Alternatives to Pouring Lead?

[drift montana]

Hello! The Melonseed plans call for putting about a 4" diameter x 1/2" thick lead weight in both the dagger board and the rudder. Both of these are in the middle two 1/4" laminates of a 4 layer sandwhich. I was hoping to avoid melting and pouring lead, for both environmental reasons and to avoid the expense of this one-time effort. My thoughts were to create the hole that would hold the lead weight, but instead get steel shot from the gun shop, fill up the hole, and pour in epoxy to seal it and hold it in place. Sort of like thickening the epoxy with steel shot.

Am I crazy? Will the steel rust and eventually leach out? Could I do the same thing, but use lead shot instead of steel? Should I blow off the weights entirely? Or bite the bullet and pour the lead?

My thanks for the input as always!

-Tony

[Thorne]

Use lead shot in epoxy, or ask around for some sheet lead. You could also get a lead fishing weight and just pound on it to flatten it...

Worth a search on this forum as this has been discussed many times.

I used sheet lead in a thin epoxy coating under fiberglass cloth on my second pass at a centerboard -- what will you cover your rudder and DB with?

It is important to get the weights firmly embedded in the foil/rudder/DB/CB, as they can cause a weak spot that will break and rot the wood -- don't ask me how I know this...

;0 )

http://www.luckhardt.com/brokenCB2.jpg

http://www.luckhardt.com/newcb5.jpg

[drift montana]

Thanks, Thorne! I just did a more careful WBF search and did find a couple good threads. Here's one that seems to talk about all the ups and downs.

http://www.woodenboatvb.com/vbulletin/upload/showthread.php?t=52561&highlight=lead+weight

Cheers!

-Tony

[Bill7254]

I agree with Thorne. I used lead shot to weight the centerboard of my Welsford Houdini. I cut a circular hole in the board and set bronze screws around the circumference. I clamped a thin piece of scrap plywood covered with wax paper to one side and filled the hole with lead shot. Then I poured epoxy over the shot. I still need to cover the board with fiberglass cloth.

[http://farm3.static.flickr.com/2295/1716567346_d0150f8d2a.jpg



Of course I should add that my centerboard has been leaning against the garage wall ever since waiting for the boat it goes in to be finished.

[htom]

Remember to adjust the size of the hole; a given volume of lead shot + epoxy won't weigh as much as that volume of lead.

[StevenBauer]

I used lead sheet as per John Gardner's instructions. My centerboard is 1 layer of 1/2" ply with a layer of 1/4" glued to each side. I think it was a 10" square that I cut in the 1/2" layer. Lead sheet is used as flashing for chimneys and is available at any lumberyard, roofing supply house, Home Depot, etc.

Steven

[Jim Ledger]

[quote=Bill7254;1756810] I cut a circular hole in the board and set bronze screws around the circumference. quote]


An alternative to the use of nails or screws is to chamfer the edge of the hole on both sides, using a chamfer bit in a router. Lead poured in will shrink a bit and pull away slightly, needing only a bit of epoxy resin to fill the gap, but epoxy and shot will bond very securely and remain locked in place.

[Thermo]

I poured my leeboard last night out of lead wheel weights collected from junk cars around town with a crucible made from a coffee-can.

Melted on my camping stove, which I already had, the cost was about $0.50 worth of propane. I'm sure the environmental impact was minimal, as I re-collected the shavings to use again on the rudder blade.

I chamfered the hole and used screws both.

[drift montana]

Sounds like I have a lot of options, and it is easier to work with the lead than I thought. Maybe I'll hit the parking lot tonight....:rolleyes: I've already got the camp stove and coffee can.....

But first the deck framing.

-Tony

[Steve Lansdowne]

The easiest thing to use is a lead cylinder of about 4" diameter and a foot or so tall that you cut to make flat and then and flatten further by pounding with a hammer. I don't recall what it is called, but get it from a plumbing supply house. It is the thin lead pipe that is used between the pipe that comes up through the floor and the flange that the toilet is attached to. Mine cost about $13 for something like 4 lbs of lead and was easy to work with. My attempt to purchase lead shot located a bag of more than I needed for more than I wanted to pay.

I cut mine to fit the hole I made in the inner-most plywood layer of my centerboard, then epoxied it in place and epoxied two outer layers of plywood over this. As it is solid lead, you don't lose much weight to excess epoxy, as with shot. I weighed mine at the scale at the post office and used that figure to calculate the size of the piece I'd need to get the weight I wanted.

[Pernicious Atavist]

I poured two, one for each leeboard. I used one of those large cans of chicken [tuna would do] as a mold. The enviro impact of melting lead is immeasurable if you don't heat it to fuming. So, when it melts--pour.

Another option mentioned that seems good is using shot. Gun shops are darn proud of their lead shot, so be prepared. But it's a reasonable cost compared to everything else going into the boat.

Or, in a pinch, you could use depleted uranium....

[ssor]

You can buy lead ingots in the plumbing supply shops or you can ask at the local tire shops for wheel weights. Lead sheet used to be used for the pans under tiled shower stalls. If you cast the plug just a little small you can hammer it to spread it to fill the hole tight. Lead comes in at about 5.5 pounds per cupful.

[LakeErieSailor]

Possibly a dumb question, but how do you calculate how much weight of lead you need to sink the centerboard? Mine is a composite of solid wood, plywood, fiberglass and epoxy. It's foil-shaped in section. I calculated its volume by averaging the thickness and then doing the usual geometry, got the weight of an equivalent volume of water, and based the weight of the lead needed on that.

Comments, please.

[Thorne]

Figure out how much, then increase by half again -- otherwise you have to crawl under the boat with a router and make a new hole and add more lead.

"Don't ask me how I know this..."

;0 )

Actually many of the designers will show the weight, but I'd sure go for around 5lbs for most CB's on 12-16' boats -- can't hurt to have a bit too much, but a real problem if you have too little.

[ssor]

boat building wood runs 30 to 45 pounds per cubic foot and water is about 65 pounds per cubic foot. anything that weighs more than 66 pounds per cubic foot will sink, slowly or quickly depending on how much more than 66 pounds per cubic foot. That's as far as I can go here.

[Howard Sharp]

When I weighted my Chebacco centerboard I used steel. I googled the density of steel to calculate the size needed to give me the correct weight, and asked a local ironworker to cut me off a chunk of 1/2" thick stock. It took him five minutes with a torch, and I think he charged me about $15. The board is 1 1/2" thick. I cut a hole in the middle 1/2" laminate for the steel and laminated it in with plenty of epoxy. It sinks beautiful!

[Jay Greer]

I guess my privious post ended being non posted. It mentioned that "tungsten" powder is non toxic, heavier than lead and avaiable from golf shops. It can be imbeded in epoxy.
Jay

[hokiefan]

I poured two, one for each leeboard. I used one of those large cans of chicken [tuna would do] as a mold. The enviro impact of melting lead is immeasurable if you don't heat it to fuming. So, when it melts--pour.

Another option mentioned that seems good is using shot. Gun shops are darn proud of their lead shot, so be prepared. But it's a reasonable cost compared to everything else going into the boat.

Or, in a pinch, you could use depleted uranium....

Another source of lead shot is to buy split shot fishing weights. Haven't compared cost to shot from a gun shop, but split shot is available at more places. Even WalMart (ducks:D) has it.

Bobby