advice needed for oil-burner foundry refractory

[Saving Private Brian]

I've hit a dilemma considering the volume of commercial castables available online. I'm attempting to construct an oil-burning foundry. I have an abundance of waste oil to use. I am to produce a foundry *capable* of cast iron, not that I will even attempt to try such things until then. I will mostly use it for copper, but since I'm making it now, I'd like for it to be able to deal with up to 1600C in the future. I hope for this to last a long time. I also hope to operate on limited budget (nothing over 100). I will be using a 20-gal steel drum I picked up.

Fireclay or castable? I'm aware fireclay shrinks, so I'm edging towards castable. But then there's the problem of dense or insulating? I think a 1-inch dense hotface (increased durability and resistance to fluxes), and the rest insulating, but I'm unsure whether these two mixes will stick together and not separate after firing, etc. Would the dense hotface reduce the possible 1600C to enough to make it safe to use a 1200C - rated backing-layer?

I could use perlite or ceramic fibre to provide additional insulation. I'm more on the side of perlite, mainly since it's so available, but also because it won't harm the structure of the refractory.

Does anyone have any experience with any of these products, and can shine some light on which I should aim my focus on, especially considering my design does not need to be economical (my fuel is free after all) but does need to be strong to last a long time under the fluxes from the oil? Is dense refractory really necessary, or is the insulation I have planned out overkill?

Thanks for your help.

Brian.

[Steve Sells]

FYI a foundry is a disposable item

they do not last long, they require constant relining and rebuilding

[Frosty]

Aren't we having this conversation in another thread?

Blue flame waste oil burners have been a target heat source for a long time and I've never seen one I'd want around. The very thing that makes us change lubricating oils makes it a serious health hazard to burn in any kind of furnace let alone a home built one.  They are full of wear particulates from bearings and wear surfaces, you really don't want to breath: babbit, bronze, brass, iron, lock tight, antifreeze seepage, etc. do you?

If you must by all means buy commercial refractories I like water setting castables but don't burn oil at all. As Steve just brought up melters are disposables, wear items and burning waste oil WILL eat them quickly.

There are other better alternatives to waste oil but no matter what you'll be relining your melter every few to half dozen melts IF you use a high end refractory.

Frosty The Lucky.

[pnut]

As you said before frosty, " Nothing like waste oil to produce a mystery atmosphere."

Pnut

[Frosty]

3 hours ago, pnut said:

a mystery atmosphere.

Reminds me of an old Los Angeleno saying, "I don't trust air I can't see."

I don't know what we'll do, our air is almost always invisible!

Frosty The Lucky.

[Saving Private Brian]

Oil is a better fuel than any of you make out. It has a higher energy density to propane and a similar burn temperature, and not all oils diffuse carcinogens upon combustion as everyone seems to make out. What about vegetable oil? We COOK with it. It's hardly harmful; to the refractory or to me; and a good oil burner will be relatively smokeless (the oils should, under high enough temperature, completely decompose under the heat -- pyrolysis for you there). Oil's greatest trait however remains to be its abundance. It is free. This means I can make my foundry the cheapest, most inefficient pile of junk possible, and it will still be economical. I will save far more money than any of you who are using propane, and I am capable of melting larger volumes of the same metals as you. You complain about the toxicity of certain oils I plan not to use, but I am also safer than propane-users in other aspects; such as how I share no risk of exploding if I'm careless with the tank, etc. In fact, advising newbies to use propane is probably as dangerous as it gets. And the final alternative - charcoal/coke - emits even more dust. Lastly, burning waste oil is far less damaging to the environment. Sure, in your immediate area it might smell a little, but at least I'm not using coal or gas, which, btw, will only continue to increase in price until one day they become redundant. Oil burners are also brilliant because they can burn pretty much anything that comes as a fluid, given you have a decent air compressor, although I wouldn't advise this.

You're not changing my mind. Oil is a far superior fuel. Your complaints about harmful smoke are simply from burning specifically nasty oils in an incorrect fashion.

