What tube for a small forge tuyere?

[tombear]

Well, the middle son, sick of my procrastination and general lame @#%&ness, has literally broken open his piggy bank, got his mother to order a Cold Steel viking throwing axe, and offered to buy a tuyere for the forge we have been threatening to make from a small cast iron barbecue thing for , er, several years now.

We haven't found a commercial one on the net so will have to make our own. So, what sort of diameter, wall thickness and type of steel do we need to get and where do you order such ? ( the local scrap yard was no help unless we wanted to by large amounts of anything ) . The pipe needs be a foot long across the bottom of the bowl. How big and how widely spaced do the holes we will drill in it need to be?

Will we need to line the bowl with fire clay or what ever it's called and if so where do you get it from? We will, be using charcoal for fuel and a hairdryer to blow at first. This forge will be for small stuff like knives , strike-a-lights, cloak pins. I think the biggest thing we have talked about is a small spear head.

We've found loads about break drum forges but not a lot that's been useful about the sort we are trying to build. We are in the UK.

Thanks !

Tom

 

[Macaroon]

This might give you an idea of how to go about it; and it's made by a man who doesn't want to spend money!

[video=youtube;KZmr74P8CYc]https://www.youtube.com/watch?v=KZmr74P8CYc[/video]

 

[Tomteifi]

Hi mate

You don't really need to over engineer these things for knife making. If you can, put a pic. on here of the actual Barbie you're going to use. It will give an idea of the minimum you need to do to get it working-it wont be much I can assure you. I await and will help you. For instance; You say its cast iron(which wont take a reasonable weld) but no matter, nuts, bolts washers and drill will take care of that.

Tom.

 

[tombear]

Cheers folks!

ill dig the thing out and take a more useful pic of it after we've eaten but it's bottom left in this pic of the bits I thought may be usable at a small forge, not shown is the 1 cwt anvil, the forged iron base with a steel plate welded on sort.

The pics out of date, I've acquired other stuff since, a hearth rake, different pincers and hammers. Need to get some suitable boots, have got leather aprons and heavy duty gloves, various forms of eye protection. Definitely want to source a leg vice . Need to source some suitable pieces of tree trunk to set in the ground out back ( will do it at the far end of the garden, well away from the neighbours ) to raise the anvil to the right height, ditto the forge and vice ( when I've got one ).

I've got decent drilling gear and a obscene number of good files ( the below par ones I've been stockpiling to use as bar stock ) to make a hole for the tube. I was was wondering if there was any putty that could take the temperatures that would act as a seal? Some folks say you have to clay small forges, others you don't .

ATB

Tom

 

[VaughnT]

Here's a pretty good video on the side-blast forge design and usage. Josh certainly knows his way around a fire and anvil!

[video=youtube;ypahcig1KQw]https://www.youtube.com/watch?v=ypahcig1KQw[/video]

 

[Tomteifi]

Hi Tom

That's a goodly pile of tools you have there. You'll quickly find that you won't need most of them for your intended tasks(at first anyway lol). Theres a nice 3lb hammer in the centre, that will no doubt be the largest you'll need for knife work. The planishing hammers will also be needed. Obviously the tongs are most useful too.(you can re-shape those to suit the work you're going to do by heating them just below cherry red and well, change them to suit with various tools and vise. Any short handled ones can be usefully lengthened to protect your precious digits from the heat by ramming on some old tent poles or the like on ends of handles(making sure they are well and truly solid of course.) Whats in the hobo stove/home bargains utensil holder? Punches? Yes, most useful. Be sure to clean the working ends gently, try a soak in malt vinegar for a few days. If they're well tempered and hardened ends you'll see a darker shade of metal near the ends as in an axe. If nothing there, clean the rest of it up and re-temper/harden in your new forge(when you get it! See plenty of YT videos for how to's its fairly easy.) Lots of mumbo jumbo about oils for quenching but any good oil will do-experiment to find what suits best. Water is water but no, sometimes better when stone cold, other times when hot! Check that out too on YT. TBH using the bbq as a forge and charcoal for fuel is not going to get you to high enough temps. to do much serious work. You will do well to get above 1200f. Cast iron is good up to around 1650f so you're not going to melt it but, for good forging work to get a bright red for anything thicker than an old file you need around 1600f to be able to work it sufficiently. I see Vaughan T has put up a vid on side blast forges and he's right-they are the best. It blows the air across the firepit creating the hottest possible area to heat and it doesn't blow the smoke/fumes/ash/sh.t in your face-all good. I personally would not bother lining it with clay or any supposed fireproof lining. For one thing they don't last and need re-doing regularly as they break down and they seem to cause more slag build up which tends to stick to it like you know what! On the subject of fuel, without any shadow of a doubt, the best fuel is called 'smiths breeze.' It is basically the rightsized(most important) pieces of coke specially prepared for any and all blacksmithing processes. It is not as you might think overly expensive either.(If you have a blacksmith near where you live) he will sell you a 25kg bag for around £10-12. You can supplement that with a bit of charcoal/coal/housecoal here and there but not too much, a few percent to eke it out without choking yourselves/neighbours!(Try to get the charcoal/coal mix the same size as the coke.) I'll finish here for now as you've a lot there to consider but, there is more- a fair bit more. Let me know if you would like to see it.

