Vacuum Annealer?

[Crossbolt]

I've been making inquiries to see if I can locate a firm in the USA that will vacuum anneal an action so I can engrave it. It occurred to me that someone here may already have been down this path. Does anyone know of a vacuum annealing business that will handle such small quantity work?

 

[SamW]

I assume you are trying to avoid scale formation? There are powders available to coat the parts to stop that problem. I have been using Brownells PCB powder. You heat the part(s) to 500 degrees and emerse into the powder which forms a crust on the metal. After annealing and cooling you rinse the crust off with water. Has worked great for me.

 

[Crossbolt]

I assume you are trying to avoid scale formation? There are powders available to coat the parts to stop that problem. I have been using Brownells PCB powder. You heat the part(s) to 500 degrees and emerse into the powder which forms a crust on the metal. After annealing and cooling you rinse the crust off with water. Has worked great for me.

SamW
Yes I'm wanting to avoid scale because it's an existing gun so I don't want any alteration of dimensions, particularly fitting surfaces . Removal of scale would almost certainly create reassembly and fit problems. Interesting product. I'll look into it although I'm still hoping for some vacuum annealing inquiries to pan out. Thanks
Jeremy

 

[mitch]

I assume you are trying to avoid scale formation? There are powders available to coat the parts to stop that problem. I have been using Brownells PCB powder. You heat the part(s) to 500 degrees and emerse into the powder which forms a crust on the metal. After annealing and cooling you rinse the crust off with water. Has worked great for me.

What sorts of parts are you annealing, Sam?

 

[SamW]

Actions, levers, hammers, forearm caps, butt plates.

 

[tdelewis]

I'm not sure but Turnbull might be able to prepare those parts for engraving.

 

[Archie Woodworth]

Often a stainless steel bag is made (folded around item) to wrap item in prior to putting in heat treat furnace. https://www.brownells.com/gunsmith-.../stainless-steel-heat-treat-foil-prod714.aspx

If you are using an electric furnace, I guess you could always place item in tray and flow argon over it during treating process....that should shield item and keep O2 off metal.

 

[Travis Fry]

In the knifemaking world we typically use either an antiscale compound like the PCB powder mentioned above (which I don't care for) or one based on refractory clay (like Nuclayer, which I do like), or the stainless foil also mentioned above. I typically use Nuclayer for carbon steels and stainless foil for stainless steels. Some folks do argon purge, but nobody, to my knowledge, uses vacuum. My advice would be to contact Peter's Heat Treating (not sure links are kosher, but the name is all you need) or a local industrial heat treater (which are more common than you might think) and let them know what you're trying to accomplish and why. Peter's is the go-to outfit in the custom knife scene; they'll know what to do. Alternatively, there are quite a few professional knifemakers in Utah that could likely help you out. I really think vacuum is overkill.

 

[Leland Davis]

When I need to anneal a case hardened action I pack it in the same bone and wood charcoal that I will use to case color it. heat to 1350 let it soak for an hour then shut off oven and come back in about 15 hours. It will be annealed without scale. It will need to be polished. I may be doing it wrong but has always worked for me.

 

[Crossbolt]

I'm not sure but Turnbull might be able to prepare those parts for engraving.

Yes I've got a detailed inquiry in to them. I don't think vacuum annealed probably reducing or scale prevention coating . Perhaps that is all that is needed

 

[Crossbolt]

When I need to anneal a case hardened action I pack it in the same bone and wood charcoal that I will use to case color it. heat to 1350 let it soak for an hour then shut off oven and come back in about 15 hours. It will be annealed without scale. It will need to be polished. I may be doing it wrong but has always worked for me.

Good to know. I may go that route as vacuum may be overkill. I have a vacuum annealing quote of about $500 but requesting steel composition which isn't available so a reasonable assessment would be needed

 

[Crossbolt]

In the knifemaking world we typically use either an antiscale compound like the PCB powder mentioned above (which I don't care for) or one based on refractory clay (like Nuclayer, which I do like), or the stainless foil also mentioned above. I typically use Nuclayer for carbon steels and stainless foil for stainless steels. Some folks do argon purge, but nobody, to my knowledge, uses vacuum. My advice would be to contact Peter's Heat Treating (not sure links are kosher, but the name is all you need) or a local industrial heat treater (which are more common than you might think) and let them know what you're trying to accomplish and why. Peter's is the go-to outfit in the custom knife scene; they'll know what to do. Alternatively, there are quite a few professional knifemakers in Utah that could likely help you out. I really think vacuum is overkill.

Thanks. I'm starting to think vacuum may be a bridge too far.

 

[Crossbolt]

Often a stainless steel bag is made (folded around item) to wrap item in prior to putting in heat treat furnace. https://www.brownells.com/gunsmith-.../stainless-steel-heat-treat-foil-prod714.aspx

If you are using an electric furnace, I guess you could always place item in tray and flow argon over it during treating process....that should shield item and keep O2 off metal.

Interesting. I wonder if that can be combined with chemical anti scale in a belt and suspenders approach

 

[Travis Fry]

Interesting. I wonder if that can be combined with chemical anti scale in a belt and suspenders approach

I think that would work rather well. The slight risk with stainless bags is distortion, but that's nearly always induced by moving pieces when they're hot, and it's only a risk when you want to open the bag to quench something. In this case, getting them up to the right soak temp for the required amount of time and letting them cool in the kiln (in the bag) should eliminate that possibility. You still might get some distortion, however; if there's any stress in the steel to begin with, relieving it by annealing could make the steel move. Again, it's not a high risk, especially at annealing temps. Honestly, the main risk with bags is that the stainless foil will cut you if you look at it wrong. Be careful.

 

[silvermon]

Often a stainless steel bag is made (folded around item) to wrap item in prior to putting in heat treat furnace. https://www.brownells.com/gunsmith-.../stainless-steel-heat-treat-foil-prod714.aspx

If you are using an electric furnace, I guess you could always place item in tray and flow argon over it during treating process....that should shield item and keep O2 off metal.

Adding pure charcoal helps outside or inside the stainless bag. I usually only put it inside, if the charcoal is very high grade. If it's charcoal I pull from one of my wood stoves, I use it outside the bag. Not as good, but seems to add some protection. Everything depends on the amount of air exchange your oven has.

 

[Travis Fry]

Adding pure charcoal helps outside or inside the stainless bag. I usually only put it inside, if the charcoal is very high grade. If it's charcoal I pull from one of my wood stoves, I use it outside the bag. Not as good, but seems to add some protection. Everything depends on the amount of air exchange your oven has.

You can get the same effect by wrapping the material in a paper towel or newspaper before wrapping in foil. It'll rapidly become charcoal. Or you could dunk in kerosene before or after wrapping, which I just thought of and have never tried, but might on my next go just to prove my point to myself. The goal of any of that is to remove any residual oxygen in the stainless bag, but since those aren't truly airtight anyway, I rarely bother.

 

[silverchip]

I asked P.V.Nelson what steel they used to make their actions with. He told me it was high quality low carbon steel. Perhaps like 1045. My inquiry was aimed at the engravabilty of the guns before heat treating case hardening. Basicly I am jealous that european guns get engraved before hardening. I have sent gun parts to a place in Salt Lake for normalizing before engraving. It helped but still was not dead soft like mild steel plate that we practice on.