March
S M T W T F S
1 2
3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
31
Who's Online Now
9 members (Jimmy W, fullandfuller, craigd, Lloyd3, gasgunner, 1 invisible), 303 guests, and 3 robots.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums10
Topics38,373
Posts543,980
Members14,389
Most Online1,131
Jan 21st, 2024
Previous Thread
Next Thread
Print Thread
Page 2 of 4 1 2 3 4
PhysDoc #575238 07/09/20 09:43 PM
Joined: Feb 2002
Posts: 1,850
Likes: 150
Sidelock
***
Offline
Sidelock
***

Joined: Feb 2002
Posts: 1,850
Likes: 150
If you Nitre Blue but run the temp of the Nitre salts up to 830/850F,,you will get the (near) same deep blue/black color as that of charcoal blueing.
Actually the color will look closer to that done with the American Gas Furnace rotary furnace method.
True Charcoal blue has a slightly 'bluer' tone. But steel type, polish and who's doing the actual bluing all come into play just as in any finishing work.

Don't take the temp much above 850F.
Don't get it near 900F or you'll get a grey color on the parts and that'll be the end of that for the parts as far as coloring them.
You'll have to pull them out, allow to cool. Then re-polish and start again.
That grey color happens just before the steel starts to turn red (heat). That red heat point is right around or at 900F I figure from the mistakes I've made.!

I've mentioned the use of the high-temp Nitre salts a few times, maybe here and other Forums. Never got much response about it.

Like the lower temp Nitre Bluing done at the 650F range, the higher the polish,,the brighter the 'Blue'.
Don't be shy about a high polish. But a sloppy polish won't be hidden by this blue or any other.

This process can be incredibly dangerous as you now have a big container of Sodium Nitrate at 850F and you must keep it at that temp of 850F through the entire bluing time.
Keep any moisture far away,,just like when casting lead. Very explosive reaction.
Safety measures/clothing/eye protection. Even then this stuff if it ends up on you will burn through most anything you can wear and then burn down into your skin.
Anything in your eye,,your eye is gone.

It's hotter than lead is during bullet casting & the quantity can be a lot more when you want to immerse long parts like straight grip trigger guards and bolt rifle triggerguard/magazines completely in it. The parts must not touch the sides of the container. They can hang from wire.

It can take a big heat source to get you there and keep you there.

Smaller parts like latches, sights, screws, ect can be more easily & safely done in a smaller container.
I used to do some restoration parts that way after using the same bath at a lower temp to either spring temper and/or common Nitre Blue some parts that I could do at the same time.

Kutter #575244 07/09/20 11:04 PM
Joined: Sep 2011
Posts: 150
Likes: 2
Sidelock
**
Offline
Sidelock
**

Joined: Sep 2011
Posts: 150
Likes: 2
Good comments. Never tried the higher temperature. Heat source limited to about 700F.
Use nitre fertilizer from the garden store, Goodwill stainless pot and a lead thermometer.
Nice blue on screws, etc. and the most reliable way to temper springs.
Chuck

PhysDoc #575247 07/09/20 11:12 PM
Joined: Jan 2004
Posts: 6,664
Likes: 372
Sidelock
**
Offline
Sidelock
**

Joined: Jan 2004
Posts: 6,664
Likes: 372
Thanks Kutter. I have some small parts that can easily be held in a 20# lead pot. I may have to give this a go.

Nitre fertilizer? Really? I'm not sure what that is. I see lots of fertilizers but they all contain a lot of other things as well.


_________
BrentD, (Professor - just for Stan)

[Linked Image from i.imgur.com]


PhysDoc #575262 07/10/20 10:13 AM
Joined: Jan 2004
Posts: 6,664
Likes: 372
Sidelock
**
Offline
Sidelock
**

Joined: Jan 2004
Posts: 6,664
Likes: 372
If you are worried about moisture in an action or other part that you are about to plunge into 800+ degree lead (and you should be), you can preheat the part on a hotplate to well over 212F for some period of time to ensure that moisture is gone.

I regularly preheat moulds and ladles for just this reason.


