Metal Casting Zone

i would fill from the top as metal loves to flow downhill. you have a valid point about the sheer mass!!!! a teaspoon of lead melts in an instance but a cup of lead really takes a bit of heat before it melts. multiple this by the mass of your lead and its going to take a real blast to melt ! once molten it will stay hot for a long time. i noticed this very recently. once you actually get the full amount molten it will probally surprise you. i wish i could come over and give a hand. my only real concern is once you get 8 tonnes moving it may take a bit to stop!!! putting a lot of strain on the end of the mould.??? maybe reinforce this area???the shape of mould may help slow it down.

aonemarine...
ya ,, with a cat..no ballast..no problem.. but my is a mono, with ballast ! bolted outside of the hull , the patern is not a problem, just few hour with a hot wire and a long board sanding plank.., and it's done.. i will be happy to do another one if i have another boat to built !! but for this one, want a one piece lead under my keel ! as it is usualy.. any clue about a good bider to make my mold like a sandstone block?? bentonite/silica sound to smoth for me... perhaps i'm wrong?

aonemarine wrote:
By the way that catamaran has my eye
Hey, I saw it first...

Just make sure you have a good solid mold, you really don't want to have a breakout. That's the only time the metal won't set up too fast. While it's running across the floor starting fires as it goes.

sodium sillicate and bentonite mixes are probably a no no for the mass you are casting
a 10-12% portland cement and sand mix is probably the way to go. Mix a test batch and see what you think.

aonemarine,
perhaps the best to do? ! i will feel more confortable with a hard mold..even if need more labor to remove and broke in parts.. also need probably let the mold drying well few days before pouring to have a dry ciment... any member have previous experience with concrete mold? lead temps is not so hight, just the mass to controle and avoid the mold to fail...
i try to find resine binder here, but//look difficut to find... in the middle of nowhere !
rgds
bertrand

mold done , ready to pour end of next week.. pure silicat sand + 12 % portland ciment + 5% wate..when cured few days , will distroy most of the foam with acetone,+ gaz torch by the vent? ... see one the last picture on the blog www.fusionshooner.blogspot.com
crazy or not...
cheer's

Sounds like your ready to go. Make sure it's dry and be careful.

Get some good pictures and maybe a video, should be pretty cool to see the action.

im very excited about it! i like the cement addition. a video would be great as i dont think people would see this done every day of the week!

let see next week..keep time for full curing, distroy all the foam i can before pouring.. but mold sound good now..hard ! i feel confortable with.. but will sleep better when the 8 ton will be inside, and hard..!!! hahahaha ! sure will take some pict...for records... cheer's and thanks for your goods advises .. we always learn, that the fun !
bertho

Mold looks good, my only concern with distroying the pattern with acetone is a big pile of slime left in the mold, maybe try to burn out first?