cheers

Tom.

 

[tombear]

Cheers Tom, lots to take in there!

yeah, I was just seeing what I had that may be of use, it would be a bit of a nightmare dragging that lot to the top of the garden every time! The stuff in the drainer is a mix of bits of hard steel I've picked up for bending stuff around and a bunch of, can't remember what they'd are called but panel beaters use them on the inside of a job while whacking them on the outside, very good steel from the sound of them.

i do have a pile of various sized cold chisels and punches didn't enter my head they would be of use.

Heres a better pic of the cast iron pot, about 12 inch by 9 across.

Enter my head they would be of use


Just needs a tuyere although i could raise the sides if needed.

ATB

Tom

 

[Tomteifi]

Hi Tom

You're thinking of a 'Dolly' re panel beaters I think and yes, they will be very useful for shaping stuff but the other way up if you like. If you can fix the dolly somehow and use it to lay a piece on and hammer it into a shape type thing, that would work. Do you have a welder of any sort or access to one? Does your old anvil have a 'hardy' hole or pritchel or both? You could weld suitable sized/shaped pins to suit hole/s onto dollys to hold them on anvil and work it from there! I'm hesitating on the forge for a bit yet as the bbq thing you have might not yet be the best/easiest way to go until I know a bit more. Can you post more pics. e.g. anvil etc. and soak the chisels/punches anyway as stated and you'll know what you've got. TBH the bbq is a bit on the small side and you'd have to put the piece you were heating in at a downward angle which isn't good for equal heating along its length to make it easier for working on. Basically you need to heat the whole length of the piece to be able to hammer it along its full length in one sequence at a time instead of having to heat up a piece of it then move on to the next bit if you know what I mean. Is that a bolt sitting in the bottom of the bbq I see? Oh and how deep is that pot?

cheers

Tom.

 

[tombear]

Dolly! That's the name!

post 12 in this thread has my anvil, it's still loitering in the hall waiting to be tidied up.

http://www.bushcraftuk.com/forum/showthread.php?t=133279

ive one of my tool guys looking for hardys, I don't have access to any welding gear unfortunately.

Ah well if the cast iron pot thing I have isn't really big enough ( it's about 2 inch deep ) rather than waste my time I'll knock this project on the head until something bigger turns up cheap or free. I'm loathe to put too much into this I case it turns out we are hopeless or it's not what we thought it to be like/as fun. It's not as if I don't have enough hobbies!

I did have my suspicions that the pot was too small. Still if there's one thing I'm good at its finding obscure stuff for very little. Very roughly what's the minimum dimensions I should be looking for? I could really do with a proper book, something like a idiots guide , on the subject. The interwebs all well and good but for some reason YouTube stuff doesn't stick in with me like a good textbook.

ATB and thanks!

Tom

 

[Tomteifi]

Hi tom

Looked at your anvil-nice one! That will do the job nicely. and two pritchel holes-bonus! I don't want to put you off using the bbq-the main thing is to make a start-its fine to start small anyway and onwards and upwards as they say(whoever 'they' are!) To get the best out of it, I would make a cut out in it on one end-just a few inches wide and no more than 3/4" deep so you can lay the piece you're heating a bit flatter in and across the fire. If theres a hole already in the bottom of it-use that as a start and widen it to put your tuyere pipe into it. You'll only need a small pipe-i'd go for about 30mm not much bigger. So if you do a 30mm hole in bbq and can get same size pipe with about 5mm thickness, just get two square steel plates of same thickness and about 3" square, drill the corners of both plates and the base of bbq where its going to fit and bolt in-voila! done.(you wont need to weld, fix, or seal it at all.) All you need then is 12 x 1/4" holes drilled in the plate as per a clockface and one extra hole in the middle. I'd make the pipe about 16" long and what you need is a 'T' piece of same pipe welded onto the side of it about 12" down of the same pipe-that will take your air supply(doesn't matter that its got to turn 90 degrees upwards) and lastly, fix a thin piece of flat sheet steel across the bottom of the pipe which acts both as an adjuster to increase/decrease airflow and an ash catcher(hang a tin underneath from that to catch the ash.) Just a simple sliding valve if you like that opens and closes off the bottom end of the vertical pipe.

