simple Hi-Tek coating

[Tazza]

Given that once cured virtually no solvent known to man () will touch it I reckon your parts should be safe.

That is my hope too

I have coated the inside of paint tins before, the coating had a rough finish, not sure why, i will need to fiddle with it again to see if it was moisture, which i doubt as there were no visible bubbles.

[HI-TEK]

That is my hope too

I have coated the inside of paint tins before, the coating had a rough finish, not sure why, i will need to fiddle with it again to see if it was moisture, which i doubt as there were no visible bubbles.

My guess is that coating was too thick in the first place

[Tazza]

My guess is that coating was too thick in the first place

That is a real possibility. I tipped the liquid in, and swirled it around till it was all covered, adding some acetone first may have been wise to make the coating thinner. I'll try it next time

[Jatz357]

Productive morning, quick batch of 232.5 kgs 100 SWC & 122 FP, coated & baked twice.

Hi-Tek is so easy to use, whether it is just small batches or commercial quantities.

[HI-TEK]

Productive morning, quick batch of 232.5 kgs 100 SWC & 122 FP, coated & baked twice.

Hi-Tek is so easy to use, whether it is just small batches or commercial quantities.

Jatz357
What a nice load of finished products done in a morning.
Well done.
The Infra Red oven certainly works well with the Hi-Tek.
Colors are very even.

[Tazza]

Wow, that would have taken me quite a while to get done, and i sure would have been feeling it afterwards.

Awesome consistency of the colour, you have it dialed in just right.

[HI-TEK]

Wow, that would have taken me quite a while to get done, and i sure would have been feeling it afterwards.

Awesome consistency of the colour, you have it dialed in just right.

Tazza
What little I know about the IR oven system I believe that the residual bake time in oven is about 5 1/2 minutes or so.
Product leaves at about 190-195C at that exit point. From watching the video, he seems flat out keeping the oven fed.
This is why he can put through as much in a very quick time.
This system seems to significantly reduce manual labor content.

[Tazza]

I'm really impressed with how well IR heating works.

Initially i never thought about IR heating, it seems to be a far better way for the heat to be conducted to the projectiles vs hot air in a regular oven.

[HI-TEK]

I'm really impressed with how well IR heating works.

Initially i never thought about IR heating, it seems to be a far better way for the heat to be conducted to the projectiles vs hot air in a regular oven.

Tazza
The most significant difference between hot air baking and IR baking, is the way heat is transferred into the alloy
Air fan forced conventional oven heating method, the heat has to push through the coating to get to heat the alloy.
With IR it seems, that alloy get heated first as the IR simply travels through the coating and as alloy gets hot, then
coating gets cured after alloy gets to cure temperature. IR does not require fan forced air circulation.
With conventional ovens, the coating insulates the alloy, so trying to heat faster, with higher temperatures, this only gets surface of coating much hotter than alloy due to coating insulating property.
With IR baking, resulting in more even colors, even with multi bakes, and as witnessed, faster production rates at lower running costs.

[Jatz357]

Tazza
What little I know about the IR oven system I believe that the residual bake time in oven is about 5 1/2 minutes or so.
Product leaves at about 190-195C at that exit point. From watching the video, he seems flat out keeping the oven fed.
This is why he can put through as much in a very quick time.
This system seems to significantly reduce manual labor content.

Those two piles took 3 hours 6 minute from first in to last in. 232.5 kg baked twice non-stop (465 kg) through the oven & averaged exactly 150 kg an hour. The 2nd coat was applied and dried while others were still baking.

Until today, the largest projectile I had baked was 158 grain RNFP 0.357.

Did a small test with .45 200 grain and appears throughput may be 170 - 180kg an hour, although I need to compete tests with larger batches.

Also completed some tests with loading a good percentage of the projectiles stacked on top of one another. Slowed the conveyor a bit and projectiles that did not have direct line of sight to infrared still cured. Overall throughput rate was around the same. Higher load but slower transit time.

[Jatz357]

Tazza
The most significant difference between hot air baking and IR baking, is the way heat is transferred into the alloy
Air fan forced conventional oven heating method, the heat has to push through the coating to get to heat the alloy.
With IR it seems, that alloy get heated first as the IR simply travels through the coating and as alloy gets hot, then
coating gets cured after alloy gets to cure temperature. IR does not require fan forced air circulation.
With conventional ovens, the coating insulates the alloy, so trying to heat faster, with higher temperatures, this only gets surface of coating much hotter than alloy due to coating insulating property.
With IR baking, resulting in more even colors, even with multi bakes, and as witnessed, faster production rates at lower running costs.

Some numbers on power usage for last bake 232.5 kgs baked twice total 465 kgs.

Oven heating capacity 4600 watts

Oven warm up for 20 minutes used 1.103 kw
Oven Bake time 3:06 hr used 8.028 kw (average 17.265 kw per ton)

Total 9.131 kw (average 19.637 per ton)

Unfortunately, I do not have any comparison data using a larger convection oven, only a small oven and that usage was very high compared to infrared.

[HI-TEK]

Some numbers on power usage for last bake 232.5 kgs baked twice total 465 kgs.

