Mould temperatures

[Martin Luber]

I have remote temperature gun device from Harbor Freight and l used it on my moulds during preheat and casting. It was interesting to note that running 3 moulds at once the 4 cav H&G 68 came up to temperature faster than the 4 cav 45266. At 276F it cast beautifully but running just that, it got to 325 and frosted the castings.

The 45266 also run in series only got to 175 and the 8 cav #130 wouldn't get over 135

I precleaned mineral oil off the moulds with Dawn and put on the stove to warm up on low heat. I did notice flash rust on the 45266 and the 130 but not the 68.

Wonder why and is this bad?

[BJung]

I don't own a remote temperature gun device - yet. But, I've started casting with the Mihec brass molds and using them is quite different that the Lee aluminum molds. Has this temperature gun helped and how?

[JSnover]

I've only used solvents - never soaps to clean my molds and have never had rust. I suspect the Dawn left a residue unless you flushed it with water, which is also a bad idea if you're going to apply heat before it dries. Flash rust In my my experience isn't a real problem if you clean it off quickly.
Carb/choke/brake cleaner, electrical contact cleaner, acetone, MEK (Methyl Ethyl Ketone) have all worked well for me. Spray, dip, or brush it on, wipe off with a q-tip, give it a few minutes to dry at room temp and then start casting. I've had no issues with contamination.

[GregLaROCHE]

If you have compressed air available, blowing them down right away helps. Don’t use very hot water either with steel molds.

[Martin Luber]

I hink i helps get enough but not too much preheat before casting. There's no temperature setting on the stove. Also let's you monitor temps for optimal casting. If too cool, run just one mould. If too hot, rn several. I usually have 3 going at once

[capo602002]

A remote temperature gun will not give an accurate reading unless you take into account the emissivity of the surface being measured. Even then it probably will not be all that accurate.
The best way to measure your mold temp is with a direct measurement device such as an thermocouple. I recently ordered this off of amazon and have been very happy with it:
https://www.amazon.com/dp/B005GFHYA8?psc=1&ref=ppx_yo2ov_dt_b_product_details

I would pick up something similar to double check your non-contact IR gun.
You can simply hold the thermocouple supplied to the mold - it reacts very fast.

[gwpercle]

I've only used solvents - never soaps to clean my molds and have never had rust. I suspect the Dawn left a residue unless you flushed it with water, which is also a bad idea if you're going to apply heat before it dries. Flash rust In my my experience isn't a real problem if you clean it off quickly.
Carb/choke/brake cleaner, electrical contact cleaner, acetone, MEK (Methyl Ethyl Ketone) have all worked well for me. Spray, dip, or brush it on, wipe off with a q-tip, give it a few minutes to dry at room temp and then start casting. I've had no issues with contamination.

:goodpost:
LIKE !
Water and moulds don't do well when mixed ... Moulds / sprue plates like to rust ... that's Bad !
Acetone beats water Seven ways to Sunday .
Good advice in JS's post .
Gary