How to Make Flawless Concrete Castings

[@PhillipDanner]

Mold maker here. Have you thought about flipping the master while molding? Master base side down and suspending the center instead would remove the bubbles you are getting on the interior. A really low shore, thin walls and keys in the shells like you have should allow you to demold without the need for a parting line as well. Essentially turning it into a glove mold. Food for thought. :) I enjoy watching your process here either way!

[@The3DHandyman]

Hi Phillip! Those are some good ideas. I will have to give some thought to the mold modifications needed for flipping the whole thing. Skipping the parting line sounds like a dream! Haha. I think I could potentially demold the master successfully without splitting it but I'm not sure about the cement. It's very brittle at the point which I demold it. Really any force on it at all will make it explode. I did try this at an earlier phase of development and it did not work quite as I had hoped... but the mold design was also different at the time. So, it may be worth giving another shot. Thanks for watching and commenting 👍

[@eastbaygrease10]

This might be my new favorite channel. Awesome design + awesome production.

[@The3DHandyman]

Thank you and thanks for subscribing!

[@notflanders4967]

cant wait to watch this! Ive been waiting for this one! Ill have to come back when im not so focused elsewhere! Thanks for sharing!

[@The3DHandyman]

I hope it meets expectations! I didn't do a voice over for this one, so let me know if you have any questions

[@stfztg3623]

Clean! Very well done 👏

[@JamieGrove]

The quality of this video is amazing. Great work!

[@seyyedamirir4977]

Great process! Even the pot itself just filled with moss would look nice. I think a thin layer of rubber on the table would prevent the mold from walking away in vibration.

[@The3DHandyman]

I am considering selling just the post as well. Thanks for the confirmation 👍 Covering the table with rubber is also a good thought. I wasn't sure if all the cement dust would eventually result in it loosing it's stickiness, but I may give it a shot for production.

[@seyyedamirir4977]

@@The3DHandyman I just recently started producing some concrete products, I built a mini vibrating table and got inspiration from yours too. Ended up using a mix that doesn't require vibration but something that showed useful as a surface brake was those kind of clear PVC sheets used as table covers, I'm not sure if they're available in your country but they do a good job and are washable.

[@The3DHandyman]

Good thought on the PVC sheet covering. It just gave me the idea to do a 3D print fixture for the mold that would keep it from moving at all. The pot could also be held at an angle too for good cement flow. I am going to need to try that...

[@spherevsgravity]

quality work I'm impressed I wish to see more of your concrete work

[@The3DHandyman]

Thanks! I hope to get back to that some day soon.

[@realhelmi]

Nice work. I like the design - you achieved something great here. Thumbs up.

[@DINHVANTAM-QTRI]

You make beautiful products

[@shaneintegra]

The work you do is absolutely amazing! Just subbed!

[@The3DHandyman]

Thank you and thanks for the comments!

[@AV1461]

Very beautiful work :)

[@The3DHandyman]

The wonders of doing something many, many times :)

[@MrKrueger88]

Extremely well done indeed 👍 instant sub

[@The3DHandyman]

Thanks for subbing and commenting! I'll put out more cement related videos later this year 👍

[@induherath2309]

Please send how to make silicon.

[@ryanshaver]

Around 03:23 I see you shake the actual slurry itself before it goes into the mold. What benefits does this have? I have been trying to make concrete tiles at home, and have only done the shaking after I've poured the mold. Perhaps I should do both? You can see my progress on my channel. I've only done 4 tiles so far, with varying levels of success. Thanks for the upload!

[@The3DHandyman]

Good question! For this particular mold, shaking the cement into the mold was the only way to fill it with a relatively thick mixture. If the mixture was more watery it would flow into the mold but the resulting cast would be too brittle to remove from the mold without breaking it. For tiles, I don't feel like that would be a necessary step. You might get less bubbles if you do, but that isn't always the look to go for. Hope that helps!

[@ryanshaver]

@@The3DHandyman awesome! Thank you. I gave you a written shout-out in my latest video: I hadn't been wearing gloves until you noted it in this video. Thanks again for the advice and for the uploads!

