100% correct ! Now with the arrival of affordable cnc and 3D printing the sky is the limit ! I'm just pissed about being 62 and having ailing health and mobility. So much creativity now available to me but I'm running out of life !

Turning fins on a lathe is like a perpetual exercise in parting......takes a good lathe and great tool. Best, Kelly

If you already have a CNC router and proficiency with CAM, Gcode and a good post processor, you'll be starting miles ahead of where I did. Glad you found the vids helpful. Happy casting. Best, Kelly

hi, do you have any lost foam question

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yeah sound is a little low for me too

Thank you zekestrom. Glad you found it useful. Best, K

Haven't had that problem but if so, a teaspoon or two of bleach will fix it. Best, Kelly

Glad you found it helpful. With your past experience it should be a much shorter learning curve. Structural parts like uprights deserve design conservatism. Get your process down then enjoy being able to place metal where you want it! Best, Kelly

hi, do you have any lost foam question

Thinner coating will help. Saw you recent vids for coin casting molds and plaques. You're on the right track. The one for your nephew that had the defect was because the sprue and contact area were too small for the pattern and couldn't feed it fast enough to prevent partial mold collapse. Best, K

@@kellycoffield533 thank you Kelly. Cool. that makes sense. I appreciate the reply. cheers

hi, do you have any lost foam question

Yah, I'll work on that but in the interim, it's easily heard by turning volume up on the YT viewer & your device, at least that's so on my phone, tablet, and LTPC that is the case with and without ear buds. K

hi, do you have any lost foam question

I do have several videos in the works I'll post in the very near future that will address your questions. Pin routers are very versatile machines, and an excellent alternative if you're not a CAD/CNC guy. With the exposed cutting bit, pin routers are a serious threat to the operator so give it due respect and make fixtures where necessary to keep you hands out of harms way. Best, Kelly

hi, do you have any lost foam question

@@kellycoffield533 Much respect Kelly, did you make a video that explains the gluing part? Thank you!

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I'd imagine either would perform about the same. I had the lightweight stuff on hand. It may have a slight advantage if the lightweight filler is more porous, but other than that, I think either woul dbe fine. Best, Kelly

hi, do you have any lost foam question

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@@kellycoffield533 love taking the time to reply in Arabic.

Yes, most lost foam casting done in industry are iron lost foam castings. Best, Kelly

I do pre-dip the sprue seperately and attach it when molding. I do modify the gating at times to make it strong enough to handle when dipping. The coating can be poured, ladled, or brushed as well but dipping is so fast and produces such a uniform coating it's hard to beat if you have thefacility for such. Best, Kelly

PLA/Wax/Foam are all evaporatve pattern casting processes. I like lost PLA/Wax/Resins for highly detailed small parts like jewlery and ornamentals but lost foam is so much more economical and practical for larger parts because the mold media and pattern material are a very small fraction of the cost, not to mention the large difference in labor to make an investment or shell mold versus just vibrating loose sand, and then the need for a very large oven and energy cost to burn it out. For a part like one of my automotive intake manifolds, it would be 300-400lb of shell or investment and take days or a week to burn it out. To demold, in lost foam I just dump loose sand on the ground (which I can reuse) and pick the part out instead of hours of chipping away and disposing of 400lbs of investment or shell. Not sure where you're going with PPG vs PG comment but I said what I meant. I use dilute Dawn dish washing detergent because one of the active ingredients is propylene glycol, along with other surfactents, costs pennies, and is much more benign than ethylene glycol. Best, Kelly

Never tried that. Best, Kelly

Reinforcing the coating is not necessary in lost foam casting because it is used to control the escape of evaporating pattern gases and improve surface finish, but not used as structural mold support. That purpose is served by the compacted sand.

@@sierraecho884 OK, that sounds more like investment casting. Precoating is common, as is adding silica to the plaster. I dont do much invetsment casting but friends that do larger castings just use wire/fencing as reinforcement cast/invested in place in the outer diameter of the investment.

@@kellycoffield533 Thank you for the quick response. You work is great btw.

No tengo la composición del recubrimiento como lo compré, pero si buscas en mi canal, tengo un video sobre este y otros recubrimientos. Saludos cordiales, Kelly

@@kellycoffield533 muchas gracias x tu atencion ;)

What is your user name? I'll watch. Sometimes our software will flag an IP address as a spam source and that will cause rejection. Drywall coatings are mainly, plaster of Paris, gypsums, and small amounts of clays. If it's ready mixed, it is non-setting. The pottery hobby may have similar refractory materials. Also companies that service boilers. For lower temperature metals, some European hobbyists have used Wytong brick as furnace refractory. Best, Kelly

@@kellycoffield533 my The home Foundry user name is ( acr ) thanks for the reply and info 🙂

@@ALANCREA You'll need to re-apply. Best, Kelly

If I understand correctly, you are asking what I apply to the foam pattern before the refractory. It is a 1/2 teaspoon of liquid dishwasher soap ("Dawn brand") in a gallon of water. The anti-spotting agent is Propylene Glycol which acts as a surfactant, reduces surface tension, and makes the refractory wet the foam without bubbles. Best, Kelly

@@kellycoffield533 ok seria sobre esse refratário do que ele é feito

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Must be the type of coating you are using. This coating is not the type used for ceramic shell casting. Best, Kelly

@@kellycoffield533 Thanks for the reply. What are the ingredients that go into this paint and their amounts?

