Simple Propane Forge Lining

This video shows how to install thermal blanket in a simple forge, install a floor and put in the burner. In addition, three projects will be completed, demonstrating the use of the forge. Please be aware that there is a "dragon breath" of fire that comes out the open end of the forge.
Upcoming videos from me will provide more details about doors, floors, a free_form forge and material sources (please be patient).
The bottom of the burner is set about an inch above the top of the burn chamber (up in the lining).
I use "INSWOOL" thermal blanket (8 lb, one inch thick). Other brands are available (like Kaowool, Fiberfrax and ??) The thermal blanket can be purchased from various blacksmith supply businesses, eBay, or from the manufacturers. The effectiveness and efficiency of type of lining can be enhanced through the addition of a hard reflective surface coating. In the "Lining the Super C Forge", I show one way that can be done.
Nichrome wire can be bought from industrial suppliers or on eBay. The wire I demonstrated with is ribbon wire (about .03 thick and 1/8 inch wide). If you use round wire, use at least 11 gauge or thicker. Buy the highest temperature wire you can find (it will last longer). Google NICROME WIRE to find sources.
Please read the MATERIAL SAFETY DATA SHEET for the thermal blanket you use. Your personal safety is your responsibility. One can be found online by Googling for it (for example.... Google "INSWOOL MSDS")

[@robertlangley258]

Ive watched several hundred videos with comedians and their best music till my ears bled. Finally, a video the way a video should be made. Thank you sir for a very informative educational easy to listen to video. I wish everyone had to watch and learn your style when making a video...mandatory! Thanks again sir.

[@aslanbekir]

I liked the way you work, so precise and neat.

[@BrushCountryAg06]

Thank you Sir for all of the time and effort you have put into making such wonderful videos. PLEASE KEEP THEM COMING!!!

[@GodzillaXAbudAwwal]

excellent video indeed. detailed and very clear. Thanks David.

[@aguynamedmike77]

Very informative and helpful. Thank you for taking the time to make this video. Much appreciated.

[@RocketCityGardener]

Nice video. One question though. I thought the additional coating over top of the thermal blanket was to lock in all the fibers so they don't get blown out and breathed in.

[@yoncofi]

That´s great. Thanks a lot for everything.

[@djhammerd]

Yes, adding additional refractory will add to efficiency. This video is just to show that a working forge can be made using just thermal blanket. If you want to see how I line forges more efficiently, view the "Lining the Super C Forge" video.

[@RobertoLeiteBR]

Hi, is it possible to use a regular kitchen gas as burner instead of propane? Congratulations on your forge, that's a great project! Roberto - Brazil

[@royehuckaby335]

It would be nice to see the results each time after hammering before re-soaking.

[@djhammerd]

Look for a local ceramics supplier first. If they don't have what you need, Google "Ceramic Supplies". I used hard firebrick in the simple lining video (1 inch for the floor, standard size for the doors. Any brand (kaowool, inswool, etc) of thermal blanket will work (buy 1 inch thick, 8 pound weight). Thermal blanket can also be bought on eBay.

[@RocketCityGardener]

Also for these three projects do you have any estimate of how much propane you use. I'm trying to get a picture of how long your typical grill size propane tank will last. Thanks.

[@joemishap2214]

You inspired me to build one..where do you get the Thermal blanket and bricks? Are they generic or is there a type or brand that should be used?

[@yoncofi]

Thanks. My intention was not questioning what you say, I just did not know the Nichrome wire. Do you know if all the 1/4" fittings can be replaced for 1/2"? Does it works?

[@djhammerd]

Natural gas can be used with gas forges. I don't have experience with using it with aspirated burners, so I can't provide guidance there. I suggest you google for information on the internet.

[@djhammerd]

I don't recall having any staples fail. You do, however, need to get very high temp wire.

[@yoncofi]

Thanks for all your videos first, you´re great. Have you tried with this forge to get at forging temperature stock of 5/8 or 3/4 inch thick??, Or What about 7/8" or 1" thick??

[@djhammerd]

Any size fitting will work as long as you have leak free connections.

[@djhammerd]

This forge should easily heat 1" stock to forging heat. Also, if you use soft brick for the doors, it will heat faster.

[@123samic]

Would it be of any benefit to add a layer of refractory cement to the inside of the forge?

[@9q7a5z]

Maybe it is just me but the volume was very low. I could barely make out what was being said. The info and your style is very good. First intelligible direction I have found on the net.

[@jayschaffer5236]

like this video much

[@djhammerd]

Another video (Lining the Super C Forge") speaks to using Sodium Silicate to "glue" thermal blanket to the forge body. Seemingly, this would be better than using staples (in some cases) as I recommend in this video... Not necessarily so. Without the reflective coating (as described in the other video) is not put over the thermal blanket, it is likely that the temperature within the blanket will cause the sodium silicate to crystalize and fail (thus I suggest you use staples instead).

