pkrankow
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Posts posted by pkrankow
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With a little more care that type of saw can make much neater cuts. You can also take the blade out, pass it through the holes, and cut neater openings. The openings do not need to be round, but neat is helpful. Ragged edges will make it harder for the valves to close properly.
Phil -
Sounds like some CO detectors for the shop are in order, as well as making sure of ventilation. Gas forges burn very clean so there is no visible cue that the air is bad.
Consider the size of your typical work pieces, so you can get a forge that is big enough yet not too big. If you work a wide range of sizes it may be better to have more than one gas forge, a larger one and a smaller one. An overlarge forge is a gas hog, and a tiny forge is inconvenient.
Phil -
The heat will conduct to where it is cooler. I expect that as you start filling under the plate you will have more problems controlling heat buildup in the plate than when the seam under the plate is mostly filled. You can cool the body and plate by spraying air and/or water on them. Be careful about cooling too much.
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Yes, I was preparing to build that exact one before I found my hand crank blower.
Phil -
If you control your airflow from the clean to the less clean areas, so it is one way airflow, you may be able to improve your air and workspace cleanliness as you maintain ventilation.
Sounds like you are putting in a rather large shop.
Phil -
On your budget you can buy a 20 ft piece of steel culvert pipe, 12 inch, like used under driveways. Hang that over the fire. Pictures of Brian Brazeal's shop show this exact setup with no hood.
you can see it in the background of his picures
https://lh6.googleus...03/PA090034.JPG
there are a lot more to look at if you want
https://plus.google....bums?banner=pwa
Phil -
http://en.wikipedia.org/wiki/Westinghouse_Works,_1904
There are a whole series of short movies listed.
Phil -
on youtube
It is an amazing video.
Phil -
If you have a wire cup brush for your drill or grinder that will make short work of the rust and provide a nice low gloss finish. It will also allow for good inspection and photography of the anvil. Wipe it down with an oil rag and it probably will be ready for use.
Or you can just use it and let that clean it up.
Phil -
If they are asking scrap rate for it why haven't you got it yet? If they are asking significantly more than scrap rate I can understand hesitating. Your example photo has rather round edges, but this won't prevent you from using it. An edge tool would be in order for some projects.
Phil -
A couple trash pumps could be rented. They move quite a bit of water.
Since this is a large mass controlling the temperature might be easier than it sounds. Hardening would be a backup plan that you can do later.
Phil -
Probably means the anvil was left outside for some time. I expect it is painted and was displayed in a garden. You will want to remove the paint from the face and horn before using it anyways, so it shouldn't be a problem as long as the anvil is solid.
Phil -
Frequently yes, and the first thing done before using the anvil is dressing the edged. Head over to Anvilfire.com ==>FAQ's ==> anvil radiuses and have a look see.
Phil -
I have some fids and a "seam rubber" for sail making made from locust. I am not sure the variety, and want to say "black" but the wood is not very dark. The wood is hard and durable, but may be stringy. It might be suitable for tool handles.
I made them from a tree I took down with my Dad on Grandma's property.
Phil -
Nice job! I turned my first try into a puddle.
Phil -
Think one gallon per pound minimum for quenching. This is an industry standard estimate, not just a blacksmith estimate. With this mass you are looking at water even though 4140 is considered oil quench.
If you control your heat on the plate tine you may have no need to heat treat. Invest in a couple tempil sticks, one each in 400F, 450F, and 500F Your local welding supply house should stock these temperatures because they are common. If you keep the face below 500F there is likely no need to re-heat treat the face! A bearing drop test would be the final test to decide if you want to go the extra step. Anything over 50% is acceptable.
Phil -
Ok, 1 bar is about 15psi. Not quite as over driven as I first thought, which was you were running straight off the bottle.
Pick up a standard stove firebrick and put it on the bottom of the forge over the hole in your insulation. The burner WILL burn through it after a while even at "normal" pressures, but it will take quite a time and is cheap.
Phil -
I just assembled one that I painted canvass last night. I might be completely uncoordinated, or I made part of it the wrong size because it does not reliably fill, but blows fair when it does fill. Maybe a bag bellows is not a good option. I was only able to get it to fill every few strokes. Maybe I need another coat of paint as it is still quite limp and shows light through in a few areas.
This took me about an hour to assemble. I probably could have done the handles better, they are just poked through the canvass and tied.
pic 1
Here are the parts, a sleeve of canvass that I painted. It has hems in both ends. This is a piece of 1 1/4 inch iron water pipe I had laying around (yes galvanized so it needs stripped with acid before putting in a fire), some rope and some sticks. This bag is about 15 inches wide when laid flat, the circumference is 30 inches. Diameter is meaningless because it is a sack. It is about 40 inches long.
pic 2
install the sticks in the hem. The two sticks are less than the circumference so the top can open.
pic 3
Tie handles for your fingers and thumb to open and close the bag. This is the only valve. I just made a hole in the canvass to tie around the stick, but something neater could be done.
pic4
tie securely to the pipe.
pic 5
finished.