@@kellycoffield533 Your paint can be used with models that come out of a 3D printer

@@goustavonana2930 No. Coatings for 3D printed patterns are intended to become hard structural mold material. Lost Foam coating is not a structural part of the mold. It merely serves to replicate the surfcae finish of the foam pattern and act as a permeable layer between the pattern and mold sand to control the rate of escaping gases. Best, Kelly

@@goustavonana2930 Probably too involved of a discussion for a YT reply but if you are casting aluminum, try using thinned dry-wall joint compound. It works well. The light weight non-setting variety is best and contains many of the same ingredients of commercial lost foam coatings. Best, Kelly

Not sure what you mean. Lost PLA would use investment casting not the lost foam method. PLA will cannot be evaporated by the molten metal during pouring. It's too dense. It must be invested and burned out of the investment before casting to remove the pattern and cure the investment. Though many investments are plaster like, they have other ingredients to improve strength and permeability after burn out. Best, Kelly

I meant using the drywall coatings in the same way that ceramic coatings are used in the lost wax method. This would consist of repeatedly dipping the pla object into the joint compound, burning out the plastic in a furnace (leaving only the shell behind), and finally pouring the molten metal into it. I was actually able to test this possible method during the past week and found the following: 1. Using a foam riser gives the plastic room to expand but there still tends to be cracking and breakage along edges/corners. Adding sand did help a little bit but having lots of ventilation is the key. The breaks are usually very clean breaks and can be repaired quite easily with more slurry followed by a subsequent firing. 2. Painting on the first coat works best in order to capture small details (if you need it) and for ensuring total coverage of the object. Air bubbles still pop up despite dipping the object in surfactant beforehand, running it all through a vacuum chamber, and adding soap to the slurry. 3. The biggest problem is the insulation with the empty shell. Transfer time form the furnace to the sand needs to be extremely quick to minimize heat loss and even then it’s still too cool half of the time. This method is much less forgiving than the sand and plaster method which stays hot for longer periods of time even in the open air. All-in-all, I would say this method has great promise and I will be experimenting with it further.

@@andrewatchaboy2762 Apples and Oranges. The coating in lost foam casting serves as a permeable barrier not as structural mold. Best, Kelly

hi, do you have any lost foam question

@@casthc6795 yes 1 I dont know which kind of Aluminium raw metirial should be used(I am using scraped brake parts) 2 I want expidite modle making with foams.and I want to know should my casting to be heat treated or not .thanks for asking help

Hi MAD, I commented on your video. I'm mostly using a CNC router now but try viewing my video "Carburetor Main Well Foam Pattern". It shows what can be done with hand guided pattern routing with wood working tools. Best, Kelly

@@kellycoffield533 yes thanks Mr Kelly.I watched your video.l think my main disadvantage is using expanded polystyrine.and i,ll use router soon.thanks again for watching my video

@@madlankan6735 I have found the extruded PS to machine and finish better. Expanded Polystyrene packaging can vary widely in density, but can also be sanded for improved finish and appearance. Higher densities machine and sand better at the expense of more material to vaporize. You can use your hot wire to pattern cut foam with a simple cardboard template. I show this in one of my videos. If you reduce the length of unsupported wire it will improve accuracy, but you are limited to 2D pattern parts. Patterns made with template guided router cutting can be 2.5D and will generally be more acurate and repeatable. Best, Kelly

Refractory just means ability to withstand high temperature, but the slurry is a coating that preserves the surface finsih of the pattern and allows the evaporated foam gas to escape at a controlled rate. Dryawll/Gypsum/Plaster mixtures work for lower temp alloys. The more refined commercial versions are usually Mullite/Alumina/Zirconia mixtures with clay binder and additives to keep the constituants in suspension, self-level, and wet the pattern better. Best, Kelly

IMO, lost foam is far more practical than conventional hard pattern sand casting for making one-offs, and small quantities, but sort of depends upon what you are set up to do. After you get your processes sorted, it becomes all about the pattern making, but best to work with some simple projects before attempting a pattern where you've invested a lot of time. Best, Kelly

KZfaq eliminated the ability to edit audio volume on an uploaded video. It may be inaudible at the default YT loaded setting but far from it if you use your volume controls. I can easily hear it on my phone, tablet, & computer.