I can try to sum it up for you. The top is on a hinge and has an air chamber that is pressurized with the blower. The shape of that chamber is not important. What is important is there are two nozzles near the outer rim that direct air along the outer walls down the sides in a spiral. They could be fed directly from the blower. It's just more convenient to have two of them with a chamber. I made sure to position one of them to be aiming down into the chamber when the lid was all the way open. That lets me use the blower to light it.

Es la espuma que crea el efecto

Designing with the constraint of using just sheet stock. I could just 3D print perfect cups instead, but I want to see how this works out first. Yes, they occlude each other. Going to try jets at 1/4 to 1/2 material thickness and use lots of them..

After the foam is stable it probably wouldn't matter. Yes, the concrete tube will expand with moisture. No, I don't think Thompson's water seal would affect the curing of the urethane. Not much does. This reaction isn't nearly as easy to 'poison' as others I have invested time/research into such as silicone. It'll probably work, but I'm sure you found that but out 5 months ago. :)

@@DarenSchwenke Thanks for the reply. Thompsons said the cardboard would probably just get mushy, so I just put several coats of spray paint and clear coat inside and out, then covered in foam. The top isn't open, it will probably degrade over time, but we'll see

I had good ventilation, but I probably should have been wearing a mask, yes. I did forget to open the door at first. There was a good sized squirrel cage blower behind the camera blowing down and across the floor. Opening the door a foot also opened the door a foot at the top, so there was always fresh air there flowing away from the camera.

Responded on HAD. Thank you for reaching out!

I didn't document this as well as I should have and this stayed in Montana, whereas I'm in TX right now. I will try to update the project linked up in the description end of this weekend.

Yes please we need a diagram and will pay

The 409 bottle was filled with water (which fast cures the urethane foam). The paint I used was white (clean metal) primer, rust colored (rusty metal) primer, brown, black and ivory flat paint, and lime green/fluorescent green for the mossy accent. The fast moving spraying was just painting... the slower ones were the paint dribbling out to create speckles. Never weighed it, but it was easily lifted by a child. That was one of my two design constraints, the other being they could sit on it. My guess would be it weighed around 3-5 lbs.

Thanks so much:)

Glad I could help. Post what you did so I can check it out.

I have tried them all (that I have found), but I continue to use 'Great Stuff' in the red can. Virtually every store with a paint section will have it, including Walmart. It's about $0.50 cheaper there per can as well. There are other versions for that brand, and other brands of urethane foam as well, and they all act a little differently. The window/door formula is lower expansion, the big gaps formula is high expansion, and the generic version Walmart used to have gives a little different pore size and dispenses a little differently. I haven't seen it lately though so they may have stopped carrying it.

@@DarenSchwenke thanks for the quick reply and explain what the other brands do!

Three cans if I recall correctly. Make sure you wear a chemical respirator if you are going to do that much, or at least have good ventilation. Isocyanates don't smell like they would require one, but a few hours of constant exposure can make you permanently sensitized to them with flu like symptoms.

Daren Schwenke thank you for responding so quickly and for the advice. I have a pretty well ventilated shop I’m working out off. Cluttered, but ventilated. I’m looking at buying at least 12 more cans then.

I believe I did that already.

look one down he says the olours

Hard to explain... I just winged it until it looked right. I will try to sum it up though: Spray some dark color first to bring out what would be the low areas and areas in shadow. Spray upwards to enhance this for the little details. Next, pick colors lighter and darker than your target color and interleave them. Again, spraying each color from a different angle will end up bringing out the surface features more. Finishing up, hold down the spray can nozzle just enough so the paint doesn't spray, but dribbles out instead. That, is how you can get a more uneven finish, speckled areas, and can generate convincing moss growth. Keep in mind moss only grows on one side of a tree. :)

Thank you.

Well... Don't rely on the foam to retain water. Getting it to not have holes which will leak water without a mold is a loosing battle and you won't do very well. Put some container inside it, and then coat that in foam instead. Keep in mind the plastics that you can't adhere to with urethane, or after the fact when they come apart, seal the two back together with something else like silicone caulk (which you can't paint!). Second, provide some internal structure to whatever you build outside of the foam. Here I had it easy as this was a stage prop and if it sat in the rain and lost the strength of the cardboard, that would be their own fault. For more freeform shapes, we have also used chicken wire, spray glue, and paper/plastic as the base structure. This worked *really* well and actually survived falling off the top of a car while moving it, several times... You don't want to know. Just make sure the foam also encases the wire frame directly by also coating the inside surface, and compress this foam just as soon as you can without it sticking, and you will end up with something pretty tough! The foam will degrade in sunlight, and I would not recommend cutting the foam at all if you are going to use it outside. If the pores are closed, such as when you don't cut the foam and use the outside surface as it is and then paint it, it can survive. However, I have had good results with both cut and not cut foam by using regular latex house paint, although cut foam requires 3x more coats to seal it. Good luck with your project. :)

@@DarenSchwenke thanks so much for answering me. 👍 it does make perfect sense what you just said. I assumed that inside was waterproof just like the outside is when it's dried. I'm going to take your advice and use the chicken wire as an armature frame, stuffed with styrofoam or newspaper to give it shape and then mold it with a hypertufa mixture. ( 1/3 peat moss, 1/3 vermiculite and 1/3 concrete mix) it turns out very lightweight and then seal it with Thompson's water seal. I was going to stick a PVC pipe in the middle so the plastic tubing can slide up the trunk. Anyways it was great to throw my thoughts out there to somebody who could MacGyver almost anything. I appreciate it thank you.

