couple tong questions

[HondoWalker]

I made a set of tongs that still need adjusting. I used a bolt to hold them together since I don't have the thing you drive rivets through to shape and size them. It got me wondering, Can't I take a bolt and use it as a rivet? Does that work? 

And my second question is: I have a broken file. Can I put the piece in the tongs when they are red hot an hit it a few times with a hammer and get that grippy texture on my tongs? 

[ThomasPowers]

You mean: "Can you use a bolt as rivet stock, cut to size and peen the cut end to act as a rivet?"   Sure; works better with NON_PLATED bolts and soft steel bolts rather than the fancier grades like 6 or 8.  Getting various platings near the forge fire can be toxic to EXTREMELY TOXIC!

I have several pairs of tongs where some blacksmith 80+ years ago did just that.

[BillyBones]

I think Daniel Moss uses bolts for rivets. (I could be mistaken but some one i was watching a video of working used them.) He gets the ones with the longer shanks and cuts the threads off. 

[JHCC]

Just make sure that they don't have any plating on them. 

[HondoWalker]

Yeah I did not know about zinc toxicity. When I put that lock in the forge the brass burned out of it and the zinc turned my coal white. Lucky for me I guess my forge is outside in the open air so I didn't breathe any of it. Still learning new things. 

[BillyBones]

You can buy unplated bolts but it is simple to just chuck them in a container, add some vinegar and let them soak over night. 

[ThomasPowers]

Does that work with all plating materials?  I personally would not suggest trying ANYTHING with zinc chromate plated stuff! 

 (One of the problems with sourcing stuff at the scrapyard is that you can run into a lot of stuff that has been banned for good reason in recent years.)

[BillyBones]

I do not know. I do know it works with zinc. I personally stay away from anything i suspect has any kind chrome in the plating process. I know that some piston rods like in shock absorbers are chrome plated so i stay away from all of them. Better safe than sorry. 

Well, i did  a little research on zinc chromate plating. Interestingly it was mostly used as a "paint". But anywho, a couple plating services say that they use nitric acid to do the job. All said do not try and grind it off the dust is very hazardous. One other solution is muratic acid.  Lots of people suggested using everything from lemon juice to Coke (the drink, not the fuel). I would go with what the professionals use and not trust what some guy on this internet machine says, if i were to attempt it. But again i choose to err on the side of caution and just stay away from it. 

*** As far as anything with chrome in it, do not take my word for it. Do your research and decide for yourself. I, too, am just some guy on the internet.*** 

[ThomasPowers]

Perhaps the next time you post on chucking them in a bucket of vinegar you could add "galvanized" before bolts?  Remember we get a lot of new people through here who don't know the nuances yet.   

I too do NOT want to deal with chrome as even (or especially) the solutions that remove it are considered quite toxic as waste and should be *officially* dealt with.

[BillyBones]

Thomas, you are absolutely correct. I should have clarified. Which also strengthens my last point of not just taking some ones word for it. 

I will go stand in the corner till recess now. 

[ThomasPowers]

No; we *all* like to take shortcuts typing; especially as many of us do better work with a hammer than a keyboard---and many folks are using the abomination of virtual keyboards.  It's just a good idea to look over our posts and try to see what an absolute new smith---perhaps with language translation issues will get from it.

As most of what I post is drivel and blather anyway, not too important; but when we get down to the nitty gritty of smithing then we need to take care!

[Frosty]

If you have a local chrome shop find out what they charge to strip it. I was surprised how little it cost when I checked but it was the early 80s.  It's worth a little money to let someone who is certified deal with the hazmats and disposal. 

The thing about free stuff is it's often more expensive than just buying new stock. Been there paid that. 

 Frosty The Lucky.

 

[HondoWalker]

I finally got to try out the tongs I made.And they worked perfectly about 5 heats. Then one of halves broke off. I quickly reformed it and tried again only it too broke off. I'm going to make another one this weekend. I think the problem was an accidental temper. The half I was working with was getting too hot to hold but it wasn't glowing. So I dippedc it in the water to cool it off. I think that tempered it. made it brittle and made it break. I might be wrong. So far it's the only reason I can figure why it happened. Any better ideas on a cause?

[ThomasPowers]

You need to tell us what alloy you used to make them for any good replies.

[HondoWalker]

It is 1/2 inch rebar. Don't know more than that about it

[George N. M.]

Dear Hondo,

Just a terminology tweek:  If you quench something and it gets brittle and breaks you have "hardened" or "quenched" it.  If you start with hardened metal and heat it to reduce the brittleness you have "tempered" it.  For example, if you weld something to a large mass of metal it acts as a heat sink and the weld may be brittle and break under any stress.  You can say that the cool mass of metal quenched or hardened the weld.  Similarly, if you have a bath that is too hot and you add cold water to make it more comfortable you can say that you tempered the hot water with cold water.

I can be a bit of a grammar geek but it is good to have us all on the same page in the hymnal if we are to offer any useful advice.

Also, rebar can be very odd to work with.  It can vary in consistency along its length.  I think it is due to the fact that it is made from steel scrap and the manufacturing process doesn't really mix things very well.  So, you may have to write it off to the material you were using rather than anything you did.

"By hammer and hand all arts do stand." 

Edited June 4, 2020 by George N. M.
response from original poster

[ThomasPowers]

Here in the USA rebar comes in a number of different grades and the cheap stuff most people find at local stores can be quite low quality.  As TJ has recently posted; good quality rebar can be quite useful in the smithy.  Which unfortunately lures a lot of people into using the poor quality stuff and having difficulties.

[Frosty]

Another issue with using rebar, especially as a beginner is it's texture. Forging it smooth can result in rolling a ridge over turning it into a cold shut. A cold shut is a sharp interruption in a material that conducts force. In this instance resistance to bending forces. What a sharp interruption does is stop a smooth conduction of force, making it stop and restart to continue. This action applies the sum of the force, call it 7 units, to the point it stops and again to the same point on the other side of the stress riser (cold shut). This is exactly the same phenomenon that a glass cutter uses to cut glass in a controlled way. They Score (scratch) the glass where they want it to break, then send force in the form of a compression wave through the glass with a tap of hammer. The iron ball on the end of the handle of a glass cutter.

Changes internally will act as stress risers as well. An abrupt change in the carbon content is possible stress riser as inclusion of some unknown alloying metal say carbide particles. Cheap rebar can be very inconsistent. 

What makes high carbon steel brittle are the crystal boundaries within the steel. Commonly called "grain growth" it is actually uncontrolled crystal growth caused by how carbon atoms align if given a chance. Pure iron has almost zero crystallization potential. What makes steel is the combination between iron and carbon. Together they form a crystalline lattice that resists internal movement between molecules. The longer steel remains above critical temperature, the temp where crystals begin to form, the larger individual steel crystals become.

The boundaries between steel crystals are NOT bonded on an atomic level and so can be relatively easily separated. 

What we see as enlarged grain growth is the visual manifestation of of enlarged crystals. It is visibly and tactilely grainy. You can feel it.

These may not be a serious issue to experienced smiths but as a new comer they constitute mysteries. 

Also different countries have different requirements so rebar in one country may be quite a bit different in others. Nothing I've said about rebar in this post applies to anything but cheap rebar in the USA.

Frosty The Lucky.