Oven heating capacity 4600 watts

Oven warm up for 20 minutes used 1.103 kw
Oven Bake time 3:06 used 8.028 kw (average 17.265 kw per ton)

Total 9.131 kw (average 19.637 per ton)

Unfortunately, I do not have any comparison data using a larger convection oven, only a small oven and that usage was very high compared to infrared.

Jatz357
I am sure that some folks already have power usage data vs production rate, with using convectional oven baking.
I may be wrong, but the power consumption for the IR seems to be be closer to 50% of power used by fan forced ovens. I also think, it seems that throughput rates are much higher with an IR oven for lower power usage, and the increase production rate, and power savings, seem a great benefit with IR baking systems.

[mjwcaster]

So I finally learned something, too high of cook temp can cause wipe test failure.

I hitek coated successfully for a few years then started having issues in 2018. I also had weird alloy issues and finally went back to recluse lubing. I wasn’t casting much until last fall after I moved and tried hitek again.

I found a grill thermometer and checked my convection toaster oven, oven was low. Set temp higher. I could burn the coating but still fail the wipe test, and I had tried everything I could think of, new mix then new acetone, containers, alloy, gloves everything, extra long drying times. I finally ordered a new batch of hitek powder (blue).

Tried it out this morning, oven temp set to 450, thermometer read 410. Came out burnt brown and failed the wipe test.
Gave up and went fishing, new rods with new trilene xl, line is a twisted, knotty mess, my daughter and I gave up and went grocery shopping.
At least I had a decent casting session this morning, my best in years, finally getting my new to me Lee 4-20 dialed in.

When I got back home I decided to fire up the oven, let it come to temp and try my new casting thermometer. Set to 450 old thermometer read 400, casting thermometer reads 460.
That could be a problem.

Set oven to 375, empty reading of 400 on casting thermometer.
Cooked a small batch of my newly cast/coated 358-125’s, they didn’t burn and passed the wipe test.
Recoated and cooked again, success. Wiped clean and passed the smash test.

Now to size, load and shoot them. Maybe during this Tuesday’s forecasted April snowfall.

My best guess is that my initial problems were caused by too large of a batch for my oven, then I tried raising the temp instead of going for a longer cook time. Coupled with a faulty thermometer that I thought had checked ok with boiling water.
Maybe I was already on the verge of too high temp to begin with.

But I am finally coating successfully again. I will try a new batch of the old red coating on my next batch of bullets for kicks. I really didn’t like going back to the recluse lube, especially the batch I way over lubed, what a sticky, smoky mess.

I guess I expected too high of a cook temp to just give issues with flaking, wipe test failures to be to low/short of a cook.


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[HI-TEK]

So I finally learned something, too high of cook temp can cause wipe test failure.

I hitek coated successfully for a few years then started having issues in 2018. I also had weird alloy issues and finally went back to recluse lubing. I wasn’t casting much until last fall after I moved and tried hitek again.

I found a grill thermometer and checked my convection toaster oven, oven was low. Set temp higher. I could burn the coating but still fail the wipe test, and I had tried everything I could think of, new mix then new acetone, containers, alloy, gloves everything, extra long drying times. I finally ordered a new batch of hitek powder (blue).

Tried it out this morning, oven temp set to 450, thermometer read 410. Came out burnt brown and failed the wipe test.
Gave up and went fishing, new rods with new trilene xl, line is a twisted, knotty mess, my daughter and I gave up and went grocery shopping.
At least I had a decent casting session this morning, my best in years, finally getting my new to me Lee 4-20 dialed in.

When I got back home I decided to fire up the oven, let it come to temp and try my new casting thermometer. Set to 450 old thermometer read 400, casting thermometer reads 460.
That could be a problem.

Set oven to 375, empty reading of 400 on casting thermometer.
Cooked a small batch of my newly cast/coated 358-125’s, they didn’t burn and passed the wipe test.
Recoated and cooked again, success. Wiped clean and passed the smash test.

Now to size, load and shoot them. Maybe during this Tuesday’s forecasted April snowfall.

My best guess is that my initial problems were caused by too large of a batch for my oven, then I tried raising the temp instead of going for a longer cook time. Coupled with a faulty thermometer that I thought had checked ok with boiling water.
Maybe I was already on the verge of too high temp to begin with.

But I am finally coating successfully again. I will try a new batch of the old red coating on my next batch of bullets for kicks. I really didn’t like going back to the recluse lube, especially the batch I way over lubed, what a sticky, smoky mess.

I guess I expected too high of a cook temp to just give issues with flaking, wipe test failures to be to low/short of a cook.


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MJWCASTER
Interesting report
I just wanted to advise, that coatings have been baked at 200C for a week.
Aside from going Black none failed smash test, and, l in fact they were most accurate ammo.
I think you may have found the problems with overloading, and radiation burns damaged coated cast near heating element.
Layers below, did not get to cure temperatures.

