Building a Better Propane Tank Furnace

Рет қаралды 47,478

Күн бұрын

This furnace performs well and can melt brass on only 2 psi of liquid propane gas using my custom designed forced air burners.
Health and safety warning: Casting metal is a dangerous activity. Molten metal can be hazardous to your health. Zinc fumes can induce flu-like sickness. Regular masonry can explode if exposed to high temperatures. Always use a respirator when working with ceramic fibre insulation. Always stabilize any exposed ceramic fibre insulation included in a furnace build.
The primary goals of the project were to create a well-insulated, highly efficient furnace - in this regard I consider the project a success. My previous furnace was so inefficient that I had trouble melting metal before the gas supply tank frosted over. The improved insulation and combustion efficiency of my forced air burners completely eliminates that issue.
Soft firebricks were used to insulate the furnace body; I used Fusion360 to design custom brick grinding jigs that achieved a very precise, reproducible fitment. The furnace was designed to fit a ProCast No 4 Clay Graphite crucible (available from PMC Supplies).
Although this furnace was specifically designed as a metal casting foundry furnace, I have no doubt that these construction techniques could be used in to build other types of furnaces (e.g., smithing forges, heat treating ovens, etc...)
It is worth highlighting the major advantages of this method over a more traditional build using castable refractory:
1) Operational Efficiency - The soft Firebricks are much lighter than castable refractory, and do a better job of insulating the furnace. This means that my furnace heats up faster than one made with castable refractory, and uses less fuel to melt a similar amount of metal
2) Repairability - Since they are not cemented in place, each brick in my furnace is individually replaceable. This is useful because they will inevitably need replacement as they erode away over time. The brick upon which the flame impinges will need replacing first, and this is an easy operation. The bricks could even be rotated to prolong the service life of the furnace
Project start: 2022-07-15
Project end: 2022-07-28
Resources: Fusion360, Da Vinci Resolve, Canon EOS70D
GrabCAD: grabcad.com/library/propane-t...
Instagram: / cigzntylrpe
Chapters:
00:00 Intro and purging the tank
01:59 Prepping the furnace body
06:54 Shaping the bricks
11:14 Blower insertion opening
12:11 Furnace lid
16:32 Painting
17:22 Final assembly and test firing
19:05 Safety hazard
19:38 Machining the cast sample
Music:
Reclamation - Silent Partner
Parasail - Silent Partner
Cloud Patterns - Silent Partner
Glue - Mikos Da Gawd
Moon Monorail - Fluffy Ducks
Idea 170 - Fluffy Ducks
Grut - Patrick Patrikios
Righteous - Silent Partner
Uploaded: 2022-09-14

Пікірлер: 59

@HodgdonH110 Жыл бұрын

Clever the way you removed the valve - amount of times I've seen other people struggle to remove it

@bryanharrison3889 Жыл бұрын

The fan idea is fantastic, but you can do these things without the use of the fan if you build a proper inlet channel. It'll perform similarly and won't need a power feed to a fan.

@markosfraser3030 Жыл бұрын

Every naturally aspirated burner design that I have tested performs significantly worse than the forced air design shown in the video. If you can recommend a good naturally aspirated design that you think will match the performance of my forced air burner, please send me a link to the design

@charlestuozzo4747 Жыл бұрын

Great looking furnace. Safety third as a friend always said.

@samuelfaszer5043 Жыл бұрын

Great job with the video. Love the style! And nice 💍I see it snuck into a couple shots 🤓

@darkrasen Жыл бұрын

Nicely shot

@pilotcirwin Жыл бұрын

Awesome! Great video!

@RogueOntheRoad Жыл бұрын

If you heat up the area around the valve threads with a paint stripper before trying to remove the valve it will come out a bit easier. The valve has sealant which locks the threads. But when the sealant is heated it becomes like soft goo.

@markosfraser3030 Жыл бұрын

Hey thanks that sounds like a great tip! I'll give it a try next time I strip down another propane tank

@paulmanhart4481 3 ай бұрын

Very nice job. Why bricks instead of cement?

@KittyCatsQueen 5 ай бұрын

Wery good job.. Nice work

@robertindabuilding2876 Жыл бұрын

The definition of "payd by hour" video

@paulmanhart4481 3 ай бұрын

Why the vertical gaps between fire bricks at their outer perimeter? You took pains making them so there must be a reason. Paul

@markosfraser3030 3 ай бұрын

Hi Paul, thanks for your comment. The vertical gaps at the outer perimeter are incidental from the geometry of the bricks and the furnace. Ideally the vertical gaps would not exist, but to grind both faces of the brick fully flat to the correct angle would require removing a lot more material, and probably an extra brick.

