The Armour Archive

Mac,

Sorry for the obscure reference.

When you do this in heat treatment in this fashion do you still have to build the crossbracing?

RPM

I'm moving toward the heat treatment of the cuirasse, and will post pics of the bracing etc. when it's ready. Due to my kiln only being 18" tall inside, I will have to treat the skirts separately form the breast and back. I'm still thinking about what that will entail.

Mac

There are places where the plates do not meet up well along the edges, so I've been heating them up and tapping them down, both inside and out.



The problem with this sort of "fix" is that it can introduce some less than graceful transitions, as well as some hammer marks. The solution will be to disassemble everything and plannish out the bad spots. That will probably create some problems as well, and the whole process will have to be repeated. But, before any of that can happen, the cuiasse needs to be stress relieved. This is the perfect opportunity get rid of a bit of asymmetry in the shoulders. This calls for making up some braces to hold everything in place while I heat the armor up.

I templated the shoulder braces in cardboard, and whacked them up in .058" mild steel.



One does not get any extra points for making the braces pretty, but they do have to fit well. Here is where I needed to put some fluting in the braces so that they sat properly inside the backplate.



In the first pic, the breast ends of the braces are left unfastened to show the extent of the asymmetry. In the second, the main braces are fastened and a diagonal brace is added to pull the shoulders into line.



The twisted wire is only there to pull things into shape so that I can fit the diagonal. I would trust the wire to hold things OK while torch heating to stress releave, but I would not trust it for the final heat treating. This seemed like the best time to just make the thing I will need eventually. Just to be sure, I added another cross brace in the other direction. It brobably won't really be needed, but it's cheap insurance against having the cuirasse warp the other way.



It would be nice to put the whole thing in a kiln at dull red heat and let is sit for a while, but my kiln is not deep enough for that. So, I will have to hang it up and play a torch over it. Since I will need a lifting point to get the breast and back in and out of the kiln for heat treating (the skirts will have to be separate) , I will make one now so I can hang the cuirasse from the ceiling while I work.

More pics after diner.

Mac

Here's the ring I made for lifting the armor in and out of the kiln. It's .075" 1050. The type of steel is of no concern here, and I just used the first scrap of 14ga I laid my hands on.



There's a big I-beam running the length of the shop, so I used a length of chain and a C-clamp to suspend the armor. That I-beam forms part of the previous owner's "clever plan". It supports the whole of the middle of the building and let him have column free work space with an engine hoist that went from wall to wall.



That orange hose on the floor is part of the weed burner. I bought it from Horrible Freight a couple of years ago to deal with the weeds in the driveway, and perhaps as an armor heat source. Well.... it more or less sucks at weed control, and I never used it for armor till today. Great Fuck! does that thing put out heat! I left the roll-up door open so as to let some fresh air in, and when I was done heating the armor I found that the door was hot to the touch. In fact, everything on the ceiling was hot to the touch. I've left the door open and a fan running. Perhaps the place will be habitable again in a hour or so, and I'll see whether the armor is properly stress relieved.

Mac

Awesome! I had wondered how you would prep the cuirass for the heat dunk.

I got a good laugh out of your weedburner comments. I bought the same HF torch, hoping to use it in a propane forge I was building.
Needless to say, it's definitely more of a flamethrower than a precision heat source! And guzzles propane like nobody's business.
I had to go a different direction for the propane forge. I'll save the HF burner. Maybe I'll need to clear out an enemy bunker some day...

It's strange about the HF flamethrower. It's almost like more heat went into the room than into the armor. Some of that is me; I kept the flame back a bit to keep from overheating the fasteners. The screws were in from the back, and the parts that extended bast the nuts were glowing orange before the armor was even warm. Next time, I will put the screws in from the outside. That aught to let me get the flame thrower a bit closer.

Mac

This morning I pulled pretty much the whole cuirasse apart one lame at a time and planished the places which had gotten ungraceful. It's all back together again, and I have done another round of spot heating with the OA torch and the long vise grips.

When it's cool, I will take it apart again and planish any trouble spots. This is an iterative process, and it's never clear how many time it will have to be repeated. Not too many, I hope.

Mac

That's reassuring to hear. There have certainly been times where I felt I was just creating problems as I fixed others; it's nice to learn that the back and forth does eventually reach a happy medium.

The flute down the middle of the shoulder braces is a really clever way to keep them rigid! Do you find that works better than creasing the edges to turn them into shallow [ shapes?

If the flame thrower is such a beast, what made it unsuitable for burning weeds?

How hot were you trying to get the armour to relieve the stress?

