Riparia Resources

Nautical Photography

General Photography

Boat Building

Rachel Dinghy

40 Ft. Ketch


40 ft Ketch

Current Status

Last Plank Party

(The Viking's Lair)

The Great

Hull Moving


(A Tight Squeeze)

Keel Pouring


Testing Panels

Riparia Boat Building
Casting and Fitting the Ballast


I threaded 1 inch bronze bar at both ends for the keel bolts. 5 of these were to be cast into the lead with washers welded onto the nuts and set 8 inches deep. This would minimize the chance of leakage, and save some expensive bronze. The end bolts will go all the way through because the shape prevents casting with them in place.


I took measurements directly 'as built' rather than from the plans. The width turned out about 3/4" wider than designed because of the geometry of angled planking and the glass sheathing and fairing. A batten maintained a fair shape and I measured offsets from a taught line.


Deducting for 1/4" ply sheathing a framed plug was made and then sheathed. Then final fitting in place.

Excuse the light and dark streak on the hull. That's left over bird dung from before the hull was turned over.



The female mold was to be weak cement, but concern re the high temp on the cement lead me to cover the plug w/ sheet metal. The diagonal ends needed to be removable and are bolted on. I expected some leakage at that seam but figured the cold cement would cause it to freeze and plug any leak. Rebar is in the mold box to help counteract bulging of the sides.


The female mold was to be weak cement, but concern re the high temp on the cement lead me to cover the plug w/ sheet metal. The diagonal ends needed to be removable and are bolted on. I expected some leakage at that seam but figured the cold cement would cause it to freeze and plug any leak. Rebar is in the mold box to help counteract bulging of the sides. A welded gig positioned the bolts based on a template taken off the hull. A frame was built to hold the tops of the bolts in parallel position at the height of the floor timbers. The mold top obviously needed to be horizontal, but the bolts had to slope slightly less than 3 degrees because the keelson has a slight slope. You can see the jig made to set the angle, 3 degrees sloping forward but square athwart the mold. Bolts are vertical when in the hull. There's diagonal bracing and the bolts go through the plank to be flush with the top and then a piece of ply was later screwed over them to be sure they couldn't go higher.

Concrete was shoveled and tamped around the mold except for above the diagonal ends. This was later filled with dry concrete to which water was not added, just planning on it getting hard, but weak, with absorbtion of humidity over the next few damp months. It was also sprayed with water a bit to assist this. This was to make the ends easy to break off to get at the diagonal and unbolt the cover so I could lift the keel out of the mold.


My smelter is a modification of a woodstove I made years before . Here I'm moving it from home with my Hill Billy Derrick on my pickup. It weighs a few hundred pounds. Notice the bend in the beam crossing under the truck. Woody is my faithful boatyard dog. He comes to "wanna go work on the boat?" far better than to any other command.



I cast some ingots at home, but mostly at the boatyard. I had 8800 lbs of wheel balancing weights. (97% lead, 3% antimony) collected from a Les Schwab dealership over a couple years. That's about 4 1/2 55 gallon drums of weights. Wastage is about 12% of steel clips, etc. Moving those barrels from my former residence was another adventure with an earlier, cruder version of the derrick. Pull the barrels over, and shovel into the hopper.


I cast about 130# at a time. Some weights were damp and I threw one shovel into the hopper when the residual lead was still molten. Kaboom!! There was lead flying everywhere. Some landed on the roof of my shed, it splattered the hull, some landed 30 feet away. You've never seen this old man run so fast! I just skimmed the clips off the molten lead. There's a pile of them on the ground to the right. The plywood here restrains some splatter during the pouring. Heat is two 500,000 BTU brush burners (3 for the big pour). The standpipe just swings down to do the pour. A valve was added for the big pour. Freezing in the pipe was a problem and torching the pipe necessary. Lots of protective clothing is worn during pouring. Think lead splattered boots.


The ingot mold. 3x3x14 inch (IIRC) angle irons welded between two uprights. Each ingot is 22-23 lbs.


The pipe attachment to the hopper was a brased 2 inch cast iron pipe flange. This was difficult to do because of warpage. It worked for a while but a trickle one day became a big leak. So I took the smelter home, cut out the flange and welded in a plate with a short stub of theaded pipe welded to it.


May 26, 2009 it's finally time for the Big Pour. The Boatyard Gang gathers for the event with a planned BBQ afterwards. I have 6 100 lb propane tanks (4 rented), not knowing what I'll really need to melt over 7000 lbs of lead. It turns out that 3 were more than enough.


The hopper is loaded with as much as it'll take. It's raised to pouring height to get above the mold. Oops, I forgot to raise the pipe! The firebox and the upper hopper are insulated with Cerawool to increase efficiency. Three500,000 BTU/hr. brush burners, one through each hole, and one under the pipe will be used.


