Gateway. You are a drongo. :)
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Gateway. You are a drongo. :)
Tes one of the main points I have found is to try and get the projectiles up to temp as soon as possible, the whole hinge point of the system is the bond between coating and the lead. Irrespective of the lead BHN.
If we can achieve a strong bond, then smash tests and shooting is no longer a issue.
From my understanding the core needs to achieve 200c to initiate a good bond.
My oven would heat to 201/202 amd cycle the power at that temp, so I thought it all good, however opening the door and sliding in the tray (single tray) of 250 casts and closing the door, would allow the temp (according to the digital read out on the thermocouple) to drop to 140/150c, then a few seconds after closing the door it would slowly start to increase.
As I start the timer after closing the door, it means that some of the time allocated to cure is wasted as the oven climbs back to the recommended cure temp of 200c. Back then my oven was only a single element, still is but we are in the process of fitting 2 additional elements.
Sitting on the patio late one night I had the idea of placing clay paving bricks in the oven. I did this so they act as heat exchangers, cheap and easily available, I stood 8 across the bottom of the oven spaced a few inches apart.
I then fired the oven up and walked away for a hour or so. I coated a batch (a batch to me is 250) and let them dry for a hour in the sun, the sun here is quite fierce at this time of year. So 2 hours after firing up the oven I laid the batch on a tray and shoved them in the oven, closed the door and studied the readout closely.
It had again dropped to 140/150c, however this time the temp recovery was 2-3c per second!! Much, much faster recovery.
Not only was the element reheating the air, but the paver blocks were releasing stored heat as well.
The lead heat absorbsion was well and truly offset by the radiated heat from the blocks.
Also I do a flash rinse of the raw batch in acetone to remove any condensation, finger oil or anything, acetone is cheap and its just a precautionary step.
Now I know that too long in the oven hurts the coating, so there obviously is a minimum and a maximum time frame window we need to aim for. Trevor has also said that he varies the time slightly depending on the size for the cast, which makes sense.
Zinc plating, chrome, copper, PC whatever, all have time frame windows that need to be observed, so this really is no different.
Just make sure you shake the mix in the correct direction, as you know fluid swirls in the opposite direction down here.
Tes mine had problems like that when my oven cycled to wide. New oven doesn't cycle and alloy steadily climbs. IIRC old oven would swing 35-40*. This one gets there and maintains. Just something to think about. I use an 8lb sledge on concrete and no flaking. I did a bunch of .380 the other day. Perfect.
whats a drongo, u live on a big island trevor.
In OZ a DRONGO = FOOL!
Trev, you ever seen a "yout" pick-up trk? Aussie convertable p/u, about 1935? Prob 100 grand to buy one.
What temp are most people using, I set my toasty oven to 210 degrees C, and the thermometer inside reads 400 Fahrenheit.
I bake as long as I have patience maybe 8 minutes?
Results good so far.
That is a hoot to go the top of the Arch! Did you know it will sway a couple of feet in a storm? Been there, done that, AND NOT FUN! Very uneasy feeling!
Good luck trying to get a 1935 Ute pick up truck or a convertible.
You have as much chance as flying without wings...lol..lol
I have a 1974 HQ Holden Premier wagon, 5Litre V8, running on LPG with twin Stainless tanks, made into a cradle, and welded in as part of the floor & Chassis. Protective stone shield is welded in as part of the floor.
Engine is fully worked to run on gas, with two stage Gas cam, high compression pistons, Chrome/Moly rings, Stainless Chevy valves with Bronze seats, twin 2 1/2 inch exhaust.
Body fully resprayed inside and outside using GMH Antelope colour.
Crushed Velour seats, electric windows including rear.
Custom 16 inch steel rims.
I just dove it into research area shed, and it has been there for 10 years under lock and key.
One day it will see the light of day. (NOT)
My son inlaw and grandsons have been agitating to get it out of mothballs so they can cruize downtown.
The problem is that it seems a Cop magnet, as when it was running on the streets, my sons were constantly being pulled up for various crazy reasons, such as "we saw a nail in your tire, You seem too young to drive, we need to see if the car is registered, etc etc.
Not to mention that even with high performance mufflers, it sounds like a semi truck.
Ah weel, they can fight over it when I am gone...lol...lol
You know how those cops can be! Not that I would know anything about that! Lol
Why don't you post a pic of it? Love the cars! I have a 66-442 that my parents bought new back in the day. Got it when I turned 16 and was my first car.
I would imagine it is like standing on a mast in beam seas. Fun but a bit scary.
You publicly admit to owning a HQ?
A drongo is a bird. It runs around in circles when startled.
I have just made a few videos of smashing. I will post them soon.
OK. here are the smashing videos.
smash 1
http://i193.photobucket.com/albums/z...-15-27_487.jpg
Smash 2
http://i193.photobucket.com/albums/z...-17-32_574.jpg
Smash 3
http://i193.photobucket.com/albums/z...-28-54_197.jpg