Hi-Tek coating trouble.

[2ndAmendmentNut]

My apologies if this has been already covered but I am looking for a little guidance on Hi-Tek coating.

Earlier this year I bought some Hi-Tek powder from Bayou Bullets. This is the powder one that only requires acetone and baking.

Memorial day weekend was the first chance I had to try out the stuff. I was really impressed with how easy it was and the boolits look really cool. I followed the directions to the best of my ability and applied two coats to some 38cal 147gr hollow points (plain base) from a MiHec mold. I then sized them down to 358dia (the same diameter I size my normal lubed boolits). After sizing I re-coated a third time for good measure. I loaded them like I have thousands of standard cast and lubed boolits into some 357 brass with 14.0gr of 2400. I test fired them in a proven cast gun (my old S&W model 28 with a 4" barrel). I got really horrible leading in the last 2" of barrel. Do I need more coats? Dial back the velocity? I didn't chronograph these particular loads but standard cast boolits clock in at around 1300fps from a 4" barrel.

Based off my experience with cast boolits I would say the lube or rather the coating failed, thus resulting in leading in the last portion of the barrel. There was no leading in the chambers, throat or first inch or so of barrel.

Tips, pointers, or a link to this topic if it has already been discussed would be greatly appreciated.

[Harter66]

Having just finished all 5800 posts .........
I would venture that during the sizing you introduced a lube of some sort and the last coat failed and may have damaged the 1st 2 coats . This presuming that you did the wipe and smash tests between coats . I have no qualifications for that except the 3 days of reading.......

[2ndAmendmentNut]

Thank you for the input. The boolits pass the smash test.

[HI-TEK]

My apologies if this has been already covered but I am looking for a little guidance on Hi-Tek coating.

Earlier this year I bought some Hi-Tek powder from Bayou Bullets. This is the powder one that only requires acetone and baking.

Based off my experience with cast boolits I would say the lube or rather the coating failed, thus resulting in leading in the last portion of the barrel. There was no leading in the chambers, throat or first inch or so of barrel.

Hi,
I would be happy to assist with your problem.
Just curious, have you contacted Donnie about what you had found?

It would be useful if you can provide more details on your coating process so I may be able to assist with what is going on.
Did you get instruction pamphlet from Donnie?
Please advise,
Hi-Tek

[Moonman]

Alloy hardness (composition).
Drying Time for each coat?
Each Coat must pass BOTH Wipe and Smash tests.
NEW ACETONE (good stuff) not nail polish stuff.
Acetone absorbs water VERY QUICKLY (bad for coating)
Coating MUST BE DRY UNDERNEATH, not just to the touch.

Did you preheat slightly before baking.
BAKING TIME and ACTUAL OVEN TEMP,
not just a dial setting.
Type of oven used (Convection)

20 GRAMS (weighed) Powder, 100 ml Acetone
do not mix a lesser amount (can lead to failures).
Shake/Shake/Shake
Wait an hour or so then
Shake/Shake/Shake
apply,
First coat should be VERY LIGHT ONE.

I let coats dry overnight in the house.

No silicone around, Sizing lube is available
for this process from BAYOU BULLETS,
OTHER SIZING LUBES could contain ingredients
NOT compatible with this process.

Cast bullets previously SIZED or Lubed cannot be coated.
You cannot CLEAN THEM ENOUGH OR UNSIZE THEM.
The sizing burnishes the lead surface and affects adhesion.

Humidity can affect adhesion as can AMBIENT AIR TEMP (as in too cold)
Baking longer times does not affect the POWDER mixes as much
as the liquid mixes.
Baking longer will darken the color some.
Coating must reach internal temps near 390F for
several minutes for the catalyst TO GO OFF.

[2ndAmendmentNut]

Let's see if I answer all the questions (and thank you for the support)

Alloy is air cooled WW

Oven is a cheap toaster oven (non-convection)

Temperature is monitored with a lead thermometer to insure a temp of 400*

Acetone and powder is mixed as per instructions.

Boolits get well shaken and coat is light but even.

Dry time is roughly 1-4hrs in between coats.

Outdoor temperature is upper 80s* with high humidity.

[zomby woof]

Heat boolits before entering oven. I place on top of oven or hit with hair dryer.

[HATCH]

Don't size between coats.
Spray a little lube on the coated boolits before sizing.
Size them and then load them.

The last step before loading should be sizing. ALWAYS.

The thickness of the coating (ANY COATING) will vary. If you want consistent quality then you need to make sure the you are producing consistent boolits.
Sizing should be done last with any method of lube (powder coat, Hitek, standard wax based, ect)

[2ndAmendmentNut]

Don't size between coats.
Spray a little lube on the coated boolits before sizing.
Size them and then load them.

The last step before loading should be sizing. ALWAYS.

The thickness of the coating (ANY COATING) will vary. If you want consistent quality then you need to make sure the you are producing consistent boolits.
Sizing should be done last with any method of lube (powder coat, Hitek, standard wax based, ect)

Sizing is usually my last step before loading, however with my first run at hitek coating I noticed sizing exposed some lead on the driving bands. I figured another coat after sizing would be better.

[HATCH]

That's why I spray a little case lube when I size.
It all depends on how much you are sizing down.

[2ndAmendmentNut]

Alright thanks for the pointers gentlemen!

[2ndAmendmentNut]

That's why I spray a little case lube when I size.
It all depends on how much you are sizing down.

Do you do anything to remove the case lube before loading?

[Ausglock]

All the above is good advise.

Ensure that you are doing a thin first coat.
If you look at the bullets with the first coat drying and you think it is not enough and looks too thin, Then you have it just right!
this is how it should be...

A fan forced convection oven fixes a lot of coating failures.
Lead thermometer is not accurate for this.
Get a digital thermo with K sensor lead.

[HATCH]

No you are only spraying a thin coating. It will dry up before you load. Not any difference then tumble lubing

[bigfelipe]

If you need to lube before you size what's the point of the coating?

[HI-TEK]

If you need to lube before you size what's the point of the coating?

The coating is self lubricating, and, in majority of end uses, no extra lube is required.
With hard alloys, or drastic down sizing or both, using the Aqualube 5000 will greatly reduce loads on punches and gearboxes.

[bigfelipe]

The coating is self lubricating, and, in majority of end uses, no extra lube is required.
With hard alloys, or drastic down sizing or both, using the Aqualube 5000 will greatly reduce loads on punches and gearboxes.

That was what I thought

[2ndAmendmentNut]

Well just to follow up. I ended up applying two additional coats with longer dry times in between. I also loaded them into 38sp cases with a light charge of Bullseye. Velocity was in the 800fps range. No leading and good accuracy just like a standard greased boolit.

For the hotter 357mags I will likely just stick with traditional boolits.

[popper]

I've shot the dry gold in BO & 308W without leading, it's not the fps that is the problem.

[Budzilla 19]

I have also shot the dry gold and the liquid green in '06 at some pretty high velocities and no leading. Three coats then sized and gas checked. I'll bet you these guys will get your problem solved for you,for sure! It's a great system. Usually it's just one little thing that's out of step in your process. Good luck to you.