simple Hi-Tek coating

[hunter74]

Thanks. The dark ones are from the bottom tray and the lighter ones are from the top tray. I assume that the temp is uneven when my oven doesn't have an air circulation fan.

The cooking time was 12 minutes at 200 C controlled by my PID/SSR box.

It's an easy fix to cook them longer but then they are not gold any more. They are turning more dark broze in colour. This is not a problem if overcooking doesn't hurt the boolits and make them better

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[pkchwy]

Hi all. I use a Magma Star Lube-sizer and i have some NOE sizing dies. is there any trick to sizing the projectiles as i am only asking as they say you should put 1 in 10 projectiles back throw to keep the sizing die lubes but we are not using lube. is is there any way to do it that i should know off

[HI-TEK]

Thanks. The dark ones are from the bottom tray and the lighter ones are from the top tray. I assume that the temp is uneven when my oven doesn't have an air circulation fan.

The cooking time was 12 minutes at 200 C controlled by my PID/SSR box.

It's an easy fix to cook them longer but then they are not gold any more. They are turning more dark broze in colour. This is not a problem if overcooking doesn't hurt the boolits and make them better

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Again, please take note;
Your PID is controlling oven air temperatures.
It is not controlling radiant heat or actual alloy temperatures.
As you have no fan inside your oven, and you don't measure alloy temperature, the PID is doing its work based on location of the probe, measuring temperature, (but where is probe in comparison to alloy location), but lack of forced air circulation and having two trays inside oven, all seems to have supplied you uneven baking.
If your alloy in top tray is going more Brown, it is possibly affected with Radiant heat. Where is your heating element located in your oven?

If cooked alloy passes all tests, over baking simply darkens colour and there is less chance of residual odours when shooting.
Indications you described, the baked projectiles that had light colour could have been responsible for what was noticed with odours as they were not adequately baked.
The baking process is designed to fully set product, and drive out any residual non used materials inside oven.

[hunter74]

The dark ones is sitting closer to the heating element.

Thank you for all the help. My next test will be to cook them a couple of minutes longer and see what that does about the smell. I guess I have to tolerate my gold boolets beeing closer to bronze than gold

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[HI-TEK]

The dark ones is sitting closer to the heating element.

Thank you for all the help. My next test will be to cook them a couple of minutes longer and see what that does about the smell. I guess I have to tolerate my gold boolets beeing closer to bronze than gold

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No problems with helping, my pleasure. (unfortunately or fortunately I have been doing such diagnosis far too long)
Looking at pictures generally reveals a lot of things that helps me to point towards right direction.

If you can get your hands on an Infra Red laser thermometer, (you can but them on Ebay), as I suspect, if you measure alloy temperature on top tray will be much higher than you think and it will be totally different to PID temperature.
When Gold gets to more Bronze, my guess is that your alloy may be around 220C on top tray, and much less on bottom tray.
That is why fan forced ovens cure uneven bakes. (mini Cyclone inside oven is ideal) and that way all the load will bake evenly and get to cure temperature much faster.
If you are doing a lot, may be I can suggest, that you invest in a fan forced oven. A second hand household free standing oven with fan can be obtained very cheaply or for nothing.

[Petander]

Those IR- meters are handy.

I couldn't believe my individual bullet readings at first, I had two thermometers in the oven reading 200 and still some bullets hit 225 when I shot them with IR. That was with a small "toaster", not my favorite.

Nowadays I can almost "bake with my nose",I get a smile on my face after a few minutes bake when I smell the curing is starting. But the same smell when shooting means the cure was not complete,been there too.

A big household oven with air circulation made baking very easy. It's the one on top in the pic.


Attachment 234534

[hunter74]

I'm sure you guys are right. I have an IR thermometer so you're right about too low temps and hot/cool spots in the oven.

One other thing I noticed was that the temp went waaaay down when the door was open to get the trays installed. No suprice there, but it took 5 - 8 minutes before the oven reached 200 c again. That was a surprise to me! Therefore I should at least increase baking time with 8 minutes, right. My next test will be 4 trays at 22 minutes. Starting my clock when trays are inserted.

I'm on the lookout for an oven with fan but for now I'll have to work with what I have.

Thanks again!

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[Petander]

I would try with one tray only,especially when there's no air circulation.

Less load for the oven,less initial temp drop. A big load of lead will warm up very unevenly, you may get both under- and overbaked that way.

The bottom oven in my pic has no fan,it's a challenge to bake with.

[HI-TEK]

I'm sure you guys are right. I have an IR thermometer so you're right about too low temps and hot/cool spots in the oven.

One other thing I noticed was that the temp went waaaay down when the door was open to get the trays installed. No suprice there, but it took 5 - 8 minutes before the oven reached 200 c again. That was a surprise to me! Therefore I should at least increase baking time with 8 minutes, right. My next test will be 4 trays at 22 minutes. Starting my clock when trays are inserted.

I'm on the lookout for an oven with fan but for now I'll have to work with what I have.

Thanks again!

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hunter
I hate to be negative, but if your oven cannot provide even bake with two trays, how are you going to fix it by baking 4 trays?

