Hi tek flaking off

[popper]

I wonder if vinegar would work better. It will remove salts and base contamination but I found it etches lead good and may add porosity to the surface for better adhesion. It also produces the white toxic solution that must be handled carefully but I had an experience with HCL I don't want to repeat. the posted 'hammer' tests look much like mine - pounding on the concrete floor will cause some chipping of the coating. They still shoot good.

[HI-TEK]

I wonder if vinegar would work better. It will remove salts and base contamination but I found it etches lead good and may add porosity to the surface for better adhesion. It also produces the white toxic solution that must be handled carefully but I had an experience with HCL I don't want to repeat. the posted 'hammer' tests look much like mine - pounding on the concrete floor will cause some chipping of the coating. They still shoot good.

Popper,
Good point.
Vinegar should work also, but much slower.
Household Vinegar is very dilute.
All metals that dissolve with Vinegar will be totally water soluble.
I suppose that after soaking in Vinegar for a few days, you can always use a fresh lot
of Vinegar to see if any more contaminations are removed.
Unfortunately Aluminium dissolves very slowly in Vinegar, so if that is
a major contaminant then it will take a long time soaking in Vinegar.

[Petander]

Now we're talking HCL!

Attachment 222855.

Different alloys,different reactions. In the middle are bleach-soaked bullets that bleach made rust brown.

My ingots are 15-20 kg, I can easily analyze each and proceed accordingly. I have marked the linotype content, nothing else. Contamination didn't bother me when I made them 15 years ago. Casts and shoots fine trad lubed.

I may end up learning how to clean the alloy instead of bullets. But I do like very much the fact that now I can get Hi-Tek bonding!

I may need a 45-70 now. Again.

[HI-TEK]

Now we're talking HCL!

Attachment 222855.

Different alloys,different reactions. In the middle are bleach-soaked bullets that bleach made rust brown.

My ingots are 15-20 kg, I can easily analyze each and proceed accordingly. I have marked the linotype content, nothing else. Contamination didn't bother me when I made them 15 years ago. Casts and shoots fine trad lubed.

I may end up learning how to clean the alloy instead of bullets. But I do like very much the fact that now I can get Hi-Tek bonding!

I may need a 45-70 now. Again.

Petander,
Looking at your soaking buckets, can you describe each from left to right?

The bucket with a Greenish tint, (in the middle) if it is Acid wash, it seems to indicate Iron, Copper Nickel or Chromium, as those sort of metals will produce such colours with acid solutions of those metals.

That Is why I am asking about full description of your buckets.
The one furthest on the right, the metal is shiny and liquid has no colour.
Please advise/clarify.

[HI-TEK]

I wonder if vinegar would work better. It will remove salts and base contamination but I found it etches lead good and may add porosity to the surface for better adhesion. It also produces the white toxic solution that must be handled carefully but I had an experience with HCL I don't want to repeat. the posted 'hammer' tests look much like mine - pounding on the concrete floor will cause some chipping of the coating. They still shoot good.

How are you doing Popper,
I agree, that all called cleaners may pose toxity problems if not handled correctly.
If Acetic reacts with the alloys you used on the surface, it was probably Zinc, Magnesium and possibly Aluminium.
These will all easily react on surface of alloy, dissolve, and leave a porous surface ideal for coating.
I read on these blogs that after storage some coatings began spalling off alloy. I am almost certain that this was caused by these sorts of contaminants.
Having removed these contaminants, should allow long term stability of finished product.

[Petander]

Petander,
Looking at your soaking buckets, can you describe each from left to right?

The bucket with a Greenish tint, (in the middle) if it is Acid wash, it seems to indicate Iron, Copper Nickel or Chromium, as those sort of metals will produce such colours with acid solutions of those metals.

That Is why I am asking about full description of your buckets.
The one furthest on the right, the metal is shiny and liquid has no colour.
Please advise/clarify.

It's all HCL aka. Muriatic Acid. One part Acid,three parts water.

The bucket to the left is still bubbling after 24 hours,bullets are turning black. In the middle bucket I have bullets that I soaked in bleach,they were rust brown after the bleach soak. They turned almost white in a few hours in HCL and the bubbling stopped. The bullets to the right didn't react with HCL at all.

Here is the 9mm bleach soak result:

Attachment 222911

Here are the same 9mm bullets (plus some 30 cal bullets that did'react) after HCL bath:

Attachment 222912.


That 30 cal alloy must be pretty good.

[HI-TEK]

It's all HCL aka. Muriatic Acid. One part Acid,three parts water.

The bucket to the left is still bubbling after 24 hours,bullets are turning black. In the middle bucket I have bullets that I soaked in bleach,they were rust brown after the bleach soak. They turned almost white in a few hours in HCL and the bubbling stopped. The bullets to the right didn't react with HCL at all.