[mjwcaster]

MJWCASTER
Interesting report
I just wanted to advise, that coatings have been baked at 200C for a week.
Aside from going Black none failed smash test, and, l in fact they were most accurate ammo.
I think you may have found the problems with overloading, and radiation burns damaged coated cast near heating element.
Layers below, did not get to cure temperatures.

Today’s failed batch was probably 4-500 452-230. Two pans, single layer in each. Top pan was burned really brown, bottom pan, partially full was mostly brown with some blue color remaining.
I used to successfully do batches this size years ago in this same oven.
Both pans wiped blue.
If my casting thermometer was to be trusted they were cooked at ~240C.
I figured there might be an issue when smoke/fumes started pouring out of the oven, lasting for several minutes. But I assumed they would be over cooked and flaking, not uncured.

I used to Cook them in the basement during the winter and never had fume issues, years ago when the coating worked for me.
When I started having issues a few years ago I was cooking outside after work in the dark, so I wouldn’t have noticed an increase in smoke/fumes.


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[HI-TEK]

Today’s failed batch was probably 4-500 452-230. Two pans, single layer in each. Top pan was burned really brown, bottom pan, partially full was mostly brown with some blue color remaining.
I used to successfully do batches this size years ago in this same oven.
Both pans wiped blue.
If my casting thermometer was to be trusted they were cooked at ~240C.
I figured there might be an issue when smoke/fumes started pouring out of the oven, lasting for several minutes. But I assumed they would be over cooked and flaking, not uncured.

I used to Cook them in the basement during the winter and never had fume issues, years ago when the coating worked for me.
When I started having issues a few years ago I was cooking outside after work in the dark, so I wouldn’t have noticed an increase in smoke/fumes.


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I suspect that your thermostat is not working correctly. For coatings to turn that colour there is a strong indication that you are not in control of your temperatures.

[mjwcaster]

I suspect that your thermostat is not working correctly. For coatings to turn that colour there is a strong indication that you are not in control of your temperatures.

I think the oven control is close, maybe runs a little hotter than set for, It is the bbq thermometer that read 60-70F low that made things worse, plus the assumption that I needed higher temp as I had already tried longer Cook times (at too high a temp it appears).

The oven is close to my casting thermometer that I put in today, still runs a bit hotter than set for.
I had the oven set to 450F for the smoking batch, bbq thermometer read 400F. When checked later empty at 450F bbq thermometer read 400F, casting thermometer read 460F

Oven was set to 375F for the good batch.

A big issue I have always had is how to test calibration of thermometers over 212F(100C).
32/212F(0-100C) is easy, ice water/boiling water.
400-800F presents a challenge, best idea I can come up with is checking the melt points of known alloys.
Now I just need some known pure lead and tin, nothing I have is guaranteed pure.

Because even if I get around to building a pid controller, what’s to say it’s accurate without testing the calibration.


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[Ausglock]

PID with a K sensor will still indicate in boiling water.
I have run 2 seperate sensors in my oven and there was 1 degree difference at 200Deg C.

[HI-TEK]

I think the oven control is close, maybe runs a little hotter than set for, It is the bbq thermometer that read 60-70F low that made things worse, plus the assumption that I needed higher temp as I had already tried longer Cook times (at too high a temp it appears).

The oven is close to my casting thermometer that I put in today, still runs a bit hotter than set for.
I had the oven set to 450F for the smoking batch, bbq thermometer read 400F. When checked later empty at 450F bbq thermometer read 400F, casting thermometer read 460F

Oven was set to 375F for the good batch.

A big issue I have always had is how to test calibration of thermometers over 212F(100C).
32/212F(0-100C) is easy, ice water/boiling water.
400-800F presents a challenge, best idea I can come up with is checking the melt points of known alloys.
Now I just need some known pure lead and tin, nothing I have is guaranteed pure.

Because even if I get around to building a pid controller, what’s to say it’s accurate without testing the calibration.


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Probably an Infra Red thermometer from eBay, similar to what is used to measure persons will be most efficient way to determine your cast temperature, and calibrate your thermometers. You simply point, apply the trigger and you get instant temperature readings displayed on the screen.

[mjwcaster]

Probably an Infra Red thermometer from eBay, similar to what is used to measure pers will be most efficient way to determine your cast temperature, and calibrate your thermometers. You simply point, apply the trigger and you get instant temperature readings displayed on the screen.

I’ve never heard good things about IR thermometer accuracy, especially when measuring lead.
There actually is a recent thread here that touches on them -

https://castboolits.gunloads.com/sho...ad-thermometer

For now I’ll call my new Tru-Tell 200-1000F casting thermometer my most trusted thermometer and try to get it tested in the future.
If I build a PID and it matches the Tru-Tell that will be close enough for me.
But I’m a geek and prefer to have at least 1 calibrated device in house, stored safely and used only to verify the daily use gauges. An in house calibration system.

I prefer to be picky when it comes to measuring devices, when I’m not I get burned like this. Or like when I built the stand for my Lee pots, used a tape for the some pieces and a square for the other ones. Put it together and the top didn’t fit perfectly.
Checked and the stupid cheap tape I used had a severely bent hook, it read probably 1/4”-3/8” short.
Shame on me for not checking it.


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