Oil forge ideas

[eco redneck]

Hello everyone 

I have been throwing around the idea of a used oil forge or a diesel forge design. Now I know there are many threads on the idea but hear me out. I'm totally new to the idea of liquid fuel forges and hAve no idea where to start. I have all the tools and such needed to build one but I just need some starter or a how to oil forge for dummies ideas or pages to look at. Simple plans would be nice 

Thanks 

[Buzzkill]

Here's my 2 cents:  It can be done.  Whether or not it is worth it to you I can't say.  I built a home made siphon nozzle system which used compressed air to pull and mist the used oil and a blower from the power vent of a hot water heater for the forced air. The benefit of that is it only pulls fuel while the compressed air is flowing, so you're less likely to end up with a big puddle of oil like you might with a gravity fed system.  It was a bit difficult to start sometimes, so I usually fired it up on kerosene or diesel and switched to the used oil once it got hot.

Here's the down side:  Used oil (motor or veggie) changes viscosity significantly with temperature.  In order to maintain a certain temperature over time you have to have the same fuel and air ratio.  This can be done as simply as a drip system and a blower with an air adjustment or some kind of pump to deliver a constant stream of oil under pressure.  For my siphon nozzle system the change in hydraulic pressure from full to nearly empty in the container I was pulling from was enough to require frequent adjustments to the fuel/air ratio. It was different from day to day as well since the ambient temperature affected the thickness of the oil and the ability of the siphon nozzle to pull in the oil. I probably went too complicated, but in the end I figured I was spending more time fiddling with the controls than banging on hot metal so I converted it to propane and haven't regretted the decision.

I'm sure there are others who had a more positive experience with a used oil forge and maybe one of them will chime in.

[Charlotte]

Never tried to build one my self, However I visited a foundry in Tennessee that was casting iron manhole covers and similar parts that used home heating fuel oil. 

[Frosty]

Do you have any idea what the #1 most dangerously explosive hydrocarbon fuel in common use is? No, not LPG, not gasoline, not jet fuel, not any of those you're thinking of. It's fuel oil as in Diesel, kerosene, stove oil. It has a saturation level in air that is smack in the CENTER of it's flammable air fuel ratio.

This means it WILL evaporate until the air can't absorb any more, saturate, then it just stops. This is middle of it's EXPLOSIVE ratio. Weld on a full diesel tank with a shot glass volume bubble where the bead will cross and it'll split the seams out of a 220 lg. fuel tank. This example was on the back of a sander belly blade at work about 25+ years ago and seeing as our trucks were heavy service the tank was 12 ga. welded steel with flutes to resist the rough service. The explosion blew one end about 90% out of it with one seam opened full length across the top.

I do NOT recommend anyone who isn't a combustion engineer operating in a commercial situation to try tinkering a fuel oil burner together. Some guys have had reasonable success using residential boiler burners and as far as I know nobody's spread their shop around the neighborhood. so far.

Trying to use waste oil is a kettle of worms with filtering, drying, preheating, metering an inconsistent BTU dense fuel, etc.

Any of these CAN be done but a Warning is all I have to add on the subject.

Frosty The Lucky.

[Buzzkill]

True enough Frosty, but the main difference is it has a very low vapor pressure.  It's not going to evaporate much unless significant heat is applied without a direct flame. If there is a direct flame it will burn as the vapor is created as long as the oxygen exists to support combustion.  The point of a fuel oil boiler, forge, furnace, etc. is to burn the fuel as it enters.  I guess if you had it up to temp and for some reason the forced air stopped but the fuel kept going in you could create the scenario you warn about, but that would pretty much require someone to leave the setup unattended (or be inattentive).  Technically it's not a true explosion either; it's a rapid burn, but that's of little consolation if it happens.  The same statement can be made about fine particles of anything flammable in the air as well.  There is a ratio of air and fuel for most things that will burn that only needs an ignition source to create a rapid burn and effectively explode if there is any containment such as building.  One of the local coal-fired power generating plants has had at least 3 coal dust explosions that I can remember over the past few decades.

Not that I suggest anyone ever try this, but I have put cigarettes out in a small container of diesel fuel just to make a point to someone.  As you point out it's the vapor/air mix that's really dangerous, but in general the scenario to create the problem you describe is fairly rare.  If it wasn't then there would be a nasty *whooomp* every time a torpedo heater kicked on and it would probably blow apart.

I guess while I agree there is some danger there and it should be taken into account, when we're talking about a practice involving pressurized flammable gases and/or hitting heavy pieces of incandescent steel with hammers I'm not sure this danger rises significantly above the others.

