questions re: Hi-Tek coating and WW lead

[BJK]

I'm going to start making my own 9mm projectiles. It's a new endeavor for me, previously I have only cast #4 buckshot and 12ga slugs, but I think I have everything on order that I need to get started; bullet mold*, LEE push through .356 sizer, and Hi-Tek coating. I'll work out the required oven when I get there in a few months since I can't cast anything until after winter anyway. I intend to use WWs for the lead.

*https://www.mp-molds.com/product/359...e-groove-mold/

I just watched a video where the liquid coating was applied by agitation in a bucket, then allowed to fully dry on a screen. OK, here's my question. Once I apply the coating and it dries can I allow the bullets to sit unbaked for a time? An hour, day, week, month? I'm betting that they need to be handled so as to not knock the coating off, but is there a time limit to how long they can sit before baking?

I intend to load 2 loads. One driven to 950 fps for minor power factor for competition and I don't anticipate any problems using coated WW bullets at that velocity (correct?), but the 2nd load will be driven faster, whatever the bullet can take (1100-1200 fps? Unknown at this time.) within safe pressure limits, but near the top end. What is the maximum velocity coated WW bullets can handle without adding tin? Do you suspect I'll run out of velocity before the bullets give problems?

One more bonus question... Should I also order a .357 sizer to have it on hand just in case that works better than .356? Or is that a waste of $ ?

Anything you write is far more than I know and is greatly appreciated.

Thanks.

[ryanmattes]

I would recommend buying the .357 sizer at least. I bought .356, .357, and .358, in order to test each in the specific barrel and see which performed better. I'm using a sig, with a barrel sized to .356, and the cast I sized to .356 showed keyholing on the target at 5 yards. With cast, you want to be a thousandth or two larger than the barrel diameter.

As for hi-tek coating, I haven't found any limit to how long they can sit before baking. I sometimes bake them within the hour, other times they may sit a few days before I bake them. They're not really sensitive to handling.

The trick is to let the coating dry to the touch during the tumble, and then you can handle them fairly roughly without any trouble.

[BJK]

Tumble? The video I saw had the bullets and liquid coating quickly mixed in a bucket, then before being fully dry spread out on a screen. I like the idea of tumbling to coat until dry. I'll try to find info'.

Thanks, you got me to thinkin'... I located a .357 sizer and have the .358 on backorder. I have other 9mms that I can use the bullets in from various manufacturers and who knows what they're sized to? I probably ought to get sizers for .38 too.

[dikman]

Swirl them around in a bucket and dump while still wet, that way you'll get smoother coverage. Just takes a little bit of practice to get the feel for it. Once dry they should keep for weeks before baking.
Oh, and do not size before coating.

[BJK]

WILCO 2x

[jsanch03]

I tried hi tek coating but made too many ruined batches. You have to let the coating dry between baking or else the coating will flake or fail during the firing of the boolit itself. I gave up on the hi tek and went with smokes powder coat paint. PC is simple shake and bake once just make sure the boolits are covered. I also shake any excess off so I do not have too thick of a coating. I bake once with PC as opposed to hi tek which requires several bakings. For some people PC works for others hi tek works just depends on the person. There are plenty of videos on YouTube showing the process for both which I’ve found very helpful.

I noticed for me, the PC holds up very well during the crimping process I have set on my crimping die. I’m crimping at about .379 (measured from outside the case) without the brass digging into the polymer. I size my boolits to .356 and I have shot them out of my buddies Beretta which slugs out to .3575. I didn’t have any issues or leading in his barrel so the old knowledge about obturation must be working out to provide a tight seal in his barrel. My lead is WW plus 2% tin then water quenched mainly to cool the boolits and whatever hardness gained is a plus. I have the .357 and .358 sizing die but ran into issues with the boolits getting stuck in the chamber without fully seating properly all the way in. I even went out of my way and bought a box of federal syntech to take a part. Their boolits were sized to .355!


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[slide]

Be careful about the videos on youtube. A lot of those guys say just throw this in and put a little of this and so on. Measure your acetone and weigh your powder. Not all the powders weigh the same. I always had trouble with the acetone evaporating too fast. A fella called wkljr ( I hope I got that right) recommends putting a lid on your swirling bucket. Punch a small hole in the lid or pressure will pop it off. Try it both ways.One thing I use is a digital thermometer with a thermocouple. You can get them on amazon for around $20.00. Drill a hole in a coated bullet insert the thermocouple,squeeze the bullet down and lay it in with your bullets when you bake them. The temp is critical with the hi-tek. With this setup you will know the temp of your bullets and not the air temp of the oven. I rarely hi-tek anymore. Got tired of the multiple coats. With powder coat I can get them coated in one go. Hi-tek is a really good product.

[kevin c]

My OFM Glock barrels seem to like HiTek coated cast sized to .357.

I've had months pass between HiTek coating and baking. No issues, other than if I left the coated boolits outdoors, condensation would make the uncured coating opaque and blotchy; ultimately not a problem, as baking seems to even out the color. Handling is not an issue: the coating dries to a film that can be touched without damaging it after the bake.

In the monster HiTek thread, the inventor Joe has mentioned that the boolit chills as the HiTek solvent evaporates. If it chills below ambient temp in humid conditions, there's a chance that water will condense on the alloy under the not yet completely dried coating, leading to adhesion problems after baking. Sometimes I apply the coat and dry overnight indoors: no blotching and no adhesion issues that way. I recoat after the first coat bake but while still warm. No problems that way either.

ETA:

The tin is mostly added for fill out. If you're talking about leading at 1200 fps, properly coated and sized to fit, you likely won't have a problem with WW alloy, or even one softer than that, with or without tin.

