Reviving an Abused Mould . . . Lyman ‘Devastator’ 356637 – 9mm 125g. HP

This is an old single cavity, removable pin mould with a huge HP, actually it looks like a 147g. RNFP with a beveled base. I’ve wanted for some time to tinker with one of these ole girls and recently, accidentally stumbled onto one. This is what she looks like…

Reviving an Abused Mould . . . Lyman 'Devastator' 356637 - 9mm 125g. HP 3

From this picture sent to me by E-mail I thought this mould was in an excellent condition, looks clean in the cavity and no physical damage on the parting line of the mould. When it arrived it didn’t look so good as in the picture…she looked like she had been ridden hard and put up wet too many times. This mould would make me use every trick in the book and took a half day’s work to eventually get a small pot full of cast done.

I usually use brake cleaner on a mould. It does a great job with its pressurized spray, it’s controllable so it won’t remove the lubricant from under the sprue plate, quick and easy cleaning of the interior cavities…but this mould obviously was going to need the acetone, ‘mean dirty machine’ cleaner.

Reviving an Abused Mould . . . Lyman 'Devastator' 356637 - 9mm 125g. HP 5

First thing I did was disassemble & remove all the screws to give her an Acetone bath and good brushing to remove all the oil and other contaminants…get back to bare and clean steel…

Reviving an Abused Mould . . . Lyman 'Devastator' 356637 - 9mm 125g. HP 7

Reassembling with all clean components is the time to use ‘anti-seize’ sparingly on the threads to insure that they never seize from heating/cooling and will be removable for the life of you and the mould. Anti seize is a lubricant too…great for the sprue plate assembly…

Reviving an Abused Mould . . . Lyman 'Devastator' 356637 - 9mm 125g. HP 9

At this point I don’t have much time invested in mould preparation and it’s time to do some test casting. Eyeballing the mould, I’m thinking…”Alright, let’s see how this ole girl does?” I was astonished at what I saw next…

Reviving an Abused Mould . . . Lyman 'Devastator' 356637 - 9mm 125g. HP 11

I fully expected to have to determine by experimenting the best temperature for the tin-rich pure lead…I was ready for temperature blemishes and problems with incomplete HP cavities, there’s always a learning curve with every mould, especially the various styles of HP moulds and what they are made of…brass, steel or aluminum. I was astonished how ugly these first few cast came out…they were screaming…”this mould needs more than a fast cleaning! It needs a miracle!”

First off, you can see how the body of the cast is uneven and wavy looking…that’s not how the mould was cut, that got there little by little over a decade or longer of hard use and little care! That is from using a ‘mould release’ and allowing it to build up after repeated uses. I have to admit that I don’t see this very often. Mould releases are not used in the circles I cast in…we cast ‘bare mould’ and use a little ‘smoke’ only when all else fails to get the mould to release properly. If a mould is cut properly on center of the blocks and it has been de-burred adequately, there’s no reason to have to resort to mould release and smoke.

You may have noticed in your casting that there is a time while casting that the mould will rain the casts for a short period and then go back to having to whack it with the sprue whacker to get it to let go. When it’s raining the casts there are several good reasons for that; the temperature of lead is perfect and no higher for proper fill-out, the temperature of the mould is constant at a couple hundred degrees lower than the lead, it’s chilling the lead in the cavity as a ‘whole unit’ with no temperature chill lines caused by slow filling or missing the center of the sprue plate hole as it is filled, and your casting cadence is such that you are not overheating the mould. You are allowing the time needed for the mould to bleed off all that excess heat from the lead pot. An overheated mould will try to hang onto the casts when you open the mould, the cast didn’t chill quickly to solidify and shrink slightly to self release easily and fall out of the cavities. These test casts were breaking all the rules in the book! Everything that could be wrong was basically wrong…it was time to really start over again!

Second attempt, this time it was going into a boiling pot of ‘degreasing’ soap, basically a good dish washing liquid soap and water. I did this twice, each time putting the pot in the sink and filling the pot with fresh water and allowing the contaminated boiling water to flow out over the rim of the pot. The third boil was with fresh water only and removing that last boil by filling with fresh and allowing the contaminated water to flow over the rim…this prevents the oils from re-attaching themselves to the steel of the mould and its parts in the bottom of the pot. If that happened I’d likely get gas lines in the cavities. Next it’s blowing the mould off with compressed air to remove the water lingering in the screw holes…after that I set it in the sunlight for 20 minutes to insure all the water was gone.

