CRAFTBENDER

Hello to my good friend Bruce. Craftbender just got back from Texas.

When you bend metal it compresses on the inside and stretches on the outside. There is a place where it neither compresses nor stretches. This place is 44% of metal thickness, so if you add the bend radius to 44% of metal thickness and multiply by Pi you will have the amount of material in 180 degrees of bend. 90 degrees is what you are looking for so you divide by two. In a formed piece you have flat places and bends, so you figure how long the flat places are and of course the bends. In this case you have 11 inches by 15 inches, both outside dimensions. So lets figure using a 1/2 inch radius. First we subtract one material and a bend radius from 11 inches, so one flat leg will be 10 inches to where the bend starts. We subtract a material and a radius from 15 inches and we get 14 inches of flat leg. So now we figure the material in the bend. .44x .5 material thickness equals .22 plus .5 bend radius equals .72 times 3.14159 equals 2.262 divided by 2 gives us 90 degrees of bend which is 1.131. So 10 inch flat plus 1.131 in bend plus 14 flat gives us the developed length of 25.13. This simple formula has served me well for over 40 years

I want to be able to do that well. Thanks for your post!

Do you have a picture of your contraption? Sounds pretty simple.

I looked up the price. $395, wow! Cheaper to get the bigger bottle or even use a manifold on two smaller bottles.

Google Pelsue bottle warmer #9651. It is a silicon rubber belt 375 watt and is made for that purpose.

I use 2% thoriated tungsten on all my tig welding, aluminum, steel, stainless, etc. Been using it for over forty years. I don't know the link, but on WeldingWeb™ there is information about the risk which turns out to be very very low. Something like over an average lifespan, you might lose a day. cough, cough, wheeze

I am ordering some ceramic blanket and fire brick from Jay Hayes to put thicker lining in my forge. While doing a search on this forum, a fellow said he used cat litter on his floor that absorbed borax and was easy to pluck out and replace with more litter. Figured I'd do a little experimenting. The closest place for buying the cement or castable is about 70 miles from where I live. I also have some plastique 85.

I want to buy some cat litter to use in my gas forge. What brand or brands are actually bentonite? Thanks.

Frosty, you are forcing me to waver. If I do two burners, what should be the spacing in a depth of 12.25 inches?

I did figure in your post before this one and decreasing the volume by putting in a brick plus Charlotte's questioning the design of the burner or forge. This is what impelled me to find the burner volume ratio. The only problem with the brick is that I couldn't get anything else in there. I've decided to add another inch of kaowool to the inside to decrease the forge diameter to 5 inches which would give me about 240 cubic inches. More heat, less fuel. Thanks again.

Thank you for your answer, also thanks to all. On the forge and burner design. I used the Michael Porter book to build my burner and forge. I think the burner is fine but I did a search for burner size to volumn and in one, Dodge said in a post that a properly tuned 3/4 inch burner would heat up to 350 cubic inches to forge welding heat. My forge is seven inches in diameter and twelve and a quarter inches deep. If I figured right that comes to 470 cubic inches. Another fellow said 250 cubic inches max for a 3/4 burner. The doors have about one by four inch rectangular openings. So if this is the case, I guess I need to add another burner or decrease my volumn. I never figured the volumn before this, but you would think the propane cylinder design in Porter's book would figure this in.

I did a search on the forum but couldn't get a good answer. Also called my gas guy and he couldn't tell me much except that he can't fill my propane tank with propylene. I can readily forge weld high carbon in my gas forge but low carbon mild steel is very borderline. Has anyone used propylene in their forge and can you tell the difference. If there is a difference, I think having a switch over valve from propane to propylene, since propylene is more expensive, for welding and then switch back to propane for forging. OK, I'm ready for answers. Thanks.

Benjamin Franklin would be jealous. Very nice.

Frosty, you have forced me to consider doing the same thing to a ball pein I have with a loose handle. I doubt mine will turn out that good though. Thanks for the inspiration.

Over a ten year period I bought a lot of cold rolled 1018 steel 1/4 x 1.0 and 3/8 x 1.0. The minimum tensile strength in the book was 85,000 pounds per square inch. Also bought and cold bent a huge amount of hot rolled steel. Cold rolled will almost always break when bending cold but hot rolled can be bent readily in the cold condition. The only way to bend cold rolled at room temp. is to heat it first to barely red and let it cool. This is a picture of some cold rolled vs hot rolled 1/4 thick bent cold on a 3/16 radius.

I like your method. I'm bad about not writing things down, so if I need to see how much material is in a scroll, I set some dividers at .2 and walk around the scroll at the center of the material. Two, four, six, etc. On bigger scrolls you could set the dividers wider. Same thing if it is drawn out on paper.

Yes, I believe you are right. The welds don't quite do the trick. Next time I'll either do the rivets or the plug weld from the back side. Thank you for your input.

Thanks. I agree about the rivets. Next time. I have some copper rivets that would contrast with the steel. Also the collars. Good points.

Here is some stuff I just finished. A couple of paper towel holders I made as a thank you gift to some good friends, and some handles. Some of it was heated in the Michael Porter forge I just finished in the near past.

That burner is absolutely beautiful! That flame doesn't look anything like the one coming out of my burner. Mine is blue. Are you using propane?

Since I live close, I'll get a first hand look when you finish your vertical forge, Bruce. You'll be the first kid on your block to have one. Ha!

That burner looks like the design from the Michael porter book. I built my 3/4 inch burner from the plan in his book. What size hole is in your jet tip? Mine is .030

Here are some pieces that were'nt total disasters. The leaf was made from a piece of 1/4x1/2 hot rolled.

Thanks for the nice comments. Bruce has seen it first hand and we cranked it up and Bruce did a forge weld. I burned up a tank of propane messing with it, and forge welded a billet from some steel cable I got from Bruce Godlesky. Made some scrolls and a leaf. Heating hammering and learning.