Waste Oil vs. Propane?

[kraythe]

I am new here so please excuse any newbieness.

I was wondering what your guys perspective is on waste oil vs propane forges. I was interested in terms of burner construction, fuel cost, heat capability (need to be able to weld), residues or contamination of metla and safety (shop is in the garage). Also do you know any good sites with info on waste oil burners? I have found a few for propane but not much on waste oil.

[ianinsa]

Hi There,
The secret here is to find a burner design that gets started on propane(to get it up to heat) and then you switch to oil.This will then be 'smoke free'.
There have been numerous posts in the past on this so i'm sure someone will be able to give you a design.
Ian

[OddDuck]

Just scroll down a bit in this section, there are two posts on this. Here is the longer of the two:
Pros and cons: Oil, pro, it can put out more heat than you could imagine. Blinding-white-inside-the-forge level heat. Prodigious amounts. Very possibly more than strictly neccessary. With my foundry setup I melt cast iron fairly easily and I'm not even really pushing the upper limits of my burner. Cons: If you don't get it running right, you have a mess and a smoke generator that your neighbors won't soon forget. I also have concerns about contamination of the metal with oil with the injector-style burners. You need a fairly good blower. You also need some way to pre-heat the forge (propane is the preferred method) before you turn on the oil. The setup can also be a bit bulky, and may not scale down easily.
Propane: pro, easier and cleaner setup. It may be easier to control furnace atmosphere. Limited contamination of the metal. Multiple simple designs easily obtained. Cons: Potentially explosive gas if you set it up incorrectly. Cost of plumbing, regulators, and fuel. Waste oil is more often than not free. May be difficult to tune the burner. Possibly limited heat output depending on burner and forge design.
Now, you can kinda get the best of both worlds if you set up your oil pre-heat with propane, in effect you have a blown propane burner at that point and you can run it that way if needed. All that being said, please note what I use for my foundry setup, if you get it running right, and get over the steeper learning curve, nothing beats oil with heat output except induction.
I trust that I have now thoroughly confused you, and made your decision that much more difficult. If you have a ready supply of free oil, go for it. If you don't like dealing with mess, go propane. 6 of one, Half dozen of the other.

[ThomasPowers]

Look at your waste oil supply: what's in it and do you want to be breathing it?

[MattBower]

Oil can work really well, and OddDuck is absolutely right that it'll produce massive amounts of heat. (The first time I fired up my big oil forge, it got so hot that I actually had to stand about six feet away, and only approach it long enough to grab the work and retreat to the anvil. I no longer own that forge. It was just way too much.) But every oil burner (unless it's a commercial furnace burner) is basically a quasi-experimental one-off. Everyone who makes oil burners seems to end up spending a lot of time screwing around with the burner. I know I did. Propane is cleaner, and really very straightforward. There's very little learning curve with propane, particularly if you go with a blown burner. You can certainly weld with propane, particularly in a blown burner. Obviously probpane is more expensive than waste oil.

It is possible to make oil burners that require no preheat. Doing it on a homemade level is tricky. Many have tried; few have achieved reliably good results.

Edit: Thomas has a point about contamination, although waste vegetable oil shouldn't be much, if any, worse than propane on that front.