hammerandtongs Posted May 23, 2008 Share Posted May 23, 2008 Hi Guys and Gals,Side draft or updraft which one should I use. I have a question to ask regarding the merits/ disadvantages of side draft and updraft air supplies to my coal nut forge. I am a hobbyist knife maker and have for a while been using the side draft into the fire pit and have behind the pit placed an arch of fire bricks to refect the heat.Hope you can imagine this. Ive been reasonably happy with this arrangement untill the last time I was forging at a friends house. My friend has more forging experience than me and does some really neat damascus work ( although in the main he uses a gas forge for this). On the day at my friends house we did some forging of damascus billet using an updraft in to a coke nut fire. I must say I learnt one xxxx of a lot that day about fire pit management. Mainly because to get enough heat into the billet you are working with the billet well burried and cannot see it, and have to have good management of the fire pit. The only problem that we had was that because we where heating up the billet repeatedly for the bash and folding , the grate in the bottom under the fire pit kept getting blocked up with slag.:mad: Im in the process of fitting an updraft grate to my forge but im wondering am i going to spend most of my time unblocking the grate when forging high carbon steels and also having a go at Damascus. Should I just stick to my side draft air blower arrangement. ? What are your experiences with each can I still get as good fire rit control with the side draft, or does the updraft give me more localised heat which I would seem to need for Damascus work. p.s. I have not got a gas forge so im willing to persivere with the coal forge for Damascus. Any advice greatfully recieved. Many thanks Hammerandtongs:) Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted May 24, 2008 Share Posted May 24, 2008 Slag (clinker) formation is a function of blast, fuel and type of work. Forge welding generates more clinker than just working in the fire. Therefore, we have three variables but only one is subject to much variation for you and that is fuel - because a reasonable blast is necessary for welding and you are making Damascus. Sounds like you are using coal and your friend is using coke but the two fuels have different management techniques and heat characteristics, so you might want to try some coke with your side blast (this assumes you have an electric blower - it won't work well with a hand blower). Clinker also tends to flow downward with gravity and clog bottom blast pots to a degree, which is why the movable clinker breaker came along. You can make a deep fire with a side blast by piling the fuel up high and burying the billet into the mound so based on what you've said, I think you'll be happier sticking with what you know...but that's just me two ha'pence, eh? Quote Link to comment Share on other sites More sharing options...
jonathan king Posted May 24, 2008 Share Posted May 24, 2008 hi hammer and tongs im also in bedfordshire england im not a blade smith but i use anthrosite in my forge i get some clinkering over the grate but it stays fairly clean try some smithy breeze or good charcoal thats another option. Quote Link to comment Share on other sites More sharing options...
hammerandtongs Posted May 24, 2008 Author Share Posted May 24, 2008 Thanks for the reply/s Please could some one explain to me what a clinker breaker is, excuse my ignorance. Im assuming its some sort of auto mechanism? I am actually using Smithies breeze coke not coal, sorry if I was a bit unclear on this. I have taken on board the comments about the xtra slag produced by Damascus billiting. I will probably nee to carry on with the side draft at least that way all I need to do at the end of the day is cool off the fire and dig out the slag. However id be really interested to find out about these kinker breakers should any one have some pictures, maybe its something I could make/ tHANKS FOR YOUR REPLIES AND INTEREST rEGARDS hAMMERAND TONGS.:)s Quote Link to comment Share on other sites More sharing options...
dablacksmith Posted May 24, 2008 Share Posted May 24, 2008 clinker breaker is a type of grate that can be manipulated by the smith to break up clinkers and cause them to fall down the grate and out of the fire .. it is usually a ball shape with 3 sides sliced off it and a shaft thru the middle that can be moved to break up clinkers they are not a end all as far as clinkers ... they will let you sometimes finish a weld before tearing apart the fire to get the clinkers out tho.. they are a feature in most comercial firepots ... I tried side draft in my portable forge and went back to bottom draft ... sode draft seemed to take a lot more fiddleing with the fire to keep it working properly.. it worked just a lot more work .. good luck! Quote Link to comment Share on other sites More sharing options...
dragonflySmithy Posted May 25, 2008 Share Posted May 25, 2008 I just dig them out when they become a problem. I have a long piece of 1/4 tapered to a long point that I use to dig in the fire. The poker also comes in handy to tell when the billet is ready to weld. If the point will stick to the billet then it is ready. Quote Link to comment Share on other sites More sharing options...
Blacksmith Jim Posted May 28, 2008 Share Posted May 28, 2008 I like side blasts better for a lot of reasons. One of the reasons is that in my experience they handle clinker better. Quote Link to comment Share on other sites More sharing options...
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