Here is the 9mm bleach soak result:

Attachment 222911

Here are the same 9mm bullets (plus some 30 cal bullets that did'react) after HCL bath:

Attachment 222912.


That 30 cal alloy must be pretty good.

Thanks Petander,
It is now more clear.
Goes to show, you have some greatly varying alloy mixes, some contaminated badly and others seem OK.
I can imagine, that the Leading problems all were with the contaminated alloys.
If the bucket that bubbled for 24 hours or longer, the Acid may have been used up.
I would test a few with fresh acid mix to see if more bubbling will occur. If not, wash well, and dry well, and have a look at surface of alloy.
It should be full of tiny pores.
That is perfect for coating.

[HI-TEK]

[QUOTE=HI-TEK;4400677]


Petander,
The frosty ones after bleach and acid soak, the surface of alloy has millions of tiny pockets/holes that is why it is not shiny,
Wash and dry them very well. Coat, dry and bake. Please post results.

[Petander]

[QUOTE=HI-TEK;4401191]

Petander,
The frosty ones after bleach and acid soak, the surface of alloy has millions of tiny pockets/holes that is why it is not shiny,
Wash and dry them very well. Coat, dry and bake. Please post results.

Excellent results in my usual .358 size for my Tanfoglio P90. I can shoot clays at 25 meters and hit them - and absolutely zero leading. Minimal burnt powder residue only.

I also loaded a couple of magazines in .357 size, just to see what happens. 357 is a lot easier to load for this pistol,feeding wise. And now I got zero leading with .357 as well. I always got leading in .357 size without coating.

358 is more accurate,very accurate indeed. But I find the 357 test interesting,an undersize bullet usually leads -and shoots-badly.

Overbaked again,I like to bake a bit too long now because I like what I'm getting.

Attachment 222981

Easy to size and load, no leading. Not much anything else either, VV 3N37 burns nice.

[Ausglock]

Virtually impossible to get 3N37 here now.
Bloody brilliant powder.

[Traffer]

Wow excellent thread. I learned a lot. I haven't tried Hi tek yet but may in the future. I too have some very strange alloys. Even having some fill problems now with molding. Looks like soaking the molded cores in Muriatic Acid will help me here. (I swage lead cores into 22lr boollits) If I read right, you are using 1 part Muriatic Acid and 3 Parts water? And am I correct in saying that Hi tek gives a more even coat than pc that is a little thinner? This may turn out to be ideal for 22lr boolits.

[Stephen Cohen]

It is ironic that this thread should come up now, I only just coated some .357 and .460 cast last week and found the coating could be picked off. I thought I had thrown all my badly contaminated lead in the sinker bin. I think I will have to do some more range lead scrounging as I am running low again. If I was not so tight I would buy clean lead but I have a bum like a fish, so tight it is water tight. Your a wealth of knowledge HI-TEK Joe. Regards Stephen

[HI-TEK]

Wow excellent thread. I learned a lot. I haven't tried Hi tek yet but may in the future. I too have some very strange alloys. Even having some fill problems now with molding. Looks like soaking the molded cores in Muriatic Acid will help me here. (I swage lead cores into 22lr boollits) If I read right, you are using 1 part Muriatic Acid and 3 Parts water? And am I correct in saying that Hi tek gives a more even coat than pc that is a little thinner? This may turn out to be ideal for 22lr boolits.

Traffer,
Using 1 part Acid and 2 parts Water is OK. If you have badly contaminated alloys with a lot of Zinc, Magnesium, the acid will fizz quickly. And depending on how much alloy you are treating, you may have to do a couple of acid soaks. When fizzing stops or hardly noticeable, simply pour acid into another container, and wash the treated metal very well, if possible through a plastic sieve like material like Shadecloth. Examine surface, and is should be very porous with millions of tiny holes from where the impurities were removed. Then warm air dry at 60-80C.
Cool and coat. Dry well the first coat to 50C . Then bake at 200c for about 10 minutes. Test after baking. If all is OK, coat second time and bake. Then finish with sizing to diameter required.

Hi-Tek coatings (two coats) adds about 1.5 to 2 thou onto cast diameter. From what I have seen with Powdered coatings, it can vary from 2-14 thou on same cast. I suppose it really depends on coating process used.