[@rickramrick8423]

Great project... I was wondering if I cut two 1" thermal blanket rounds to line the inside chamber up against the rear bricks, would that generate more heat ?, if I needed to heat longer work pieces I could put a slit in the blanket to push my work through or would it be a bad idea to touch the thermal blanket with your work piece? If the thermal blanket can be touched with the work piece why not lay 1" of blanket on top of the 11/4" hard brick floor? Also how often should I reline the chamber with inswool? Please let me know which ideas are feasible... I am building the simple version and not treating the thermal blanket & have 50 sq.ft. of 8lb. inswool... Thanks

[@HammerMan999]

+rick ramrick.... This is a long answer, but.... It wouldn't generate more heat (that comes from your burner), but it will contain more heat in the forge (a good thing). Reducing the size of the burn chamber by adding thermal blanket is perfectly OK, as long as you don't make the chamber too small and still have some opening for gases to escape (which you will on the side you put your project in from). In fact, if you are using hard brick for the doors, putting thermal blanket in the back as you suggest would result in the forge heating up faster (it will lose less heat heating up the hard brick on the back). The same is true if you are using soft brick, but the increase in efficiency is greater if you are using hard brick. Since you are not putting a covering on the thermal blanket, it doesn't hurt to touch the thermal blanket with your project as long as your don't tear the blanket while putting the project in. For efficiency, it would be better if there were some room between the blanket and your project (it is better to let the burner heat the entire chamber, and let heat radiate to the project from the thermal blanket). The same is true for the floor. Again, you can just lay a project on a thermal blanket floor, but it will take a little longer to heat through if there is not radiant heat coming from the floor (the most efficient heating occurs from heat radiating from the walls to the project. You could suspend the project above the floor (such as with a device holding the project from the outside of the forge). This is actually a common occurrence with some forge designs. A hard floor will absorb heat from the burner and sides of the forge and get hot enough to transfer heat from below with direct contact to your project (a blanket floor will do the same, but not as efficiently as a yellow-hot refractory or brick floor). As long as you do not use flux (for forge welding) in your forge, all this will work fine. If you do use flux of any kind, it will immediately destroy any thermal blanket it comes into contact with. It will melt the blanket where it touches it. This is one of the reasons those of us that do forge welding NEED a hard floor. The flux will damage the hard floor also (eventually it becomes a gunky mess), but at least it doesn't melt it. Most of the projects I do... do not involve forge welding and I will temporarily replace the floor (with a floor I have forged welded on) when I do forge weld. Thermal blanket, without the refractory covering I show in other videos, can be damaged (melted) by getting your forge too hot (remember, the blanket has a heat rating). In general, you don't need to get it too hot to damage the thermal blanket because forging temperatures are much lower than that. Note: Although not necessary to heat projects to forging temperatures, the refractory (and mortar) I use in the other lining videos (over thermal blanket) has a higher temperature rating than thermal blanket. It makes the forge more efficient because heat is radiated more efficiently from and off of it. Also, note that, for smaller forges, it is not necessary to do multiple layers. Adding mortar and additional layers of slurry (refractory) does make the interior of the forge stronger. If, in the future you decide to put a refractory coating on the thermal blanket, it is NOT a good idea to touch that coating with your projects... it can easily damage the coating) Thermal blanket can be damaged by your projects if you push the project into the blanket and tear it (break off small pieces of blanket). You only need to replace blanket that has been damaged enough to make it thin. As long as you are careful and don't overheat it, thermal blanket will last a LONG time. It will become visually evident when it needs to be replaced (thinned from burning it or damaging it with projects). I will caution you that there are people that worry about using thermal blanket without a coating because they say small fibers do burn off the blanket and exit with the exhaust (dragons breath), and might have long term consequences for you if you breathe them into your lungs. I have never found anything in print (or online) that a study was done that confirms danger to us... so I (personally) didn't worry about it for the many years I just lined with thermal blanket without putting on any refractory covering over it. Obviously, as shown in my video, the covering is not necessary to get projects to forging temperatures. I will also say that, with the refractory I put over thermal blanket now, will cause a forge to heat to forging temperatures (and bring up projects to forging temperatures) faster. Whether or not, it is worth your time and money for the difference is up to you.... One more thing, you can heat a longer length than the inside of your forge by constantly moving the project in and out (through the end of the burn chamber). If general, this is not necessary if you are forging... because most of us only work on a little area before the project looses too much heat for forging. Exceptions are when want to bend (or straighten) a long length.... or are heat-treating a project longer than your forge. It these cases, moving the project in and out of the forge is a good technique to have even heat.

