Citric acid to final clean new mould?

[prs]

I received a new Lee 452-200-SWC 6 cavity Yesterday. Lee's cleaning and lubrication instructions seem to have changed a bit, but I never followed them any way

I used dish washing liquid, an old toothbrush, and hot water to scrub it thoroughly. Lubed with Stihl synthetic 2 cycle oil. Well, I still had a too high rate of culls with those scarab beetle patterns on them. Got about three hundred keepers and decided to repeat the cleaning befoe the next try.

Same cleaning this AM, except I followed the rinse of the detergent with a liberal soaking in a quart of hot water plus a teaspoon of Lemishine citric acid crystals for half an hour. Relubed with same product. The mould dropped almost all keepers right from the get-go, except when I bungled the pour. Could just be the second wash, but then again......

prs

[Airman Basic]

Along that line, thinking about running my next mould through my HF ultrasonic cleaner with Dawn and Lemishine. Anybody tried that?

[Danderdude]

I wouldn't feel comfortable putting any kind of acid on aluminum, personally. Hydrochloric and sulfuric eat at the passive aluminum oxide surface, exposing the highly-reactive bare metal to oxygen constantly, including air dissolved in water.

I wash new molds with lacquer thinner and a disposable shop toothbrush. Lacquer thinner contains all the fun, good stuff: acetone, MEK, toluene, benzene, alcohols and ether. Never had a problem with needing a second wash.

[btroj]

I scrub with hot water and Comet.

I find Lee moulds often need a good cleaning, a full heating, the a mother cleaning.

Acid type cleaner not required, it is oil that you need to eliminate, not corrosion.

[MtGun44]

If you DO manage to remove the oxide layer on an aluminum mold, you are not helping
it - this is what the citric acid does.

I have long recommended a scrubbing with Comet and a toothbrush. This is all you need
to prep a mold.

Bill

[Shiloh]

Been cleaning mine as suggested above, then boiling them. After that, a liberal scrubbing with a paste of Comet.
WHen done boiling, take them out of the water right away and rinse. If you don't they turn a silver-ish brown. Reboiling removed the color.
Virtually no bad boolits when up everything is up to temp. The fall out with nothing more than a light tap if even that.

Shiloh

[prs]

Hmmmmmm? So a mild organic acid to modestly etch the metal after a detergent scrub is bad, but an abrasive pumice plus detergent cleanser is good. Yes, that's the ticket. Makes perfect sense; not.

prs

[williamwaco]

Another theory:

I cannot explain this but here is my experience.

Take a new Lee mold. Some of them cast perfect from the second or third pour. Many do not.

Of those that do not, no amount of de-greasing will help. Soap and water, 409, tooth brush, carburetor cleaner, comet, nothing.
After several hundred fillings, they will still be wrinkled even when hot enough to frost.

Set that mold aside and let it cool to room temperature, then start over and heat it back up to casting temperature then set it aside again and let it cool.

After about half a dozen trips from cool to very hot to cool and repeat. It will begin to cast better and better bullets.


.

[Shiloh]

Hmmmmmm? So a mild organic acid to modestly etch the metal after a detergent scrub is bad, but an abrasive pumice plus detergent cleanser is good. Yes, that's the ticket. Makes perfect sense; not.

prs

The molds throw great boolits that shoot very well. Do what ever works for you with your molds. One of these molds is the very same LEE .452 200 gr SWC. Mine has had the bevel base trimmed almost all off, and what was left has been reamed out. It is virtually an H&G 68 clone and drops 200-204 gr. boolits depending on the alloy that day.

Shiloh

[blikseme300]

I would not use any acid to prep a mold as this won't help any in removing the very small burrs that are left over after the machining. A nylon brush and Comet does more than degrease the mold as it is proven to be effective in smoothing out these small burrs that cause a boolit to stick in the cavity. The evidence is clear enough from all the positive outcomes reported so I don't need to try and invent another method for mold prep.

[geargnasher]

The Comet serves a purpose beyond degreasing for Lee moulds. Plus, caustics help form a patina on aluminum. If it's not a Lee, just a good wipe with some brake cleaner and q-tip followed by a rinse-off with same, then a splash of denatured alcohol or laquer thinner gets the rest. Blow it dry and start casting.

Gear

[Old Caster]

I use Comet also and I think the reason heating the mold up a bunch of times will also work is because the oils are finally burned off after a number of times. This is why the mold will start to drop better bullets, each time it is used.

[454PB]

You guys need to quit putting oil on your moulds. I haven't put lube on any of my Lee moulds for many years......and they work perfectly.

[Garyshome]

Brake cleaner & toothbrush!

[tengaugetx]

I have that mold in a tumble lube. I had the same issue the first time or two I used it. It has gotten better each time I have cast with it. I also ran my melt at a higher temp the first couple times I used the mold which seemed to help.

[spfd1903]

Same experience as William Waco mentioned. I have been ready to toss a few Lee molds during a session where I was getting wrinkles, deformed driving bands, etc. from a cleaned and shiny mold. Set it down and cast with another mold. Picked up the offender an hour later, and got a winner
every time. Never could understand using a bleach/powder mixture like Comet, when a plain non-bleach abrasive like Bon Ami is available. Makes a nice paste also.

[leadman]

I have had a couple of really stubborn Lee molds recently that did not respond to the Comet, acetone, lacquer thinner, or boiling.
I finally moved the sprue plate all the way off the blocks and poured hot lead in one cavity and let it overflow into a pan. Then quickly opened the mold while the lead was still semi-molten and used a rag to brush off the loose pieces of lead. After each cavity was done it cast perfect boolits. I think the hot lead streaming into the cavity burns off the oils, or something, but it works.