 

[Frosty]

You should ask someone who works at a loading dock. Fuel oil's vapor temp is around -40f though if it's #2 maybe a bit warmer. You are making assumptions that have killed many. It's considered THE most dangerous to transfer hydrocarbon around.

You don't have to take my word for it or anything but this is serious, ask someone who handles the stuff.

About putting butts out in diesel fuel. Two things make it a BS demo. 1, most butts burn below the ignition temp of of hydrocarbon fumes so long as you don't get one of those little spit sparks. #2. . . SATURATION point, fuel oils will evaporate till it reaches saturation. A pan of oil in open air can NOT reach a flammable fuel air ratio. You can snuff lit matches in liquid fuel oil in open air.

You really need to get your facts straight before someone tries to perform your demonstration in a closed room with a lit match.

Frosty The Lucky.

[Buzzkill]

I'm not looking to pick a fight Frosty.  I work with diesel fuel every day.  It's not an assumption it's fact.

Vapor pressure and vapor temp are not the same thing.  Diesel simply doesn't evaporate quickly enough to saturate the air at normal temperatures in anything other than a small enclosed place with no air movement.

[Frosty]

Saturation implies an enclosed space. If you can smell it it's evaporating and you can smell diesel at -50f.

As you say I'm not interested in arguing. I'll go by what I learned at the safety classes I had to take to even enter the gate at the Chevron tank farm at the docks.

I'll not take up any more of your time.

Frosty The Lucky.

[Buzzkill]

All of this discussion should be in the context of the original post.  He's clearly NOT going to have a storage tank with thousands of gallons capacity.  I agreed that there is danger and continue to do so.  I questioned, and still do, whether in the context of a small forge the danger is any greater from diesel fuel than it is from propane or the fact that glowing steel is repeatedly struck with a hammer.

A diesel or kerosene burning forge functions nearly the same as a torpedo heater with the notable exception that we try to keep the heat in rather than blow the heat out.  Those devices have the fuel tank mere inches from the business end that is glowing orange and has open flames behind it when running and they typically hold about 10 gallons of fuel.  I've never heard of one exploding that was properly functioning and using the designated fuel.

I tried to think of a scenario (again in the context of a small forge and consumer quantities of fuel in storage) where your expressed concern is likely to occur.  The only thing I could come up with is a hot forge with fuel going in and the air shutting off.  That could create the situation as the oxygen in the forge would quickly be consumed, but the temps would still be high enough for some time to quickly vaporize the fuel after the flame was out.  Other than that it's a highly unlikely concern. Perhaps I did mistakenly make the assumption that the OP would know enough to operate the forge outside or in a well ventilated building and to store the fuel in closed containers.

Is there danger in burning a fuel oil in a home forge?  You bet there is.  Is it significantly more dangerous than LPG used for the same purpose? Not in my mind, but each to his own.

[Mikey98118]

Well, gasoline and kerosene blow torches are still made (with steel heads nowadays), and the new ones, are just as safe as ever; on the other hand they are quite dangerous if mishandled, just as they always were. The main difference between a casting furnace and most forges is position. Casting furnaces are all vertically positioned; most forges are horizontal. People can look up successful motor oil casting furnaces on Backyard metal casting; none I've seen there must be left in the vertical position. HOWEVER,  none of these furnaces burn clean, and none of them are used indoors. There is nothing cheap about burning kerosene or diesel fuel. The push behind homemade oil burning systems is so-called "free" oil, despite all its complications--including all the additives in used motor oil.

[Buzzkill]

Mikey,

What do you mean by "burn clean?"  The waste oil forge I built didn't produce visible smoke at all once it was hot and not much even when it was first fired.  Of course there are always exhaust gases released whenever any fuel is burned and I always ran mine outdoors.   For me the biggest drawback was keeping a constant flow of oil with changes in temperature and even the depth of oil in the feed container.

[jlpservicesinc]

Buzzkill, Any luck? 

I"ve watched old video footage of many a forge being oil fired even back into the 1920's  The most recent was of an axe company in Maine that ran into the 60's.. They used oil fired forges..  

There has been more technology that has gone to the way side as modern innovation has taken hold.. Funny we still use coal forges, wood forges, gas forges right.. 

When will a solar forge be developed??? 

Anyhow, I'd love to see how they used to do it..   I still have a gasoline blow torch which I used to use all the time.. It's only since i moved into the new house that I stopped using it simply because the leather finally wore out  on the pump.. 

