Adam R.

So as it turns out, I am now much more confident this is in fact S7.  During my initial heat treatment I think it was in the oven too long and I ended up getting a fairly deep decarb layer that i didn't grind sufficently through.  I tried taking a hacksaw to the 2nd tool I made and it stopped dead about 1/16" deep.  This would also make sense, I think, why I couldn't get it to air harden on a 2nd attempt.

I suppose when I got mad and tried to water quench it there was still enough carbon to harden.

So good news all around, I am pretty sure I got what I paid for and learned a valuable lesson about heat treating.  Not bad for the price of one chisel.

Thanks for the response guys, it helped me noodle through this one.

Good afternoon David,

$150 is a good chunk of money, and while I agree it would be satisfying, it could turn a $30 loss into a $180 loss.

Mcmaster did confirm their color coding on their end is correct and is going to check with their vendor on Monday.  I've had a very good track record with them so far on purchasing alloy steels, so I am certainly not accusing them of anything willful.

Your point is a good one though, I really should have; as a minimum good practice, taken a piece of the bar and test hardened it before putting any work into it.

I think I will spend some money on another bar of it and spark test in comparison to my current bar.  If a new piece works as anticipated I think I can just chalk it up to bad luck.  If not than I am just doing something wrong and will need to figure it out from there.

Thank you for your response.  It is appreciated.

I know I can oil quench steel, I do with other alloys.  S7 is supposed to be air hardening steel.

Thanks for the information though.

I purchased some S7 from Mcmaster Carr to make some punches and hot chisels.  The trouble I ran into is that it will not air harden.  I tried in my electronic controlled oven first, held at about 1725 and took it out to air cool, but never got hard (a file bit pretty easily).  I though maybe it was just decarb so i tempered it and finished up the grind.  I tried the hot chisel to cut some material and the edge flatten out like mild steel.

I tried to re-heat treat it in the forge, brought it just to about orange heat and let it cool but it is still soft.  At this point I got irritated and reheated it and water quenched it.  Hard as glass and during my testing I was able to very easily break off the edge of the chisel.

Am I doing something wrong?  Any suggestions to try something different?  Or would you also assume it's a mix up from the vendor (or the vendor's vendor)?

I am actually hoping I am just doing something wrong, but I suspect I got the wrong alloy.  My very first test with A2 worked great and without issue.  Mcmaster is going to be checking with their vendor to see if there was a mix up, I doubt that will bear fruit.

Should I be gun shy from ordering s7 from Mcmaster in the future?

1 hour ago, Steve Sells said:

a proper forge weld is as strong as the parent metal because its fully fused

This is what I was under the impression of as well.

1 hour ago, Irondragon Forge & Clay said:

Probably didn't soak the stock long enough to get the deep penetration of the weld. As others said it should be as strong as the parent steel. Could you see a line where the two were joined?

Yes, there was a visible line.  It is quite likely it didn't soak long enough.  I got the piece to the same color as the forge but didn't wait much after that.  So the surface may have been ready to weld but not internally.

At least I have an idea now what to improve on.  Thanks guys!

Good Evening,

I just started practicing forge welds and so far have been successful.  At least in getting the metal to stick and actually be welded.  My concern is that while it was definitely welded, the weld didn't seem as strong as I expected.  I practiced with a faggot weld (i think this is the right team for this) and checked its strength by severing the bend, putting it into a vice and trying to separate it.  I wasn't able to do this by hand, but it didn't take much to get the weld apart with a hammer and chisel.  I expected more.  The metal where it was welded looked very clean; almost shiny.

The details of the weld:

I used 1/4"x1 A36 hot rolled, folded the steal over to make a tear drop shape (about 1"x1-1/2" of surface area for the weld)  20 mule team borax and a chile forge 2 burner at about 19 psi (20 is max recommended).

Should the weld be nearly as strong as the parent material?  Or is this a typical amount of strength for a forge weld with low carbon steel?  I expected more because I wouldn't trust what I experienced to hold on a pair of tongs using a drop tong method, so I am guessing i did something wrong or incomplete with my test weld.

By the way everyone, thank you for your responses.  I think I have a fairly clear path to keep my forge healthy and happy.

I am really glad you mentioned this!  I was wondering if I could just make my own shelves.  The Chile forge is well designed to have a removable/sacrificial shelf directly above; and supported by, the actual floor which makes for easy removal of a simple rectangular shelf.  Because of the design I think it would be quite simple to just create a casting form outside of the forge and install the cast part after; assuming the cast shelf is strong enough to support its own weight from movement.

Would you suggest Mizzou for this?  I can get about 4 to 5 shelves out of a 50lb bag for the cost of 1 kiln shelf.

Will coating a DIY shelf coated with something like ITC-100 help keep the shelf alive?  Or just mostly be a waste of money? 

1 hour ago, Mikey98118 said:

Maybe; but like many things, whether or not you think the help is worthwhile will be an individual call.

A maybe might be worth a try.  If i get even two times the life from a shelf for an occasional wash it would be.

Perhaps I will have to try out one of the less expensive kiln washes to try this out.

