white duct tape. In this photo you can also see the paint removal progress, and the bow repair.


The paint removal went pretty well, especially with Dave and I both sanding it off. There was quite a few layers of paint on there. The photo above shows the topography of the hull: we had two very very thick layers of green paint, a gray primer coat, a layer of blue paint, then the blue gelcoat. We took the boat all the way down to gelcoat to make a good base for the awlgrip primer.


Since were sanding off the boot stripe, we'd need a way to replace it. There is a scribed set of lines on the hull, but I was worried that we'd end up filling that in with primer and filler. Instead I transferred the waterlines down to the bottom paint with a permanent marker and a batten. We may raise the waterline a bit, which will be easy to do using a slightly longer batten for transferring it back.

The bow damage was pretty extensive, and I had to grind a lot of material out to get to undamaged glass. For about 4 hrs, we nearly had a plumb bow! We then made a cardboard mold from inside the boat, which acted as base for laying up new glass.

Dave and I then had the pretty fun job of laying in new glass. We used 4" 18oz biaxial tape to wrap the bow and build up new structure. I like his "ankle wrapping" analogy. We've got a very strong structure up there, as its 5 layers at the tip and top. It's very nice to have a pointy Shields again! Dave is shown here below our handiwork.

Not shown:
The tabbing job on the inside of the hull/deck joint and bulkhead.
Our blue (for now) boat!

Todays going to be: fairing, sanding, pinhole filling with acryl putty and cleanup. When we left yesterday there was a lot of dust in the air that I want to get vacuumed up before people get there and track it everywhere.

Friday Mar 21:
Dave 6 hrs
Kristian 6 hrs

Fiberglass/paint prep update

I'll put up photos soon, but it's been a very busy week on Shields 88. We're prepping the boat for primer and paint, and it has to be done by the end of next week. Along the way we've got three major tasks:

Remove old paint from topsides and deck (deck is complete, hull is 50% there)
Fair scrapes/dings in hull, fill and fair old holes in deck (20% complete)
Fix broken nose (bow damage to hull and deck)

In getting ready for the bow repair and hole filling, we made the really alarming discovery the the hull/deck joint for 8' along the stbd bow had failed, and the deck was loose from the hull. This wasn't noticed before as it was barely hanging on, and only loosened once we drilled a few holes out for filling.

As far as I can tell this was caused by a) poor prep on original tabbing b)sloppy repair some years ago c)previous owners collision and subesquent duct tape repair

To repair, we removed several feet of damaged tabbing, and reattached several more where the deck had worked loose from the tabbing. There are some good photos of Niki and I prepping for this, using my new favorite tool (Fein Multimaster)

Today Dave and I spent the whole day on the boat. First we reattached the deck to the tabbing using 404 adhesive filler and epoxy. Then we remade the missing tabbing using 3 layers of 17oz biaxial tape. Both of these repairs went just fine, and we used a space heater and halogen lamp to warm (hot!) the interior and deck. The tabbing cured in about 3 hrs, so I'm very happy with the new bond.

We also retabbed the front bulkhead, as Chris Craft Shields are notoriously weak in this area. This all went fine, but doing the prep work yesterday involved grinding off the old tabbing which well and truly sucked. Instant white out dust storm in the front tank! Literally couldn't see after only a few seconds grinding. Glad thats done!

We were on a roll so we ended up glassing the bow repair. I'd previously ground off the damaged areas, and with some advice from glass guru Mick, extended the ground area for about 10" aft of the bow. Dave and I then prepped and wrapped the bow with several layers of 17oz biaxial. This went really well and we're ready for fairing, pending a possible second application of glass (unlikely) In the very front, there are 5 layers of 17oz cloth, so it should be a very strong repair, and a good place to anchor the bow chock. It's going to take some grinding to get this to the right Shields shape (I think we're a bit too pointy right now) but thats one big job done.

Tomorrows another all day job, and we're going to finish the paint removal and get a good stretch for the paint prep/sanding done.