[@rickramrick8423]

+David Hammer Thanks for the prompt reply and the great ideas... I just finished welding the unit up today and painted with header and manifold paint so I'm anxious to get it lined and fired up as soon as the paint cures... Forgot to mention I'm running propane with a JF 1 burner so it should get plenty hot for my needs... I'm a carpenter/welder by trade but didn't want to end up making doll houses once I retire so I thought I would give blacksmithing a shot and found out I love it... Your videos are precise and easy to follow, keep up the good work...

[@garethjones6623]

Hi, I'm in the process of making a forge and have obtained a quantity of bricketts from a night storage heater. I have applied heat to one and they seem to stay stable and not fracture etc. I wonder if you have used similar materials and your recommendations to their suitability. In addition I wonder why you have such a large clearance between the heater tube assy and the welded fixture tube which has the retaining bolts. Regards Gareth Jones, Isle of Wight, England.

[@HammerMan999]

Gareth Jones I have not used bricks taken from a commercial heater to line forges. If those bricks have been in the burn chamber of a heater, it is likely (although not guaranteed) that they will work fine. If I were using brick to line a forge, I would want the brick to be IFB (Insulating Fire Brick), which is very light, compared to hard brick. If you can cut the brick with a hand saw (carpenter or hack saw) as I do in my "Super C Floors and Doors" video, the brick is soft fire brick. If you cannot cut the brick, it is "hard" brick. Hard brick certainly can be used to line a forge, but I don't consider it suitable. With hard brick, It will take much longer to get hot enough in the burn chamber for forging (and it may never get hot enough, depending upon the capability of the burner(s) and the size of the burn chamber). Please note that soft fire bricks do get damaged by heat over time (especially if you run your forge hot enough to forge weld). I consider soft fire brick a consumable and expect to replace (or repair as shown in my videos) them when they break (cracked bricks can be used as long as they stay together). This is true of (literally) any type of burn chamber lining, except hard brick (which I generally consider unsuitable for lining forges because of the time (and burner requirements) it takes to heat the burn chamber) The tube I weld on the side (or top) of the cylinder to hold the burner needs to be large enough (inside diameter) to get the burner in AND out of it. If you run your forge hot for extended periods, such as for forge welding, or have the burner too far down the tube (it should be at least an inch above the ceiling of the burn chamber), the end of the burner will eventually be damaged from the heat. Usually, the burner end will flare from the heat (yes, even the flare itself) and the burner will be fatter on the end than when you first put it in. I use "what may seem like larger diameter pipe than necessary" so I can easily get the burner out when it gets damaged from the heat. In any case, it is important to "block" any space between the burner and the holding tube so heat cannot escape there. As shown in my videos, I use thermal blanket to do this. If you don't have thermal blanket, just use small cloth rags and pack them tight (they won't let heat escape either and will not burn unless air is escaping through or by them).

[@garethjones6623]

Thank you very much for the very comprehensive explanation and advice. Incidentally I have been using a open coal forge I made from a truck brake drum, I used to use coke but its generally unobtainable in the UK.Your designs of a Propane forge are ideal for my purposes (Gates, Railings and some art work) which with the proper ventilation I can use in my workshop (Garage) Thanks again, Regards Gareth

[@Bowtie41]

I have been wanting to do a small forge for awhile and trying to decide between a design like yours,or a square one as I have a lot of plate steel to weld a box.All things being equal,which is more efficient,the ceramic blanket,or fire brick?I can get brick pretty cheap at Menards,etc,but if the blanket is better,I'll go with it.Thank You.

[@HammerMan999]

You can make a Super C square forge if you want to. I have made them both ways. In fact, I just made a Super C using a piece of channel iron (C-channel) for the bottom and half a cylinder for the top. I did add a piece of heavy plate to one side of the half cylinder so I could bolt it onto the backside of the channel (removable top). Personally, I would recommend ceramic blanket for either a round or box forge. For a hobbiest, the ceramic blanket will be more efficient (it heats up and reflects heat more efficiently). The firebrick you can buy at box stores will be hard firebrick and should only be used for floors (they take too long to heat up for use as walls and ceilings of forges (not that they could not be used, only that they should not be used). Your floor should be put over thermal blanket (to keep the shell from getting too hot). The floor should be thin (thin hard firebrick is generally 1.25 inches thick, or less). You could use soft firebrick for lining the walls and ceilings if you want to (supporting the ceiling may be a challenge). As you see in my videos, I generally use soft firebrick for my doors and to close horizontal openings. Soft firebrick (commonly known as Insulating Firebrick or IFB) is usually NOT available in box stores. They can be bought online from ceramic supply stores, or from a distributor like the ones I reference in my "Super C Lining Supplies and Sources" KZbin video. Good luck with your project....