[@mikropower01]

So much work. But it looks very good. :-)

[@The3DHandyman]

Thank you! Many months of work indeed.

[@pabloG3d]

great results. 1. are you not using a a pressure pot to reduce bubble when making the mold? 2. are you adding any dyes/stain/coloring to the concrete mix? 3. have you tried adding super plasticizer to the concrete mix (to make the cement harder)? 4. what material are you using for the second clear mold? can you post an affiliate link?

[@The3DHandyman]

1. I had mixed results with the pressure pot when making the mold. It seemed actually increase the amount of bubbles on some molds. I think what was happening was that air was being forced out of the wax that sealed the the outer mold. So, just letting it sit seemed to work better on average. 2. The concrete is stained and sealed. I didn't really get into this because these will be on sale and my partners didn't want me to give away every last detail. 3. I have not. I'll give it a shot though. At this point the recipe is so dialed in, I may elect not to change anything for production. If the mix is harder the final finish may become more difficult to achieve. 4. I will work on getting an affiliate link. Good call on that. I experimented with the full line of Smooth-on's Vytaflex Series. Arguably the higher durometers would be better for most castings.

[@fcrick]

Mixing your own concrete mix would give you a lot more control here - recipe matters a ton, and it's as simple as just stirring things together. I would just buy some fine sand and portland and start with that. The mix you're using is for repairing elements of structures - not for making tiny pots.

[@The3DHandyman]

So true! I have much to learn. Probably not coincidently the only thing I have ever done with cement prior to this was repairing structures 👍

[@jules_69420]

i stumbled across your videos and i love your content! as a maker, i'm always looking to improve and pick up new techniques. could you maybe do a video on how you make your matrix molds? i'm still a rookie when it comes to making efficient mothermolds that save on silicone and produce much better results than plaster bandage and resin. Thanks for all your hard work in your videos

[@The3DHandyman]

Thank you! I hope to be making more mold making videos later this year. Those videos will have voice overs to explain things in more detail. My matrix molds are always drawn up in CAD and 3D printed. It's a great way to get the perfect shape but it's not a very user friendly way to do things. Do you have a 3D printer?

[@jules_69420]

@@The3DHandyman That sounds awesome! Looking forward to see what you produce! And yes, I do have a LCD resin printer as well as FDM, with some CAD and 3D modeling experience. But I've never tried to implement 3D printed Matrix molds. Would love to see the design process and the kind of problem solving you used to approach your rock bowl creation. I thought the suspended method was a great way to avoid claying and extra pours.

[@The3DHandyman]

Most definitely. I was really trying to avoid using the clay at all but the clay method does help produce molds with great registration. I'll be sure to talk about this and my methodology when printing the mothermolds when I get to those videos!

[@eduardo_2805]

Have you ever tried vaccum molding on concrete pieces? I wonder if that would work to achieve no bubbles results. Great video, btw! Thanks for posting

[@The3DHandyman]

Maybe this could be done with a very low level of vacuum? I'm not quite sure. The trouble with high vacuums, like inside a vacuum chamber, is that water boils at room temperature under very low pressures. Also dumping a lot of water vapor into a vacuum pump can ruin the oil inside of it quite quickly. A venturi valve and an air compressor would be a better choice for this. It would be an interesting experiment. Maybe I will give it a shot one day!

[@freeman6147]

@@The3DHandyman yes, please

[@The3DHandyman]

@@freeman6147 Noted. Hopefully some time this year!

[@robertochavarria1972]

Hi spectacular job, congratulations, question, after you pour the mix in the mold how long you leave it after you take the pot out. i enjoy your dedication and fine work. thanks.

[@The3DHandyman]

Thanks! Demolding depends on the the mix, the moisture in the mix, the relative humidity, and the outside temperature. The best time to remove it is typically be between 16 and 48 hours. You may have to experiment with it :)

[@robertochavarria1972]

@@The3DHandyman Thanks for the info.

