simple Hi-Tek coating

[Rich22]

[QUOTE=HI-TEK;3567489]

You raise some interesting points.

From what I have read, and I may be wrong, but my guess is, that coating many times in fact will provide the failures experienced.
I will try to explain, why I am thinking along these lines.
I have in the past, referred the coatings to an example, of comparing it to a sheet of glass. If your glass sheet is say 1/4 thick, and you try to bend it, it explodes.
However, if you make the glass sheet a few microns thick, then it is very flexible and will deform easily without breaking just like Glass wool.
I am thinking, that by building up several layers of the coating, due to its tough nature, then it may be possible, that the fails mode is reached simply, by the fact of the physical property of the coating becoming much more brittle with the extra thickness.
The smash tests, are certainly well in excess to what is done during sizing, and, no coating comes off, and, these are with two coats baked.
This "theory" seems to be supported by the mere fact, that after passing sizing tests initially, and re-coating again, the smash tests then fail.
Attached is an example of smash tests on coated alloy. The destructive forces used, far exceedsAttachment 162750 sizing shape changes.
May be, there is room for experimentation to determine at what point the coating will fail/crack, based on thickness applied.

My question would then be, if I am having failures doing coats thicker than .75 ml/lb / coat, how do I obtain the coating thickness for both appearance and performance if I am limited to a max of 3 coats? No matter what I have done using more coating then this had led from partial failures to entire failures. So if I cannot go thicker without it not drying properly and I cannot go more numerous, what is the answer? Or is it just that liquid black is generally inferior and I would be better served by going to a powdered metallic?

[Rich22]

What is the temperature of your bullets during the 30 hours of drying?

In the colder weather I have found that if I dry my bullets at 100 deg F to 130 deg F for 1 hour and bake 12 minutes at 400 deg F they pass the test fine.

You might try this before you try to remove the coating, I doubt it can be removed.

Approx 65-75 degrees F. I do the exact same baking time/temp as you do. Drying them in a turned down oven may be doable but not really in the amount that I like to do at 1 time. I am talking about removing coating that is dry but not yet cooked, no way I am removing anything baked on

[dikman]

Rich, just curious, why would you want four coats? I run two coats and while I know the overall colour would look better with three they wouldn't perform any better with an extra coat. If you're doing everything the same as you usually do, then it would appear that you may have reached the practical limit for what you're doing?

On another note, went to the range yesterday (to try out my new holster) and fired off a few .38's. Cleaning the barrel this morning and started getting streaks of lead!!! Then I remembered I was using up a few left-over, pre-coating, plain lead wax loobed boolits. That was it, the remaining few are in the reloading shed where I'm going to pull the boolits and replace with pretty coloured ones!

No more wax loobed for my cartridge guns!!

[Ausglock]

I use 4 coats sometimes.
Mostly when testing experimental coatings.
2 coats of the experimental.
Take photos and test.
then apply 2 coats of Black to cover the old coating.
Size and shoot as per normal.
4 coats is no problem.

[HI-TEK]

I use 4 coats sometimes.
Mostly when testing experimental coatings.
2 coats of the experimental.
Take photos and test.
then apply 2 coats of Black to cover the old coating.
Size and shoot as per normal.
4 coats is no problem.

Ausglock
I agree with you to a great extent. I am also keeping in mind, that coatings over all thicknesses, may be a governing factor in them becoming more prone to shatter the thicker it is built up.
We all know, that we admire a beautiful finish and colour. The reality is, that I have had many that reported, that they coat with one coat, dry well and bake, and get great results.
I cant seem to get my mind around previous report on this blog, where two coats passed OK, and 4 coats failed with same coating used.
This seems contradictory with your findings where you use 4 coats over all, with success.

[Rich22]

Rich - add acetone to your tumbler, teaspoon/# and tumble again, pour excess off - should reduce the coating thickness. Cook again then check. I think I got ~0.001" thick for the 4 coats I did, about what your measurement says. Accuracy wasn't great (20 mph wind) but NO leading @ ~2k fps. Next round is 2100 fps (normal load for ESPC). Coating another 150 or so today for testing - to see if I got it right. I'm letting dry for an hour or so, put in conv. oven @200F for 15min. then go to 385F for 12 min. second coat passed smash test - on third coat now. I've had no problems with liquid green 2 thin coats 1 thicker for 9 & 40, same process. Anyway, if this gold 1035 works @ 2100 then on to 2400 in the 308W carbine
edit: 4 coats gold - pass smash test.

