A little help please ?

[cabezaverde]

I have a Lyman 2 cavity that sticks on opening just slightly when it is up to casting temp. Any thoughts on what causes that ?

[kenjuudo]

Might be the alignment pins are set a little deep. Try tapping them back just a few thousandths.

jim

[Buckshot]

Might be the alignment pins are set a little deep. Try tapping them back just a few thousandths.

jim

...........Ditto

.............Buckshot

[cabezaverde]

Might be the alignment pins are set a little deep. Try tapping them back just a few thousandths.

jim

Just tap them lightly with a punch ?

[kenjuudo]

I set them on a large ingot and use a brass punch with a dimple drilled into the business end so it won't slip off the pin, have thought of making a small C-press with a threaded shaft.

If ya can't get your hand on a brass punch, buy a brass bolt at the hardware store for 30-50 cents.

jim

[Tom Myers]

The last time I tried to tap the pins back a bit, all that I accomplished was to further swell the pin so that it stuck tighter in the alignment hole.

Having determined that if one first makes an orientation mark on the exposed nose of the pin and then drives the pin completely out from the rear of the block, the pin may then be oriented and re-inserted by carefull tapping or pressing to the desired depth from the rear of the block.

Probably, if the pin is not too tight in the block, tapping on the nose with a brass punch would move it without deforming the nose, but experinece has shown that fewer problems are encountered by not even trying it.

Tom Myers

[44man]

Sometimes taking a countersink and just touch the hole opposite the offending pin will correct the problem. Make sure you turn it by hand, just a tiny turn without pressure. If you get it too loose, just tap the pin from the back a little.

[cabezaverde]

Okay, how about slightly rounded edges on the bearing surfaces at the grease groove. I am running pretty hot, but Lyman manual says it's temperature or venting.

[David R]

Can you attatch #s to "Pretty hot"

Venting is possible, adding a little tin to the mix will help fill out sharp edges in the mold.

I pour till they start to come out frosted, then back off a little. I keep my pot around 700 to 750. I pour fast to get the mold hot, then when they start comiong out too hot, I start using a second mold or turn the lead down, or just slow down.

Bruce B cools the sprue and mold on a moist towel once the mold is good and hot.

You probably need more heat.

[cabezaverde]

Bullets are frosty using the Bruce B method. Just some rounding of the bands.

[felix]

Mold is too hot. Keep the lead as hot as possible. Cool the mold on wet sponge or paper towel after a drop. ... felix

[Willbird]

Also worth a try is to CLEAN the mold............This has worked wonders for me with aluminum molds that "seemed" clean, and had been cleaned with brake clean, Other posters can share what they scrub/boil steel/iron molds with.

Bill

[David R]

I use Wellworth ShopSolve, or Castle Shopkleen. Its an alcohol based cleaner that seems to just wipe out any grease. I spray it on a toothbrush AND the hot mold. I scrub the mold with the wet toothbrush, wait a minute so all the solvent is gone and go back to casting. This works wonders for me especially on a new mold.

[slughammer]

Bullets are frosty using the Bruce B method. Just some rounding of the bands.

Sometimes a mold requires a faster fill to get the bands square. Perhaps the flow rate is not enough.

Only other suggestion is drop height and lucky socks.

[Willbird]

Several other booliteers have reported something I have seen, some molds work better filled one way than the other, IE starting from front or back cavity might give better results.

some feel it is venting, some thing heat sink from the handles....

Bill

[Buckshot]

http://www.fototime.com/2D536DBA57B9FA1/standard.jpg

The above photo isn't a real good one, but it'll have to do. The slug is the Lee 358-158RF(BB). this shows the effects of mould block tempurature on boolit appearance AND diameter. The alloy temp (16BHN) was constant for the 3 boolits cast. It was running around 800 degrees.

ON THE LEFT: The slug was cast in a cooler mould. After pouring, the blocks were inverted with the sprue pressed against a damp towel, then dumped. After closing the blocks, they were pressed against the damp towel. Boolit diamater .3607"

CENTER: This was cast with the sprueplate pressed on the damp pad before dumping. The bullet displayed and even frosty dull appearance.Boolit diameter .3598"

RIGHT: These were cast from a set of blocks which had been set on the hot alloy, and then cast with no artificial sprue cooling. Just as soon as the sprue puddle hardened it was struck, dumped and refilled. These slugs were evenly covered in a discreet crystalline pattern such as a piece of galvanized steel. Boolit diameter .3605". This is close enough to the Left slug to be of no real difference.

All boolits were well formed with sharp features, although the right hand one was not only perfectly cast, but a few from each dump (6 cavity) would be whiskered to one degree or another. The brilliant slug on the left was cast as well as anyone could like, but it's edges didn't display the 'broken glass' sharp corners of the other 2.

.............Buckshot