@taftancastingchannel 3 ай бұрын

بسیار عالی بود 👍🏽

@dbfletcheryt Жыл бұрын

Just a quick question about the firebrick comment being a consumable item. How long do you expect them to last? I also used firebrick on my build and I probably have 3 years (80-100hrs) on my forge so far with no obvious signs of any breakdown in the bricks. I mostly melt Aluminum, but I have done a few copper melts as well. I did put a thin coat of Satanite over all of the bricks, so not sure if that helps or is just masking an internal problem.

@markosfraser3030 Жыл бұрын

Your forge has many more running hours than my furnace ; ) I'm glad to hear that you've not had problems with the bricks breaking down. I expect these should last for quite a while, but I'm still glad that they are easily replaceable in case of mechanical damage (e.g., dropping the furnace while moving it, or gouging them with crucible tongs). I also tried coating the bricks with a dilute solution of furnace cement, but found that it tended to peel and flake off the bricks.

@knickly Жыл бұрын

Hi Markos, I'd love to hear more about the burner - I've been considering a very similar layout using a similar fan in order to induce swirl. Do you have anything posted about the burner design?

@markosfraser3030 Жыл бұрын

Hi, You can actually find a CAD model of the burner on my GrabCAD (linked in the description), so you could 3D print one yourself and try it out. It is designed to print entirely without supports, and with minimal infill material. I don't have any other content posted about the burner at this moment, but I hope to soon make a video comparing the performance of my forced-air burner against other standard atmospheric burner designs.

@knickly Жыл бұрын

@@markosfraser3030 fantastic, thank you!

@user-sb2cz1jq4p Жыл бұрын

Благодарю, песня ЮрийАнтонов-Мир зависит от нас.

@matejogrinec4111 Жыл бұрын

I am missing a video abouth the burner itself

@markosfraser3030 Жыл бұрын

The burner is really easy and cheap to make because most of it can be 3D printed! I'm hopefully going to make a video soon showing performance improvement from naturally aspirated to forced air, and release the CAD model, electrical diagrams, and Arduino code!

@jesseli9868 Жыл бұрын

Neat!

@frankhenry645 Жыл бұрын

Before attempting to copying l would suggest a stop on amazon 😅 you may want a respirator To say the lid would get hot may be a understatement you will need to remove and replace it several times I would like to know the total cost to build and the time involved (cost of brick shapers?) How do you move it around ? It looks very nice I would like to see it after 25 fireings , especially the lid Thank you

@markosfraser3030 Жыл бұрын

Thanks for your comment. I wore a respirator at all times during the build where airborne particulates presented any safety hazard. It took several evenings of casual labour to build this furnace (while filming the process, which slowed everything down). I would estimate a rough total of ~12hr of continuous labour. I will consider doing a more accurate cost analysis in the future, but as a rough estimate in Canadian dollars: Bricks - 90 Ceramic fibre - 30 Furnace shelf - 15 Shaping jigs (x3) - 20 Misc costs (consumables, etc...) - 30 Total: 185 [CAD] It's not difficult to move the furnace, I can lift it above my head and I store it on a shelf in the garage. If my next metal casting projects turn out better than my initial attempt (instagram.com/p/CliJypVuqjU/?), this furnace will certainly be making some appearances in future videos!

@toastedone2478 Жыл бұрын

Really awesome video, thank you for sharing!! With the blower added, do you think this furnace would melt steel?

@markosfraser3030 Жыл бұрын

It may be possible but I have not attempted it yet. I'm also considering building a forced air, liquid fuelled burner which should be capable of melting iron and steel. Unfortunately, the firebricks I used in this furnace are not rated for those temperatures, so I'd have to replace them with higher temperature bricks

@stankrieger3598 Жыл бұрын

How much difference in using a 30lb cylinder and a 20?

@goodtimeeric Жыл бұрын

You mentioned being unprepared while pouring the molten brass. You were wearing your fireproof safety short-shorts, what else could you need?

@craftzars Жыл бұрын

he forgot to wear his safety crocs :D

@spyder2782 Ай бұрын

Did you ever release stl files for the fire brick jigs

@Metal_Master_YT Жыл бұрын

I think your lid simply got hotter because the hot air naturally rises, and there was an opening in the center which exposed the edge of the conductive metal lid to the fire, which of course spread that heat to the rest of the lid.