Yeah, I will acetone off the coat that I put on but as far as adding another coat, I don't know how that would turn out any better. I'm just going to replace .75 ml/lb with .75 ml/lb. I am at a loss as to how I get 3 coats that every single bullet passes but then this coat does not yet there are several people who are doing 4 coats without an issue. I was thinking maybe wait to size until all the coats are done but then I am sizing down even more.

[Rich22]

Rich, just curious, why would you want four coats? I run two coats and while I know the overall colour would look better with three they wouldn't perform any better with an extra coat. If you're doing everything the same as you usually do, then it would appear that you may have reached the practical limit for what you're doing?

On another note, went to the range yesterday (to try out my new holster) and fired off a few .38's. Cleaning the barrel this morning and started getting streaks of lead!!! Then I remembered I was using up a few left-over, pre-coating, plain lead wax loobed boolits. That was it, the remaining few are in the reloading shed where I'm going to pull the boolits and replace with pretty coloured ones!

No more wax loobed for my cartridge guns!!

Two reasons really are looks and I am having to apply so little coating, approx 1/2 of what Ausglock is doing, in order to get it to dry properly and pass, that in my 4 coats is about the coverage that the rest of you guys are getting in 2.

[Ausglock]

The 3 coat fails was with 2 sizing operations.

2 coats of Bronze 500.
1st from "as cast Dia of .433" down to .430"
2nd from .430" down to .427 and a single coat of Bronze 500 applied and baked.
Fail smash test. Wipe fine.
This was about 6 months ago.

[Rich22]

so going down 6 thou is not going to work. I can understand that. we need to find a method so we can size before coating and have it still work normally for situations like that. So go .433 to .430 first, then two coats, then to .427, then 1 final coat

[Ausglock]

Rich.
If I was actually doing .433 down to .427.
I do it the old fashion way. 2 coats bake then Size with Sizing lube.
I do this and everything is fine.
My above example was for re-sized bullets after the first production. I normally do not do that.

[dikman]

Reading all this suggests to me that extreme re-sizing is the likely problem? "Normal" re-sizing (couple of thou'?) obviously works, even when some resize first and then coat. The fact that we are putting on a rigid, hard coat, even if it is only microns thick, means that there has to be a point where it will come loose from what is after all a softer sub-strata that it's baked on to if it's worked too much.

Re-sizing is a fairly brutal process when you think about it, I would have thought ideally you'd want to have minimal re-sizing once its coated.

[ioon44]

Approx 65-75 degrees F. I do the exact same baking time/temp as you do. Drying them in a turned down oven may be doable but not really in the amount that I like to do at 1 time. I am talking about removing coating that is dry but not yet cooked, no way I am removing anything baked on

I am talking about dry unbaked coating also, as hard as it is to remove from measures and any thing else it gets on. I have never tried to remove it from bullets might work OK.

I am using a lot more coating on my first and second coats than you are, I think the higher drying temp's have a lot to do with this as the coating is a heat barrier. I am still testing and learning lots of good help here

I have used the liquid Black and am using Candy Apple Red powder now, my first coat is mixed 125 ml/20 grams and second coat 100 ml/20 grams applied 7 ml of coating to 5 lbs of bullets.

[DerekP Houston]

PID installed, will give the "zombie green" another try today. My 3rd attempt still came out too dark, though the coating passed both tests and shot without leading in my bersa. I'm giving it a full 24hr to dry in between coating, approx 70-80f in the afternoons here. Bronze 500 has still been the best for me for color.

[Ausglock]

If I leave the Lee push through sizer dies to sit for a few weeks, they get "dirty" on the inside that will scratch the coating. I run a piece of 2400 wet n Dry paper on a rod in the battery drill to polish them before use. Doesn't take much to get them working 100%.

[Rich22]

I am talking about dry unbaked coating also, as hard as it is to remove from measures and any thing else it gets on. I have never tried to remove it from bullets might work OK.

