simple Hi-Tek coating

[HI-TEK]

Mean Mr. Bean Green.



TMG Gold with 25% Tru Blu. Approx. one minute too long in 10°C too hot. Just to be on the safe side with my alloy.

They look great. What ever method you adopted seems to be working well.
Keep up the good work.

[Petander]

They look great. What ever method you adopted seems to be working well.
Keep up the good work.

Thank you. A tough and durable coating,yes.

Surprisingly, my basic method is as instructed, 10 min in 200°C.

I went over the top with all the analyzing and ended up with incompletely cured bullets so I dumped my (four) thermometers and returned to KISS.




I do turn the tray @ 5 min now, like Ausglock is doing.

[HI-TEK]

Thank you. A tough and durable coating,yes.

Surprisingly, my basic method is as instructed, 10 min in 200°C.

I went over the top with all the analyzing and ended up with incompletely cured bullets so I dumped my (four) thermometers and returned to KISS.




I do turn the tray @ 5 min now, like Ausglock is doing.

Unfortunately many try to over analyze the coating technique.
I wonder how it became a revelation or something like that, why they now ended up call it "Simple Hi-Tek"
As I said, what you are doing is just great.

[Stephen Cohen]

Petander, have you ever used those H/Ps on game, I have a feeling one would have to vacuum up the meat after, but they do look really nice. The last few times I have used my oven I have had to crank up the temp and time to get a good bake, I think its time I got a new oven, but after 6 years and a cost of $15 I think it has done well. Regards Stephen

[dikman]

I find it's often tempting to get too involved with the intricacies of something and try to improve it. In the case of the Hi-Tek coating I've found 200C @ 10 mins. gives me consistent results, as long as I use thin coats, so no need to change what I'm doing. I did make up a boolit with a temp. probe inside as I was curious what was happening on the tray but it merely confirmed that my "system" was working (which I already knew).

[Petander]

I did make up a boolit with a temp. probe inside as I was curious what was happening on the tray

Me too and my curiosity killed the coating.

My probe reads up to 215°C at the end of bake while oven dial and two different oven meters read 200... so I went by the "actual bullet temp" and ended up with raw bullets. Been there before. IR gives another,different reading.


But this is a dead horse,sorry,let's not go there again.

[ryanmattes]

Made a batch of .45 colt in red copper. I think they're a little darker than they're supposed to be, but they passed the smash test with flying colors, so now I just need to go shoot them.

I did take a throwback and drill a hole in the bottom, and the probe I put in there lets you set a temp and an alarm goes off when it reaches that temp, but really all it did was give me a heads up when the oven timer was about to go off. Didn't change my cook at all.


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[HI-TEK]

Made a batch of .45 colt in red copper. I think they're a little darker than they're supposed to be, but they passed the smash test with flying colors, so now I just need to go shoot them.

I did take a throwback and drill a hole in the bottom, and the probe I put in there lets you set a temp and an alarm goes off when it reaches that temp, but really all it did was give me a heads up when the oven timer was about to go off. Didn't change my cook at all.


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ryanmattes
These look great. A little over cooked but not a problem. They should work just fine

[Ausglock]

Ryan... My very first coated bullets back in 2012 was with the liquid coating red Copper.
They looked just like yours.. a bit on the dark side.

But once I got everything dialed in, the colour came to the correct Red copper colour.

Keep going, mate. you are doing good.

[SweetMk]

I think they're a little darker than they're supposed to be, but they passed the smash test with flying colors,,,,,,,,,,,

I did take a throwback and drill a hole in the bottom, and the probe I put in there lets you set a temp and an alarm goes off when it reaches that temp, but really all it did was give me a heads up when the oven timer was about to go off.

Hmmmmmmmm,, I would have to think about that thermocouple inside of a bullet thing,,,,,,,,,

Compare that to your home,,
put your heat pump (or gas furnace, for you Northerners!!) thermostat inside the turned off oven, in the kitchen.

Now, the heat is gonna stay on, until the inside of the oven comes up to the temperature the thermostat is calling for,
If you have a real good heat pump, or gas furnace, the home air temperature might hit 90 degrees, before that furnace thermostat reaches 72 degrees.
The same thing on cool down, the inside of the oven will stay way warmer than the air, while the thermostat is cooling down enough for the furnace to turn on again. Heck, your home air temperature might go down to 55 degrees, waiting for the inside of your oven temperature to drop low enough to get the furnace thermostat to come on, calling for heat, again.
I can guarantee the comfortable temp that your skin is expecting will WAY overshoot.

All you have to do to make your home uncomfortable temperature-wise, is to locate the thermostat near the ceiling, or the floor.
put the sensor for your home heat source thermostat inside a small block of lead,, you will be calling the HVAC guy, because everyone will think the furnace (heat pump) is broken.
A modern thermostat that is digital uses a thermocouple virtually identical to the thermocouple used by the PID to monitor the home air temperature.

Another example: in our kitchen, the cabinets are mounted on a north facing exterior wall.
That wall behind the cabinets is well insulated,.
In the winter, the dishes in that cabinet can easily be 20 degrees colder than the kitchen air temp, if the cabinet door is closed.
If it is real cold outside, we try to remember to open the cabinet 20 minutes, or more before dinner, so the dishes are not too cold.

