Mold preheating

[jamesp81]

I have been using Lee molds and preheating them by dipping an edge into the melt. Soon, I'm going to order a mold from Accurate molds...because we get what we pay for and I want something nice.

Accurate's aluminum molds use a different aluminum than Lee. Not knowing how this aluminum reacts, and being a lot more worried about warping a $130 mold vs a $20 mold, I want to ask what are the acceptable preheat methods for this particular aluminum alloy? I'm nervous about dipping the edge...worried about warping the blocks.

I've got a heat gun I could use. I'm willing to go buy a hot plate if needed, though I don't have a spare circular saw blade laying around...I'm told that laying a mold directly on a coil is a bad idea. To that end, I'm wondering if anyone has used a "glass top" or other non-exposed coil hot plate without a saw blade or similar item sitting on the plate directly with the mold on the blade, and if that works safely.

[Bohica793]

I use a non-exposed coil hot plate with Accurate, NOE, Lyman, RCBS and Lee molds. Works great. I find I get the best results when I turn the hot plate to high at the same time I turn on my pot for the melt. When the melt is ready, the mold is just about the right temperature.

[OS OK]

You had the answer...cut an old tin can to cover the mold, drop an oven thermometer (0-550*F.) in the top of the can, set the thermostat about 1/2 way to max. and when the thermometer is around 400*F. (for my Accurate Mold) they start dropping boolits, keepers, from about the 2'nd fill. No more wrinkled noses and glitches on the sides of rifle boolits or HP's...all the other pistol boolits generally drop perfect from the first fill. Something else I've noticed...I've been running my Pb Pot a lot cooler...generally around 700-725*F. for rifles, especially the heavy long ones.
My-my, how simple little things can make life so much more pleasurable.

194231

[runfiverun]

an old cookie sheet, an electrical box, or the bottom off another coffee can will work until you get a saw blade. [yard sale season is coming up]
if you were near me I'd drop a couple of blades off to you.

[mjwcaster]

I use small cookie sheet/cake pans on the 2nd burner of my camp stove.
One end cut and bent down for an opening at the edge of the stove and the other for a lid.
Just whatever I had laying around that I could make fit.

Sent from my Z958 using Tapatalk

[JonB_in_Glencoe]

For about the first 6 months of my casting hobby, I dipped the corner of many molds into the melt. The mold never got hot enough, I would be hammering on the sprueplate to break the sprues off, til about the 10th pour or so. At that 6 month mark, I added a hotplate to preheat my molds...and that was easily the single best thing I did as a newbie, to make casting boolits more enjoyable.

About 2 years after that, I added a PID to the Lee pot, that was just as big a deal, to simplify the casting session...but I digress.

[Bzcraig]

The hot plate is the way to go. Any type of material that will dissipate the heat more evenly will work; steel, aluminum, ceramic, etc. Didn't have any coffee cans so I used a double metal electrical box covered with aluminum foil to retain heat.

[Grmps]

I use a hotplate with a 3/8th inch piece of steel plate on top. ## be careful, some hot plates can get hot enough to damage your molds. I like to Test any new hot plate with an inductive thermometer to dial in the temperature I want before using it.

[lightman]

I learned about using a hotplate from the guys here on Cast Boolets. I started with a cheap saw blade but it warped and did not make good contact with the burner. I just now got home with a piece of 1/8th steel plate that I cut out with a plasma cutter. Before my old Lyman pot died, I would set the mold on the top of the pot, on the cast iron lip. This did not work as well with the thinner stainless liner on my ProMelt. My hotplate was a cheapo from Walmart, about $10.

[JeffG]

I used a hot plate without a saw blade for a while and honestly don't see a difference, but am using one now. I now start heating my mold when I start up the lead pot, letting the mold stabilize at 350-375 degrees for a while. Come time to pour, a lot of times the first pour is good, definitely by the second pour. It really beats the heck out of dipping the mold, leaving it on the pot, etc.

[DHDeal]

I asked the same question a while back. Get a hot plate and put something on top, if exposed coils, and experience the best casting sessions you've ever had. All of my casting problems were due to the mold not being at a correct temperature. Yes I was able to cast great bullets, but I had to dump back into the pot way too many bullets. After the hot plate, there have been times I could keep the very first mold full. I never have to dump back in more than the first 3 casts.

