spothound, when you say fail the smash test, what exactly is happening? Is the coating coming off in big flakes?
The boxes to tick are:
Thinner solution 20 grams in 125ml Bunnings acetone. Those 250 ml bottles are just right for the Hi-Tek mix and I’ve been using them for about 4 years now. Empty out half acetone and mix the epoxy in the remaining.
Let this mix stand for a minimum of one hour before use.
Shake the solution for a minimum of 3 min
Less is more- 1 ml per lot of 50 handgun Bullets. Stop swirling in 10!sec and look at the book it’s. if they’re dry and appear thickly coated, add another ml or two of acetone and swirl for a further 10 sec.
drying time - I pour the coated Bullets into a tray on top of the hot oven- make sure a few drops of coating solution are left over , and pours into this drying tray. If your pills come out of the swirling jar all coated and dry and no excess solution, coating may be too thick. I leave them on the hot oven until HOT to touch, and the beginning of the colour is seen.
Oven temperature- my 2nd hand 10 buck toaster oven grill runs a max of 230*C empty. I keep it booted up there while pills are drying in the tray on top.
Open door and pop in Boolit tray and start timer. You’ll see the temp drop as the boolits start absorbing heat.
Temp will stop dropping-once it stabilises, move it up if necessary, to make sure it’s at 200*C.
Depending on quantity to Bullets in the tray, play around with the time, increase by a couple of minutes. Time - anywhere between 8-12 min. If you over cook them, they only darken.
Try with 25 or even 10and see how your local humidity and temperatures affect overall process.
I’m currently coating in a shed where it’s 6-7 *C and rain is off and on. So I prolong the drying time to drive out the water from the acetone it needs to come out by heating/ drying.
Eyeball check- you’ll probably see the actual shade forming in the last 2-3 min of the bake - and boolits should look shiny. Which means you’ve got the dilution and coating correct. A rough finished , dull pill means many things: thick coating , not bonded enough to the lead etc.
I sometimes get splotchy , leprous looking pills after the first coat, a second coat covers the blemishes and they pass the acetone rub and smash test.
Good luck.