hardfacing a helmet

[Johann Lederer]

Here is a question I have had for a while...

Is it possible to hardface* a helmet with welds (on the inside) to increase its dent resistance?


*Hardfacing like hardfacing an excavator bucket

[Sean Powell]

From what little I understand hardfacing is laying down a higher carbon steel in a welding process to make a 'hard candy shell'. I suppose it would be possible but about as obnoxious as coloring the inside and outside of a helm black with a sharpie marker and then heat treating followed by grinding the entire surface smooth again. It's a better process for making anvil tops.

Case hardening on the other hand has been done to convert the outer layer of mild steel into a higher carbon spring steel and then followed up with a heat-treating process. Since the case hardening can be done by submerging the workpiece in carbon powder or certain gas environments so the entire surface is treated at the same time I think it would be more efficient.

Sean

[Johann Lederer]

Sean,
That certainly makes sense. I was looking at the cost factor. I have a friend who hard faces excavator buckets and he asked me why we did not do that to our helmets. In my area a solid hit to 14 ga mild steel will equal a decent dent and I was trying to cut down on that in addition to getting better at blocking (LOL)
I know you have investigated hardening helmets. What kind of prices were they looking at to do a helm? and, is there any place in Pa, that would do such a thing?

[Sean Powell]

I haven't really investigated it thoroughly. I asked about it on the archive and did a google search. You could probably dig up the thread for reference.

There are a few armorers who have outsourced doing it to professionals and gotten good results (Ugo) and some who have had to do major re-shaping after the helm came back (Mac?). There are a few industrial shops within 25-30 miles of where I work (some that my job has experience with but I do not) that are capable of doing the work but I haven't talked to them about pricing yet. Case hardening a bunch of gears in easy and they can quote if based on diameter and hub length. Bracing and support for a helm with liftable and interchangible visors is an entirely different beast. I was going to wait for my new helm to arrive before carrying it around and asking for prices in person.

Please note: case hardening applied ONLY to mild or low carbon steels. There is a similar process for stainless called kolsterizing but you want to specifically work in 316L and not 302 or 304.

Do they really hardcoat the ENTIRE excavator bucket? I thought they just hardcoated the teeth?

Sean

[mattmaus]

I put some gussets in my latest one.

Not my idea, but it is friggin brilliant I think.

[img]http://members.armourarchive.org/mattmaus/shpanglygus.jpg[/img]

I also know one of our local Dukes case hardened his whole helmet with Kasenit. Based on his story about drilling holes in it after the fact, I'm thinkin it worked pretty well.

[AwP]

What about maybe putting a grid of beads on the inside?

[chris19d]

or just make it out of SS, 12g mild, or spring

[D. Sebastian]

I'm thinking that if the shot is going to dent my helm, that's force absorbed that my head isn't subject to.

YMMV

[Johann Lederer]

Do they really hardcoat the ENTIRE excavator bucket? I thought they just hardcoated the teeth?

Sean

They do the sides and bottom pretty frequently. The teeth they replace when they get too rounded to rip up the ground.

I kind of like what Mattmaus did with the gussets and was saying about Kasenit. I have used Kasenit on frizzens and repaired tumblers for firearms, and it is relatively easy to use. It may take a lot more than what I have in the shop though.

I agree with what D was saying about absorbing the energy too, I just hate removing dents.

[Thomas Powers]

Note that hardfacing is generally done to resist ABRASION. If you are abrading through the metal of your helmet with your head or rattan you have a bigger problem!

Thomas

[Sean Powell]

Well the answer is obvious. Take an old helmet to your friend as ask him the cost to hard-coat it... then have HALF of it hardcoated, set it on the pell and take a nice piece of black-iron pipe and try to dent-it. See if it is cost-justifiable.

If you decide to go the Kasenit way (which is what many profesionals uese also) then remember that you want to cover the part but that DOESN'T mean you need to fill the bucket. You can put a steel can (vented) inside the helm where the head goes to take up space. Air is a lot cheaper then Kasenint.

Sean

[Johann Lederer]

Note that hardfacing is generally done to resist ABRASION. If you are abrading through the metal of your helmet with your head or rattan you have a bigger problem!

Thomas

Yeah, that would be bad, especially if it is denting also!

[Destichado]

There seems to be a degree of confusion here among some posters. HARDFACING and CASE HARDENING are two very different things.


Hard-Facing is using a welder, usually MIG, to deposit high-carbon weld-metal onto a surface that's either a) softer than the weld, or b) abraded away and needs to be built back up.

Case-Hardening is using a carbon powder, usually a box full of graphite or a specialty compound, to improve a piece of steel by increasing its carbon content via carbon-migration at sustained high temperatures.


I'm of the opinion that Hard Facing might well have some value in armoring.
If I were doing it myself, I think I'd use a thinner base metal than usually necessary, and run a lattice of wide, shallow beads in high target areas.