Hours:

Niki 4hrs Tuesday 6hrs Wednesday
Kristian 4 Hrs Tuesday, 6hrs Wednesday, 7.5 hrs Thursday
Dave 7.5 Hrs Thursday

Not included but interesting Shields 88 work:

Have delrin mast partner shims
Working with Robert at Carbon Copy Composites on a Carbon Fiber compass mount
fixing mast damage using Shields emblem backing plates (cool!)
Working on Splice Setter (not actually Shields 88 related but a cool project)
Doing actual work, I have 12 open invoices right now, inluding 2 other Shields, 7 furling systems, 1 complete rerig and a pair of match racing boats. This is good, as it helps pay for 88!

Paint Prep

Haven't had enough time for our boat lately, but spent a couple hours last week prepping the topsides for paint.

The best way to do it seems to be to scrape off the layers of old paint, then clean up the scrapes and remaining paint with 50 grit on the DA, followed with 80 for paint prep. Will try and get a nother day of prep in this week.

Scrape and Sand 8hrs

Partner Box Installed

Installed the partner box in the deck today. All went very well and I'm excited to see how it works this summer.

The box was made of G10, which is a building material made of epoxy and cloth laminate. It's quite a bit stronger than regular fiberglass, although that property is a bit of overkill in this application. Took a couple hours to design and make the box, which was then assembled using west system epoxy and 404 adhesive filler.

To install we first located the proper location for the partners. Our old oval partner hole was 3/8" offset to port, which would translate to several inches at the mast tip. It was also longer than the class allowed opening. The new partner box is centered, and at the class legal fore/aft location. Not wanting to screw this up I had my dad to help as a second pair of eyes, and we checked everything 4 or 5 times. Centerline was established using the forestay fitting, and arcs from it were made at the gunwale, which were then used to establish a series of centerline marks along the deck. Once these all agreed, a chalk line was made down the center of the foredeck. The box had it's own centerline, which let us lay it out on center. While measuring, we found that the gunwale to center measurment was off by as much as 1/16" of an inch, in the area of the chainplates. This was probably due to lateral compression of the deck caused by the shroud loads. Our centerline seemed to be the more reliable measurement, and when installed the box measured as center to within 1/32" of the gunwale.

I cut the deck using one of my favorite tools, a Bosch jigsaw. I've used a couple other brands, and nothing comes close in terms of power or control when cutting. This is a newer model and the blade change mechanism is great, to eject blades you pull a lever and the blade pops out on spring action. This way you can launch hot blades at people that come to BS while you're trying to work. Very handy.

Cutting the deck was a bit nervewracking, but the box fit just fine and matched all the marks we made.

To install the box, I first sanded and cleaned all the surfaces, and then wet out all the bonded surfaces with neat epoxy. Laid on quite a bit of epoxy thickened with 404 adhesive filler, thinking it was better to scrape off excess than to have any voids. I set the box in place, and cleaned up the epoxy that squeezed out the sides. I used one of the west system mixing sticks, as they have a rounded end that lets you make great corner fillets, and the square end makes it easy to clean up leftover epoxy on finished surfaces. This mix is hard to sand, so the better you get the surface before it cures, the easier your finish prep is! I did the same on the underside, where the partner box extends below the deck for about a 1/4". I left the overlap here so I could make a nice clean fillet joint on the bottom. If the top fillet isn't good enough, I'll use 407 fairing filler to make a better one before painting.

Partner Box On Deck

Under deck view of partner box, fillet around edge

The yard is pretty damn cold, so I made a small heat tent using the boats 6mil plastic cover, a space heater and a 700w work light. The temps under the deck were in the 70's around the box, and above deck the temp was 65 on the surface. I kept this up for about 4 hrs to cure, in which time the epoxy was tack free. I'll return tomorrow and heat it up again to post cure it make sure, by keeping the temp as high as possible for the entire time I'm there.