The ply holding the Cerawool in place bursts into flames from contact with hot steel. Don't burn down my shed! Shield the shed post with plates of steel and let it burn out. To the right all the lead is melted and I'm skimming off slag. Filled to the brim the hopper will hold 8000 lbs. I've forgotten to put pipe clamps across the top to restrain the sides from bulging but it appears I didn't need them. That valve is rated to 1100 degrees. When I swung the pipe down to pour, the valve wasn't preheated enough and froze the lead in the pipe. About 15 minutes of direct torch heating was required to get the pour going.



There was a lot of splatter which I was able to control with the valve. I'm glad I added the valve. Here (above) the mold is filled and the celebration is about to start! But!!!! In a few minutes a leak was noted at one corner of the box. Attempts to plug it by shoveling gravel there failed and ultimately over half of the lead leaked out onto the ground. The level dropped just below the bottom of the bolts. Nevertheless, the BBQ and beer was good as we all swore at what went wrong. The failure was that the hot lead found a path out from one of 4 corners and didn't freeze against the concrete as planned. It was at the bolted end of the mold. Well, 3/4 of the corners worked! ;-)

Now what????



A few days later, after some attempts to cut up the puddle in place failed, I instead jacked up the mold box, wrapped chain around the puddle and dragged it out with my trusty Toyota T-100.



A forklift lifted the puddle and it was blocked up for working. I tried various types of saws but they didn't work primarily because the entire bottom of the puddle is covered with gravel stuck into and surrounded by lead. The final solution was an Oxy Acetylene torch with a welding tip to melt a narrow swath. The drippings were saved and the puddle cut up into blocks of various size and shape.

The blocks of wood are oak wedges that were under the box to support and level it.



Reggie, one of the BoatYard gang is hoisting a block back into the hopper with my "Sky Hook" variation of the HillBilly Derrick.

What to do about the joint between the upper and lower ballast? First, I tilted the mold and poured in a few hundred pounds of lead to verify that it no longer leaked. Then I drilled and placed 32 diagonal pins of 1/2 inch by 8 inch bronze. 16 on each side and diagonal in opposite directions so they will mechanically lock the casting together. The warped sheet metal was pounded into place as best I could and I was ready for round two.




A successful second pour filled the mold to the brim. I then melted some scrap to fill the shrinkage hollows. You can see the splatter that happened with the first pour.



Here's the corner that leaked. I dismantled the box and started busting up the concrete w/ a sledge and wedges.


item30The diagonal forward end with the bolted plate and the source of the leak. On the right the layers, from the bottom, show 1) The first pour, what was left, 2) the leak testing when the mold was sloped, 3) the 1st part of the 2nd pour, which I let go in slow, and then 4) the rest of the 2nd pour, going in faster.


The ballast is finally in view. I lifted it w/ the bolts thru cross beams jacked up and then pulled tho mold out from underneath.


I found several hundred pounds of lead had leaked under the mold. (The concrete hadn't been tamped in well enough to fill in underneath.) This lead was then cut up and remelted into new ingots.


The hull has been jacked up, (and moved forward about a foot, using the technique described below. The front of the cradle has been removed and the keel and bow blocked and shored. Chain reinforces the cradle. The ballast is on 6" peeler log rollers. A chain hoist and additional chain goes to my anchor point aft. One of two lifting cradles, (welded from parts of the mold box) lies to the left. It's ready to move.


My 1st anchor was the bundle of rebar driven in. It easily pulled out. #2 was the Bruce anchor but it plowed the gravel on top and wouldn't bury. #3 was a 4 ft pry bar (barely visible) driven in. A chain attached to it and the whole weighted down with about 600 lbs. of ingots set it a shallow hole.


Hauling aft, I first used a chain hoist but found that a come-along worked better.


The ballast has been moved aft. The chain leading forward had been attached to my truck bumper in case the keel started to roll uncontrolled. Hopefully the truck would stop it. The ground had been raked but was none too smooth, or flat. Most of the time the entire weight was born on only two rollers.


Here you see how I moved the ballast sideways, using the lifting cradle and jacks set at a bit of a slant. When jacked up, the jack will stand up straight (as long as the contact point above is over the base), and move the ballast 1/2-3/4 inch sideways. This was slow, but allowed fine control. The lifting cradle is welded up from pieces of the mold box.



Another problem I found. The shrinkage of the lead was truly an irresistable force. The spacing was maintained at the welded jig and at the plank. However, take off the plank and the tops of the bolts spring away from the center. The bolt bottoms shrunk together. So, they are no longer parallel. The bolts are a fraction of an inch closer together than planned. Despite the welded jig aligning them, they moved closer together, bowing the jig. I need to drill a slight difference in angle and spacing of the holes up through the wood keel so I set a jig up and solve that problem too.