_________
BrentD, (Professor - just for Stan)

[Linked Image from i.imgur.com]


PhysDoc #575266 07/10/20 11:21 AM
Joined: Jan 2002
Posts: 7,698
Likes: 99
Sidelock
***
Offline
Sidelock
***

Joined: Jan 2002
Posts: 7,698
Likes: 99
Molten lead scares the bejeebers out of me. Watching those guys on TV heat a knife red hot and then poking it into oil does too...Geo

Joined: Jan 2009
Posts: 381
Likes: 8
Sidelock
**
Offline
Sidelock
**

Joined: Jan 2009
Posts: 381
Likes: 8
Originally Posted By: Geo. Newbern
Molten lead scares the bejeebers out of me. Watching those guys on TV heat a knife red hot and then poking it into oil does too...Geo


If no volatiles (water esp) then should be no problem.
I use lead for tempering springs, at 600F

Last edited by DmColonial; 07/10/20 11:40 AM. Reason: info

Dumb, but learning...Prof Em, BSc(ME), CAE (FYI)
PhysDoc #575271 07/10/20 12:51 PM
Joined: Feb 2009
Posts: 7,441
Likes: 204
Sidelock
**
Online Content
Sidelock
**

Joined: Feb 2009
Posts: 7,441
Likes: 204
I think the fertilizer thoughts are referring to potassium nitrate, also easily found in stump killer. Its usually mentioned for nitre blue colors, but might benefit from checking if running up to the carbona black color. Low temperature heat treating salts are easily available and would cover that mid 800* range if the color was just temperature dependent.

PhysDoc #575278 07/10/20 02:01 PM
Joined: Feb 2002
Posts: 1,850
Likes: 150
Sidelock
***
Offline
Sidelock
***

Joined: Feb 2002
Posts: 1,850
Likes: 150
Potassium Nitrate should work for this.
I've used it for 'regular' Nitre blue and spring tempering.

We even did some coloring in a certain shop I worked in using Ammonium Nitrate fertilizer melted at high temps to try and mimic AH Fox cyanide case colors.
Not completely successful!, but not a total failure either as far as getting some different colors to appear.
I suspect some other chemical salts were dumped into the mix as well. Shade Tree Science.
It's just plain scary to work around that large of a batch of any of this stuff,,at least for me it is. Too many things can go wrong,,and fast.

Disposing of the entire super heated batch while still liquid was the biggest trick of that operation.
Calling the experiment a failure, but trying to save the large heating pot before the stuff cooled and became a solid mass inside of it.
Very lucky no one got hurt on that one.
It was decided to continue to use Heinzelmann's after that circus act.


As far as getting any moisture off of and out of any parts before they go into the Nitre,,that's something you have to be absolutely sure of. That there IS no moisture involved.
Doesn't matter if you're are working with the stuff at 650F or 850. The results will be the same and not pleasant.

Slowing warming them is the best after a wipe down. All this after a thorough degreasing.
Nitre will not degrease the parts for you. Just like regular bluing, any oil, grease, fingerprints will show in the new blue.
Silicone oil is particularly hard to get rid of. Usually shows up as tiny white specks.

Water...If you warm the steel parts too quickly to make sure they are dry of all moisture you risk having them flash rust in front of your eyes.
Those areas of that very slight rust will not blue or will be off colored reddish, brown or even grey.

The water may also bead up as any excess moisture in a high humidity environment evaporates and as the last tiny bead of water leaves the surface,,a small speck of mineral deposit is left behind.
There's a blemish spot in the new bluing.
Plus usually a halo blemish around it where the water evaporated.

Dry environment, wipe down carefully and inspect.
Then quickly into the Nitre. Don't let parts set around more than an hour or so after final POLISHING as they will start to form an oxide though you can't see it. It will effect the blue and all your work. If they have to sit,,oil them.

When de-oiling and cleaning for bluing,,do it right before the parts go in the Nitre.
When the hot parts come out, they probably will have some nitre on them in places and it will harden to a white coating.
Leave it alone and let the part cool off with the coating on it.
It's still way too hot to put under even the hottest tap water you might have.
There's a real possibility of the stuff splattering yet if hit by water in trying to rinse the excess Nitre from the surfaces of the parts.

Once you do rinse them and inspect them, if you find some blemishes you can SOMETIMES touch up the areas and place them back into the Nitre after cleaning and making sure that all the WATER is once again removed.

Sometimes this re-Nitre attempt doesn't work and you are forced to let them cool,,strip the old finish, repolish, touch up and engraving if necessary and then go again thru the whole operation. Best to do all your parts one time thru and then decide if one or more need any re-bluing

This strip, re-polish and nitre again usually means shutting the Nitre pot down while you do the prep work if you have more than a part or 2 to do.
So a re-start of the pot once again with all the necessary work and time involved.

Like a lead pot,,don't leave the thing un-attended or open to unauthorized persons from possibly getting to it while you are not around such as during it's cool down phase.