I tumble in my container rather than swirl. At least for me, some boolits on top of the pile in the container didn't get coated well with just swirling. I also try to dump while still just a bit wet, as per my recollection of the instructions.

[ryanmattes]

Tumble? The video I saw had the bullets and liquid coating quickly mixed in a bucket, then before being fully dry spread out on a screen. I like the idea of tumbling to coat until dry. I'll try to find info'.

Thanks, you got me to thinkin'... I located a .357 sizer and have the .358 on backorder. I have other 9mms that I can use the bullets in from various manufacturers and who knows what they're sized to? I probably ought to get sizers for .38 too.

By tumble I meant like you tumble lube: put them in a tub and shake/swirl. I use a tupperware bowl, start swirling with the lid on so they get good, consistent coverage, and then pop one side of the lid open and keep shaking while the acetone evaporates.

After you bake the first coat, do a smash test to make sure it's bonded to the lead. If the first coat is good, they're good.

I do two coats, recoating as soon as they've cooled and passed the smash test, and I set them on top of the oven to warm while the other set is cooking (speeds drying). Probably not strictly necessary to coat twice, but I feel like I get better coverage. Then push through size.

If you over bake it makes them darker but doesn't affect performance at all. So I tend to err on the side of too long in the oven, rather than too short. They only look pretty till you shoot em, anyway.

About 30lbs of Lee 356-120-TC, ~20:1 water dropped, coated twice with Hi-Tek Old Gold.


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[Stephen Cohen]

I think everything you need to start has been covered. Read the instruction and follow, use correct Acetone or Mek and you will have few problems. The 9mm can be one of the most difficult to get to shoot well in my experience and I have never had luck with any cast under .359 and in fact all my cast for .358 and 9mm are sized .360, those who get cast off me have no problems but your pistols may differ. you can get a .357 sizer and lap it out a little and try as you go as I did. Oh and while you can leave coating without baking for at least a year that I know of, you can not apply second coat till first is baked. The first coat should be a very light coat just like a light stain for best results. Regards Stephen

[Sleeping Dog]

Hi Slide,

A follow up question. Do you just stop when the thermocouple reached the 380-400°F or do you hold it there for a while (the suggested 8-12 min).

I've been using Hi-Tek for couple of years and coated my 380 (356-90), 38 (358-125), 45 (452-200) and shot a lot of rounds (Cowboy Action). The coating work great with two coats. The only issue that I have is that my toaster oven's temperature varies a lot so it goes between 350 to 450. I end up with boolits that have a great coating (following the directions closely), but are darker, as if the Hi-Tek is getting browned/burnt. Thus, my zombie green isn't.

One of my friends did some testing and ran his Hi-Tek at shorter times and lower temperatures until it failed the acetone test. Then he switched to using a heat shield to protect the boolits from the direct IR light from the oven's heating element. I haven't had a chance to test that yet. His boolits look great.

[BJK]

Oh yeah, I absolutely intend to weigh and measure. I dislike chaos and the results I suspect I'd get from that approach. I'm just waiting for stuff to arrive at this point and for spring to get here so that I can start casting again.

Stephen I'm thinking about slugging my barrel. That should help me a little bit I would think.

Thanks gents! If you think of anything else I'm a sponge.

Sleeping Dog, have you tried adding a piece of steel plate (heat mass) to the T/B to attempt to even out the heat cycles? It might also act as the heat shield you refer to. Its just a thought.

[slide]

SleepingDog, The inventor of hi-tek says that the coating needs to hit 360F and stay there for two to three minutes. Before I got a P.I.D. I had learned the temp dial like a map. When the temp hit 360F I started a timer for four minutes. The temp would flucuate between 360F and 380F. Before I came up with the t-couple bullet I had flaking and wipe off. After everything was good. It will only cost you around twenty bucks and you can use the setup for other things. Sure sounds like you are overheating the coating. A P.I.D. on that oven will make all the difference. The highest temp for hi-tek is 400F.

[Stephen Cohen]

Unless I have missed i, no one has mentioned that over cooking coating does not effect its performance only its colour, I have had cast drop in the bottom of my oven and stay there for at least 10 trays worth of cooking and they work just fine, but they were very black. I actually tend to over cook mine just so I have no problems as I am not fussy about colour just performance. Great people here and the inventor Joe is a very nice guy who is only too eager to help. Regards Stephen

[BJK]

Stephen, if I understand, pay attention to the temp' of the oven and bullets, but an extended stay is OK unless I want true color. Correct? I'm assuming too high or low of a temp' will hurt.

[Sleeping Dog]

I'm pretty sure that I overcook my boolits, but they shoot fine and the coating stays on quite well. I just want ruby red and zombie green. I'll try the heat shield and take them out once the probe (with the boolits) gets to 260 for 4 min -- I can work with that idea.

[ioon44]

I use a lot Candy Apple Red and my old oven has a big temperature swing, so I get up to 212 deg C and it does not change the color much but my Kryptonite green will darken at this temp. Too hot is a lot better than being under baked.

[Stephen Cohen]

Stephen, if I understand, pay attention to the temp' of the oven and bullets, but an extended stay is OK unless I want true color. Correct? I'm assuming too high or low of a temp' will hurt.

Yes that been my experience just as you say. My oven is getting old now and has done a great deal of coat baking, I have no PID set up and have no problems, I do however set my heat a little higher than needed and bake for a couple extra minutes and this has worked for me. This system will not work for the new Blue colours that Joe has invented as they are very heat and time reliant. If you use good alloy and don't get oil or grease on cast and don't size before you coat you will have no problems. make sure the first coat is very lightly applied as a thick first coat will not adhere very well to cast, if you think your first coat is too little and see through you have the right amount. It sounds daunting but it really is not. Regards Stephen

[BJK]

Thanks. Thankfully I didn't order any of the blues.