Keegan Ingrassia wrote:That's reassuring to hear. There have certainly been times where I felt I was just creating problems as I fixed others; it's nice to learn that the back and forth does eventually reach a happy medium.

So long as you are making progress. If not, then some part of the process must be changed.

Keegan Ingrassia wrote:The flute down the middle of the shoulder braces is a really clever way to keep them rigid! Do you find that works better than creasing the edges to turn them into shallow [ shapes?

I'm not sure how it compares to flanging the edges. It just seems easier somehow; you don't have to figure in any extra width.

Mac

Aussie Yeoman wrote:If the flame thrower is such a beast, what made it unsuitable for burning weeds?

How hot were you trying to get the armour to relieve the stress?

I'd like to see the armor just barely glowing..... maybe 900°F or so. Unfortunately, that's probably what I tried to do to the weeds as well. My understanding is that you just have to get the weeds to boil and not to char, but I found the charring a lot more satisfying.

Mac

I spent much of yesterday dealing with the bevor/breast interface. This is one more thing that has to be ready to go before I can heat treat. For some reason, I made the central crest right below the neck too high to accommodate the spring catch hardware I had built. In any case, that had to be "tamed" a bit before the catch would fit. I also reduced the crest on the bevor bib just a bit for the same reason. I did not get any pics of that, but here where I cut off the part of the bib which had been serving as my attachment. This is one of those bridge burning steps that needs careful consideration.



Here is where I got the staple fitted to the breast. Note that sort of sill under it. That's needed to make up for the thickness of the bevor bib.



I'm sorry the focus is bad here. This shows the catch and staple bolted on and everything appearing to be OK.



My plan is to put the as much of the cuirasse into the kiln as I can to stress relieve it as a unit. One of the last minute additions are these "washers" to help hold the free ends of the backplate lames in place. This is a new idea, so we'll see how it goes.



I count this procedure as a sort of "warm run" for the heat treating. As we can see here, there is very little room to spare. If I ever make any more armor I really should get a bigger kiln.



The other issue is with the lifting ring. There are two issues, really. The first is that it sticks up a bit too much. As it is I can't get the lid of the kiln closed. If that were the only problem, I would just remove the rest of the fauld and cullet and carry on. Unfortunately, the placement of the ring doesn't let the armor hang vertically. This is an issue when the fit in kiln is so close.



So... I redesigned the lifting system to go from this, to this.



Which made the hanging angle go from this to this.



That's going to make a lot of difference when it comes to the heat treating. With the armor hanging vertically, I have some chance of getting it into the kiln before my sleeves burst into flames

I did not take this opportunity to practice swinging the armor into a hot kiln, but rather just put in in cold and then brought it up to temperature. Here is a peek into the kiln at about 1200°F. That's hotter than I said the other day, but I really wanted to see a distinct glow and I just didn't get that at 1000°F.



I did use the hook to take it out, though. Even at this low temp it's a bit of a trial. The fit is close enough that it has to be raised out slowly and carefully so as not to damage the kiln walls and the temperature probe. It looks like the new lifting point will work OK.

I snapped a shot of it as it cooled and gently showered scale on the floor.


Mac

This always makes me nervous. Heat treating for me is a bit of a ritual and getting closer to it pokes my nerves. When it is time, may warpage and PLINK noices stay far away from your shop.

Mac,

Good to see that you have sorted out the image posting thing.
Many thanks for the great info packed updates.

Xtracted wrote:This always makes me nervous. Heat treating for me is a bit of a ritual and getting closer to it pokes my nerves. When it is time, may warpage and PLINK noices stay far away from your shop.

It makes me nervous too.....

Mac

Tom B. wrote:Mac,

Good to see that you have sorted out the image posting thing.
Many thanks for the great info packed updates.

I've sorta' got it under control, but I still feel a bit lost trying to get around in the new format. Sometimes I can't figure out how to get to the album I want, and I never did figure out how to label it. There was a screen that purported to let me change the name etc, and it took some (but not all) of the changes I made and then disappeared like friggen' Brigadoon and I can't find it again.

Mac

What I needed was a way to brace the fauld and cullet as individual assemblies. Here's how it goes. I first made up a template for the shape of the frame.....



...and then cut that out and used it to mark up a piece of 1" by 1/8" angle iron.



You can all see where this is headed.



The frames tie into the screws that are already there by means of these steel fingers. They are just some .060" mild steel. It's a bit tedious getting them all in place. The plan is to get them to fit so that they are not putting any new stresses on the assemblies.



After heating up each of the steel fingers with a torch to stress relieve them, I removed the frames from the skirts and the skirts from the breast and back. I then reattached the frames to the separate skirt assemblies.