[@Bowtie41]

David Hammer David,Thanks for the rapid reply! I had been looking at www.walmart.com/ip/19590169?wmlspartner=wlpa&selectedSellerId=74&adid=22222222227015536721&wl0=&wl1=g&wl2=c&wl3=40872539912&wl4=&wl5=pla&wl6=78765314912&veh=sem Trying to figure out if it was soft brick or not.It definately looks different than www.walmart.com/ip/Rutland-604-FIRE-BRICK-Fireplace-Duty-4-5-inch-x-9-inch-x-1-25-inch-6-Bricks-Box/25486595 which appears to be a hard brick.I will start searching for the best price on blankets.Thank You!

[@HammerMan999]

Those are hard bricks. I would not use them to line a forge. They would be OK for the floor (and the doors, as shown in the simple forge lining video), but for me, they would take too long to heat up to be used for walls and the ceiling.

[@djhammerd]

It serves both purposes.

[@courtneyparrish6918]

Nice work. Could you tell me what size anvil that is and where you got it?

[@HammerMan999]

If I recall correctly (my son has that anvil now), it weighs about 300 pounds. It's a London pattern (Peter Wright, I think). I bought it at a BGCM blacksmith conference (tailgating) in Westminster, Maryland in 2005. I replaced it with a Northern German Refflinghaus anvil (dual horn, which weighs just under 700 pounds) several years ago. You can see the Refflinghaus in my newer KZbin videos. I love the dual horn.

[@djhammerd]

I don't have an estimate for any given project, but a grill propane tank will generally last about 8 hours if used with a small forge (like this one).... The more efficient your forge, the longer it will last.

[@ke6bnl]

Do you have to seal the insulation blanket to keep the fibers from going into the air. sorry wrote this before the end of the video

[@HammerMan999]

There are varying opinions about whether or not thermal blanket fibers are actually dangerous or not. There are a lot of commercial forges with just bare thermal blanket in the forges. I (and many others) used thermal blanket without any coating for many years. If you want to be as safe as possible, I would recommend coating thermal blanket with a refractory (watch my videos). There are numerous alternatives to what I use (ITC-100, Plistix-900 and others. Even just ridigidizing the thermal blanket would help. There are commercial products specifically for ridigizing themal blanket.

[@Tri_3D]

HOW FAR DO YOU INSERT YOUR BURNER? DOES IT SIT FLUSH WITH THE INSULATE?

[@HammerMan999]

The end of the burner should be about an inch above the burn chamber ceiling. If it is lower, it will burn and ruin the flare.

[@leeknivek]

how long does the kaowool last bare like that? i know it works, but you see some people online claiming blasphemy to doing it like this, so just curious.

[@HammerMan999]

It will last long time... Years, if you don't keep hooking it with your projects... I do strongly recommend covering it with refractory though..

[@leeknivek]

how do you feel about hardware store 2000 degree "furnace cement"? i have some that i plan to use as a rigidizer. i am building a small forge (6"od, 3-4" id) and likely will not do any welding. i have read that "it works", "better than nothing" etc. - i can always go with some more exotic coating later, but i think it will suffice for now. what do you think?

[@HammerMan999]

I don't know how that will work on thermal blanket. I would suggest, at least, that you brush a little of it on a small "test case" of thermal blanket outside the forge and see how it applies, dries and works as a rigidizer.

[@mattbehnke779]

I thought that insulating wool is bad to touch and breathe in, so why did you not cover the wool with anything? Is this not true?

[@HammerMan999]

Actually, this is a controversial topic. Although there are some folks that believe the risk is high, I believe the generally accepted information is that it is safe to handle if you wear simple protective gear when you handle it (face mask, gloves, etc). I have found no studies that show insulating wool has resulted in sickness of any kind beyond irritation (assuming no pre-conditions). There are numerous commercial forges available that use it without a covering. I built my own forges and used it without covering for many years.... This video is meant to show that a forge can be simply lined without a lot of fuss.... and it will actually work very well. I always recommend the viewer read the MSDS for the products they use. All serious considerations are covered there. Having said all that, I generally do recommend using a high-heat refractory over thermal blanket. It makes the forge more efficient. If I didn't, I should have mentioned it in this video. When I make a new forge, or re-line an old one now, I always put a refractory covering on the thermal blanket I use. If you look on KZbin for a series of videos about a Super C forge, you will learn what chemicals I use, how to mix and apply them, and where I buy them.

[@mattbehnke779]

+David Hammer thanks!

[@HammerMan999]

Your welcome.... If you make a small forge, it is not necessary to use multiple layers (slurry-mortar-slurry). One layer of slurry is enough. Multiple is better (for strength), but not necessary for efficiency. Good luck with your projects.

[@yoncofi]

but the staples will melt...?

[@feelgood2454]

I would definitely add gloves to this project. I rather not burn my hands.