Jump to content
I Forge Iron

Sweet Spot


Recommended Posts

I have a rivet forge that I made from everybody's favorite, a deep brake rotor. I've been using it for nearly a year now with coal I have been getting from Amazon. I'm tired of paying $30 for a 30 pound box of coal. The nearest place that sells it is a 4 hour round trip. I work 55 hours a week and have a beautiful wife and 6 wonderful children which makes it hard to take a road trip for some coal. Now, long story short, I'm going to start buying bags of lump charcoal to forge with. It's relatively inexpensive here, much more so than what I have been paying for coal. I know coal has a reducing layer, a sweet spot, so to speak, that produces less fire scale for doing forge welds. Having used coal for so long, I have gotten fairly decent at finding that sweet spot in a coal fire and have done some decent welds, such as attaching two separate pieces with a scarf weld and faggot welding bar stock to make basket twists and such. My question is two-fold: Does the sweet spot depth change much with charcoal? If so, I will have to make the appropriate changes to my forge, and 2: Does charcoal produce more or less scale in general? 

Link to comment
Share on other sites

Charcoal uses much less air than coal and you should have a deeper fire. When I go to charcoal in a coal forge I usually stack firebrick along side the firepot to make it deeper but keep the width as small as possible---I want more of a  |__|  fire not a \________/ fire.  If you have access to scrap wood you can make your own charcoal or even build a wood fire and use a shovel to transfer hot coals to the forge.  Note highschool Bonfires can be a good supply of charcoal the next day!

Sorry but there is *NO* IN GENERAL to that question.  It will produce more, less or the same depending on your forge, air flow how you position and work the piece.  Charcoal is better used with a hand crank blower or bellows as an electric blower usually burns up way too much charcoal---and steel!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...