Need info on molds for aluminum

[carbidecraters]

Ok I need to recast these old style valve covers and I need to do it without much out of pocket... We have a full machine shop but I am wondering what is the best way to make the mold and the material...trying to avoid h18 or hastalloy if I can. We are looking at 400-600 pieces

HELP!!!

[Marcelissen]

What casting process do you plan on using? That will partly be dictated by the design of the part and type of finish you need. Once that is established, that will then be able to identify the possible choices of materials for the tooling.

Are you the caster or do you need a foundry source? If you need to find a caster, they maybe able to recommend some tooling material that have had good lick with in the past for the volume you need.? Plus they should be able to work with your machine shop up front to establish the runner, gating and riser resign into the tooling.

If you have several thin wall that will need to feed thick wall sections then you would be looking at possibly a HP Die Cast process to allow the metal to feed the thicker section before freezing off in the thinner sections. Then you are talking $$$ for tooling, such as H13.

If the design and finish will let you can get by with using sand cores, there are a couple different materials you could use. I would recommend "Pattern Plank - PP1052" which would hold up for the volume you are looking to cast.

For a sand cast, all thickness is fairly constant and thick enought to allow good metal flow without freezing off to soon, and draft is 5 degrees or greater (to lessen tooling wear). This would also be the cheapest way to go.

There are a several different versions of Pattern Plank or Rein Board available that could also work. You may want to check with the suppliers for specs on the products. The "Pattern Plank - PP1052" (red stuff) cuts fast and clean and if you do need to do a fix, that can be done using an epoxy resin that cures within minutes. I've used this on core boxes used to make a few thousand sand cores.

Hope this helps.

[Jim Estes]

From the size of the run you are talking about, I would recommend doing investment casting. You can build a mold out of aluminum, that will be used to mold a wax pattern. This wax pattern will be used to create a ceramic shell, and that will be used as the mold to cast the material. You can do investment casting in all sorts of steel, stainless, aluminum, bronze, just about anything you want. It really is affordable.

Jim

[Jim Estes]

From the size of the run you are talking about, I would recommend doing investment casting. You can build a mold out of aluminum, that will be used to mold a wax pattern. This wax pattern will be used to create a ceramic shell, and that will be used as the mold to cast the material. You can do investment casting in all sorts of steel, stainless, aluminum, bronze, just about anything you want. It really is affordable, and they can actually hold some pretty close tolerances.

Jim

[carbidecraters]

great advice!!! I sent the part to a gentleman in Canada who is dabbling, lets hope he gets it right! Where can I pick this stuff up at guys...I have other parts that need casting

[Jim Estes]

Originally Posted by carbidecraters Where can I pick this stuff up at guys...I have other parts that need casting

What areyou wanting to pick up? Investment casting?

If you are interested in investment casting then I can give you the name of one of my customers who has a foundry and does investment casting. But I'd look in the Thomas Register under foundries, there are a lot of them around.

If you are looking for somthing else then just disregard this message.

[Marcelissen]

I'll also ask "What are you wanting to pick up?" If you are looking for Pattern Plank material, you can try: http://www.toolchemical.com/

[gcz]

if you need investment, your local dental supply will have 25 lb boxes - they practically invented the whole process - they'll have your waxes for ppl who mill it, too
to conserve investment, it's common to paint the wax with it and dust with silica sand and repeat til you're thick enuff shell on it.