I am using a lot more coating on my first and second coats than you are, I think the higher drying temp's have a lot to do with this as the coating is a heat barrier. I am still testing and learning lots of good help here

I have used the liquid Black and am using Candy Apple Red powder now, my first coat is mixed 125 ml/20 grams and second coat 100 ml/20 grams applied 7 ml of coating to 5 lbs of bullets.

I am also looking at some of the powder, if I did not have SOOOO much liquid black I would grab some, still may to play with. I got the coating off or at least the vast majority, I will bake tomorrow the tiny bit left on and hopefully all will be good. Are you heating the bullets first then coating and then heat drying or coating room temp bullets and then heat drying?

I also attempted the fourth coat again on a small amount that had 3 coats on already and were sized after coat 2, failed badly. I am considering trying 4 coats and then size. Has anyone definitively proven which is better if doing 3 coats, coat 3 times and then size or coat twice , size, and then a third coat. I will play with heat drying

[Rich22]

Mic'd 7 that I coated yesterday. Largest was 312, smallest 310 sized to 308 with Lee. Inspected with magnifier and saw a few had very small scrape at the base. Had sized down some uncoated previously so sizer is the problem, dirty I guess. Still trying to order the NOE set, can't get past the password.
Sped up the drying process on these (3&4 coat) by setting oven ~200F for 15 min, then up to 385F for 12 min.

You were successful on 4 coats, did you size after 4 or somewhere in between?

[ioon44]

I am also looking at some of the powder, if I did not have SOOOO much liquid black I would grab some, still may to play with. I got the coating off or at least the vast majority, I will bake tomorrow the tiny bit left on and hopefully all will be good. Are you heating the bullets first then coating and then heat drying or coating room temp bullets and then heat drying?

I also attempted the fourth coat again on a small amount that had 3 coats on already and were sized after coat 2, failed badly. I am considering trying 4 coats and then size. Has anyone definitively proven which is better if doing 3 coats, coat 3 times and then size or coat twice , size, and then a third coat. I will play with heat drying

I have a lot of Black liquid that I will keep using along with my other colors.

I preheat my bullets to around 80 deg F before each coat, then let the Acetone flash off for 1/2 hour then put them in a heated cabinet to get up to 100 deg
F to 130 deg F for 1 hour. Once the weather gets warmer here with full sun I can lay trays of bullets on my dark Red deck and the temp will reach 130 deg F.


Using the Black liquid I found that a mix of 5-1-10 with 3 coats and sizing after the last coat worked best for me. If you try powder I recommend Candy Apple Red or Bronze 500 and I only use 6-2-92 alloy.

I have shot a lot of coated bullets that did not pass the smash test with out any leading but different barrels may not work you just have to try it.

[Ausglock]

With sizing on the Magma Lube master, I only use Lathesmiths short sizer dies. Best sizer dies in the world.

[Rich22]

I have a lot of Black liquid that I will keep using along with my other colors.

I preheat my bullets to around 80 deg F before each coat, then let the Acetone flash off for 1/2 hour then put them in a heated cabinet to get up to 100 deg
F to 130 deg F for 1 hour. Once the weather gets warmer here with full sun I can lay trays of bullets on my dark Red deck and the temp will reach 130 deg F.


Using the Black liquid I found that a mix of 5-1-10 with 3 coats and sizing after the last coat worked best for me. If you try powder I recommend Candy Apple Red or Bronze 500 and I only use 6-2-92 alloy.

I have shot a lot of coated bullets that did not pass the smash test with out any leading but different barrels may not work you just have to try it.

I know what you mean, another 6 weeks and all of Orlando will be a half way decent heated cabinet, except when the 4 pm rain storms come. 5-1-10, now that is thin, I do 5-1-7 currently. I may give that a shot. I will have to check and make sure my largest dropping mold can do 3 coats and not have an issue with sizing after 3.

[Rich22]

Looks like I am getting failure from anything to do with a fourth coat. I took the vast majority off the bullets that I had coated and dried but not baked and I am getting failure, I put a fourth coat on another batch that had past 3 previous coats without problem and that failed. Looks like I am going to just have to do 3 coats and then size and hope that is a sufficiently thick coating.