Tuesday, February 28, 2017

Renovating the Lady C - Bottom

Lady C prior to renovation

Starting in August of 2016, I am renovating the Lady C, a semi-dory that I built in the early 1990's. It is Tracy O'Brien's V-20 design. This project will involve mostly sanding and painting.

Remove from the Trailer

The first step is to remove the windshield so the boat can be rolled over on to its roof.

Windshield removed



Ready to be pulled off of the trailer


After removing the windshield, the boat is pulled off of the trailer so it is sitting on the driveway ready to be rolled over. With a rope tied from the boat's bow loop to a tree behind the stern, I used the truck to slowly pull the trailer out from under the boat. As the trailer was pulled out, I installed wheel sets on the roof of the boat so that, after rolling, I can wheel the upside down boat into the shop.

Trailer pulled about 4 feet from under the boat

Trailer pulled about 8 feet from under the boat

OOOPS!!!



Failed trailer bunk




Failed trailer bunk

When I got the trailer nearly completely pulled out from under the boat, I placed a stack of tires under the stern on the port side so the boat will be listing in the direction that I will flip her.

Then I unlocked the trailer hitch, but left the safety chains connected. The theory is that when the boat is far enough back on the trailer, the hitch will pop off of the ball and the trailer will have a perfect slope to slide the boat gently to the ground.

However, the hitch is so rusty that it did not pop off of the ball and before I could pull the trailer all the way out, the right bunk of the trailer failed.

The boat slammed onto the driveway. There was no damage to the boat, which indicates how structurally sound the boat is. This is the first of many stressful situations during renovation that will indicate the soundness of the boat.

The 12-foot 4x6 bunk was ruined and was convert to two 6-foot 4x6's



Failed trailer bunk with carpet

Failed trailer bunk without carpet

Failed trailer bunk


Flip the Boat

With the boat ungraciously placed on the drive way, it is time to start the slow process of flipping it.

Tires were placed under one side as the trailer was pulled out




The slow process of jacks and come-alongs for rolling

As it gets close to flipping, restraint lines are tied to the truck



Inch it on over. NOTICE THE WHEEL SETS

A little further
It is easy to get a dory up on its side. The hard part is rolling it up and over the rubrail. But it is even worse in this case due to the cuddy cabin. During the roll, the entire weight of the boat will be on the starboard aft 6 inches of the cuddy roof - another stressful situations that will indicate the soundness of the boat.


Ready to roll over the edge of the cuddy roof onto the wheels
Time to find out if this renovation project will involve rebuilding the crushed cuddy cabin.

Safely on her roof
Even though the entire weight of the boat was on the starboard aft 6 inches of the cuddy roof, the cuddy cabin was undamaged.

As I used the truck to tow the upside down boat into position for pushing it into the shop, the wheel sets failed. The failure was due to the swivel casters base not being parallel to the ground, but parallel to the slanting boat hull. In this case, they could not swivel and got dragged sideways until they failed. This is another stressful situation that indicated the soundness of the boat and gave me confidence to be rougher with the boat.


Luckily the scrap lumber used to make the wheel dolly remained under the boat and the boat was not contacting the ground. Now I am frustrated so I grab a come-along and use it to skid the boat into the shop.



Eventually the anchor for the come-along failed so I got really frustrated and just backed my truck into the transom of the boat and pushed the boat into the shop. The boat skidded with the scrap lumber beneath it. Again, highly stressful on the boat with no damage to the boat. However, the truck bumper got slightly dented and scraped.

Spin the Boat

Now that it is in the shop, I see that it needs to be turned around with the bow facing out of the shop. Time to jack the boat up on cribbing, install a properly constructed wheel dolly under the boat, wheel her out of the shop, spin her around and wheel her back in to the shop.

I built a strong wheel dolly. Four wheels will support the aft end of the cuddy roof and four wheels will support the sheer deck near the transom.



Jack up the boat, crib it and install the dolly.



Use a come-along and rope tied to a tree to pull the dolly and boat out.



Spin it around and use the come-along to pull it back into the shop.




Now there is room to walk around the bow and access the shop without opening the overhead door. Much better.


Remove the Sole Battens

The sole battens were part of the original flat-bottom design. To convert this boat to a semi-v, I need to remove the sole battens.

There are also wedges at the base of the transom that must be removed.

Wedges (mustard color) at base of transom

The wedges were recommended by the boat designer to reduce porpoising. Porpoising is when the bow of the boat comes further and further up out of the water before the boat gets on step. Once on step, the bow comes down to a reasonable level. Porpoising is common for flat bottom boats.