Reviving an Abused Mould . . . Lyman 'Devastator' 356637 - 9mm 125g. HP 13

Looking at those first three cast again you’ll notice that the beveled bases has a little excess lead that flared/flashed out of the cavity under the space between the sprue plate and the top of the mould. In cleaning, I have removed all the built up carbon from under the sprue plate but I haven’t yet examined the bottom side of the plate itself. Here I found that the sprue hole was not cutting evenly either…it has only two slight shiny edges that are cutting as shown in this next photo…

Reviving an Abused Mould . . . Lyman 'Devastator' 356637 - 9mm 125g. HP 15

To sharpen and flatten the bottom of the sprue plate I sand it on the 600 grit wet/dry paper placed over this plate of glass…hold one finger in the top of the sprue fill hole and a couple more fingers hold even pressure on the whole plate as I sand in circles for a few minutes…the bottom of the sprue plate will look like this when it’s ready to be re-installed…now this sprue hole will have sharp cutting edges all the way around the hole & the plate itself is flat…

Reviving an Abused Mould . . . Lyman 'Devastator' 356637 - 9mm 125g. HP 17

Before re-assembly, I have to address the unevenness of the cavity. Normally a dirty/carbonized cavity can be easily polished up with a trimmed swab dipped in paint buffing polish, buffing compound…unfortunately this is not to be this time…

Reviving an Abused Mould . . . Lyman 'Devastator' 356637 - 9mm 125g. HP 19

This was going to require something tougher in the cavity applying the compound…it will take one of the casts themselves. I drill the cast and apply a deck screw for a drill shaft like this…

Reviving an Abused Mould . . . Lyman 'Devastator' 356637 - 9mm 125g. HP 21

The cast used in the above picture is from the second casting attempt…the cast looks much better than the first attempt but it’s still not satisfactory…I put the rubbing compound on it and carefully nest it in the mould and give it a minute of spinning several times, each time using the brake cleaner to clean the mould and re-apply more compound and spin again until you think your satisfied and ready at another casting attempt…

Reviving an Abused Mould . . . Lyman 'Devastator' 356637 - 9mm 125g. HP 23

The mould was re-assembled once more using the anti-seize, it was placed in the mould oven to pre-heat. The mould is set on the sprue plate side and the HP pin is placed in a hole on top of the mould oven and the pot was re-heated to 715ºF. for another try…

Reviving an Abused Mould . . . Lyman 'Devastator' 356637 - 9mm 125g. HP 25

This is the cast from that next casting test…

Reviving an Abused Mould . . . Lyman 'Devastator' 356637 - 9mm 125g. HP 27

This time I have a new set of problems to solve. The sides of the cast body look ok but I have temperature chill lines in the casts…the lead is not getting into the cavity straight through that tiny sprue fill hole, the hot lead is chilling as it funnels into the cavity, its excess heat is being robbed by the sprue plate. Now it’s not filling the cavity, it’s chilling as it enters forming these awful chill lines and voids around the HP pin on the cast…I could increase the temperature on the lead to 750ºF. but that would likely cause flashing around the HP pin in the nose of the cast and also force me into taking more time between pours so I can bleed off all that excess heat…No…instead of fighting this problem with more fire under the kettle, I have to use a different technique on this mould and keep the pot at 715ºF. …

 

That little drop of lead hanging off the spigot will cause you a chill wrinkle just like this one did in this next picture…

Reviving an Abused Mould . . . Lyman 'Devastator' 356637 - 9mm 125g. HP 29

Well after all that cleaning and re-cleaning and polishing and most of the day working at it…I finally got a pot full of lead cast into these Lyman Devastators…in the end the casts are acceptable for powder coating in colors, but if I were to want to put clear gloss on the casts I’d need to polish the cavity once more to get it to a new looking finish on the cast itself…as it is I can go on tinkering here with this new profile. It is a 9mm cast but already I’ve run it in the .38 Special and it grouped pretty dang well…one of these days I’ll do an article on loading this little pill in the 9’s and the .38 . . .

Reviving an Abused Mould . . . Lyman 'Devastator' 356637 - 9mm 125g. HP 31 . . . Reviving an Abused Mould . . . Lyman 'Devastator' 356637 - 9mm 125g. HP 33

“Till then, I’ll seeYa’s later in another article boys…take it easy out there, watch that 6…be careful and don’t hurt yourselves!”

c h a r l i e

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