[HI-TEK]

It is ironic that this thread should come up now, I only just coated some .357 and .460 cast last week and found the coating could be picked off. I thought I had thrown all my badly contaminated lead in the sinker bin. I think I will have to do some more range lead scrounging as I am running low again. If I was not so tight I would buy clean lead but I have a bum like a fish, so tight it is water tight. Your a wealth of knowledge HI-TEK Joe. Regards Stephen

Stephen, Thanks for complement. (unfortunately I have more such stuff stuck deep in my brains that is slowly coming out of retirement. I have never thought I would get into helping with alloy cleaning advice)
In order of onestep at a time discovering problematic areas, as as you are aware, the usual and reason for poor adhesion is inadequate drying of first coat combined with applying too much coating as first coat.
If that area is OK, then examine baking conditions/temperature.
If that is OK, then examine alloy.
Chemically cleaning alloys after casting is possibly easiest but may be required. You can try a few in Acid wash/soak. If it fizzes, it will answer your questions.

[Petander]

Hi-Tek bonds really,really good on my acid cleaned bullets.

I tested on white ones with a little more diluted Hi-Tek solution. (Hot weather,I add denatured alcohol for a thin coat. Also more acetone than the instructions say.)

Attachment 223054.

Attachment 223055

This is the first coat. You need a knife to scratch it,it's kinda "inside" the lead surface. I get very good second/third coatings on this. A separate Diluted First Coat Bottle is a good idea.

Everyone doing WW should test a bullet or two in acid (or even bleach like I did at first.)

It's hard (for a beginner) to judge the quality of bonding itself. I started with good looking but badly bonding,contaminated bullets at first. Now I'm just amazed, I will check all my alloy ingots soon.

[HI-TEK]

Hi-Tek bonds really,really good on my acid cleaned bullets.

I tested on white ones with a little more diluted Hi-Tek solution. (Hot weather,I add denatured alcohol for a thin coat. Also more acetone than the instructions say.)

Attachment 223054.

Attachment 223055

This is the first coat. You need a knife to scratch it,it's kinda "inside" the lead surface. I get very good second/third coatings on this. A separate Diluted First Coat Bottle is a good idea.

Everyone doing WW should test a bullet or two in acid (or even bleach like I did at first.)

It's hard (for a beginner) to judge the quality of bonding itself. I started with good looking but badly bonding,contaminated bullets at first. Now I'm just amazed, I will check all my alloy ingots soon.

Petander,
I am glad that all has worked out.
I was getting quite concerned with your previous failures.
You have exposed the difficulties when using "unknown" alloys.
Please finish last coat, and take picture, then load and shoot and report back.
Joe

[glockfan]

all i know,is that in my case the failures i've got at my first few attempts at hi tek were due to water quenching.since i stopped WQ , never had a problem since.

[HI-TEK]

all i know,is that in my case the failures i've got at my first few attempts at hi tek were due to water quenching.since i stopped WQ , never had a problem since.

glockfan,
I suspect, that water quenching causing failures, may be due to coating not completely bonding.
Water may have gotten in between coating and alloy, and sudden expansion of the water with heat, simply hydraulically lifted off poorly bonded coating.
This simply goes back to making sure that first coat is absolutely dry before baking.
That is my thoughts any way.

[Stephen Cohen]

glockfan,
I suspect, that water quenching causing failures, may be due to coating not completely bonding.
Water may have gotten in between coating and alloy, and sudden expansion of the water with heat, simply hydraulically lifted off poorly bonded coating.
This simply goes back to making sure that first coat is absolutely dry before baking.
That is my thoughts any way.

I feel you may well be right with that assumption Joe, I have been water quenching for years with no ill effect however I feel that a suspect alloy that may allow bonding of the coating may fail with water quenching as you say. I am doing some testing at the moment with same bullet and a good alloy of known composition and same batch of coating, one quenched and the other not. I am glad you come up with the acid idea as I may be able to use a alloy I know to be contaminated but casts well. Regards Stephen

[HI-TEK]

I feel you may well be right with that assumption Joe, I have been water quenching for years with no ill effect however I feel that a suspect alloy that may allow bonding of the coating may fail with water quenching as you say. I am doing some testing at the moment with same bullet and a good alloy of known composition and same batch of coating, one quenched and the other not. I am glad you come up with the acid idea as I may be able to use a alloy I know to be contaminated but casts well. Regards Stephen

Stephen,
I am looking forward to your results.
If things are considered, a lot of crazy alloys are acid treated, (Anodized) using Phosphoric Acid type systems, so that coatings can be applied that will bond.
Unfortunately, Phosphoric Acid is not suitable for removing such things as Zinc and Magnesium, as these metals form an insoluble compound with Phosphoric acid, that would leave a loosely adhering powdery surface which will compound the coating adhesion problems.
As suggested, Vinegar will work but very slowly as it is very dilute. With Hydrochloric, you control strength, and metal contaminants that you are removing are soluble in water using the Hydrochloric acid and the Vinegar.