If the wedges are too short or too flat, they have little to no effect. If the wedges are too long or too steep, when on step the bow dives and the boat is nearly unstable at planing speed (I learned this the hard way). After a couple of wedge configurations, I got them just about right. But the wedges are now in the way of the semi-v hull.


Wedge removed with Sawzall. There is no sign of rot after 25 years.
With the wedges gone, I can remove the sole battens

Sole battens (3) before removal

I would prefer to use my power planer and simply plane the sole battens away. However, 25 years ago, when this was the second boat that I built, I was foolish enough to leave metal fasteners embedded in the wood. In these sole battens I left brass screws every 6 inches and the screws will destroy the power planer blades.

I will remove half of the sole battens' depth with a Sawzall. The Sawzall can only penetrate half the depth because the Sawzall body and guard preclude the blade laying flush with the boat bottom. The Sawzall will not be harmed by the screws.

The remainder of the sole battens will be sanded off. The sand paper will not be harmed by the screws.

The Sawzall and sanding is a painful method but is necessary due to the brass screws.

Sole batten partially removed by Sawzall.
Note the brass screws that I left installed
when I built this boat 25 years ago.
There is no sign of corrosion of the brass screws
and no sign of rot in the oak sole battens.
It is OK to use metal fasteners to clamp an epoxy joint as long as the metal fasteners are removed after the epoxy cures. But, there is no reason to leave metal fasteners embedded in an epoxy joint. In fact, there are reasons to NOT leave metal fasteners embedded.

Leaving the metal fasteners adds no strength to the epoxy joint since, done correctly, epoxy is stronger than the metal fasteners and the wood itself.

Leaving metal fasteners embedded creates a possible corrosion issue even if the fasteners are stainless steel. Stainless steel is stainless because there is chromium in the steel and the chromium reacts with oxygen in air and/or water to create a chromium-oxide barrier coating on the steel that prevents corrosion. If the chromium-oxide coating is dinged or scratched, chromium underneath is exposed and reacts with oxygen, creating new chromium-oxide coating - it is self-healing. However, if stainless steel is well embedded in epoxy and deprived of oxygen, the the chromium-oxide coating cannot form and stainless steel can corrode.

Another reason to NOT leave metal fasteners embedded is what I am experiencing right now. If you want to modify the boat, you will have to deal with metal fasteners left behind by the boat builder.

Leaving metal fasteners embedded in an epoxy joint is a rookie mistake. A mistake that I made as a rookie 25 years and 9 boats ago.

In my latest 3 boats, there is not a single metal fastener in the wooden hull.

Sole battens after cutting with Sawzall
I removed the remainder of the sole battens using a 15-watt angle sander (jokingly called the "anger sander") with a 9-inch backing pad and 9-inch 36-grit fiber discs. This was some seriously aggressive meat removal and it created gobs of dust. I wore long pants, long sleeves, a hat, safety glasses, dust mask and ear muffs. The dust still found its way into unbelievable places.

Sole battens partially removed using anger grinder
Then I used the anger sander to remove the paint and primer so future epoxy would stick to the old epoxy impregnated fiberglass. I am amused at how I have yet to find any wood rot. And, the wood is not saturated - it has normal moisture content for plywood off of the shelf at the lumber yard.

Sole battens, paint and primer removed. The black splotches
are the old graphite epoxy which can safely remain.
I am finding very little fiberglass delamination. The few delaminations are where the bottom was dinged by rocks on the beach. I ground them all back to bare wood and the divots will be filled with thickened epoxy.

I tried to remove only the sole battens, paint and primer - leaving the old, sound epoxy and fiberglass intact on top of the plywood. But the anger grinder is very angry and it removed quite a bit of  the old sound epoxy and fiberglass. No worries - I'll just fill the divots and re-coat the entire surface with a new layer of fiberglass set in epoxy.


Milestone Accomplished!

Sure am glad to be done with that difficult messy sanding/grinding!

I will never again leave another metal fastener in a wood boat!

Looking forward to designing and installing the keel and bulkheads for the new semi-v bottom.


New Fiberglass on the Old Existing Bottom


Before I installed the bulkheads and stringers, I applied a fresh layer of fiberglass set in epoxy over the entire old flat bottom.







New Bulkheads and Stringers for Semi-V

Then I used AutoCad to design the bulkheads


Bulkhead dimensions




I cut and roughed-in the bulkheads


Bulkhead layout




Both sides of each bulkhead get a layer of fiberglass set in epoxy.







The aft (transom, station 0) bulkhead is installed.

Aft bulkhead fillet and 7oz. tape on interior

Aft bulkhead fillet and 17oz. biaxial tape on exterior




Stringers are cut to fit between bulkheads. Both sides of each stringer get a layer of fiberglass set in epoxy.