I think anything can be safe (lots of things were used for 100years safely) as long as you understand the procedures and/or the assumption of risk is taken into account..  

 

From what I understand, the oil can be be fed via gravity though it is ran through a heat exchanger of sorts before it reaches the fire..  But again I lack 98% of the information to be helpful..  

[AKHunter]

I built one. It runs on any liquid fuel that's equal or less volatile than gasoline. It burns plenty hot, but the varying viscosity of fuels are a pain to deal with. I have to "cut" the fuel with diesel or gasoline to thin it enough to meter through the valve. Filtering is also a nuisance to deal with, especially when using bacon grease (but it burns better than anything else).

If you have reasonable access to propane or coal, use it instead! Much safer and simpler. If propane is ridiculously priced ($10.00 per gallon here!!) and coal not available, it's a viable heat source, but give it a LOT of respect. 

I got most of my burner info from backyardmetalcasting and alloyavenue. I built the forge based on this Bladeforums sticky thread. Everything about a propane forge applies to a waste fuel forge except the burner assembly. When calculating burner size, double (or more) the airflow you think you need and add some more. Liquid fuel, especially waste oil requires a lot of air to burn clean. You can always choke off airflow (remember to install a "valve" or choke of some sort to control forge atmosphere), but it's kinda hard to shove more in after you build the burner. Oh, and another thing, use a real needle valve for fuel control- don't cheap out and use an old gate valve- they don't work well. Don't bother with a pre-heater for the oil. They are the most dangerous part of the system, and usually are quite temperamental- vapor lock is a pain!

No, I don't have plans for it. You'll have to reverse engineer it, but if you know enough to build and run it safely, that should be no problem. 

If you have any questions, feel free to ask.

 

[Lou L]

Torbjorn Ahman recently built one in a video on YouTube recently.  Personally, I don't think the benefits would outweigh the risks for me unless I had I constant, cheap supply of the necessary fuel that I just couldn't pass up.

[Buzzkill]

On 10/3/2016 at 8:28 AM, jlpservicesinc said:

Buzzkill, Any luck? 

Sorry I missed that question.  I was successful to some extent.  It was the first forge I built.  I was able to heat and beat out a few things, but it felt like I had to tinker with the air and fuel settings a lot.  Ambient temperature affects the viscosity of the oil.  Unless you compensate for it, even the level of the oil in the fuel supply container will affect the fuel to air ratio as the level drops.  Oil should be filtered before use to keep it from plugging up the atomizing system, it can be a bit messy, and the hot face material needs to be able to withstand significant direct flame impingement.   I don't think there's any good way to run one naturally aspirated, so a separate blower is required.  In the end for me propane is a better option even though I have access to a fair amount of free used motor oil.  Having said all that, it is possible to attain very high heat, and I think with the right equipment they could work well.  I built everything from what I had on hand and a few parts from a local big box store.  Repurposing the burner assembly from a commercial waste oil furnace or boiler is probably a much better way to go if someone is serious about forging with used oil.  At this point I only have the slightest tinge of regret when I go to buy more propane.  Other than that I feel that propane is hands down the better option.

[jlpservicesinc]

5 hours ago, Lou L said:

Torbjorn Ahman recently built one in a video on YouTube recently.  Personally, I don't think the benefits would outweigh the risks for me unless I had I constant, cheap supply of the necessary fuel that I just couldn't pass up.

We generate about 300gallons of waste oil a year..   I believe the old oil forges use a #2 fuel oil.. Wish I could have talked with one of the guys in the know.  The old forges would reach welding temperature pretty easily..  Better than propane or LP..

Once I get the shop up I'll investigate further... I have a lack of time to devote to a project like this now..

 

[Wes Henderson]

On ‎10‎/‎3‎/‎2016 at 3:28 AM, jlpservicesinc said:

When will a solar forge be developed??? 

They have been since 1949 I believe. The Mont-Louis solar furnace, in France, was the first of it's kind. There are several others since then. Solar energy application isn't as widely applied because of the acceptance that there needs to be further development in certain fundamentals for it to become reasonably affordable, even for commercial application. More recent development in concentrating photovoltaics by the use of parabolic reflection or multi-panel concentration to a micro solar chips that can collect energy from hundreds of square feet of reflected sunlight have helped substantially. That limits the cost to mirrors instead of individual collector panels. It does increase the dangers associated with it however, thus limiting it in some applications. Researchers at MIT have also developed solar panels as "light as a soap bubble" as described further here DailyMail MIT Solar Cell. I'm sure that further development on some of the building blocks will make the reality and practicality of solar forges more applicable.