@jimkemplin9079 Жыл бұрын

Fire brick can be easily cut with a saw and you can use a simple Bondo rasp to round off any of the corners it would’ve been a lot quicker

@markosfraser3030 Жыл бұрын

It would be possible to cut the bricks with a saw, but there would be no way to achieve such a precise and reproducible fitment as my jigs produced by working freehand. To achieve a comparable fitment you would have to construct a jig that holds the brick and guides the saw. And all the curved faces would still be time-consuming to shape using a rasp.

@littlehills739 Жыл бұрын

try to add dish-washing liquid and kick it around the yard with water. bubble displace the lpg and make inert atmosphere wile cutting

@markosfraser3030 Жыл бұрын

Ty that's a good idea!

@user-sb2cz1jq4p Жыл бұрын

Графит для тиглей,форм предлогаю.

@74KU Жыл бұрын

Why not remove the valve with a shifter or a spanner BEFORE cutting on it at all? Was the way I did mine as I didn't feel happy making fire anywhere near a cylinder let alone on one.

@goodtimeeric Жыл бұрын

Maybe it depends on your tank's valve guard. I did one last night and could not snug the valve with the guard on, so i used a hacksaw to cut it off, giving better access the valve.

@user-xg1dy1nm5e Ай бұрын

What denyer are you Oliver?

@waynefaszer5823 Жыл бұрын

👍

@jarredsegal6842 6 ай бұрын

Personally I just ratchet strapped the tank to a tree and used a pipe wrench to remove the valve

@lamptoonclipslapoon9301 Жыл бұрын

u sound insanely different from what I remember, what mic are you using? ps. u should be the new king of random XD

@markosfraser3030 Жыл бұрын

AKG C535 EB. I have a lot more time on my hands now that I'm out of eng school ; )

@lamptoonclipslapoon9301 Жыл бұрын

@@markosfraser3030 keep at it my guy

@lamptoonclipslapoon9301 Жыл бұрын

@@markosfraser3030 best of lucks to you mate

@chaz353535 4 ай бұрын

Your safety must come first watching your pour that molten metal was ridiculous Otherwise a good post

@jeffhiggins3794 Жыл бұрын

Great video, but the music is nauseating.

@user-sb2cz1jq4p Жыл бұрын

Здравствуй МИР! Здравствуй друг! Здравствуй песен щедрый круг! Здравствуй миг! Здравствуй век! Здравствуй добрый человек!

@luislopez-pf5fi Жыл бұрын

@shelbyconstructions7256 Ай бұрын

Bricks are not temperature resistant. They dont blow up from heat, they explode.

@phoenixflames2455 Жыл бұрын

While your technique is novel, and we all love playing with our 3D printers, this build is dangerous to health and safety of the user. Putting aside the deadly risk of metal fume fever you put yourself in by breathing zinc fumes, you've placed regular brick as filler inside the heat envelope, which risks the pieces exploding (while less risky when broken down like that, it can still happen), but the biggest risk is that you've included in the bottom unsealed fiber wool material. When heated this can give off harmful particulate matter that can cause some pretty serious health effects. There is no advantage to this type of build over a simple fiber blanket sealed in castable refractory. This is a lot more work for a lot less benefit.

@markosfraser3030 Жыл бұрын

Ty for your comment and concerns. 1) Crushed brick floor - I know this method is safe and effective because I have used it for several years in my old furnace build. Most of the crushed brick doesn't actually get very hot, and the stuff that does get warm vitrifies rather than exploding. After it vitrifies, it becomes very stable and I've never had issues with the floor shifting substantially. Another benefit of this method is that it's very easy to replace if molten metal ever gets spilled inside the furnace (ask me how I know) 2) Ceramic fibre - I always wear a dust mask while working with ceramic fibre, and I will place a safety warning recommending the same. However there is no exposed fibre in my build. The thin mat of fibre in the base is completely enclosed by the kiln shelf, and the soft firebricks. Here is an image to assuage your concerns: vgy.me/u/fJCIdW The mat of fibre is primarily helpful to evenly distribute load from the crushed bricks to the kiln shelf This method has two major advantages over more traditional cast designs: 1) Operational Efficiency - The soft Firebricks are much lighter than castable refractory, and do a better job of insulating the furnace. This means that my furnace heats up faster than one made with castable refractory, and uses less fuel to melt a similar amount of metal 2) Repairability - Since they are not cemented in place, each brick in my furnace is individually replaceable. This is useful because they will inevitably need replacement as they erode away over time. The brick upon which the flame impinges will need replacing first, and this is an easy operation. The bricks could even be rotated to prolong the service life of the furnace. A castable refractory furnace could not be easily repaired in the same manner, and many people typically demolish and rebuild their entire furnace when it reaches the end of it's lifecycle

