• Scam Alert. Members are reminded to NOT send money to buy anything. Don't buy things remote and have it shipped - go get it yourself, pay in person, and take your equipment with you. Scammers have burned people on this forum. Urgency, secrecy, excuses, selling for friend, newish members, FUD, are RED FLAGS. A video conference call is not adequate assurance. Face to face interactions are required. Please report suspicions to the forum admins. Stay Safe - anyone can get scammed.
  • Several Regions have held meetups already, but others are being planned or are evaluating the interest. The Ontario GTA West area meetup is planned for Saturday April 26th at Greasemonkeys shop in Aylmer Ontario. If you are interested and haven’t signed up yet, click here! Arbutus has also explored interest in a Fraser Valley meetup but it seems members either missed his thread or had other plans. Let him know if you are interested in a meetup later in the year by posting here! Slowpoke is trying to pull together an Ottawa area meetup later this summer. No date has been selected yet, so let him know if you are interested here! We are not aware of any other meetups being planned this year. If you are interested in doing something in your area, let everyone know and make it happen! Meetups are a great way to make new machining friends and get hands on help in your area. Don’t be shy, sign up and come, or plan your own meetup!

Welcome to Westwood Metalworks, What is he building in there?

From the limited amount of lead casting I have done, the venting is crucial to smooth sided finished castings. In bullet casting the vents can be very small but if they get clogged with dross the effect is immediately noticeable.
 
Venting is very important with all castings, and you have to evacuate the air in order to replace the cavity with liquid. The trouble sometimes is trying to think like water and being able to visualize how a mold will fill, and how the air will get out. The "rules" for lost foam are a bit different that traditional casting as I'm learning (the hard way), but the physics are similar.

I posted about this over at the homefoundry forum, and was able to get some great info from Kelly Coffield and others, and have a better understanding of my failure points, and a few more helpful tips to make sure the third time is the last time.

I've never been one to get all that pissed off about failures, as long as I could understand why I failed, and make the proper corrections moving forward. I realize now, my initial molding orientation was probably the best way, and most likely would have succeeded if I had enough sand to cover the pattern by a couple more inches. The undercut area was due to insufficient vibration. That was the reason I rotated the orientation for the 2nd go round, but I didn't think about that orientation being worse for filling/venting. I had my blinders on just thinking about the undercut. So, for #3, I'm going back to #1 layed down, and will take my time vibrating it thoroughly this time to ensure that undercut gets filled. If not, I can always machine that out too.
 
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