Pc flaking off

[deepdarkwaters]

Hello all. I got some absolute powder neon green it shoots on good but not the prettiest using shake and bake but i can't get it to keep from flaking off after sizing i have tried under/ over baking water dropped and air cooled even different ovens hf red i never had a problem with anyone used absolute powder and had a problem with it

[Walter Laich]

are you sure you don't have any contaminants on the bullets before baking?

where is the flaking: all over or just along the bearing surface (diameter)?

what are you using to size with? (Lee sizing die, lyman 4500, etc)

[Grmps]

It could be baking temperature and time.
Check your oven temperature setting with a couple oven thermometers (buy 1 and borrow 1 to make sure they are accurate)
set them in the middle of the shelf you will be baking on, run the oven up to where both thermometers read 400° and notate the setting on the oven (this setting will change everytime the temperature in the temperature around the oven changes due to the type and location of the heat sensor in the countertop ovens)

Time, different PC's require different bake times, I have some that require 10 min. in a pre-heated oven to some that require 20 min. after the PC starts to melt/flow on the boolit.

I do the smash test on a sample from every batch of boolits I coat before I size them.

[reddog81]

I'd guess a temperature problem. I don't think a small amount of contaminants makes much of a difference. I have baked bullets after sitting in my basement for months. I have 3 large dogs in the house and everything gets covered in dust/fur. I have to pluck German Shepard fur out of my shake and bake colander on a regular basis and have never problems.

[fredj338]

Gotta be oven temp. I bake a bit over 400deg, 15m, always smash test, never flakes, even the cheap HF red.

[deepdarkwaters]

Oven temp is good checked it. It is flaking off where it is sized but its only on my 9mm and 300 blackout bullets my 9mm and 40cal were cast cooled stored and baked together but it fails on 9mm and holds on the 40cal it may have something to do with the weather it has been cold and rainy

[deepdarkwaters]

Ok must had been a contamination problem cleaned them in acetone and reshot them coating came out good i hammered out a new and old

[Moonie]

Are you sizing before powder coating? They are getting contaminated somewhere in your process by the looks of it.

[Grmps]

Like Moonie said, sizing before coating or water quenching before coating is a good way to contaminate your boolits and get flaking.
I just recently cast and coated several batches of 502-383-RF. I thought I did everything the same BUT the second batch literally shed PC like a snake sheds its skin. I don't have a clue why or how the 1st, 3rd,4th & 5th batch worked perfectly.

[Walter Laich]

I coat then size and am successful

I've PC bullets where I have had to blow off the dust and dirt; it's the oil that messes up process

[bangerjim]

Clean EVERYTHING that touches your boolits.....from you hands to sizing dies and loading equipment. If you went from grease to PC, you probably have residual grease in the dies or equipment. A one time GOOD cleaning is all you need. Acetone or laq thinner will do the best job, just watch out for painted surfaces!!!!!!!!

I have baked boolits from 370 to 440F (for 10-12 min after shiny) with no flaking problems. Gotta be grease from something.

I size out of the mold and/or after PC.......just depends on what size I want for what I am loading....and barrel diameter.

banger

[evoevil]

I run my oven with a PID at 370 for 18 minutes and it work good

[deepdarkwaters]

I size after i pc. i took uncoated bullets from the same bag and used harbor freight red and they coated good it must just be the absolute powder is sensitive to contamination i haven't got it to tumble on very good buy using es it leaves a good looking coat