Some more trial and error with the other side cover. I was able to sand down the curved edge somewhat that It didn't break off when lifting the mold and separating.
each time I did a pour, it was a failure:
I didn't secure the curve edge with enough sand when rebuilding so the aluminum escaped the mold.
I didn't allow enough of a vent for holes so they had to be bigger.
areas didn't get cast enough to make a usable piece to add another aluminum fill like the other side.
On the last try I got a decent cast with a couple of areas that can be filled, but like the other side once it is filled, there is a lot of work to drill and shave off the excess aluminum.
Also I have not tried the aluminum brazing to see if it will fill in the cracks and holes.
I went back to the drawing board.
since I was out of beer cans aluminum I cut up all the previous failures that were made with that aircraft grade aluminum I bought on ebay and decided to do another pair of finned side covers.
the melt time was quicker. when I poured the aluminum the pour was alot smoother filling each of the areas where before some areas didn't fill at all.
I went back into the casting forums rereading intros and tips.
From what I read It looks like I need to go bigger.
going to purchase a 5KG crucible for more aluminum. this will allow more flow on the fill when I add a top stack to keep the gravity pressure higher to push the aluminum where before it would stop.
rebuild a bigger sand mold box to allow me to add a couple of things in aiding with the aluminum through the cavity.
also I was thinking that this has all been done with beer cans. even after degassing and removing all the dross the material might be on the low scale compared to what I bought off ebay. this thought was after seeing how much better the last pair of finned covers came out.
I'm going to keep going on the pair of side covers with the prongs and see if they will hold after grinding the excess material away to create the tabs.
