Just to let you fellas know I haven't been completely loafing, I'm putting together some of the experiences from my other threads, especially the tubular lost foam thread, and applying that to some real life parts. Here are a couple versions of the water neck, some foam patterns, and several tooling fixtures for the finish operations on the metal parts. I've got a lot of gating, sprueing and mudding to do and after that I'll have one heck of a casting session. Looking forward to it and already started a couple more projects. Best, Kelly
That looks like work to me! Retirement is one or two for a couple of friends. A table full means you are in business! Nice precise foam work, but something tells me, BP's might pay better! I know a local kid that does glass work. His thing WAS bongs and water pipes... Then he got a job at one of those sleezy stores in the wrong part of town. Turns out, fancy glass pleasure toys for women pays better. TRUE STORY!
Hand guided templates on an over arm pin router then gluing the pieces together. Have a look at my machining foam thread. Best, Kelly
Well here they are all sprued and mudded. All set up……shall we make them metal? I think so. Great day. I managed to double up each pair of water necks and the tooling fixtures in the sand rig so it was 9 cups and 6 pours. I batted 1000! Wasn’t sure how the 4-on trees would turn out but they came through without incident which was a relief……..netted 8 thermostat housings in two pours. Here’s the tooling castings. They will come in handy as drill fixtures for the water necks and thermostat housings. I think I’m going to call it a (good) day. Best, Kelly
You cant ask for better results than that! Did ya film it? I want to see a bunch of stinky black smoke!
I found it. http://forums.thehomefoundry.org/index.php?threads/machining-xps-foam-patterns.14/#post-59 I call myself looking at that thread, but I guess I skipped over the first part completely. Cool stuff.
Yah, they're all good parts......now I have a good batch and need to get my vacuum impregnating rig up and running. Maybe I could glue bat wings on them and enter them in the Halloween contest LOL Nah no video......that's pretty much all it is....a little smoke. Well at least today I did. I had enough metal in play today that I had to dump and refill my 5-gal water quench bucket....too hot to put my hands in! I also just dumped and spread the sand on my driveway between pours to cool it off. I have two 5-gal buckets full of stinky sand now so while I'm prepping and pouring in one the other is cooling on the concrete. Then I just scoop it up and sift it into a bucket for the next round. I have sealed snap lids for the buckets to store it so I don't have to smell it other than on casting day. The first 50 lbs of sand must have 40+ pours through it now. Best, Kelly
Thanks Jeff. I've developed a strange psychological paradox with lost foam casting. I started out thinking it would never work for my purposes. But then it worked for everything I threw at it. So now I expect everything to work.....but must confess that every time I pull a fully formed part out of the sand and am walking to the water barrel to quench to knock the mud off of it, I'm still slowly shaking my head.....with a grin and that's fun. Best, Kelly
I've said it before - the best indicator of a successful lost foam pour is that awful certainty that it didn't work. So I'm thinking coming into it expecting it not to work right from the start turned out to be a clever way to get ALL your lost foam parts to come out right! Jeff
I gave my updated furnace a work out today casting some more water necks. The casting stock was A356.2 ingot with Strontium modifier and TiBor grain refiner. I got the Sr and TiB rods from a member here and this is my first go with them. 3 rods/100lbs is the recommended dose. I used 1/3 rod per full A10. Here’s the bounty from four melts, brim full A10s. …and sprue stock I’ll remelt and use on other castings. Best, Kelly
I found out the hard way that any sand must be removed from the aluminium runners before reusing them as the sand will not float and be skimmed off. The density of aluminium is 2.7 grams per cubic centimetre and quartz sand or SiO2 is 2.65 grams per cubic centimetre. You can see grains of sand embedded in the aluminium casting even in in machined areas below the surface. On an identical bronze casting made from recycled runners, the casting looks sound and uniform as the sand and contaminants are floating and get skimmed.
That's a bummer. I've made a lot of these and other parts now and haven't had that problem with my lost foam castings. Besides good casting surface finish, I think it is another benefit of using mud coating and expendable foil sprues......they maintain a good barrier. Best, Kelly
I was recycling aluminium runners that had a thick layer of sand and burnt resin coating them as I assumed the sand would float to the surface. Also I didn't have access to gas purging so maybe that makes a difference too?. The only issue is during machining as you are pulling the grains of sand out with your cutting tool which then loses it's edge and gives a rough finish.
For reference, here's Joe's post on Sr and TiB. http://forums.thehomefoundry.org/index.php?threads/happiness-is.339/#post-6433 Best, Kelly
For my purposes the recycled runner aluminium is perfectly fine , so long as I physically clean the most sand off runners with a wire wheel or belt linisher. I guess if your runner is mud coated there should be minimal sand stuck to it anyway.