I have a couple of lifting rings to bolt on, but there is a problem. The locations of the frames does not let the skirts hang the way I want them to when they enter the quench. I'm going to need to weld something on to the cross pieces to let me attach the lifting points an inch or so away. I hope to have a cunning plan by tomorrow.

Mac

I didn't have a cunning plan, but I did come up with an adequate plan, and it looks like it will work. I needed to move lifting point away from the central support, and the obvious thing was to just weld something on. But, that thing had to be easy to weld and strong enough to bear the cantilevered load. I found that I had enough 1" x 1/8" square tube to make something up without having to go back to my local Metal Supermarket. The two loops I had planned to use were modified slightly and pressed into service.

Here is what the new arrangements look like.....



....and this is how they're hangin'.



The moral of the story is that I should have thought this out before I made up the supports. If I had positioned them on the other side of the rivet lines that would have put the supports closer to the centers of gravity of the assemblies. The result would have been close enough that the cantilever kludge would not have been necessary. As an added benefit, the steel fingers would have been easier to install. Oh well. One can't always have the better idea until one sees what the bad idea looks like in three dimensions.

Mac

Mac wrote: One can't always have the better idea until one sees what the bad idea looks like in three dimensions.

Mac

This perfectly captures my life as an Exhibit Designer!

I never thought the term "So, How's it hanging?" would be used in a serious discussion about armor... but there it is.

Mac, Given the width of the faulds, will the kiln be large enough on an angle or do they need to go in facing forward?

Sean

Sean Powell wrote:I never thought the term "So, How's it hanging?" would be used in a serious discussion about armor... but there it is.

It only goes to show that I am a vulgar as I look, in spite of a good education.

Mac

So, there I was, eating my lunch and catching up on the world when I see this....

Sean Powell wrote: Mac, Given the width of the faulds, will the kiln be large enough on an angle or do they need to go in facing forward?

Sean

I had been confident that the skirts would fit diagonally in the kiln, but I had not actually tried them. Experience has taught me that if I ignore Sean's intuitions, I do so at my peril. So I shoved the rest of the Trader Joe's burrito in my mouth and headed out to the shop.

The fauld will fit OK. It'll be a bit fussy to lower it in nice and straight, but I'm not worried.



The cullet, on the other hand, is a real problem. It fits, but it's tight; maybe too tight.. Getting it out will be OK, but putting it in is going to be a real issue. Loading the part into the kiln happens at orange heat, and there is only so long that one can stand with his arm over the inferno. That time is less than 10 seconds.



I see two possibilities....

--The first is to rig a separate set of wires to use for lowering the piece in. These would (ideally) hold the armor at the best entry angle and keep it form swinging and rotating into the kiln walls.

--The second is to remove the last lame/butt tasset and adjust the lifting ring for the new center of gravity. I'd rather not have to do that.

I'll start by experimenting with the first option and see if that will let me get the part into the kiln fast enough.
Mac

Mac, would heat reflective PPE work to extend the time you can spend in the inferno enough?

A quick google search gave this but there is surely loose sleeves to buy.

http://www.sfm-tusker.com/products/ppe- ... sed-jacket

Edit: Like this
https://www.amazon.com/Sleeves-Aluminiz ... B0078S42D8

I was thinking something like this

http://eifstucco.com/wp-content/uploads ... 50x450.jpg

I decided to start with plan "C". By adding more angle iron to the legs of the frame, I made it into a thing that would stand upright. This takes up a bit less room in the kiln, and has the added benefit of taking all the weight off the "tail bone". There will be no close up pics of the welds because they are disgraceful. Now.... they don't need to be pretty.... but really, they aren't.



I still have to deal with the part where the thing wants to rotate around a vertical axis while I am trying to lower it into place. It seems like having a tube rather than a ring for the hook to engage might be the way to go. This necessitates a different hook, but I was about to build a new one anyway.

Mac

I would have gone with two hooks to control the tendency to spin. Not that I have done kiln work in decades... I just make temporary KO Wool structures and one or two of the jet-engine weed burners (one with a trigger) and off we go.

Mac wrote:
I had been confident that the skirts would fit diagonally in the kiln, but I had not actually tried them. Experience has taught me that if I ignore Sean's intuitions, I do so at my peril.

Mac

20+ years of mechanical engineering has given me an eye for space and volume plus a good intuition on stresses and mechanical devices... or perhaps having that eye has made me a successful engineer these past 2 decades. Who knows.