Happy Nitre Day

craigd #575280 07/10/20 02:21 PM
Joined: Feb 2008
Posts: 11,313
Likes: 378
Sidelock
**
Offline
Sidelock
**

Joined: Feb 2008
Posts: 11,313
Likes: 378
Originally Posted By: craigd
I think the fertilizer thoughts are referring to potassium nitrate, also easily found in stump killer. Its usually mentioned for nitre blue colors, but might benefit from checking if running up to the carbona black color. Low temperature heat treating salts are easily available and would cover that mid 800* range if the color was just temperature dependent.


Correct craigd. Ammonium nitrate would decompose explosively at a much lower temperature of 390-400 degrees F. Potassium Nitrate melts at about 633 degrees F and begins to boil at 752 degrees F.

The stump killers and fertilizers are not pure lab grade product, so these temps may not apply exactly. A pot of previously melted salts may erupt explosively when re-melted unless there is a means for pressure to escape.


A true sign of mental illness is any gun owner who would vote for an Anti-Gunner like Joe Biden.

PhysDoc #575284 07/10/20 02:58 PM
Joined: Jan 2004
Posts: 6,664
Likes: 372
Sidelock
**
Offline
Sidelock
**

Joined: Jan 2004
Posts: 6,664
Likes: 372
Kutter,
I've never had flash corrosion from heating too fast. But it is usually convenient to plug in the hot pot you will be heating your PNO3 or your lead pot and, at the same time, plug in your hotplate with the parts on it to be warmed. This is standard bullet casting procedure. The plate heats up gradually and brings the parts up to temperature with it. I do not know how hot my plate is, though I could measure it, if anyone cares to know. I just have it cranked over to 3/4 of max. I also throw a double or triple layer of heavy duty aluminum foil over the mould, part, or tool to be heated. This helps the piece warm evenly.

Doing this with the casting ladle is especially helpful since the grunge on any ladle seems to attract moisture from the air. Heating it minimized the vibration and "boiling" that comes from immersing it deep into the pot for that first helping.

If you have not worked with high temp liquids like this, you just need to be careful and wear only cotton, leather, or maybe wool clothing. NO NYLON BOOTS OR SHOES OR ANY SYNTHETIC CLOTHING! Lead goes through synthetics much faster than a hot knife through butter. A shooting friend dropped a pot of lead on nylon hiking boots with disastrous results.

I have once time poured hot lead into a cold, dusty/dirty Bar ingot mould. The dust and dirt had accumulated some moisture and the mould emptied before it was even close to full. Some lead got thrown around the garage and the lesson was learned. Clean, dry, warm is safe. Everything else is not.


_________
BrentD, (Professor - just for Stan)

[Linked Image from i.imgur.com]


Page 2 of 4 1 2 3 4

Link Copied to Clipboard

doublegunshop.com home | Welcome | Sponsors & Advertisers | DoubleGun Rack | Doublegun Book Rack

Order or request info | Other Useful Information

Updated every minute of everyday!


Copyright (c) 1993 - 2024 doublegunshop.com. All rights reserved. doublegunshop.com - Bloomfield, NY 14469. USA These materials are provided by doublegunshop.com as a service to its customers and may be used for informational purposes only. doublegunshop.com assumes no responsibility for errors or omissions in these materials. THESE MATERIALS ARE PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANT-ABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. doublegunshop.com further does not warrant the accuracy or completeness of the information, text, graphics, links or other items contained within these materials. doublegunshop.com shall not be liable for any special, indirect, incidental, or consequential damages, including without limitation, lost revenues or lost profits, which may result from the use of these materials. doublegunshop.com may make changes to these materials, or to the products described therein, at any time without notice. doublegunshop.com makes no commitment to update the information contained herein. This is a public un-moderated forum participate at your own risk.

Note: The posting of Copyrighted material on this forum is prohibited without prior written consent of the Copyright holder. For specifics on Copyright Law and restrictions refer to: http://www.copyright.gov/laws/ - doublegunshop.com will not monitor nor will they be held liable for copyright violations presented on the BBS which is an open and un-moderated public forum.

Powered by UBB.threads™ PHP Forum Software 7.7.5
(Release build 20201027)
Responsive Width:

PHP: 7.0.33-0+deb9u11+hw1 Page Time: 0.074s Queries: 35 (0.053s) Memory: 0.8682 MB (Peak: 1.8987 MB) Data Comp: Off Server Time: 2024-03-28 11:58:49 UTC
Valid HTML 5 and Valid CSS