Be sure to notify the local FD before you pour this. The amount of smoke this is going to put out will be epic. What is that, about 8lbs of foam?
As massive as it looks, it's actually feather light. The pattern weighs .38lbs but a third of that weight is wax fillet so only about 0.25 lbs of foam. Post 18 has more of those details. In the past, when I've managed to get the gating and coating right, I've had 15lb pours where I get zero flame or smoke. .......But, I'm prepared for the potential of a big flamer with contingencies. I'm just getting back on the project. Went on a 3-Day trip with the guys and the penance for that was 4 days of honey-do's. Best, Kelly
I dip coated the intake pattern today. It came out fine. I’d say it’s pretty hard to screw up but it was very buoyant and took a fair amount of force to submerge but what really made me nervous was the potential breakage of the features on the end I was hanging it. It went from a fraction of a pound to 5lbs+ with the wet slurry. More than half of that will evaporate when dry but breakage and/or a dropping it would have been a disaster. I’m glad it’s sitting on its drying legs. I made a larger pouring basin. https://forums.thehomefoundry.org/i...le-offset-pouring-basin.688/page-3#post-38781 Now just need to finish up that Gantry Crane for the pour. https://forums.thehomefoundry.org/i...crane-–-a60-crucible-handling-equipment.1703/ -I’m sneaking up on it. Best, Kelly
Remind me Mark, what was the story on the 3-candle pour? A challenging religious piece was being cast and the Monks lit candles, meditated, and prayed for success....Yes? Best, Kelly
Interesting problem---the bouyancy. Does the slurry have to make full and complete contact all in one dip? Can the coating be done in more than one step? I take it it has to be done in one fell swoop or one swell poop. Denis
We were casting a pair of bronze sacred/ceremonial swords for a Hmong temple from bronze ingots that had been prayed over and blessed by monks somewhere for two years straight in a temple. Lee (the priest?), lit three candles before the pour which was successful. So it's now a rating of casting difficulty, roughly exponential in units of "candles". Since then we have had Chinese ceremonies at the foundry complete with dancing dragons to bless a temple monument with four bronze castings on a stainless steel cube.
Whoa, talk about pressure. I usually feel a bit anxious when opening molds. But, for me the worst outcome is a feeling of time wasted and then I just quietly remelt the iron later and get on with it. But having special ingots and the process overseen by folks anxious for perfect results and reporting to a congregation---I'd be sweating in mid winter. Hmmmmmmmm, do those rituals work? Denis
No, you can dip as much as you like. Sometimes you get air locked areas. You can fill those areas with slurry and dump them, and/or ladle on with a cup too. You can also touch up a dipped pattern with a slurry laden brush if necessary. Best if done when freshly dipped so it runs off and levels like the rest, but can also be done in isolated spots after drying. It really doesn't matter with respect to how it levels and dries as long as there is enough slurry to shear and run off naturally. My slurry is actually thinned slightly from how it is made by the manufacturer. On most parts it's just plunge in one dip, walk away, and let it drip. I actually did the intake manifold in two partial dips, one from each end. The sprued end is stiff enough to handle the dipped weight (though there is some worry about the glued on wooden block shearing off at the foam), but the features on other end that I attached specifically for handling were quite marginal. I've been fielding questions about the slurry and coating process so I have a video in the works on that subject. Dipping the intake manifold is shown as an example in the video. After I wax on for a few moments about how wonderfully simple and effective dip coating is, I proceed to struggle a bit with the intake. It's large, even for the 30 gal vat so it can only be submerged longwise vertically. The end with the little wooden board attached was noticeably bowing under the weight of the coated pattern. I was sweating bullets in fear that it would break and send the pattern careening into the vat wall, so I didn't let it hang as long as usual and set it on it's drying legs much sooner than I normally would and was quite relieved to have there without incident. But, that caused the slurry to puddle in some isolated areas on the top side of the pattern. I could have left them but at the puddle thickness it would have taken forever to dry, so I brushed out the excess out with a small brush. I should have built the handling end more robustly, put a peg on it, and then made a little stand for it to rest on so it could be rotated in different positions for natural drainage of all surfaces. On small patterns, I just cock them at angles on the drying arms of my dip rig. You mean fork handles.....right? I'll have to give that some thought and pay due respect at pouring time. When the gantry is done and I have practiced a bit........remember I'm retired now.......Probably a week or so. I've got some goofing off to do between now and then. Best, Kelly
Kelly, where I was going with my question you already partially answered. So, you can make added features for handling and those could include bits that might either weight or obstruct the interior. I was thinking in terms of adding internal weights that could help submersion of large parts and adding a external handling armature and maybe hitting the exterior. Then remove the armature and internal weights and slosh the interior. Perhaps the internal slosh could be aided by attaching the foam to a second fixture via added features to be removed later that would not be so sensitive to a perfect coat of slurry. Internal weight could be added using sand, for instance. Of course, that would add to flexion stress of the mold so, that might rerquire and external fixture... Maybe we should have a live feed fo the pour. ;-) Then again, fork handles or no, I would not want to jinx you. Denis
Interesting thoughts. On this part, if the one end was more rigid and robust, I think it could be dipped and handled ok. I must say, videoing the dip wasn't helpful to the process, standing and moving so as not to obstruct the video. My audio sucks. I bought a wireless remote mic that doesn't work. I'm impatient so my willingness to make and edit long videos is marginal. You'll see. Best, Kelly
While I complete the other equipment to support the pour, I uploaded a video on the pattern construction and preparation. Best, Kelly
Man this is a fantastic thread. You are a true master Kelly. Respect! As the say in the german speaking work, "Ich halte die Daume" - I'm holding my thumbs. Means the same as crossing my fingers to hope it works. Could you set up a YouTube live stream so we can watch the casting of this in real time? That would be cool, but I know from my own foundry dabbling, that is probably the last thing you need to think about. Mark
Thanks Mark. It's going to represent a number of firsts for my home foundry and lost foam castings and has required a growing list of additions and mods to my equipment, but once all of that is done, it should mean 50-60lb aluminum pouring capability. It's going to be somewhere between by best effort to date and an epic fail......not sure there's much middle ground. I'll definitely video the pour. No guarantees on live streaming. There'll be a lot going on and I'm not much of a videographer. Best, Kelly