Setup And Install Partner Box 5hrs (+2hrs cure time)


While sitting around watching epoxy cure, I decided to make and fit the mounting plate for 88's spin sheet ratchet blocks. Most of the time when racing the shields, you keep the spin sheets on the winch, but rarely use the handles. In order to make a faster trimming sheet-as well as to take some weight off the boat-I removed the spin sheet winches and made plans to install Harken 57mm Carbo Ratchet blocks. I kept the winch mounting pad, as I liked the angle it made to the cockpit, but needed a way to seal off the hole for the winch spindle, as well as a way to get the block up a bit higher in order to have a fair lead over the coaming. I used 1/4" HDPE (Starboard). I cut a half circle that matched the old winch base, and then cut the inside edge of the mounting plate on an angle to match the coaming. This makes the blocks high enough, means the sheet will clear the coaming, and seals off the old winch mounting holes. They fit well, but I'm going to put a nice routed edge on them before installing, which we'll do after painting. The blocks are positioned so that the spinnaker sheet can be cleanly led forward to the jib winch if we ever need winch power for heavy air trimming of the guy. We'll see how well this works out. I'm a pretty average sized guy, and the only time (as a spin trimmer) I ever needed the winch was in 20+kts.

Spin Sheet Ratchet Block Dry Fitted

Fabricate and Fit Ratchet Block Plates 2Hrs

Partner Box Install Prep

Only had time for a quick boat visit today, but it was time well spent. My dad came by to check on progress, and I used the extra set of skilled eyes to lay out a couple items of deck gear. Most important was the location of the partner box.

Surprisingly, the old partner box was pretty sloppily located, being 3/8" off center to port, and pretty far forward relative to the classs mandated location. We triple checked to make sure that we were right and CC wrong, but there it is. I also used the grinder to remove the damaged port edge of the current partner hole. I don't know what caused it, but the port middle side of the oval hole is crushed and pushed up. If I had to guess, I'd imagine that while unstepping the mast, it twisted and one of the below deck exit boxes caught and ripped the deck. Careful!

The new one is being installed at the class legal spot, and also on centerline. I layed out the markings, and will cut and install tomorrow. Very exciting, as I've been trying to find a good solution for the partner box issue on Shields. So far this seems leike a good one!

Kristian 1 hr
Victor 1hr

Deck Prep

Spent part of Friday and Saturday prepping the deck for paint. For this special occasion Niki came out to help sand!

Between the two of us and two days, we've got the stbd side nonskid sanded off. I ground and filled holes in the deck, everything aft of the winches.

Kristian 8hrs
Niki 4hrs





What the heck are these??? Find out later this week.

Shields Partner Box

Keel stepped masts, like the one on the Shields, have to pass through the deck. The structure that the mast goes through is called the partners.

Most Shields I've seen have pretty bad partner box systems. Originally the partners were just an oval hole in the deck, sometimes with glass protecting the core, and sometimes not. The mast is stepped, and then various wedges and shims are used to hold it in place. Over time, the shimming and wedging makes the hole irregular, larger, and broken. I recall (fondly) sailing on #90, which had the most comically oversized partner hole ever. We would jam wood shims, doorstops and god knows what else in there to get the mast stabilzied, and then wrap the whole mess in duct tape. It was ugly, but that boat went pretty quick!

On 88, it's not that bad, but the partners need repair, as the port side has curiously lifted up from the deck, and then been repaired with an unknown putty. Rather than mess around with fixing the oval partner, I'm going to replace with a raised rectangular box style of partners. 150 had this and it works great. You make up HDPE shims that fit the box and the mast, and get 0 movement when installed. To make this out of glass and fair it into the deck takes a lot of time, and if you want it done right, vacuum bagging skills. Instead, I've come up with a simpler bolt on (well, glue on) solution by making a flanged box out of G10 material (epoxy glass), which can be installed into a rectangular cutout in the deck.

I've got our box more or less finished (as well as one for 126), and am going to try installing it next week.
Make Partner Box 4hrs