@phoenixflames2455 Жыл бұрын

@@markosfraser3030 First of all, let me commend you for actually responding to my comments rather than ignoring them or becoming angry/defensive. It's refreshing to see on youtube. I think the warning is a great idea for #1. As for #2, you've effectively said, "It's safe because I've never had a problem with it." That doesn't mean it's safe. At the end of the day all it takes with regular brick is a humid day, or improper storage of your furnace, and they will absorb moisture. Then when heated, they can literally explode. This is hardly up for debate. Is it likely? No. Can it happen? Yes. Hell, it even happens with high quality construction concrete (there are literal lab test videos I can link you to), it's certainly going to happen with cheap masonry bricks. Based on your response, though, I'm confused why you wouldn't just fill the bottom with zeolite sand, it would give you an actually level surface, it would provide a great thermal sink (storing energy and releasing it, helping you keep a consistent temp), and in the case of a spill, you could let everything cool and then remove the solid mass, and just replace the appropriate amount of sand... As for #3, while the fiber isn't visible in the picture you sent, from what I saw in the video at 5:36 you have exposed fiber at the corners, which appears to be where you have the "missing corners" of the bricks, providing a convenient "chimney" for giving off fibers. It's a minimal risk, but if you're already sealing the fibers for the lid, you've already got all the material, you're already going to the effort, why not just seal the bottom layer too? For the design advantages: While the bricks might be lighter than a full castable build, that isn't how it is usually done. You take a fiber blanket (preferably Biowool over the older, more toxic Kaowool style materials), and wrap it around, then coat with rigidizer (tip: add a drop of food coloring to your rigidizer so you can see if you missed a spot). Then, once that has hardened, you coat with just a top layer of castable refractory. This gives you lighter weight and superior insulation, the best of both worlds. A top coat of ITC-100 will futher improve your thermal efficiency by reflecting IR. Repairability - Yes, you can replace an individual brick, sure, but you still need to shape that brick. To quote your own words in the video, doing so "was a slow process". When all I need to do is remove the liner, make one single cut out of a roll of insulating fiber, spray with a spray bottle, then paint on the refractory, it hardly seems worth the effort, especially when the fire brick is going to cost you more money in the long run.

@markosfraser3030 Жыл бұрын

@@phoenixflames2455 2) I've added a warning for this one as well : ) Yes I don't dispute that it is possible for the crushed brick pieces to explode. But it is within my personal tolerance of acceptable risk. Someone with a lower risk tolerance should consider alternatives.I actually wanted to minimize the thermal sink, because I don't want to waste fuel heating up the furnace rather than the metal. Other people with a different setup might have different priorities, and prefer to build a more thermally stable furnace. But my goal was to prioritise fuel economy. 3) I just took a look at the furnace, and you're right there are a few tiny areas of exposed fibre down the cracks of the bricks. I had completely overlooked those areas. You're right I should have stabilised it during construction, and I'll try to spray on a coat before the next firing. However I also agree the risk is minimal from these exposed areas because there is no forced airflow over those fibres. Regarding advantages: That's true I am comparing my furnace against one constructed entirely of castable refractory, not a hybrid design. I concede that this design may be comparable in performance to a hybrid design. It was a lot of work to grind the bricks, but it's also a lot of work to do a good job of casting refractory material. This method might be slightly more work in total, but it's more so a different distribution of work. As for cost, my local supplier sells 2" wool for 15.39/ft (2ft width). It works out to ~$50 of wool for a furnace like this. I cannot estimate how much would be added for refractory, because my supplier does not carry it. To ship castable refractory is exorbitantly expensive. The soft bricks used in this furnace cost me $84 in total. So I'd argue that this is a comparable amount of work, and a comparable cost to building a hybrid wool/refractory furnace. But most importantly I was able to build this furnace using materials locally available to me; castable refractory for a hybrid design was not even an option.

@FeatherHorseforge Жыл бұрын

Not all insulating blanket is hazardous to our health I know of some that is body soluble and doesn’t need coating

@phoenixflames2455 Жыл бұрын

@@FeatherHorseforge Yes, we discuss biowool on the Reddit post, but this is a silica based insulating blanket.