Yesterday I attempted (and succeeded ) to forge weld in my recently purchased Chile forge.  I have a sacrificial kiln shelf for the floor of the forge (two actually, the floor itself is a kiln shelf and Chile forge sells an additional sacrificial kiln shelf for forge welding).

My first night forge welding I noticed; and expected, that the borax would eat away some of the shelf.  I know i could have another kiln shelf on the rack for replacement, but could i prolong the life of the sacrificial kiln shelf floor by coating it with something? 

Would kiln wash help here?

If so what would be a good and appropriate coating?

I have some ceramic blanket from a project years ago lying around, might fit the bill.  I've read there is a concern about  fibers being released at temperature with Kaowool and the like?

My first weld attempt was going to be on making a fire poker.  I was thinking of using a faggot weld as opposed to making a loop and using scarfs.   Suppose I could go with (try) either.  Gonna need to learn it all eventually.

24 minutes ago, Frosty said:

 

...

Having fun yet?

Frosty The Lucky.

 

Thank you for the info, sets my mind at ease.

And most certainly YES!  I am having a blast.  I'm on my 4th set of tongs already.  Making a 3/8"x1" pair of box jaw tongs right now.  Gonna try my hand at forge welding in the next couple of weeks. 

23 minutes ago, Mikey98118 said:

Also, it is a good idea to use something to temporarily partition off the half of the forge that you don't want heated; this has been discussed several times on this forum.

Probably a good idea, but so far I mostly seem to need a long piece to pass completely through the forge but only heat a certain section.  I may look to get some hard firebrick though for the purpose if it comes to it.

46 minutes ago, Irondragon Forge & Clay said:

I know this is a silly question, but are you also turning off the fuel to that burner?

Oh yes, certainly.  The ball valve gets closed first and then the choke gets closed.

50 minutes ago, Frosty said:

That's why you close the choke on the one you aren't using or pressure in the forge blows flame out the burner. it. If you think it's getting too hot you might block the end in the forge with a wad of ceramic blanket. I don't think you should need to but I don't have one to hand so I don't know for sure.

Frosty The Lucky.

I don't think is is getting too hot, but it is getting "hot" (not relative to the temps that blacksmithing requires).  Near as I can tell the fresh air that comes in for combustion cools the top of the burner when it is running.  The closed/off burner is getting the radiating heat from the forge and heating up.  Still this sounds like it is a somewhat common practice.  I was mostly just concerned about damage to the burner, I would rather use extra fuel than ruin the burner.

I recently get into blacksmithing and purchased a Chile Forge 2 burner (Cayenne).  No complaints, the forge seems really great.  I find that at times I only care to run the front burner to heat up less area of what I am working on.  According to the literature that the manufacturer provides, this seems okay as long as you close the choke.  However I have noticed the burner that is off heats up fairly well; considerable more than the front one, enough that I wouldn't want to touch it without a glove on.

Will this extra heat damage the rear Diablo burner?  Or is this a common practice and nothing to worry about?  

1 hour ago, Mikey98118 said:

Regular POL hose fittings, backed up with a valve has been standard forever for very good reason...

Point taken, I think i am going to abandon the Q.D. idea.  Thank you for the advice.

12 hours ago, Irondragon Forge & Clay said:

If you do use quick disconnect fittings make sure they are rated for propane, air hose connections will not work for long before leaking.

Thank you for the warning, I do plan to purchase MB Sturgis brand propane specific fitting, they seem to be fairly reputable.

12 hours ago, Irondragon Forge & Clay said:

where in the world you are located

PA, I've updated my profile.

12 hours ago, Mikey98118 said:

but they can begin leaking minor amounts over time, so make sure they are kept well away from ignition sources.

Fair point.  They will be located outside of the shop, but still; especially for the added cost, perhaps something I wouldn't want to deal with long term.

Hi; for some background, I am just getting into blacksmithing and am getting my shop set up.  I decided to go with a commercial propane forge (2 burner Chile Forge) and have a 100lb propane tank waiting for its arrival.  I plan to keep the propane tank outside the shop about 20'-30' away from the forge, and run a line in though an open man door to the forge regulator.  I realize the regulator could theoretically leak over time, but I want to have the pressure control close at hand.  I also have a 20" louvered ceiling vent right over where the forge will go to help exchange air.  I do not at this time plan to run a permanent propane line through the wall of the shop. 

My question is about the proper connectors for this arrangement.  Ideally i would like to use a propane quick disconnect near the tank so when I shut everything down and purge the lines I can conveniently bring the hoses into the shop.  My concern about the QD connections is whether they are sufficient for the high pressure side of the tank? Or do they restrict the flow at all to prevent adequate fuel to the forge?

Option 1 Q.D. on high pressure side:  Propane Tank ->   Q.D. line -> forge regulator -> factory supplied line -> ball valves -> burners

Option 2 Q.D. at lower pressure:  Propane Tank -> 30 PSI high pressure regulator -> Q.D. line -> forge regulator ->  factory supplied line -> ball valves -> burners

Option 3 No Q.D. and deal with unscrewing the line:  Propane tank -> Extension line -> forge regulator ->  factory supplied line -> ball valves -> burners

Are any of these options dangerous or otherwise inadvisable?  Which is likely the best/safest option?  Anything I am missing that should be included?

Best Regards,

Adam