hows that sound so far?
ps in the same way as you might build that, you could also easily increase the usable area of your mini forge by getting hold of say an 18" square piece of mild steel, doesn't have to be thick-cut a hole in it to drop your forge in so it don't fall out the bottom and turn the sides up an inch or two-that'll give you a larger area to put your fuel on-put another cut out on the same side as your cut out in the bbq as well to match it.
Tom.

 

[tombear]

Cheers for all that, I'll let you know how we get on., the lad got his mam to order some thick walled steel tube off of eBay.

Last night we made a list of all the really small stuff like strike-a-lights and broaches and there's quite a lot we can be getting on with. To be honest while we are learning the ropes, there seams to be a lot of judgement calls to make especially with regards colour of the heated material and when to add fuel, increase of decrease the draught etc, better to get plenty of time doing lots of small jobs than owt else.

Thanks!

Tom

 

[Tomteifi]

There's nothing like rolling your sleeves up and getting stuck in to learn the 'trade.' My very first buys would be eye and hand protection. Safety glasses and a good pair of strong leather gloves. Don't be too worried over details like colour of metal, fuel and draught. If the metal is hot enough it will be pliable enough to work it with a hammer, if not, heat it up a bit more-once its not showing any redness at all it needs re-heat. On the fuel side as I said, far better fire with proper fuel-smiths breeze-if you haven't got a 'smith near you, you can get it online. To a certain extent, the more air you force in, the brighter the fire will glow but not enough and it won't at all, too much and you blow all the fuel out of the pot! But with a hairdryer or small pump you're most unlikely to do that. A little tip, if you do manage to get too much air going through and can't adjust very well, you can always drop a few little bolts into one or two of the holes in the tuyere you'll be drilling. That will reduce flow somewhat-experiment with that as you need. Keep me posted.

cheers
have fun

Tom.

 

[tombear]

Went looking for the not fit to restore but good brands so good steel old files and could only find a few so at the next boot I will have to get a bunch of right off 12-14 inches to use as stock. They are usually only pence each if they are battered and rusty. Easy enough to do a quick acid clean if the rusts a problem. I did find a bunch of big brace spoon drills that on derusting proved to be too pitted to be worth fully restoring and the odd chisel that was too stubby or battered to merit doing up when I already have the same size and style.

no doubt as soon as I get more the old Stubbs and Bedfords will turn up.

One thing, what sort of tubing to connect the blower to the tube that leads to the tuyere? I mean how far from the hot bits can I use less heat resistant materials?

ATB

Tom

 

[Tomteifi]

Hi Tom

About a foot long horizontal metal pipe from the vertical should be plenty long enough and from there whatever flexy hose youre going to use. The shorter the flexible one, the slightly better airflow you'll get. With the old files or whatever youre going to use for stock, don't bother cleaning them at all-it'll all come off in the process of heating, working etc. If you've got a rail line or local small gauge railway or similar anywhere near you too, you can probably get hold of some old railway line spikes. Usually two or three different sizes plus they did use some large (8or9") screws as well. They are all good quality 01 steel and will forge well into knives. If you get anything with galvanised finish be careful as it gives off poisonous gasses when heated. Look online to see how to treat before you heat!

cheers

Tom.

 

[tombear]

Cheers! There's the East Lancs Railway a couple of miles down the valley. I'll see if the wife's connections run that far, the scout and local history Mafia can normally reach out to most sources.

I think I'll just avoid galvanised stuff.

Just gone dark, had a few flakes of snow and now it's boding. Glad non of the ancient serials have had a chance to germinate yet.

We found another rusty bit of iron not far from where the 14 lb sledge head and hot chisel thingy was dug up, looks like a even bigger chisel what sit or maybe a log splitter. Pretty far gone, been underground a loooong time, I'll knock the slabs of rust off and put it on the grinding wheel to see what sparks come off it. We really need to sweep the whole garden with the detector turned so it doesn't pick up small stuff like nails, of which there are many due to the numerous fires there's been.

