Incomplete casting pour

look at your third picture, add a health wax fillet to the end of the ingate or even just a 1/4 inch of wood basically just overlap the pattern with the ingate a little more.
the ingates contact area has to equal or exceed the cross sectional area of the ingate , just looking you are dead on or a little small, and small is bat as it will increase the pressure of the metal and create turbulance at the worse possible place

V/r HT1

 

Didn't the pieces with one gate cast better than those with two gates?

 

Make your ingate a thin long ingate feeding the thin parts. Trust me...its the easiest way to fill the thin parts. Use a .040" contact point and make them contact the length of the thin sections. You runner is plenty sufficient if not too big.

 

So you would feed from each end and risk a cold shut in the middle? As I understand it, these parts have thin blades at each end.

 

You are in some cases giving the metal 8 simultaneous choices as to what direction it flows. Rather than start out casting 4 parts simplify. Just do one. And when you do it, just gate it with any old gate at one end. Then set the pattern on an incline with the gate low. I will almost certainly fill fully.

Then make your four part setup. But again incline your mold. Gate each of the four parts at the low end of the part NOT in the center. Make your runner so that it first feeds the two lowest parts and fills them. Next it should feed the next two parts from their low ends. Don't give the metal so many choices. (Added: Another option would be to just forget the runner and make four sprues. )

Currently it flows the easiest way a little stops when resistance to the initial flow becomes greater than the next easiest route and freezes, then it flows the next easist way and stops and freezes. It fully fills the last arm or two arms it is left with.

You are, in essence, pouring a wide thin "plaque." Incline the mold and feed it like a plaque. Your failures are the same as nearly always seen with wide thin plaques poured without inclining the mold.

Denis

 

Clear and concise thinking, Denis.

I think I'll summarize your post and put it above my molding bench. It is just so hard to remember when you're in a hurry to get something in the sand and cast.

 

I'm sorry, but this is antiquated thinking and counter productive to production work, it will give you sound castings, no doubt about it , but it will give you one, he wants 4 . what he is attempting is a case where AFS actually works very well, I've got alot of patterns that prove this every week


V/r HT1

 

One? Might want to reread my post.

I'd be interested in seeing pics of a setup where 4 or more long thin castings are made in a single level mold and fill from their centers creating 8 simultaneous advancing fronts of metal. That would be educational.

Denis

 

Yes they are thin on each end

 

What is health wax? Where do I purchase it?

 

Somewhat yes. May have to revert back to that.

 

Thanks.

 

That was a typo. He meant "healthy wax" as in generous. You don't want a wax fillet for 75 runs, just ignore the wax comment and add a fillet. For a test run he was suggesting put some wax on it to see how it does. If you don't have wax you can use 50/50 toilet bowl ring wax and paraffin. Note he also suggested wood.

 

Do you have any useable castings yet?

 

HT1 knows his stuff, and so does Denis. I hate it when two competent people disagree. It shows you there is no single answer. Many gating systems work, some better than others. I have a matchplate I made years ago with poor gating. I would not make one like that now but it works so it's not worth the time to change it. You want 90% successful pours. Since you only want 75 runs, if you have six flasks you can pour in 15 sessions. How many pounds does it take to pour one flask?

You have a very good start. When you poured two with one gate each and two with two gates and the single gate worked and the double gate didn't, why did you do the next pour with all double gates? I can tell you, we all make mistakes like that and slap our forehead when we went the wrong way.

It would be best to minimize runner volume both to conserve hot metal (pour more flasks from the crucible) and to maintain heat. If it were mine I would pour from one end with a pouring basin under the sprue and a small runner in the drag. Then take off the runner with a gate to each piece. Try a roughly 1/2" square runner from the pouring basing to the first juncture. Make that about 1". Then use a 1/4" runner to each part in the cope. 1/2" square is 1/4 sq inch flow area. 1/4" is 1/16 sq in flow area s two of them are about half the runner. So then make the runner half size. You can use 3/8" sq or you can use 1/2" wide and 1/4" thick. Square preserves heat better. Run the 3/8" square runner to the next juncture and stop it 1/2" past. Take a 1/4" sq runner to each part in the cope. So you pour through the cope into a basin in the drag and come off the basin with a runner in the drag. Gates come off the top of the runner in the cope.

Pour hot and hard keeping your sprue full at all times. Dish out the top so you have plenty of target. It gets easier to pour hard the more you do it.

Here's a poor picture of two small pieces poured in the cope. I used a rectangular block for a well and runner and a small piece for gate. The gate is in the drag as well. The one face down has an ingot behind it and the other I overpoured to burn my flask and knocked the top off removing the metal burning the flask.



But I think you can get the idea. This is yellow brass. The gate is about 3/16" square (tapered of curse for draft) so it has about 0.035 square inches of flow path. No trouble filling these parts. The cross is about five inches long.

 

Do you think I should pour the parts with the decorative side facing up in the coat or down in the drag just a thought?

 

Really appreciate you taking the time to explain this. Everyone here is great. Some days I just want to quit and give up but you guys keep me going. Thanks a bunch. Back to it ..

 

Do you like Ford or Chevrolet?

I prefer up in the cope (not coat). Any stray sand is likely to wind up on the back.

But pull the matchplate off the drag then flip. Rap it well and lift it off the cope and you'll have a better mold. In my opinion. Opinions of others will differ.

 

Did you get any you can use yet?

You may have to thicken the ends on the back of the matchplate to get them to fill well. then you can file, grind, or machine the extra thickness off.

 

I have had a couple Pull nicely where they're usable so I I'm pretty sure it'll work if I get this figured out I appreciate it thanks I am trying to limit my time after they're pulled from the molds for production purposes but I will do what I got to do to get them to come out right