Has anyone tried using untreated wood mulch/ wood chips for fuel. If the right size they pile up in a mound pretty well, but I would like to ask around  to see if anyone else has tried it first before I do it myself.. 

Just like you are really using coke as a fuel when you use coal in the forge; you are really using charcoal in the forge when you burn wood.

One issue with charcoal is the increase in sparks over coal; this is GREATLY increased using wood chips.  Also there is an effective size for charcoal; wood chips pass through it faster than wood chunks.

If it is what you have; use it but it won't work as effectively as chunk charcoal.  I recently linked a video of a japanese swordsmith using a charcoal forge to the improvised anvils thread---take a look at whet size fuel he is using.

So if i have access to both wood chunks(rough size 3-4 long and 1-2 inch in diameter) and wood chips, would the wood chunks perform better? 

Yes and work better if you make the charcoal elsewhere and use the charcoal in your forge---less smoke in your face and less heat on you too and less sparks.

Thanks for the advice.

Apologies for reviving an old thread, but has anyone tried converting mulch or the contents from a wood chipper into usable charcoal in a retort of some sort?  Since I don't necessarily have the room to set up a 55 gal drum retort and I may be able to score some free wood chips (maybe)  I was thinking that it might produce workable fuel for the forge without all the smoke and sparks I would get from just the wood chips.  Or would I just end up with a pile of unusable charcoal that is too small to work?

I think you would get a lot of forge fleas and charcoal dust going that route. When I started blacksmithing back in 1981 I made my charcoal in two stainless steel kitchen sinks, one overturned on top of the other.  I used the direct process and when I was dialed in would get about 50% yield. (Direct process is when you build a fire with the wood to be processed and close it up and let the residual heat complete the charring; indirect process uses a retort heated from outside.)

Of course historically smiths have used everything from buffalo dung to peat to charcoal to coal and then the gasses as well.

Keep in mind that the chips are usually fresh green wood.   You can use the wood chips directly as a forge fuel.  It takes some getting used to as a fuel.  Be aware that they sometimes chip poison ivy, poison oak, and sumac which contain an oil called urushiol (yur-oo-shee-aal).  Because most people are allergic to this oil, just about everyone who comes into contact with it develops a rash.  If burned the oil becomes airborne and can spread to a wide area.

To touch on the poison ivy thing.

In colder climates the oils will become more concentrated in the cold weather. (I learned this the hard way pulling out vines in Dec.) So if the chips are made in the cold there will be more oil. Also when the oil becomes airborne there is a danger of inhaling it. When inhaled it will cause irritation to the respiratory tract that is extremely painful and usually requires a hospital visit,   and in some cases can be fatal. Same with eating it. Urushiol oil can remain potent on surfaces for up to 5 years. 

 

Cold does not enhance the concentration of urushiol. It is found in poison ivy’s roots and stems throughout the year. In spring, as the sap rises into the stems and the plant leafs out, poison ivy has the most places from which the oil can spread to you. The best time to actually dig it out is fall/winter, when the leaves are less oily or gone....but all the usual precautions are still needed. And of course, the oil can transfer from tools, clothing, etc to your skin.

If your chips are from a suburban tree service you’re likely to be ok, but ask them anyway. Most lawn and street trees they deal with are not likely to be poison ivy infested. I had a willow near me that had poison ivy vines in it for years...going up over 30’ and about 1.5” thick. Tree service would’ve been crazy to touch that one!