Lost Foam Finned Engine Cylinder Casting 

Man that sounds like a drag, how did you cope with it? 😉

@@TheDandyMann Family business! I used to help out when they were busy or short on staff. Usually 1-4 weeks at a time. It was primitive, dark with smoke and fumes. Just like the Industrial Revolution times but I learned basic foundry technique.

The refractory paint helps! It forms a hard shell. I've done some very intricate platinum and stainless castings that occur almost entirely in a refractory dip and the sand is just there for extra support and mass so you can have some control over thermals

@@grinchyface Ah that makes sense.

@@grinchyface What type of refractory paint, and where can I get some? 😁 It sounds really useful!

@@RC-fp1tl ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-LdgGkqvk5mc.html

I didnt believe it's just lost foam in dry sand as well. He coats the foam in something similair to ceramic shell casting

300lbs? Wow, I bet that takes some fuel and time to come to temp on the first heat! Best, Kelly

@@kellycoffield533 Yeah, I use that one for bigger melts, or for ingots. I use a **NEVER DO THIS or the Internet safety police come** ceramics kiln for small stuff. Works fine if you're not an idiot about it.

Thank you Andreas. Best, K

Glad you liked it!

That's very kind of you to say. Glad you enjoyed the video. Best, K

If you are really interested in casting at home you should join www.TheHomeFoundry.org.

Thanks Bruce. I built the furnace first and then added equipment for additional capability, ease of use, and process refinement over time. 5 years on now. I just built a gantry and hoist for larger pours that can be seen in my automotive intake manifold vid. I'm going to have to stop building equipment....running out of space! Best, Kelly

Thank you Preston. Best, K

You can still see them in some newer engines. Styrofoam pattern on the inside of the valve covers ect.

I was going to say the same thing. I worked for Saturn and it was cool to watch a casting being poured by a robot. :)

it does have a thin shell around the part to help maintain surface finish and form. 6:50 "dipped in refractory slurry" so basically a plaster coating.

If you are already versed in handling molten metal and conventional sand casting, you will only be limited by the quality of foam pattern you can fabricate. Lot's of info on that at www.TheHomeFoundry.org Best, Kelly

Thank you! Cheers!

It's def the easiest way to cast for the DIY'er in my opinion. I made some lost foam back in the day and it "just works"

Awesome, thank you!

Hi Mark, for the short story, it's such low value media I've found it better to replace it than renew/recycle it. The long story, it's true, the single most important thing other than refractory for LF sand is that it moves under vibration and dryness is important to that. Their byproducts of decomposed polystyrene degrades the sand with repeated use. You can heat the sand to remove these organics but the energy cost to do so is more than the value of the sand ($20/ton in bulk for $5/5 gal bucket retail). I used my first 300lbs of sand for almost 5 years before I replaced it, and I treated it with disregard, except dryness, and the driveway contact didn't seem to be a problem as long as it was not visibly wet. Any fines or organics I may pick up arent a problem for aluminum. I only perform gross filtering through .090" perfortaed plate to remove clumps. That 5yr old sand saw a lot of use was sufficient for all but the most challenging vibratory packing and fresh ne sand does perform better. Also, since the foundry was allowed to dispose of thir sand in landfills, I assume the same for mine. Now if it was higher value media like the commercial ferrous LF operations, they have fluidizing furnaces to recondition/reclaim the high value media. Best, Kelly

Great Idea ! Many months of hard work may result in a set of heads producing 250hp na from factory short blocks, the objective. Along with all the others into aircooled opposed flat fours and sixes, for the last 60 years, lol. Like my world domination plans, yours includes the canted valve arrangement of the Boss Fords, or semi-hemi, the ports sized for the swept volume of the +2.7L Corvair short blocks. A unique solution to the pushrod angle problems is the secondary pushrod design of the 60's hemi prototypes by GM, so very viable in the Corvair application, and neatly done, allowing 3 and 4 valve variants, heh heh. > A cored watercooling jacket or exhaust valve ' HD loop ' could allow modern turbocharging levels and requisite cooling. A great deal of thought and engineering would have to be exercised for the culmination of 4.2L Corvair Turbo heads, cast, and machined. The lost foam methods demonstrated here is likely the simplest, the cast and coated bigbore cylinders too. Imagination, opportunity and ambition may be sufficient to achieve the necessary desire. ' Simplicity is the highest goal, achievable when you have overcome all difficulties. ' ~ Chopin ' One thing we do know, that we dare not forget, is that better solutions than ours have at times been made by people with much less information than we have. ' ~ Wendell Berry ' Vision without execution is just hallucination. ' ' Whether you think that you can, or that you can't, you are usually right. ' ~ Henry Ford

There is a guy in town who said he'd sell his corvair part's pile. And 4 or 5 car's, and 8 to 10 engine's in total for 8500.00 if your interested..from Wyoming USA 🇺🇸 🤠

You should consider joining www.TheHomeFoundry.org and pwruse the lost foam sub forum. I have many informational and project threads there. Best, Kelly

Sorry about that I pushed the wrong button I didn’t finish. I think making the fan blades pictured in my profile would be the best method.