This was really easy to whip up, but it does not blow very well. I think it needs adjustment, or something like a hoop or a board at the bottom to hold the bottom open. In all the videos I see there are two of them being used in a small forge, usually on the ground.
The reason I was trying to make a bag bellows was to try this paint product (spray polyurethane truck bed liner) on the canvass to see if it would become a flexible material that was airtight for making a larger bellows, not because I need bag bellows. The canvass is cotton drop cloth and I sewed it on my wife's sewing machine a few says ago. I think I need another coat of paint at the very least.
Phil
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http://www.google.com/url?sa=t&rct=j&q=harris%20and%20heers%20blacksmithing%20pdf&source=web&cd=1&cad=rja&ved=0CEQQFjAA&url=http%3A%2F%2Fwww.webpal.org%2FSAFE%2Faaarecovery%2F6_pioneer_methods%2FBasic_Blacksmithing.pdf&ei=0qcyUMbdCMu50AG9woDQAQ&usg=AFQjCNEH7j31lJg0z18t7wKkaQaXqMUmgA
Rich is right, pick an idea and run with it.
Phil -
here's a few threads with pictures of taken apart blowers. They are very simple. The intake is a large hole in the side of the case inline with the axle, and the exhaust is out the side. The large paddles move the air. If the exhaust is centered the fan can operate in both directions, if it is tangent it should operate in only one direction.
My blower uses about a 50:1 gear ratio and is about 12 inch diameter. Some hand crank blowers are about 16 inch in diameter. There is no need to limit your material choices as heavy sheet metal or thin plywood will be stiff enough for paddles, the case can be made out of an old cookie tin from the holidays. The hard part is getting the bearings set up, but if you have the back portion of a bike and its crank then you can mount the cookie tin to the frame and the paddles to the rear wheel hub, without the rest of the wheel.
You could also use thin wood that can flex around to make the case, or heavy wood for the sides and thin metal to wrap. Inexpensive bearings or bushings can be mounted into a lumber U frame supporting the blower as long as the space for air intake is allowed for. Bushings (bearings) can be made from copper water pipe and if kept lubricated be expected to last a couple years of use against a smooth steel shaft.
http://www.iforgeiro...lower-overhaul/
http://www.iforgeiro...cranked-blower/
http://www.iforgeiro...kewheel-blower/
Feel free to take apart any available blower from an old dryer or furnace to use. If it is belt driven you can just make it hand crank instead of motor driven. A 12 inch furnace blower running at a slower speed will still put out a whole lot of air. Might as well use the whole assembly if it can push the air without too much effort.
Phil
12 inch is about 30 cm
16 inch is about 40 cm -
Looks like an old work jacket. That material should be fine but may need to be painted with a flexible material if it leaks too much air. I am not sure what the black material is, but if it is durable and flexible you could make a hinge or valve out of it since it looks small.
Google
harris and heers blacksmithing pdf
and you can download a copy.
Bag bellows are illustrated in Harris and Heers, Basic blacksmithing on page 105. Box bellows are a couple pages later.
I realized last night that a pair of sturdy pants (slacks) could be made into a bag bellows, or pair of bellows, very easily, but would destroy the pants. Your old jacket sleeves may work as well. Because your hand acts as the intake valve, a valve on the exit is not explicitly necessary (but may be helpful). Two smaller bellows can be joined with a T or Y. Two smaller bellows would of course require both hands to operate. In videos they are frequently operated by a second person.
Phil
I argue a soft sided bellows is easier to build because less exact carpentry is required, or in some cases no carpentry. The leather, or canvass take up small errors in measuring and cutting of the wood.
A more sophisticated system will give you better, long term performance with less effort to use, but a simple system can get you forging sooner. If your hair dryer is working I would stay with it for a while.
Phil -
What regulator are you using? What pressure were you set at?
I run my forge at 3-10 PSI according to my gauge. It does take about 10 minutes to get to temperature.
If you are over pressuring your burner it will not mix the air and fuel charge well and you will get excess scale and unbelievable dragon's breath. (as seen in your first picture)
Phil -
Thank you Tom.
Phil -
Links, apologies for duplicates
http://www.iforgeiron.com/page/index.html/_/blueprints/100-series/bp0141-building-a-bellows-r373
http://www.iforgeiron.com/page/index.html/_/blueprints/100-series/bp0128-forge-blower-r361
http://www.iforgeiron.com/page/index.html/_/blueprints/100-series/bp0127-bellows-construction-r360
May or may not be helpful I am working on a small bag bellows and may need a diverter
http://www.iforgeiron.com/page/index.html/_/blueprints/100-series/bp0107-air-diverter-r343
Phil
Ventilation vs Air Scrubbing/Filtering
in Shop Tips n' Tricks
Posted
You can put in local, additional, fume extractors with some adjustment to them. This way you can place the extractor intake near your work so the fumes are removed with less mixing in of room air, so less air exchange required, so less heating is required.
Phil