Treating a mold with HBN

[Dragonheart]

Has anyone has tried treating their molds with (HBN) Hexagonal Boron Nitride? I treated a 45 caliber 4 cavity Saeco Mold this weekend then ran a 20# pot of metal through it. I cannot believe the difference, most of the bullets just fall out of the mold as the mold is opened or only needs a gentle tap. I believe the cast bullet's surface has improved also. The HBN doesn't color the metal, but leaves the metal extremity slick as it is actually a ceramic the is so fine it penetrates into the pores of the steel. HBN is temperature stable to over 3000 degrees F.

HBN is typically used in gun barrel coating and is supposed to be good for the life of the barrel. I plan to treat the remainder of my molds and probably my pistol barrels just for the corrosion and fowling resistance.

I was just wondering if anyone out there has played around with HBN and what their results were?

[nhrifle]

Curious about this. What is your process and what does it take to get set up?

[country gent]

I am interested after reading your post. What is the process of coating the mould? just the cavities or all of the blocks and sprue plate?

[CastingFool]

I did a quick search and found this link:

http://sandblastingabrasives.com/hex...-page-781.html

Notice the suggested uses: release agent, and lubrication.

[Dragonheart]

To begin with I purchased the HBN at Lower Friction( http://lowerfriction.com/product-page.php?categoryID=2 ) a Canidian Company. My main purpose was to use the material to coat gun barrels and bullets. I also started powder coating bullets instead of traditional lucubration a short time ago and was thinking HBN also might be useful in this process. After seeing how slick the finish is on bullets I thought this might work on bullet molds and if it does the same for bullet molds it will be terrific.

To start, I separated my mold into three pieces, two halves and the sprue plate. I then put each part into a separate plastic jar with a screw on lid and added about 1/4 cup of plated BB's and about half a teaspoon of HBN to each jar. I added a layer of of plastic off a freezer bag over the mouth of the jar then screwed down the lid. I then sealed the lid with a wrap of duct tape. HBN is so fine it can travel around the screw threads of a container. I placed the three containers in the media of my Dillon 2000 tumbler and let the tumbler vibrate and turn the jars. This is a gentle process and also works well in coating bullets. After 3 or 4 hours I removed the contents and towel/brushed off any excess powder on the parts. The mold looks the same, but is now super slick. Since my first mold has only gone through 20#s of lead I cannot comment on the longevity, but so far I am sold on the results. I have not added any lubricant for protection of the mold as I want to see if it is also protected against corrosion.

Caution is a must in handling HBN, especially the 70 nano meter size, which is smaller than a human skin pore. When handling this material I wear a full face respirator, gloves and long sleeves, just on be on the safe side. If everything I read about barrel coating is true this process supposedly is a life time treatment for both fowling and corrosion.

I was just curious is anyone else had used HBN for this or any other purpose. I did try mixing some HBN with my bullet powder coating to see what effect it might have. The powder coated bullets lost the luster they usually have, but they seemed to glide through the sizing die with little effort. I may play around with this in the future, but the standard powder coating process eliminates the need for greasy lube, leaves the barrels clean and appears to improve accuracy, so it's hard to improve on this process.

[Echd]

While nowhere near as good of a value, here is a much smaller amount for about $15 shipped. I'm assuming like moly a little goes a long way, so I can't see myself ever using $100 of HBN.

http://www.amazon.com/Reloading-Hex-...+boron+nitride

[Forgetful]

http://www.caswellcanada.ca/shop/boron-nitride-kit.html

There is probably something similar, if not better, available within the US.. This would be the way to apply it anyway:

Ideal for all types of guns, engine pistons, fry pans, in fact anywhere where dry lubrication and non-stick is an issue. We see interesting potential in lining parts of Paintball Guns to prevent wear of the soft aluminum.


The coating can be applied in 20 minutes, to aluminum, steel, nickel, copper, brass and bronze. Other metals can be treated as long as a nickel plate is previously applied.


Where corrosion may present a problem (such as on steel) the part should be previously plated with at least 0.0002” of Electroless Nickel plate. Generally gun components can be plated directly without a base primer of nickel.


The coating is applied at 0.0002” in 20 minutes. The system runs exactly the same as Caswell Electroless Nickel, except that it has a special filter pump, which agitates the Boron Nitride powder, keeping it in suspension. . The pump has a plastic tube, which should be secured to the pump body aiming the jet towards the bottom center of the tank. As the nickel is plated onto the surface, the minute particles of Boron Nitride are bonded all over the surface of the nickel, giving the part unique properties.


The kit includes a glass lined tank and thermometer, and is heated by placing the tank on a hotplate or stovetop. The system should be operated between 165 deg F and 185 deg F. In an ambient room temp (approx 70 deg F) a 1.5 gal setup will take approx 20 minutes to cool to the minimum operating temperature of 165 deg F., so no further heating should be required. Careful attention to temperature during the last 10 minutes may show the need for a short burst of heat from the heaters. Operating at above 185 deg F will cause the bath to plate out too rapidly and it will start to deteriorate.


The system requires constant agitation, so a pumping system is required. The pump must be able to withstand 185 deg F. If you do not have such a pump, we sell an optional unit. You will also need fittings and tubing to connect the pump to the plating tank - available in any hardware store.


After plating, the pump should be left to run until the solution temperature has reached ambient again. At this point the plating reaction ceases. Failure to do this will result in the BN particles dropping to the bottom of the tank, where they will be plated into a solid mass. This will ruin both the particles and the solution. The bath must be maintained at between 70-105% nickel content by replenishing with Part A & Part C.


The BN Particles are slowly depleted from the solution. However, there will always be about 50% of these left over after 5 nickel replenishments. To recover the BN particles, the solution may left idle for 3-5 days and they will settle on the bottom. The spent solution may be carefully siphoned or decanted off and the BN particles may be re-used if they are free from nickel. For high output users, this may be an economical saving, as BN particles are a major expense of the kit. There is a special retrieval procedure involving nitric acid, which will remove the nickel. This information is available on request.
The BN EN finish has a satin look to it.

[Dragonheart]

Agreed, a little HBN goes a long way. My one pound will probably be a lifetime supply. As far as something better to reduce friction than HBN I don't think you are going to find anything better that's available to the public, affordable and a one time treatment, if you do please let me know. I think my tumble process is pretty simple and appears to work. HBN is temperature stable to 3000 degrees F and so far seems to be a one time coating. Since it actually impregnates into the metal I would say it is more in the line with changing the metallurgy than a coating.

I started bullet casting almost 50 years ago and have done it off and on since. I have about 15 different molds; Ideal, Lyman, Saeco and a couple of Lee. I have never had any mold drop the bullets as easy as the mold I treated with HBN, whether the mold was clean, smoked, or sprayed with a mold lube like Brownells. As you know when the bullets just fall out the whole process is much faster, especially running two 4 cavity molds at a time. Also when things run smooth it is a whole lot less frustrating. So I am now in the process of treating the rest of my molds.

I have just coated my first pistol barrel so I will see how that works out.

[Forgetful]

In another thread I experimented with a satin coating on brass, using copper sulfate and water only. It was hard enough not to rub off by hand, even with pressure. In fact, the friction ridges in my fingerprints seemed to polish it further and remove excess 'powder', as how it felt but I could not see any trace on my fingers. It was also delicate enough to easily polish off with a steel wool rotary brush, in one stroke by hand. Such coatings won't hold up against the sprueplate, and may interfere with mold mating (or tighten tolerances but wear out before it can be appreciated). I'm unsure how HBN would hold up, but any satin finish/patina would be perfect inside the cavity. HBN has a hardness comparable to graphite.