@@prettybird2588 The foam when compressed while curing *is* actually strong enough to stand on it's own, but this is kinda hard to do right and will require some trial and error to get right. It is *mostly* water proof as long as you don't cut it and can seal the surface with something like latex paint. If it is in continuous contact with water though, it will absorb it. I have tried Thompsons, acrylic enamel, polyurethane, dry wall compound, and automotive body filler for sealing and smoothing the surface here. Dry wall compound worked great for smoothing it, and then just regular latex paint worked the best as it created a definite skin, which then laid smoothly over the top of the foam. The Thompson's mostly soaked in and although it may provide protection from UV and such, it didn't really add anything to the structure. The drywall compound is probably not something you want to use for an outdoor application though. This is my personal channel, although I did have aspirations of eventually creating content which is something more polished. I have yet to achieve this, but that was the goal and I'm doing that here: kzbin.info/door/Yu_LuDhsQ62_XPZKdGtT_A

Thank you. I'm glad it was useful to you.

Sounds pretty solid! The one I did here the lower barrel will end up being disposable. I give it a year tops. I started with 2.5" air inlet pipes, but I ended up restricting the flow down to a little more than half that with a nozzle of sorts later on. Seemed to make it burn a little hotter. Probably depends on the back pressure your fan tolerates as well. Make sure to post a video so we can check it out. :)

I used primer where I had a suitable primer color, flat or satin spray paint where I did not: Flat black Clean metal primer (flat ivory white) Rusty metal primer (flat reddish brown) Flat tan Flat brown Then the green mossy areas near the end were speckle and spray painted. Aka... hold down the nozzle just enough to get a spattering. Those were done in fluorescent green/lime green.

It's an inductive bench grinder motor and the blower/housing itself was hand made/balanced. That's the motor he had extra of, that would last. 3600 rpm no-load speed, 1/3hp, capacitor start, 115v, probably about 6-8A. I believe it runs full speed, but I did not measure it. I ended up not needing that much airflow and only need about 1/2 'throttle' for a good burn, so some slightly larger blades and using a regular 1750 rpm motor is probably doable. That would be quieter, and much more tolerant of less than perfect welding as well. The first time I spun that one up, I was about 10 feet away and behind a sheet of plywood. :)

@@DarenSchwenkeThanks. That helped me a lot. Really appreciate your work.

You can load it about 2/3 full and still run clean. Try not to put anything high moisture in until it's fully up to temperature though. You can pretty much see the extent of what was required opening the lid. A plate over the exhaust, at center. Something in the exhaust stream to arrest sparks. Air injection around the edge down at an angle. A good seal where it opens.The rest (preheating the intake air with the upper chamber) is gravy.

@@DarenSchwenke thank you

There are two. When the lid is up, the one on the left aims straight down into the barrel. Helps to get it going.

Nice touch. Thanks.

Adding multiple colors while interleaving white gives the color more depth. Spraying some colors from one angle, and then others from another angle also helps give it more contrast. I also enhanced the existing low spots first with black to make them stand out more. Holding down the spray nozzle just a little causes the paint to dribble out as spots, which I use at the end to make the moss look more mossy.. You can use any paint on urethane foam. It is styrene that reacts to solvents.

Thanks for your answer. I will try my best ;)

I had a question. I want to make some water waves and would you suggest me to use the high gloss colour or matt for watery effect ?

@@sleepwalkersneverland Translucence is hard to reproduce, but I would try adding some metallic blue and silver. Reflections fake physical depth to an extent. Good luck.

Water. The urethane foam I use here is moisture cure, so spraying it with water accelerates the cure time from hours to minutes, and let's you apply it as thick as you want.

thank you so much for your quick response, i am making my wife a bodice/corset that looks like it was made from bark, and your video has helped me tons. thank you again

@@jcfsaiyan If you want something that looks like bark to wear, start with closed cell neoprene foam and wire brush it. Insulation foam for pipes, the soft, expensive kind.

what about eva foam, cause thats what im using with the spray foam will it make the same effect if i wire brush it?

@jeremiah fletcher Polyethylene foam works too, but is harder to make look right due to the larger cell size and open cell nature. I have not tried EVA foam, but I imagine it should work. The higher the density, the more brushing you need. Use a stiff bristle wire brush, and if it tears the foam in a linear way along the brush lines, keep going and it will look like bark eventually. Example: kzbin.info/www/bejne/nJ2miXaZqdRmndU

Yes. Polyethylene and vinyl don't stick to urethane.

It was just water in a 409 bottle, although using 409 works too. :) That urethane cures by interacting with the moisture in the air, so spraying on water while you build it up greatly accelerates the cure of the urethane. You go from needing hours to possibly days for thick areas, down to about 10 minutes, and then it will still cure at any thickness provided you spray it in between layers.

Thank you for the quick reply. Impressive!

Thank you. I had intended to go back over them and add a voiceover if anyone was actually interested. However, this project has sucked away all my available free time since then: hackaday.io/project/45404

Thanks! It seems I forgot to link some of these videos back to the project itself. The build from beginning to end is here: hackaday.io/project/27573