Also, I found the hot plate helps me get a new mold up and running almost immediately. I used to KNOW I was going to get a few bullets with a new mold during my first casting session. Now, after giving a new mold a good cleaning, I'll be getting great bullets quick. I only have Accurate Molds for revolvers/pistols so that may be part of it.

[nun2kute]

James, you could always e-mail Tom at accurate molds, I'm sure he'd have some good advice. Maybe he could explain the difference in those two different aluminum blocks. I'd be interested in his explanation.

[rondog]

My solution. http://castboolits.gunloads.com/showthread.php?313287-My-hotplate-quot-oven-quot-for-molds

[44man]

The only warped mold I ever had was a used one I got for $5. It was caused by making the handle screws too tight and when heated it spread the blocks. I use a floating pin. I played the devil fixing the warped mold but I did. I put floating pins in it after.
Just keep a mold off the coils on a hot plate.

[trixter]

https://images-na.ssl-images-amazon.com/images/I/41oBH+79YBL._AC_UL246_SR190,246_.jpg

This is on Amazon for less than $17.00. git one or one like it. just be sure the 'burner' is solid. You'll love it. I checked it with my

https://images-na.ssl-images-amazon.com/images/I/413lMCo0b-L._AC_US160_.jpg

Lyman temp probe and at the hot side of MEDIUM, it registered 550º, which is hot enough to start casting.

Enjoy!

[454PB]

I guess I'm a caveman, I use a hand held propane torch to preheat.

[deadeye ruck]

I guess I'm a caveman, I use a hand held propane torch to preheat.

I use propane also, but in the form of a propane burner on a deep fryer. I get much better coverage than with the torch. I would imagine you can get it too hot but I usually try to use common sense ;)

[toallmy]

I picked up a hot plate to use but it kicks the breaker , so I have been using the electric kitchen stove with a 1/4 steal plate on it , it's supposed to be temporary .

[lightman]

I picked up a hot plate to use but it kicks the breaker , so I have been using the electric kitchen stove with a 1/4 steal plate on it , it's supposed to be temporary .

After I retired I started having a couple of buddies come over to cast, usually once a week until the weather turns hot. We set up on my work bench with 3 electric pots and a hot plate and cast for most of the day. We just visit, talk guns, sometimes open a beer in the afternoon, passing the time. I added a couple of circuits behind the bench so that we would not have extension cords stretched around the work area.

[bangerjim]

ELECTRIC hot plate is the only way to go! Solid top is best. Very inexpensive. Can also be used to pre-heat your feed ingots for you casting pot. Really speeds up things!

One is as essential as a mold or casting pot to get good boolits on the 1st drop. Don't waste any more time. Just buy one....................and don't look back.

[gwpercle]

No extra electricity , one 15 amp circuit isn't enough for lights , pot and hot plate....I have to heat on the top of the pot and corner dip them....cast a few and the moulds up to temp.

[JonB_in_Glencoe]

I picked up a hot plate to use but it kicks the breaker , so I have been using the electric kitchen stove with a 1/4 steal plate on it , it's supposed to be temporary .
When I built up my casting bench, I ran two separate circuits. One 15 amp circuit may be enough for a Pot and Hotplate (depending on which pot and which Hotplate), do you have anything else on that circuit?

[dragon813gt]

You don't need anything fancy to make an "oven" out of.
http://i198.photobucket.com/albums/aa39/dragon813gt/TimeToMakeAmmo/E463A94C-15BA-4F4A-98FF-CB07E7074F2F-452-0000000FDC7A6FFF.jpg (http://s198.photobucket.com/user/dragon813gt/media/TimeToMakeAmmo/E463A94C-15BA-4F4A-98FF-CB07E7074F2F-452-0000000FDC7A6FFF.jpg.html)

[Whitespider]

You don't need anything fancy to make an "oven" out of.
Agreed...
http://castboolits.gunloads.com/attachment.php?attachmentid=194672&d=1493837380
*

[Leadmelter]

Wallymart $17. I set the hot plate to a little less than medium and 20 minutes I am good to go.
Leadmelter
MI

[Boolseye]

I have dipped every mold I own, Lee, Accurate, NOE, Lyman, about 45 in all. Never warped a-one.
I do both, hot plate first then dip.

Like that set-up, Whitespider.