If that same cabinet has a water pipe in it, the pipe can easily freeze, if the cabinet door is closed.
A frozen pipe it WAY colder than the surface temp of the cabinet,, just because there is little heat transfer into the cabinet.
I lived near Boston for a couple years, I remember the radio weather announcers reminding its listeners to leave the cabinet doors open on real cold nights,, so the pipes would not freeze..
(do the weather guys still remind you of that??)

The actual air temperature that the paint is being exposed to is way more important than the inside of the bullet.

There are three ways heat moves, conduction, convection and radiation.

1) Until you are at a temperature close to where you can see the metal glowing,
little heat is transferred by radiation (~1,000 degrees F)

2) Unless the object that is changing temp is in direct large surface contact with the higher temp source of heat, there is little heat transferred by conduction.

3) that leaves us with convection,, we are depending exclusively on heat transfer by air moving past the bullet, giving up heat.
If the bullet is sitting on a solid tray, silicone mat, or parchment paper, the convection heat transfer is reduced.

All of this boils down to the inside of the bullet being at a lower temperature, than the surface, where the paint coating is.

One other thing,, lead is a poor conductor of heat,, near these painting temperatures, lead only conducts heat at 1/10 the rate of copper.
So, the lead is kinda acting like insulation.

I do not know how much overshoot of temperature it takes to darken the paint,,
but, I would bet money the surface of the bullet is always at a higher temperature, than the center of the bullet, while the oven power is on.

[Ausglock]

good post.
However..
When I first started testing with imbedded probes, I had 3 probes.
One drilled into the centre of a 45cal bullet from the base to the center. the second one drilled through the same bullet, diagonally from one side to just below the surface of the opposong side. the probe was .5mm from breaking through. The 3rd probe was attached to the exterior of the bullet with fine wire. this had the tip of the probe parrallel to the bullet surface.
Oven was pre-warmed to 200 Deg C and was cycling via the PID. temp swing was 200 to 205Deg C.
2 trays of bullets (5KG)combined were inserted with the test bullet in the centre of the top tray.

Once the oven returned to set temp and started to cycle, there was only a 3deg C variance between all 3 attached probes.
3 deg C variance over the 7.5minute bake time is no issue to the coating colour.
My oven is a converted wall oven.

[Petander]

I quit all probes and meters and went back to slight overbake with good results. My alloy likes it.

[Petander]

I can drive my car with an automatic transmission without analyzing every tiny little thing happening in the transmission itself. I don't want every possible gauge and meter down there.

Yep that's a good analogy.

[dikman]

While it's interesting to try and understand the fine details of a process, the bottom line is once you have a system in place that works for you (and is repeatable) then why waste any more time on it. In my case I don't exactly follow the "rules" but it works for me. A small non-convection oven, I weigh the boolits to be coated but I don't measure the coating, just give a squirt into the bucket and swirl, dry in the sun - if it's out, if not dry on top of the oven - then 10 mins@200C. Done quite a few 1,000 with minimal problems. Sticking a probe in a boolit in the oven was interesting but didn't change anything.

[kevin c]

But some of us LIKE over analyzing the process and tweaking the parameters...

Yeah, there's a limit to that though. I'm fine if my Black Cherry, Brick Red and Kryptonite Green are a little dark from a longer or hotter bake. It's just the Tru Blu I'd like to get right, and it seems a bit more tricky.

Maybe if Donny starts to carry it, I'll try the latest blue that Trevor posted a little while ago. Standard instructions for that one, IIRC.

[Petander]

Another way to get dark bullets is to add some black.

[ioon44]

I like the color I get with Gold 1035 and Black mixed 50/50, I don't know if this is what is called Texas Tea but it looks good.

[Petander]

I like the color I get with Gold 1035 and Black mixed 50/50, I don't know if this is what is called Texas Tea but it looks good.

My black is a mystery ratio bottle... I forgot a bottle with the cap open for several months so there was a dry,hard black thing in the bottom. It is slowly melting back in acetone now.

[kevin c]

My black is a mystery ratio bottle... I forgot a bottle with the cap open for several months so there was a dry,hard black thing in the bottom. It is slowly melting back in acetone now.

Maybe I'm just not patient enough, but I have never been able to get such settled out solids to redissolve well enough to be usable; too many floating clumps and bits jam the nozzles on my squeeze bottles and syringes, and if they get through, make for blotchy coating, and that's with a shaker bullet or two in the bottle to speed the mixing.

I know that Trevor has stored mixes for months refrigerated and reported no problems using them. Is cold storage in the dark the secret? I've had capped bottles of mix kept outdoors in temps ranging from the 40's to the low 80's with variable sun exposure and got clumping. This was only 10 grams per hundred cc acetone, BTW. Other mixes kept in my basement, made up at the same time, were fine.

I coat in big batches infrequently. Unless I can fine the right storage conditions, I'm beginning to lean towards Joe's recommendation to just mix fresh each time.

[Petander]

My 10g / 100 ml bottles are in room temp and stay fine if I shake them every now and then. I think six months is about the limit shelf time here.

I'm not trying to save all the lumpy stuff but there's not much really. I might actually combine it all and wait... now that we're talking about it.