If you want my further intuition: I like the orientation that the feet put the frame in but I can't 'feel' the weight on the fauld and know if it will sag under heat. If the weight of the fauld would have caused the frame to fall that way without the feet then it will put pressure as if it were falling that way onto the feet. The more the feet flex, the farther it will lean increasing the load on the feet until it falls anyway. Depends how soft the mild steel gets at temperature. If you had some 1/4" round stock or similar I'd connect the feet back to the legs like a triangle or perhaps up near the lifting point. And maybe even connect the feet for overkill. Don't just think triangles, think tetrahedrons or pyramids.

Sean

Mac wrote: I've sorta' got it under control, but I still feel a bit lost trying to get around in the new format. Sometimes I can't figure out how to get to the album I want, and I never did figure out how to label it. There was a screen that purported to let me change the name etc, and it took some (but not all) of the changes I made and then disappeared like friggen' Brigadoon and I can't find it again.

Mac

Here is some info on the album search,renaming, and/or sorting of photos:

First of all I like to go to the Album View of Google Photos, this just seems to better fit my mental model.
Click on the "Albums" icon on the left hand side of the screen to get into this mode/view.
The screen grab below shows this icon shaded blue this means I am already in this mode.



It is pretty easy to find an album if I know its name or at least part of its name.
Just click the search bar at the top center of the screen, refer back up to the screen grab above.
This takes you to a search screen, all of the usual wild card type stuff (* & ?) will work here.
For example I have an album for images I post here on the AA.
Just by typing AA it brings up a list of all of my albums that contain AA in the title.
I can open the desired album by clicking on its name.




If I have an album open and want to rename it or rearrange the images, here is how you do that.

Screen Grab of open album below:


To rename I just click or highlight the album



note that the bar at the top of the screen has changed to blue
I can now change the album name and drag/rearrange the images.



Here is the key part that may have eluded you before:
When you are done editing click the check mark in the top left of the screen, this saves your changes.

Tom B. wrote: Here is the key part that may have eluded you before:
When you are done editing click the check mark in the top left of the screen, this saves your changes.

Thank you, Tom! It's always something like that; some little thing that makes perfect sense to the programmers, but the rest of us are baffled.

I'll try this out some time when I am feeling calm and serene.

Mac

Here is a pic of the hook I have been using to get things in and out of the kiln since my second try at heat treating some time back in the '90s. It's made out of a length of 5/16" mild steel rod that came to hand when I needed it. It more or less worked OK, so I never bothered to change it.



The astute observer will see a slight curve in the horizontal length. That bend happened while slinging something heavy out of the kiln. I don't even remember what it was. This turns out to be harder to photograph than it is to just "see" when it's in your hands.



For a number of years I had been thinking I would make a new hook out of something slightly heavier, and the other day I bought some 3/8" rod for the purpose. I had thought that I would pretty much just make the same thing, but then I got to thinking about how there might be a better way.

So.. We'll recall that the current problem is that the items I need to get in and out of the kiln are a pretty tight fit. They need to be oriented in very particular ways. This becomes a problem as soon as you try to swing a piece into place with the hook. There will always be some rotation around the vertical axis, and this rotation will take time to damp out. If the piece of armor is a loose fit in the kiln, it doesn't matter much. So long as it ends up pretty much in the middle and the lifting loop is still accessible, everything is fine. On the other hand, when there is little room for error and no time to wait for the oscillation to decay there is a problem which needs a new solution.

My thought the other day was to make there be two loops in a line, so that the hook could exert some control on the rotation. This idea morphed into welding on a length of tube. That gave way to adding a sort of roof of sheet steel. I was in the process of templating that when I realized that I already had a suitable "tube" in the square stock I had welded on to alter the balance. All I had to do was to drill a 1/2" hole through the angle iron. The sheet metal loop is now redundant and I will remove it.



I changed the shape of the old hook for it's new job, and here is how it works.



I have tried this new system in cold runs and find that I can get the skirts in and out of the kiln with much greater ease and precision than I could with the old system. I am so pleased with this that I am now considering how to apply the same thing to the cuirasse. This may well be a sort of paradigm shift.

Mac

I've replaced the "bridge" on the cuirass's bracing.......



.....with one made of 1" x 1/8" angle iron. To that I've welded a short length of 3/4" x 1/8" square tube.



I played around with different angles for the tube by clamping it in place until I found the angle that worked most conveniently. the armor needs to be oriented orthogonaly to the kiln while at the same time, I need to be over at the corner so I can operate the foot pedal that lifts the lid. When I tried to think this through, I could not convince myself that the system would work properly with the tube at an angle, but it turns out to work brilliantly.



I am extremely pleased at how much control I have over the armor using this new system of lifting tubes rather than rings. The difference it makes with this project is the difference between ".... I think I can do this" and "this is going to work". The only way I can remain on an even keel is by reminding myself that I could have done this many years ago.