[@AbdulAziz-cj4hg]

Sir, if you want to make a small concrete planter out of cement like this, how thick should the walls of the pot be so that it doesn't become fragile?

[@The3DHandyman]

You can buy these! www.etsy.com/shop/CrucibleCompany There are 6 videos in this series! 1: Intro kzbin.info/www/bejne/h4qbYqGie7CGnpo 2: Casting clear resin mushrooms kzbin.info/www/bejne/gnzXXmCBas93h5I 3: Casting Cement Pots kzbin.info/www/bejne/p5qrZ4uga6ihaZo 4: Growing Moss kzbin.info/www/bejne/n3LRZZShrtx5rK8 5: Prototype vacuum formed packaging kzbin.info/www/bejne/imnFnmt9q6xmis0 6: DIY silicone injection machine kzbin.info/www/bejne/iWq3h6aofZt4mMU I hope to make more specials like this in the future, so be sure to back The 3D Handyman on Patreon! www.patreon.com/the3dhandyman You can buy these! www.etsy.com/shop/CrucibleCompany

[@AbdulAziz-cj4hg]

what kind of concrete are you using to cast, looks beatiful

[@GaryMcKinnonUFO]

Lovely result. I have a similar process with Jesmonite, 3d print the master mould then make the silicone one from that. Jesmonite is too thick to pour well down thin gaps but your concrete looks nice and viscous. What brand and type of concrete ?

[@The3DHandyman]

Thank you. The more viscus the better! I would consider the mix a bit wet though. I use plain old Quikrete Sand Topping Mix, nothing fancy.

[@GaryMcKinnonUFO]

@@The3DHandyman Thanks. Found some Hydrocal i'd forgotten about so giving that a try. Made a crappy little vibrating table too, nothing like yours!

[@The3DHandyman]

@@GaryMcKinnonUFO The vibration table is key. I couldn't pull this off without it. If you are still getting bubbles, that might be the culprit.

[@GaryMcKinnonUFO]

@@The3DHandyman Thanks, ye my table's not so good with the heavy weight, it took 5.7L of silicone to do a bucket mould of a shape that really doesn't suit moulding, a hydroponic planter that's basically a hollow cylinder with two netpot holder shapes sticking out from it. It's been the usual trial and error but i finally got a shape that was fairly demoulding friendly but still took some smashing-by-hammer of 3d-printed mould-cores. I like how you polished your prints with the release agent, great idea. I sprayed mine but of course the micro-roughness of the printed surface is just a massive nano-gripping zone for the rubber to cling to.

[@The3DHandyman]

​@@GaryMcKinnonUFOSounds like a pretty cool idea. I did a 3D printed hydroponic planter a few years ago with good results. That was before I started this channel. As far as the mold material sticking to the prints... you can always sand the mold just to knock down the highest layers. The roughness of the sanded plastic also holds the mold release agent a little better than when it's smooth.

[@DuhRake]

What sort of product did you switch to in your second attempt at molding? (The clear yellowy one). The pots turned out excellent.

[@The3DHandyman]

Thanks Drake! The second product is a lower durometer urethane rubber from smooth-on. Not sure of the name but the color gives it a way.

[@The3DHandyman]

Vytaflex 20. Although higher durometer rubbers may work better and be longer lived for more standard pot shapes

[@DuhRake]

@@The3DHandyman Thank you very much for sharing your knowledge.

[@Palestinian987]

How do you get a gloss look?

[@The3DHandyman]

I used some clear 2 part epoxy. Any should work fine. To get it to absorb correctly, you may have to brush off the "skin" on the fresh concrete after about 24hrs or so (depends on mix and mold). I may do a more in depth video on this at some point.

[@kalinovsky9444]

You can try use white cement. It is much stronger than grey cement.

[@The3DHandyman]

Good to know!

[@ConcreteLand]

@@The3DHandymanit’s not any stronger. Strength is from mix ratios and water content.

[@gregm5636]

use some plasticizer, reduces the water needed and vastly improves the flowability

[@The3DHandyman]

Thanks for the tip!