Brian.

[Buzzkill]

You are correct about quite a few things in there, but you may not have taken everything into account yet.  Under the right conditions you can indeed have an explosion from used oil, so that part is not risk free.  Oil tends to be messy to deal with and soak into any porous material which of course increases fire risk.

I built a used oil forge and used it for a short time before even using coal, mainly because of a source of free oil.  In the long run I didn't like the mess and the constant tinkering with my setup to keep a certain temperature.  If you filter your oil, heat it to a consistent temperature for use, and have a feed system that is unaffected by the depth of the liquid in your supply source you may find it worthwhile. If you do not account for varying viscosity from temperature and different oil sources and changing hydraulic pressure due to the depth of the oil in your feed tank you may find that it loses some of its charm.

I wanted a cleaner option which did not tie me to a power source or an air compressor, so I switched to propane several years ago. Despite having a free source of used oil I do not regret the decision when I've taken everything into account. Your experience may be different.  If you get something running that works well for you by all means share your experience, good or bad, with us.  We love pictures and success stories.  Be safe.

[Frosty]

Had you specified waste cooking oil, toxic wear particles wouldn't have been brought up. 

Waste motor and lubricating oils poses fewer problems than cooking oils for the burners. They are a consistent viscosity and known filtering issues. Preheat and metering is easily monitored and adjusted automatically. Unfortunately. . . 

Ah, deleted the story of how expensive the waste oil heating system turned out to be for the equipment shop at work. Just maintaining it cost more than the old fuel bills plus disposing of the waste oil.

You have it all reasoned out why your plan is superior and won't be dissuaded. Why then did you bring it to our attention? Certainly not to work out questions or potential problems. Right?

Frosty The Lucky.

[Saving Private Brian]

My question was not on the use of oil as a fuel, only on advice for commercial refractories. I chose to defend my use of oil after it became the subject of discussion, not bring it to your attention in the first place. Propane is simply not feasible for some of us -- it costs too much in my area and many other areas around the world to make it ever hopeful of being economical.

A well-engineered oil burner could last a while, and not cost in maintenance the same as both purchase of propane and disposal of waste oil combined. Oil seems to be an area of intense pessimism on this site. Have you all had bad experiences with it or something?

[Frosty]

3 hours ago, Saving Private Brian said:

Have you all had bad experiences with it or something?

I've never heard of anyone I'd believe having a good experience with a waste oil burner. I've heard claims but no verification.

I took in the testimony of folk who have experience trying coupled with the claims from people I wouldn't believe if their tongues came notarized. I shelved my plans for an oil fired forge burner. 

Frosty The Lucky.

[SLAG]

Frosty,

I never ever notarized a tongue, in my career,  as a notary public.

Affixing my notarial seal to a tongue might have proved fairly painful.

Regards,

SLAG.

[Irondragon Forge ClayWorks]

17 hours ago, Saving Private Brian said:

Have you all had bad experiences with it or something?

The only experience I have had with oil fired burners was with a unit the city used to cremate dead animals. The EPA shut it down due to air pollution.

[Frosty]

14 hours ago, SLAG said:

Affixing my notarial seal to a tongue might have proved fairly painful.

You shouldn't have felt a thing if you did it right.

Frosty The Lucky.

[SLAG]

Frosty  san,

Where were you when I first started practicing law and notaria-tioning?

It might have saved some of my clients,  (victims?),  a lot of pain.

I suspect that my charm and wit distracted them.

Regards,

SLAG.

[Frosty]

Uh, I didn't think lawyers tried to ease anybody's pain. You bill by the hour, not case.

I don't recon using the notary seal embossing thingy would hurt a lot more than tatooing the ID # in livestock's ear or branding. 

If your client complains take out the electric branding iron and letter, number index. The index of letters and numbers has duplicates of each to account for multiples in a registration number/tatoo.  setting the branding iron was fast and easy compared to the tatoo gun, that one is just a bunch of needles and little sockets to hold them.

Frosty The Lucky.