Above, you see the expansion jig I made to rebore the bolt holes. Ballast shrinkage had moved the bolts a bit closer together. The bolt holes through the wood keel had been prebored 1/8" oversize, yet the shrinkage meant I needed to move the most forward and aft of the holes 3/16-1/4" toward the center bolt. The jig indexes off the center bolt. The spacing is set on the bolts and then the jig is set with the dowel in the center hole and redrilling through the steel plate at the other end to shift the bolt hole. The jig keeps the bit frow wanting to walk into the original hole. A jobber bit gets the hole started and then a long wood auger is run up through the jig until it comes out the top of the keelson.

The bolt are really quite flexible, so if I get the spacing at the seam right, they'll spring into place at the correct angle as they go through the holes.


Here the ballast is moved into place (for the second time) and now the bolts line up with the holes, OK some springing into place was necessary. It's most important that where the bolts exit the ballast aligns with the keelson holes. For the first time it's being jacked up into place to see how close the fit is. Incredible creaking of bolts in holes as it's jacked into place.

Jacked up, I start planing the high areas off with a power plane. WD40 works as an effective lubricant. Later I remelt the buckets of shavings into more ingots.



The ballast had to be raised and lower several times as I got the fit closer and closer. The bolts in the holes kept it aligned and upright so 2 jacks on the centerline was all that was needed. The top needed some filling with a sawdust/epoxy mix, rather than planing the entire top down.


The aft end of the top needed the most filling. When it was between 1/16 and 1/8 inch to fill I battered it with the mix and jacked it up with polyethylene covering the batter. This registered the final fit shown as flat plateau areas above. Now it was close enough for final battering and raising.


While raised the last time I bored through the ballast for the bolts that go all the way through the diagonal ends plus two additional bolts in between through the keelson and ballast. These were added to remove any doubt about the top and bottom of the keel staying with the hull.



You see the longbits and extensions used.First I start a 1/4 inch pilot hole. (That long 1/4" bit is a bell hanger scarfed and brased to a welding rod. ) Then 1/2, 5/8 and 3/4 inch bell-hanger bits lubricated w/ WD40. Then I followed with the 1 inch auger. I had to be careful to only drill an inch or less at a time and then clear the chips or the bit will jam with the chips in the deep hole and be very difficult to remove. I ground the shanks of the bell-hangers to a hex so as to fit the extension and give something I can put a wrench on. If lost in the hole it gave some chance of being able to back it out with the hex socket of the extension. The big drill had lots of power, but no reverse. It was easy to drill too far and not be able to back out. The most forward hole, (to the left of the WD40, took the entire length of the auger and extension. I couldn't figure out why I wasn't coming out the bottom, until I discovered that I was drilling into my wood wedges and blocking that was under the ballast.

Above, the ballast is ready for the final raise.


Battered with an epoxy and microfiber mix with slow hardener, (despite the 40-45 deg. temp), I'm about to jack it up.


Squeeze out was slow but satisfying. Now I know there's a perfectly intimate and bonded fit. The gap filled by the epoxy is less than 1/16 inch. It appears wider because the bottom edges of the wood keel are rounded over for the glass sheathing.


While the ballast is held up with jacks, the oversized bolt holes are filled with epoxy. The wood is therefore permanently sealed and the bolts will act in compression in addition to tension.


The ballast permanently in place, ready for more fairing and filling.


A jig for routing the nut recesses in the bottom of the ballast. This is the last one done, and the chewed up edge of the recess shows that I wasn't careful enough setting the router into the recess for the final cut. It grabbed the edge and the router flew out of my hands. My fingers hurt as the router lay still running on the ground. Quickly I checked to see if you had all my fingers. No, the bit had missed me, but my fingers had still been whacked a good one. Fortunately this will be filled and faired after the nuts are tightened on the throughbolts. The recess is 1 inch deep to accommodate nut and washer.

I made the 4 through bolts and on 2/24/10 I installed them. The longest is 32 inches. Despite having no problems running a 1 inch bit through the holes, and despite oiling the bolt shafts, it still took a sledge to drive the bolts through the ballast. Today I'll start encasing the portion in the deadwood with epoxy. The nuts are on and I'll be able to remove the jacks with no worry of anything moving. That ballast ain't going anywhere now!

Still to do? Finish the filling and fairing. Paint!




Unfortunately there were substantial low areas from mold warpage that needed filling. To help hold and shape filling compound, (which included lead shavings mixed w/ epoxy), I formed it in place roughly with this blocking strategy. There's also a panel underneath forming the edge in plan view.

Here's the port side pretty well faired and ready for painting. I've got a bit more to do on starboard, plus the bottom. That white stuff on the hull? Bird shit from before I turned the hull over. I've since washed it.

There is more to come.

Riparia Resources

Nautical Photography

General Photography

Boat Building

Rachel Dinghy

40 Ft. Ketch


Last Plank Party

(The Viking's Lair)

The Great

Hull Moving


(A Tight Squeeze)

Keel Pouring

Current Status