[@Pixeltrainer]

Have you tried high alumina cement?

[@The3DHandyman]

I have not yet. What is good about it?

[@Pixeltrainer]

@@The3DHandyman It is extremely fine, and takes longer to set. I was thinking this might be advantageous for casting things. It might make it easier to avoid honeycombing because you have longer to vibrate it to fill the voids. Check it out.

[@The3DHandyman]

@@Pixeltrainer Sounds interesting! I will have to check that out when I am able to move on from air filter content in the future :)

[@JimboJet737]

Thank you for taking the time to produce these videos and for showing us the process. I'll be honest and say I love the concept and implementation but personally I'm not sold on the mushrooms as subject matter. Do you have any plans to offer flowers as an option?

[@The3DHandyman]

Any time! If the current product sees a remarkable turnaround there can be more products in the future.

[@lio1234234]

What concrete did you use (aggregate type, etc). Also, the specific pigment you used would be great too! Thanks

[@The3DHandyman]

I used Quikrete Sand topping mix and sifted out the large aggregate for a smoother finish. Regular black pigment for the color came from the same store isle as the concrete.

[@cy8646]

These are awesome! I've been making some things casting with cement and I'm getting stuck for a finish to seal it. Did you use any or have any suggestions?

[@The3DHandyman]

Thanks! The simplest thing I've found so far is to put some mineral oil on it. Concrete sealers from the hardware store offer a lot of satin/gloss options. For a wet and glossy look epoxy resin also works well. What are you making, if you don't mind me asking?

[@cy8646]

@@The3DHandyman I made a bunch of plant pots funnily enough. Only small, good for a succulent on your desk. I've tried a trade sealer and it was rubbish. I've also tried a few spray lacquers, polyurethane, and right now I'm uses 'Clark's' soapstone wax. It's drying as I'm type but it looks as though it'll be uneven. All have been okay in some ways, but ultimately not what I hoped for. Which was quite subtle (not glossy) and maybe picks up some texture. I'll throw mineral oil in to Google, do you have any brand preference?

[@The3DHandyman]

@@cy8646 I think any mineral oil would work fine. I'm not sure if the plants would like contact with mineral oil though. So far I've only used that for non-planting purposes. For the succulent in this pic I actually used some canola oil (any cooking oil might work just as well) to give it a little color. instagram.com/p/CdTqtL6pj0l/ So far the plant appears happy and the finish on the pot is mostly intact. I can reapply the oil at any time as it soaks into the concrete... sometimes unevenly. The wax you are using might be a fine choice in general. Maybe you can cut it with some sort of solvent to prevent it from drying too quickly?

[@cy8646]

@@The3DHandyman It's the next morning and the wax has finished as suspected. It may be too thick to cut. You stipple it on with a stiff bristle brush. I'll try cooking oil. It'll be the cheapest thing I've tried yet and depending on how that goes it may point me further towards mineral oil.

[@The3DHandyman]

@@cy8646 Let me know how it goes

[@senorduck384]

Do you sell the molds?

[@The3DHandyman]

I do not currently. Maybe one day!

[@Rollmops94]

For this life I can not change Hidden hills, deep of in the mains M&Ms…

[@DevArt59]

Stopped selling ?

[@The3DHandyman]

Yeah, these did not sell very well and were very difficult to make.

[@DevArt59]

@@The3DHandyman that’s unfortunate I’m sorry to hear that, I would have really liked one But thank you for sharing your process I got a lot out of it !

[@cchemmes-seeseeart3948]

Hi tech art making with 3D printer, but a low tech - no voice speaking- you must read the text video? I try to multi task & these 'read along' videos are a nightmare where I must drop everything to watch. It does make a huge difference for some of us.

[@The3DHandyman]

Yeah, it was an experiment

[@karenwindspirit5907]

I don't have a 3-D printer so you are useless to me!

[@litho1069]

Figures your name is Karen….

[@karenwindspirit5907]

@@litho1069 TY for the complement, God bless you!