i have a couple of questions for ya ll

[azureskys]

One thing to always remember is a lathe or mill dosent care what it cuts metal or flesh.A fly cutter will give a nice smooth cut when facing a flat surface in my case here ill be contouring the whole peice anyway so being absulate flat is minor, finding a center is just a matter of finding length as well as width and dividing that in half and thats the center either by tool or by eye. Useing brass or stainless is up for debate? i just have brass on hand thats all no particular reason other than that, i think both will work just fine.My squaring up methed i used here works for me, someone might scoff at it and thats fine but im happy , its exact according to my dials on my machine , i set it within .oo1 at one end then move to the other and do the same , i think thats pretty darn close dont you lolol As far as lube goes wd is ok i guess i did try it once but wasnt impressed it cost and smells smokes and is messy a better choice would be a water soluable oil , you ll need a tank and pump grizzly has one at a decent price and you can reuse it just add a little oil and water every once in a while , i dont have one yet but i will be getting that for my stuff here, itll work for aluminum brass stainless etc etc .Im doing some casting tonight ill be using sterofoam for my patterns ill get some pics for you before and after .hope i answered your questions Bent and thanks for your comments Russ

[azureskys]

these are the peices im casting one is an end plater the others are corner peices with a place for a leg mount . russ

[Bent]

Russ, looking forward to more pics and explanations on your little casting hobby

Pics of the oven(?) would be nice to see.
Is it hard to make an accurate template in styrofoam? I mean the cutting isn't all that bad, but the accuracy is what I'd have a problem with. Do you cast the piece and then just sand and polish it? Or do you machine it first?

Another thing I have been wondering about... Say you use scraps of 6061 aluminum for the casting. Once it is poured , well there goes the special properties out the window...no? And it reverts back to regular aluminum without the special annealing that was done to it in order to arrive at the designation of aircraft aluminum 6061 T6...am I right or no?
So many questions, Some likely silly ones but it needs to be asked

[azureskys]

what i do Bent is make a pattern a bit larger than what i want because aluminum will shrink a small amount and to get a better finish on a casting you can dip it in a drywall batter ( yes i said drywall mud ) make sure you delute it with water to a consistancy of thick soup so it will stick to the foam and do this a couple times to build it up , let it dry then add a peice of foam for the riser s . As far as your other question and anealing and so forth , i do not know see i dont know everything now do i ha ha ha , i kinda dought it makes any difference anyway i do know to harden aluminum it has to be heated around 700 degrees for a couple hours ( i think dont quote me on that ) for an engine of some sort if they didnt do that the motor would melt , thing is here were not dealing with heat after the guitar part is already made, so in effect i really dont think we have any worries there, here is a couple castings without the drywall mud coating they are fine just need ssome machining and finishing ill post some with the coating next time, i cut the risers off on my bandsaw . hope ya enjoy and get something out of what im doing thanks . Russ

[azureskys]

About metal properties , i know if you cast something out of aluminum can s which is pure aluminum sometimes it will get a bit gummy while doing maching but the alloy aluminum wont do that so in saying that im pretty sure the alloy will and does retain it s properties

[Bent]

Russ...no such thing as a stupid question, right? Here we go...
You say dip it in drywall batter I take it you mean the styrofoam pattern? Is this extra thickness from the batter what you are after when you say oversize the pattern?

Ok so you stick the foam pattern into the sand and then what? Leave it there and just let it melt and disappear from the heat of the molten metal?

Will a propane torch (the tank and hose kind with the long wand) be sufficient for heat?

[bobby burns]

This is very interesting. I have a friend with a small foundry, and I am always making patterns of stuff for him to cast. I had heard of a lost foam technique, but have never tried it myself. Is the foam just regular craft store styrofoam, or is it denser like the building insulation board? Does the plaster coating ever crumble and leave defects in the surface of the casting, or does it melt away with the foam?
I had thought about trying expanding foam insulation. Because it forms a smooth skin on the outside, there may be no need for additional coating. I thought about making a rubber mold around a small part, then using this mould to form a casting pattern in expanding foam. The foam would be packed is sand. Then the molten metal would burn out the foam as it is poured. I think this may be a time saving way to make duplicates of fairly complex shapes, without having to make multipart patterns, and it would make packing the sand mould a lot easier. Any thoughts about this? I'll let you know how it turns out. Sorry about all the questions.

[azureskys]

Bent the reason i make a pattern a bit bigger is because aluminum will shrink a small amouts so therefore its better to be a little bigger than to small and yes you just pour the hot metal right in over the foam and it ll almost burn away instantly , the coating is for a smoother surface, another thing is be very careful when melting metel its very hot and will hurt you , please be safe and wear safety glasses gloves and the like , fumes are bad also a respirator will be needed , im posting a pic of one of the peices i cast yesterday along with it i did a little maching to show you the results however its not done i still need to sand and polish up a bit but this will give you a good idea what you might do , aint nothing like hands on to learn if you know what i mean lol. there is all kinds of ways you can cast metel foam is on wax is another the traditional way of making a pattern with a sand mold is another etc etc the list goes on and on but foam is fast.i never tried foam insulation but that might work like was mentioned making a rubber mold is another way you can use that with wax also , im running out of breath here lololl check the pic s out and thanks again guys . Russ

[azureskys]

Bobby the best foam is the denser the better i use whatever i get hold of , with that rubber mold you mentioned you can make very intricate peices and duplicate them over and over , id love to see what your doing i need to learn too lol thanks again Russ

[azureskys]

Bent i use propane sometimes it ll work and its clean