Mac

That's a pretty ingenious solution. But realize that your hook is now an L and if the front of the L sags the armor piece may want to slide off. If the heavier hook reaches all the way through and then turns up it will help. You can even file the tip smooth like a fish-hook to aid entry.

2 possible future improvements: Rods like to sit in V-slots even better than tubes. Rotate the square tube 45 degrees and it will always find center. If you are forced into using a single loop in the future, consider drilling a hole SMALLER than the rod or just using a rat-tail file to cut an inverted keyhole slot then file the edges to 45 degrees either side. This will wedge the 'loop' into a fixed position and lock rotational vibration (it can still swing like a bell though). Bonus the hook will still have the positive return as above so even if you rotate your hands the hot piece won't slide-off and hit the floor.

(I'm sorry, I shouldn't be critiquing from a distance. If you want I can stop.)

Luck!
Sean

Sean Powell wrote:That's a pretty ingenious solution. But realize that your hook is now an L and if the front of the L sags the armor piece may want to slide off. If the heavier hook reaches all the way through and then turns up it will help. You can even file the tip smooth like a fish-hook to aid entry.

2 possible future improvements: Rods like to sit in V-slots even better than tubes. Rotate the square tube 45 degrees and it will always find center. If you are forced into using a single loop in the future, consider drilling a hole SMALLER than the rod or just using a rat-tail file to cut an inverted keyhole slot then file the edges to 45 degrees either side. This will wedge the 'loop' into a fixed position and lock rotational vibration (it can still swing like a bell though). Bonus the hook will still have the positive return as above so even if you rotate your hands the hot piece won't slide-off and hit the floor.

(I'm sorry, I shouldn't be critiquing from a distance. If you want I can stop.)

Luck!
Sean

The v rod concept could be achieved by welding the square tubing to the cross support so that a corner of the extrusion points upwards rather than welded to the flat wall of the extrusion. Self centering then as you mentioned. Not sure if it is worth it at this point.

Thanks for showing all of this process Mac. I feel I will be at least a little better prepared to heat treat once I get a chance to try it.

Sean Powell wrote: If you want my further intuition: I like the orientation that the feet put the frame in but I can't 'feel' the weight on the fauld and know if it will sag under heat. If the weight of the fauld would have caused the frame to fall that way without the feet then it will put pressure as if it were falling that way onto the feet. The more the feet flex, the farther it will lean increasing the load on the feet until it falls anyway. Depends how soft the mild steel gets at temperature. If you had some 1/4" round stock or similar I'd connect the feet back to the legs like a triangle or perhaps up near the lifting point. And maybe even connect the feet for overkill. Don't just think triangles, think tetrahedrons or pyramids.

Sean

I missed this post the other day, and just now read it. I am worried about the feet as well. As you say, it depends on whether the angle iron can bear the bending load at orange heat.

If I set up a scale and measure how much weight the ends of the feet are feeling do you think you can make a guess about whether or not they need additional bracing?

Mac

Sean Powell wrote:That's a pretty ingenious solution. But realize that your hook is now an L and if the front of the L sags the armor piece may want to slide off. If the heavier hook reaches all the way through and then turns up it will help. You can even file the tip smooth like a fish-hook to aid entry.

My original plan was to turn the end up a bit, but it turns out that there is almost no tendency to slip and disengage. I am surprised and delighted to be able to do without it.

Sean Powell wrote:2 possible future improvements: Rods like to sit in V-slots even better than tubes. Rotate the square tube 45 degrees and it will always find center.

I was all prepared to do just that, but for the sake of experimental convenience I clamped the tube in place flat and found it worked just fine. The tube is not much bigger than the rod, and there is not enough slop to cause trouble. Also, it's just plane easier to weld it on flat than at 45°, so I did the quick and dirty thing.

Sean Powell wrote:If you are forced into using a single loop in the future, consider drilling a hole SMALLER than the rod or just using a rat-tail file to cut an inverted keyhole slot then file the edges to 45 degrees either side. This will wedge the 'loop' into a fixed position and lock rotational vibration (it can still swing like a bell though). Bonus the hook will still have the positive return as above so even if you rotate your hands the hot piece won't slide-off and hit the floor.

I had been thinking about that, but had not done any experiments. I will try to remember it if I need it in the future.

Sean Powell wrote:(I'm sorry, I shouldn't be critiquing from a distance. If you want I can stop.)

Luck!
Sean

Your input is very valuable, Sean. I look forward to your posts as reality checks. It's reassuring when I see that we have covered the same ground and eye opening when I see that I've missed something.

Mac