In my previous reply. I did not refer to your element being too close to tray of cast. In 22 minutes, they will be dark brown, and others will be not cooked.

Opening oven, I presume that it is winter there and air temperatures are close to Zero C. If that is the case, no wonder your oven chills quickly.

I am sorry, but I think you may be doing a lot of work, ending up with large variations in finished product, that may give high level of variations as well.

[HI-TEK]

[QUOTE=hunter74;4557165]I'm sure you guys are right. I have an IR thermometer so you're right about too low temps and hot/cool spots in the oven.

Hunter, please look at my Facebook site. Below is link.
It shows with pictures, how over cooked coatings behave.
Your results should be similar.
If you like it please share it with your friends. Thank you.

https://www.facebook.com/JM-Speciali...dmin_todo_tour

[Conditor22]

Joe, love the pictures. For us in the US, It would be nice if they were all labeled with the names Donnie sells the colors as and how many coats of HiTek were on them.
Cheers

[Avenger442]

Hunter74
When I first started it was with a used convection oven that I bought at a yard sale for $15. It had poor air circulation, didn't maintain temperature well even after adding a brick in the bottom and would only handle one tray. Yet it produced coated bullets that performed well in my .308 rifle. 1 1/2" groups at 100 yards typical sometimes under an inch and no lead in the barrel. You can do shoot-able bullets in a cheap oven. Joe is right you can bake them almost black and their still good to go. But if you want consistent color and good performance it will take the PID you have and some heavy air circulation. Some are actually covering the elements to keep the direct heat off the bullets.

My new oven has better, while not cyclone, air circulation. If I decide I just have to have a consistent color, something I rarely do, I bake one tray in the middle of the oven with about five pounds of bullets. My oven with that load and after the temp is at 200C for a few minutes before loading bullets then wait till it recovers temp before timing will bake the bullets in 10 min. If I'm not after consistent color but volume I'll load two trays 10 pounds total and after the oven has been at 200C for a few minutes I'll put the trays in wait for temp to recover and bake for 12 min. Against advice from some, I also use a cheap temp verified thermometer in the tray to start the timer. And the PID is set so that thermometer maintains bake temp throughout the process. A far cry from the $15 yard sale oven by itself. Since the infrared thermometers are so cheap now I've considered purchasing one of them.

If I had money to throw in that direction or if I were going to produce commercially I would probably buy a used commercial convection oven. They don't use the same placement of the heating elements that exposes them to the lead and the fans produce a lot of circulation. You can get one of the counter top ones used for around $300. Consistent color all the time with volume. But I spend too much on my guns to go that route. I can have the usable coated bullets with a convection oven costing less than $100.

Joe
You asked me what I thought of the Facebook site and I would say you have an excellent start to a resource all of us can use. And now we can not only send new guys to Donnie's site but to your Facebook page. I don't remember seeing that atomic logo before. Nice touch. Is it new?

[Avenger442]

How close to Canberra Australia are any of you guys?

[Tazza]

How close to Canberra Australia are any of you guys?

About a 14 hour drive from me, i'm in Brisbane, north of Canberra. Trevor is south of me, so he has to be a fair bit closer, not that he wants to be, Canberra is where the politicians live, making all the bad dissensions we need to abide by (trying to take our guns)..... Like i assume Washington is over there?

[Avenger442]

I hear that that is where Google is testing their newest spy platform. What a coincidence.

[Ausglock]

Canberra is about 10 hrs South. Full of soy Latte' sipping politicians with no clue about the real world.

Best thing about Canberra is the Australian War Memorial. Outstanding place and very moving emotionally.
Lest we forget.

[Petander]

My mini 600 watt "toaster convection oven" also blows the air from the outside. It only has on/off switch for the fan. It's almost freezing in the room ... absolutely useless oven for €30. Well,in summer it makes good fries,although uneven. But outside temp determines the inside temp,oh man...

The big household wall oven (2000 watts) is in an outside shed,well below freezing. It has everything controlled,including the air intake. Same temps all year round for €50.

Coating bullets in a wrong oven is like trying to use a wrong size wrench.

[Tazza]

I use an old free standing oven from the in-laws, the elements for heating pots and pans on the top were burnt out, but the oven is just fine. It has cooked a good 400,000 projectiles.

People are always upgrading their ovens, you should be able to pick up one for free or almost free. A toaster oven is great for the fact it's compact, so you can put it away and not use up much space.

[dansedgli]

Anyone know where I can get an 09-180 or 09-170 BB RN mold for my master caster?

I've emailed magma but it's not on their list.

[Petander]

I use an old free standing oven from the in-laws, the elements for heating pots and pans on the top were burnt out, but the oven is just fine. It has cooked a good 400,000 projectiles.

People are always upgrading their ovens, you should be able to pick up one for free or almost free. A toaster oven is great for the fact it's compact, so you can put it away and not use up much space.

You really have been baking! :O

S/H ovens really are everywhere. A $1000 oven becomes a $50 oven in a couple of years. Money aside but I really feel that I wasted some time and effort, trying to learn coating with a new,cheap "toaster convection oven". I use it for drying coated bullets on top of it now.