What am I doing wrong??? Flashing around the base.

[Trapperscott]

Hello everyone, I just bought a new 6 cavity lee model 401-175-tc mold. I cleaned it this morning and got the pot going. I am using a lee bottom pour electric pot. I'm casting or attempting to cast with wheel weight alloy. My problem is that I am getting flashover between the sprue plate and the top of the mold. I tried lowering the temp of my pot and it helped some but didn't fix the problem. The sprue plate seems to be tight enough when it is locked and ready to pour. I can see no more light between it and some other molds that throw good boolits. I haven't taken it off and put a straight edge on it to see if it is warped yet as it is still hot as I am typing this.

When I try to run one of the boolits through my lee push thru sizer the fins become wadded up and turn out bad.

Is my melt to hot? Is the sprue plate the problem?

Any help would be apprciated.

[nekshot]

Did you lube the top of mold when it was warming up and the sprue plate? Some times the tension on the sprue plate determines a clean sweep when opening. I clean all lee molds with a scribe in the pin-vent areas and wash them with gun scrubber and cast real hot at first and they all cast good after 4-6 casts then turn the heat down.

[44man]

Either the plate or mold top. The plate might be too tight.
I make my own plates for my molds and it is a big problem and I have tried lapping but it makes it worse. Seems a flat plate will get cut at the edges more then the center and will turn into a rocker no matter how strokes are applied. Even glass with lapping compound never worked.
I now mill the top of the mold before cutting cavities and leave the end mill marks. I mill the plate and that cured flatness.
But the plate still needs to be adjusted to lay flat. Pivot screws play hob with how they fit.

[Trapperscott]

Well, I let the mold cool and cleaned the heck out of it with hot water and dish soap. I checked the sprue plate with a straight edge and it is pretty darn flat. Put it back together and tried it again. I cast as fast as I could to get it up to temp, and then started letting it cool a little in between just as soon as the boolits started coming out frosted. I'm still getting the flash at the base between the mold and the sprue plate. I lubed the hinge pin, and just a touch on the under side of the sprue plate Nothing seemed to help.

I'm at a loss as to what to do now short of taking the sprue plate off and putting it on my surface grinder and just kissing it to make sure it is flat.

[williamwaco]

Well, I let the mold cool and cleaned the heck out of it with hot water and dish soap. I checked the sprue plate with a straight edge and it is pretty darn flat. Put it back together and tried it again. I cast as fast as I could to get it up to temp, and then started letting it cool a little in between just as soon as the boolits started coming out frosted. I'm still getting the flash at the base between the mold and the sprue plate. I lubed the hinge pin, and just a touch on the under side of the sprue plate Nothing seemed to help.




I'm at a loss as to what to do now short of taking the sprue plate off and putting it on my surface grinder and just kissing it to make sure it is flat.

Before you do that, experiment with the tension on the sprue plate screw. Too tight or too loose either way can cause the problem.

If it is too loose, it can lift up. If it is too tight, it can tilt.

.

[runfiverun]

the cavity[s] that are flashing will tell you whether it's too tight or too loose.
if it's only one out of six it might just be the area around that cavity is too low. or the sprue plate has an issue.

[Trapperscott]

the cavity[s] that are flashing will tell you whether it's too tight or too loose.
if it's only one out of six it might just be the area around that cavity is too low. or the sprue plate has an issue.

Run, it seems the cavities on the ends dont do it as bad as the 4 in the middle. And, it seems the hotter I get the melt and the mold, the worse it is.

I cant see any daylight between the mold and the plate anywhere.

[JIMinPHX]

A few pictures would help us to help you.

In the mean time -
Is the flashing equal around the whole boolit? Or is it heavier on one side than the other?
How heavy is the flashing?
How hot are you casting?
How long do you wait before you cut the sprue?
Are your boolits shiny?
Are your boolits frosted looking?
How long does it take from when you pour the lead to when the sprue puddle hardens?
Is there any lead stuck to the top of the blocks or the bottom of the sprue plate?
Are you getting the sprue plate closed all the way every time?

I would avoid surface grinding the sprue plate if possible. First, you will loose that rough flycut finish that acts as a vent. Second, surface grinding aluminum is generally a pita & it's hard to get good results. Aluminum likes to clog your wheels.

[DLCTEX]

Are you pressure casting (holding the sprue plate against the nozzle of the pot)? If so, leave and air gap. If not, +1 on loosening the sprue plate bolt.

[44man]

Could be uneven expansion of the mold. So much metal for blocks can do it. Hot and cooler spots.

[Trapperscott]

Are you pressure casting (holding the sprue plate against the nozzle of the pot)? If so, leave and air gap. If not, +1 on loosening the sprue plate bolt.

I am pressure casting. I watched a video or two on youtube this morning and saw that the person was pouring from a bottom spout pot and there was a gap of about a half inch to an inch between the mold and the spout. I'm going to try it again this morning.

I will try some of the suggestions that you guys have given to see if I can get it to work. I'll also try to get some pics of the boolits if there is still some flashing going on.

[Goatwhiskers]

Trapper, the problem I had may or may not have a bearing on what you have. I'm using a RD(Lee)359165 with 3x3 setup. I usually pressure cast, seemingly the only way to prevent wrinkles in that long nose. My GC boolits were coming out with "flashing" on the base causing real problems with putting the GC on. Then I noticed when I sheared the sprue and looked at the bases that sometimes I would have clean bases, mostly not. I slowed down and gave the sprue a little more time to harden, completely solved the problem. Hope this helps. GW

[Charlie Two Tracks]

There is also the rate of flow out of your pot. May try slowing it down. I'm no expert but I know that a guy has to experiment while casting. Just as with developing a load, try just one thing at a time and see what happens. It will eventually work. It really will. I keep my mold about 1/4 of an inch away from the spout for the way I cast with my alloy with my molds and my thermometer. I believe that our alloys, thermometer temperatures, molds and techniques are different from one another and yet we still are able to share info. and end up with great shooting boolits.