Now hailing quite hard.

atb

Tom

 

[Tomteifi]

Hi Tom

There is a very good youtube vid for you to watch re: spikes its called "Forging a railroad spike knife." There are others of course but this one will give you a very good insight of whats involved. Study it carefully and enjoy.

cheers

Tom.

 

[tombear]

Cheers, will do,

i want to raise the sides and back of the hearth with a two inch strip of steel to fit inside the rim ( I can think of various ways of holding it on ) with a cut out or gap at the front. To cut costs and make the stuff easier to bend for the corners,what's the thinnest stuff that will do the job? I have a tendency to over engineer.

i've been looking at some horizontal tube small forges on the net. None of them say how big or widely spaced the holes are and I'm loathe to guess. We have some 1 inch steel tubing with 4mm thick walls, it would need a extension before we could fit a blower or tube to it but that I could sort. I've a 25 mm tank cutter which would eat through the hearth and could pin the use in place at the front easy enough. I assume you wouldn't pin at both ends in case the expansion is different between the tube at the hearth? If we go this way it means I just need to get some of that coke and we are off!

ATB

Tom

 

[Tomteifi]

Hi

If you put the cutout on the front, for one thing you're reducing the useable width of the fire for laying the piece on. If you're right handed, put it on the right side of it-easier to get hold of with your dominant hand and gives you maximum width of fire to heat the piece! Plus any flying bits and pieces and fumes are likely to be directed away from you and to one side or other! The part where you intend to increase the height will get hot but no way cherry red - it wont melt but might distort depending on what it is and how thick/how you fix it. You could literally make a two inch wide rectangle, not mechanically joined either to its both ends or to the hearth and just drop it in-sized to fit obviously. Anything thicker than tin can will do. The tube is usually open fully along its length including the welded plate on(with a 2" hole in it)the end of it. Just do that and put as many 1/4" holes in the top plate within the diameter of the hole as you think fit.(Think sink plughole but with a few less.) You'll realistically only get 5 or 6 anyway-that is enough. 1" tube is on the small side-go bigger-2" would be much better. Just drill the plate corners of both plates and the hearth around the hole and bolt it all together.

then you're good to go

Tom

 

[tombear]

Sorry, I was particularly obtuse there, I did mean the cut out one of the handle ends rather than the long sides.

Rather than wait to get bits and stuff done that I can't do myself like welding I've gone for a simple horizontal tube job and used fire clay to seal the ends, I know it will crack and wear out but it's easily redoable The whole thing will be rapidly replaced with something bigger if we take to it.

A 25mm tank cutter and a bit of file work easily made a hole for the tube, a small pilot hole was really useful as I misjudged the first. which I profiled the end of to match the inside curve of the hearth. Once that was a good tight fit I marked the centre line and drilled in the 9 vent holes, cleaned them up and then riveted it to the end of the tube to the far front end as is. I've used big blobs of fire lay to seal the tube in place at either end, making sure there's no bubbles. A few goes with the blow torch has started the curing process. I may have to use some barbecue briquettes to finish that off, see where the cracks form and fill them. The tub says use with in a year of unsealing so I've plenty time of use it up.

If there's too many vent holes I will drop bolts into some them as one site suggested. I erred on the small size for the holes as it's easier to ream them bigger than make them smaller.

The kids and wife have now ventured out into the snow. I'll now see if I can turn the top of the old tumble drier into a 45 inch strip two inch wide to make a extension . That will mean at least two joints , either riveted or tin mans. Then I'll make a tube to extend out of the blow tube and rig a connection to the hair dryer.

More when it's done. I'm aving trouble finding a seller of blacksmiths coke in the Valley, if push comes to shove I'll find a local smith but if I can I l like to get stuff with the fewest middle men.

Uw, the supposedly stopped snow is coming down in big fluffy flakes now! So much for the forecasts!

ATB

Tom

 

[Tomteifi]

With the design you've gone with there, you'll have air being blown up all along the hearth which will make for quite a large fire in a small hearth. you'll use up all your fuel very quickly. If you try to keep the fire small, you wont have enough air coming through in that spot as the holes are very spread out. As I suggested, the holes should be in a smallish circle similar to a sink plughole. The idea is to have a hearth with a fairly small firepot and have unused fuel around it that you can push into the fire as needed to keep it going. If you get a good fire going in that one, the whole thing might get very very hot indeed. If you want to continue on with what you've got now-I would close off the 3 outer holes on both ends and drill perhaps another 4 holes in between the inner 3 at an angle, say 2 on each side at about 60 degrees to the vertical. That will give you more of a concentrated hearth area. The holes are plenty large enough.

Tom.