Each bulkhead and stringer is custom cut to match the existing hull, Marching along gluing (epoxy thickened with silica, glass fibers and wood flour) the bulkheads and stringers in place. 



First 2 bulkheads and 3 stringers clamped and glued


First 3 bulkheads and 6 stringers glued




Five bulkheads and affiliated stringers glued


In the aft portion of the boat the existing boat bottom is fairly flat so the custom-cut bulkheads and stringers are fairly simple. 

Forward of about midship the bottom of the existing hull begins to form a vee and curves in two directions. This was accomplished when I built the original hull using laminated-in-place strips.


Strips laminated in-place
during original build in the
early 1990's


In this curved portion of the existing bottom, the custom-cut bulkheads and stringers require some strange curved shapes.



New stringer curved to match existing bottom and curved to
accommodate the new bottom that will be curved in this area.



The foremost portion of the existing old bottom will be exposed after the vee-hull is installed. I added a new layer of fiberglass set in epoxy over the exposed portion.

10oz fiberglass being layed with epoxy


10oz fiberglass complete. Weave will be filled
when the entire new bottom is faired - a good
reason to use non-blushing epoxy.
New Bottom Panels

Due to the complex shape of the forward new bottom panels, I took measurements off of the bulkheads, stringers and old bottom then I cut a template out of cardboard.


Supple batten used to mark curves on template

After cutting the 3/8 meranti BS-1088 to match the template, I used my power planer to bevel the chine-egde of the new bottom panel to mate with the old existing bottom. I coated the inside face of the new bottom panel with 4oz fiberglass set in epoxy. Then I glued the new bottom panel (first of four) in-place with a thickened epoxy mix of resin, hardener, silica, micro-fibers and wood flour.


Dry fit of first of four new bottom panels




Dry fit of first of four new bottom panels




4oz fiberglass dry fit to inside face of new bottom panel





4oz fiberglass saturated with epoxy




New bottom panel glued in place. The screws are temporary
clamps that will be removed after the epoxy cures.
The keel line of the panel was cut proud and will be trimmed
to match the keel after the screws are removed.



First of four new bottom panels glued in place.





Front of new bottom panels - fairing to match existing old bottom



Dry fit third of four new bottom panels




Glassing the inside face of the new bottom panel




Temporary clamping screws to hold
bottom panel in-place until epoxy cures


Sand the keel portion of the panel to mate
with next panel


Screw holes filled and end grain sealed

There is very little room in the back corner of the shop where I have to place the last of the four new bottom panels. With no room to pre-wet and apply thickened epoxy to the mating surfaces then carry the last panel and place it, I decided to use the overhead pulley system that I installed in the shop when I built the boat BW.


Last of four new bottom panels suspended from ceiling
for pre-wetting and applying thickened epoxy.



Lowering the last panel into position



Excess thickened epoxy oozing out of the scarf joint at the front
of the last new bottom panel. The excess epoxy does not go to
waste. It is scraped off and used to fair the new bottom panels
placed previously.



Final panel glued and clamped with temporary
clamping screws 



Excess epoxy oozing
out of pre-drilled clamp
screw holes




After curing, removal of temporary clamp screws and
filling of screw holes, the bottom panels are pre-coated
with epoxy prior to applying 10oz. fiberglass.



After the pre-coating epoxy is tack-free, 10oz. fiberglass is
set in epoxy




New bottom panels completely covered with 10oz fiberglass



The 10oz fiberglass is wrapped around the chine, overlaying
the existing old 24oz biaxial tape



Using the Stanley Surform to knock of the high spots
before fiberglassing the keel



4-inch 17oz biaxial fiberglass tape over
the 10oz fiberglass along the new keel.

Note:It takes 200cc of
epoxy to saturate 5-feet
of 4-inch 17oz biax.



17oz biaxial tape applied to the exterior of the
joint between the transom and new bottom panels



Edge of 10oz. f/g faired along the side panel







Edge of 17oz. biax faired along the keel then all weave filled
with epoxy thickened with silica and wood flour applied
with a trowel






After final sanding of weave-fill, epoxy thickened with
graphite is the final epoxy layer before painting.





Contrary to conventional wisdom, graphite powder does not increase the scuff resistance of the epoxy. The graphite would have to be strands with length, like fiberglass, kevlar or carbon fibers, in order to have any possibility of adding reinforcement. But graphite powder is simply specks of graphite dust that physically cannot reinforce the epoxy. 

Moh's hardness scale ranges from 1 (softest - talc) to 10 (hardest - diamond). With a Moh's hardness of 1.5, graphite is the second softest mineral known to man and, therefore, cannot increase the hardness of epoxy which has a hardness of 3.