Thanks Mihai. The pouring cup is made from moldable ceramic fiber. There is a video about them on my channel. Best, Kelly ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-MIydO69CNao.html

@@kellycoffield533 Thanks, I owe you a lot in learning how to do things properly and with reasonable costs!

Thank you very much!

For very small finely detailed stuffed you may be better of with printed patterns and investment casting. Though those materials are pricier, the molds and patterns are small so not much material or cost involved. For larger machine parts that's a different story and lost foam certainly has advantages. Best, Kelly

A356 Aluminum, 1425F, T5. Best, Kelly

I use A356 for most everything because it's a good all around casting alloy but can and needs post heat treatment for best strength. You might look into AlMag 35 (aluminum alloy 535) as it has good as cast strength and machining properties.

@@kellycoffield533 Would a high percentage copper alloy (like 25% 30% Cu) need heat treatment?

@@tomassosaoconnor IDK. I don't think I've ever seen an aluminum alloy with that high of Cu content. I suspect it would be very brittle.

Not a fortune but some time. It has evolved over a number of years. You just need to peruse some of the more recent videos on my channel to see finished projects. Best, Kelly

When the sand is vibrated, it becomes loosely bound by the mechanical contact of the granular media. It's not bound as tightly as green clay or chemically bound sand, but more so than non-vibrated/compacted sand. As the metal evaporates and replaces the foam it creates pressure on the mold wall which also helps hold the sand in place until it solidifies. Best, Kelly

There's also a refractory slurry dip @7:00 ish that plays a pretty big part. Effectively a ceramic coating that keeps the sand from sticking to the metal and keeps the foam holding the shape even as it melt/burns off. The part isn't metal to sand, it's metal to ceramic.

@@mad1337nes Your right in this case but many people do it without the slurry. A company I bought a melting pot from specialized in making machine gun parts for the military. They used wax patterns (lost wax casting) but dipped the wax in a slurry first and when it was partly dry they dipped them in fine sand and then let the slurry fully dry. They would come back later and repeat the process to build up a heavy coating on the outside. After fully drying they went into a burn out oven to completely remove the wax and turn the slurry coating to glass. While still red hot they then poured the metal. After cooling they dipped into cold water to shock the glass casing and most of it would fall away. The parts came out perfect.

@@tenlittleindians sure, but the original question was "how do you do sand casting with no defects from sand particles?" and the answer is, and always will be, don't have sand be the final barrier. The OP guessed correctly. Myfordboy does plenty of green sand casting bare/directly to sand...and you can always see some minor imperfections (which is fine when it's getting milled to final anyways).

@@mad1337nes Myfordboy also does a lot of investment casting these days and uses his 3D printed parts instead of foam patterns. All methods mentioned work it's just a matter of how much detail you need in your final product. A company I worked for still gets their split mold petrobond sand castings from India and then finish machines them into industrial hydraulic valves. I've got a centrifugal caster in my basement for objects I investment cast. If all I needed was a sledge hammer head I'm sure the sand alone would get the job done provided it's vibration packed. Another old video here shows the vibration process. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-nxcG7MF0KIE.html When 3D metal printers become common none of us will be casting.

you could make the ceramic refractory mix last a lot longer by using it as a thin shell coating like he did. not sure he used the ceramic variant though. 6:50

It's a bit dated but here ya-go. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-rvzkEE9NEHE.html Also may want to check this out: forums.thehomefoundry.org/index.php?threads/furnace-cart-and-lift-build.278/page-3#post-9376 Best, Kelly

I'm interested in this too, could old, used 2 stroke cilinders be re-melted ? I have some damaged ones laying around. However, would you have the chrome or nicasil lined or would you press a cilinder sleeve? I want to make a custom cilinder for my moped to use a yz80 sleeve

use old engine blocks/cylinder heads, plenty of quality material from bikes and cars available, pretty cheap too.

On the large cylinder .063" would probably be enough but I'd allow .125" machine stock on all surfaces just in case there were some surface imprefectins in the casting. Half that on the small castings. Best, Kelly

Inswoool. I bought the moldable and pumpable ceramic fiber from my local refractory supply distributor. Inswool is a Harbison Walker brand but there are many, like Kawool, Fiberfrax, and others. They are all air setting moldable alumina silicate mixes, usually available in a caulking tube, 1 gal, 5 gal sizes. Moldable is putty like, and pumpable is like pudding. Moldable works best for forming shapes, pumpable as glue, filling cracks and patching. It can be bought online. Search "moldable ceramic fiber". You'll occasionally find it on eBay and Amazon. Shop price.....it can vary significantly but is all the same stuff. Also, search my channel for a video entitled "Reusable Pouring Basin" for more info. Best, Kelly

Depending upon the parts you typically cast, IMO, it's the most versatile and practical process for hobby casting. It offers all the design freedom of other evepaortaive pattern methods with low cost reusable mold materials that require no special processing or maintenance. So basically, if you have a furnace and a foam pattern, all you need is a bucket of dry sand. The process is limited by the level of detail and quality of pattern you are able to achieve ad the labor to produce a pattern. For machine parts it's great. It typically cannot produce the detail or finishes required for jewelery and small sculptures. Best, Kelly

Mark, you should ask Kelly about the model aeroplane engine castings.