[HangFireW8]

I am pressure casting. I watched a video or two on youtube this morning and saw that the person was pouring from a bottom spout pot and there was a gap of about a half inch to an inch between the mold and the spout. I'm going to try it again this morning.


Pressure casting requires more highly vented molds. Different molds require different techniques. Some like no gap/pressure, some tiny gap, some large gap, some like swirl on the sprue plate, some straight down, some angled/swirl in the cavity, etc.

In addition the top of the mold may not be flat, as 44man and runfiverun indicated.

For every new commercial (Lee, Lyman) mold I get, I briefly lap the mold top and the sprue plate to check for flatness. Some irregularity is OK and even beneficial for venting. I'm looking for the gross problems.

HF

[44man]

Yes, a few strokes to lap is great, just remove burrs. Also file the edges of a plate with a real fine file so there is nothing to scratch a mold. All edges should be polished.
But to lap a lot to flatten anything just has not worked.

[Trapperscott]

Wow, lots of great information in a short time here trying to help me with my problem. I have found a new place to hang my hat for sure.

I appreciate all the advice you guys have volunteered to help me with my problem. I think I'm gaining on it.

I went out this morning and fired up the pot again. I took the mold apart before I started and cleaned it well with Q-tips and acetone. I put it back together and put it on top of the pot to warm up. When the mold was warm I used the only thing I had on hand, some Husquavarna 2 stroke oil to lube the pins, the bottom of the sprue plate, the hinge pins, and a little dab on top of the mold. It smoked a little but wasnt to bad. I then poured the mold full holding it about a half inch away from the spout. I let the sprue hardend for about 10 seconds and opened the mold. What do you know, no flashing around the bevel base. I continued casting like that for about an hour. I have almost eleminated the flashing problem I had yesterday with just by holding the mold about a half inch away from the spout. I still have a problem with one of the cavities. I still get a little flashing on one edge of it. Not sure what that's about but will see if the sprue plate has a problem on that one cavity.

Now, my only problem is keeping the pot full. LOL. This mold sure eats a lot of material in a hurry.

Thank you everyone for helping a newb out. This is a great forum.

[44man]

I cast some this morning and the plate was TIGHT. Perfect boolits but I loosened the plate. The lock set screw and copper piece was loose from heat so I tightened it too. As I turned the plate the bolt was turning. All was good until I got bad flashing on the next pour. The plate was tilted so I tapped it down before the next pours and it was fine. It was the wave washer on the bolt pushing one side down. All is good now, it straightened out.

[JIMinPHX]

Pressure casting works well with some molds, but not with others. It's frequently, but not always, related to the amount of venting that the blocks have.

If your current method is working better, but not quiet well enough, try turning down your pot temperature just a little bit & see what happens.

Casting is all about finding the sweet spot where all the variables match up & work well together. Every mold will have it's own little quirks. There is no standard method that always works best with all molds.

[MBTcustom]

Glad you got 'er figured out. I just thought I would mention that the Lee 6 cavity sprue plate is made of aluminum and is hard anodized. You take a surface grinder to that and you'll really have problems.
Another thing, I was thinking about making molds for a while there, and I bought some spare Lee 6 cavity sprue plates thinking I could use them for my molds. I was shocked at how warped they were right out of the factory. They were pretty strait longways, but they had a crest to them in the middle kind of like a potato chip. There was no way in heck those plates would seal to the top of a mold.
However, upon disassembling my 6 cavity Lee molds (bought the previous year) and observing the plates carefully, I noticed two differences. First, they were truly flat, and secondly, they were anodized a more "bronzish" color instead of like the replacement plates that were anodized black.
Not that this has any bearing on your situation. I only mention it to say that Lee has made mistakes in this area and allowed those sub-standard plates to be sold, so you might want to check 'er out.
Glad you got it going. Lee 6 cavities are just about the most effective way to pile up a gob of boolits that I have ever used.

[R.M.]

Every Lee 6 cav plate I've looked at lately has been dished in the center. I've gave up and put on aftermarket steel plates. Problem fixed.

[JIMinPHX]

Another thing, I was thinking about making molds for a while there, and I bought some spare Lee 6 cavity sprue plates thinking I could use them for my molds. I was shocked at how warped they were right out of the factory.

I used to make replacement plates for Lee 6-bangers out of 1018. I got good feedback from the people who bought them. If you want my drawings, just let me know.

Regards,
Jim

[Trapperscott]

I used to make replacement plates for Lee 6-bangers out of 1018. I got good feedback from the people who bought them. If you want my drawings, just let me know.

Regards,
Jim

Jim, I would really like to have a copy of your drawings for the Lee 6 banger sprue plate. I am a custom knife maker and have an almost full machine shop to build such a thing. Did you surface grind your plates or fly cut them for venting?

[JIMinPHX]

I just used plain cold roll, as-is.

Now that I think about it, I believe that I already posted the drawing here on the board a year or two ago. I'll have to do some searching to see if I can link back to that web page.

Everything but the 6-cav drawing can be found here - http://castboolits.gunloads.com/showthread.php?88319-Improved-Sprue-Plates-Any-Interest

I'll have to dig some more.

Edit:
I can't find the post with that drawing. It may have gotten deleted when I gave up my vendor sponsor status. I had thought that I had referenced links to it in at least two other threads, but I can't find any of them.

Another edit:
The search function here on the board didn't find it, but an advanced Google search did - http://castboolits.gunloads.com/showthread.php?132060-Lee-six-cavity-sprue-plate-wear
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