Even though graphite does not increase the scuff resistance, it does three good things to epoxy. One, it thickens the epoxy reducing the likelihood of the epoxy running or sagging before curing. Two, graphite pigments the epoxy uniformly allowing easy identification of surface irregularities. And three, it leaves a beautiful near-showroom finish. Unfortunately, it does not provide UV protection so covering that beautiful near-showroom finish with a UV protecting layer, like varnish or paint, should be considered.


Read more on debunking the graphite myth at 




Graphite/epoxy layer lightly sanded to remove sheen



Masking to denote the original limits of red bottom paint.


After applying the first layer of Rust-Oleum Topside red paint I noticed that the original old paint is rough leaving the new paint with an ugly rough surface. Sanding all of the old paint completely off would be difficult since it is cross-linked linear polyurethane which is harder than the hubs of hell. I sanded the loose areas away and left the areas of solid old paint in-place then covered the old paint with high-build Rest-Oleum Topside primer. The primer was then sanded. Now there is a layer of primer over the old rough paint. The sanded primer provides a smooth surface for the next layer of red bottom paint.


Sanded primer ready for top coat of red 



Sanded primer ready for top coat of red




Third coat of red paint - sides will need another
coat or two



Third coat of red paint on bottom - no more
coats needed on bottom



Third coat of red paint on the sides



Fourth coat of red paint on the sides





Fourth coat of red paint on the sides





Fifth and final coat on the sides




Fifth and final coat on the sides


Some Notes on the Rust-Oleum Topsides Paint

When I used the gloss black Topsides paint on the bottom and sides of my boat BW, the black paint was applied straight out of the can without thinning. I rolled the paint on with a thin-nap foam roller then I tipped-out with a foam brush. The paint flowed out well and dried to a near-perfect high-gloss finish with no drips or sags.

When I used the gloss red Topsides on the bottom of the Lady C, I had the same results as the black Topsides on the BW. However, on the sides of the Lady C, the gloss red Topsides paint was not as easy to apply as the black Topsides paint was on the sides of the BW.

Unlike the easy-going black paint, when the red was applied straight out of the can without thinning (rolled on with a thin-nap foam roller then tipped-out with a foam brush), to the sides in a coat thick enough to flow out, the red paint sagged. When applied straight out of the can in a thinner layer to prevent sagging, the red paint did not flow out and dried with brush strokes in it.

I had to thin the Topsides red paint in order for it to flow-out in thin layers. I thinned it 5 to 10% with mineral spirits. The thinned red paint was applied to the sides as usual (rolled on with a thin-nap foam roller then tipped-out with a foam brush). The paint flowed-out nicely and did not sag and had a beautiful finish. However, due to the thin nature of the paint it did not cover well - the original mottled layer beneath showed through slightly. Several coats were required to get good coverage. Due to the thinness of the layers, sanding between coats was achieved with a ScotchBrite pad instead of sandpaper since sandpaper would practically remove the entire thin coat.



I stepped away from the Lady C renovation for a bit to create plans for building my boat design BW. Click the link below for more information 




Back at the Lacy C renovation...


With the bottom painting complete, I am painting the sides. I sanded the unsound old paint away, leaving only sound original paint. WOW, that System Three cross-linked LPU top coat that I applied 25 years ago is still harder than the hubs of hell. However, it is cracked and discolored so I am re-painting. But removing the old cracked LPU ate through many sheets of 60-grit 6-inch RO sandpaper discs.

Side sanded down to sound paint


Two coats of RustOleum Topside high-build primer everywhere
that the top coat will be white. A third coat was spot applied
where needed

Read about my fun with high-build primer here

Applying a white topcoat of Rest-Oleum Topside paint.

I am not as happy with the Rest-Oleum Topside paint as I was after painting the BW bottom and this Lady C bottom. I can't seem to find the right balance between coat thickness and brush strokes. Too thick and it sags. Too thin and it does not flow out, leaving brush strokes. It is probably my perfectionist side being out of control.


Two coats of Rest-Oleum Topside white





The rubrails will be replaced after flipping the boat. No reason to replace them now since when the boat flips it will roll on the rubrails, scrathcing them. Better to scratch the old rubrails than the new ones.

I received my new casters. This boat crushed the cheap plastic casters from the local DIY store. Went out and got eight heavy-duty casters, each with 1,250pound capacity.


I will build a new wheeled dolly then flip the boat onto the new dolly. But I can't flip the boat until some more snow melts.



I need access to the base of these trees. That is where I anchor my come-alongs for winching to boat over during the flip.



2 comments:

  1. Bill, have you run the Lady-C since the bottom mod and if so, how did it go?

    Brian

    ReplyDelete
    Replies
    1. I have not run her yet. Yesterday I turned her over to start work on the top side. She probably won't see water until spring 2018.

      Delete