Blocking off a cavity?

[cabezaverde]

I have a Lee 6 cavity mold that has one damaged cavity.

Any good ideas on how to block off that cavity so that it doesn't fill when bottom pouring?

[OS OK]

Solder or spot weld that sprue hole over that cavity...file the bottom of the sprue plate flat if the plug protrudes.

[Chainsaw.]

Try sending it back to lee, they may replace it for free.

If not, maybe plug the sprue hole with jb weld?

[cabezaverde]

Try sending it back to lee, they may replace it for free.

If not, maybe plug the sprue hole with jb weld?

Will JB Weld tolerate the heat?

[OS OK]

JB Weld wouldn't keep my coffee can stuck to my skill saw blade that sits on top of my hot plate mould warmer. It gave up about a month later.

[country gent]

most epoxies are heat sensitive. commercial grades are around 400*-600* some industrial grades may get up to 800*-900*. Soft solder will probably release also at the operation temps of the mould. Silver solder or braze will probably hold as will weld but with the temps to use you may warp sprue plate. Another way would be to drill out and press a thin disc in to close off hole. .001-.002 press should hold very good. If the Lees sprue cutters are mim or powdered metal welding may not be an option

[frkelly74]

Just skip the bad one?/?

[nvbirdman]

Just file a good sized notch in that cavity so you can see at a glance which boolits came from that cavity when you are sorting them. Remelt the bad ones.

[Dusty Bannister]

I have a Lee 6 cavity mold that has one damaged cavity.

Any good ideas on how to block off that cavity so that it doesn't fill when bottom pouring?

Usually, if I have a bad cavity, it results in a stuck bullet in the cavity. There is no reason to block a cavity at that point. If the blocks close evenly, what would be the problem? Apparently your mold and eyes are not in position to see the flow of the alloy. You might also consider changing that as well. Dusty

[reddog81]

Take a file and notch the sprue plate next to the bad hole. Then avoid that hole.

[dondiego]

I have never done it, but could you fill that cavity with plaster of Paris or dental plaster?

[country gent]

Now there is a thought drill 2 holes at an angle to form a vee in on sides bad cavity and fill with lead when mould is hot. this creates a mechanical lock to hold bullet in. would mean only spure would fill and provide added alignment to the blocks.

[mdi]

Would it be too much trouble to just skip the bad hole? How damaged it that one cavity? I'd use nvbirdman's idea of casting and culling. Would an empty cavity throw off the mold temp on the two adjoining cavities?

[JonB_in_Glencoe]

Just skip the bad one?/?

That's what I'd do.

In fact, I have one mold that has half of the cavities are Plain base and the other half is GC style...I usually just cast the cavities I desire and skip over the ones I don't need.

[17nut]

Solder or spot weld that sprue hole over that cavity...file the bottom of the sprue plate flat if the plug protrudes.

Lee 6-bangers wear an aluminium sprueplate so welding is pretty much of.

[8mmFan]

Try sending it back to lee, they may replace it for free.


This. Lee's customer service has been BEYOND phenomenal for me over the years. I don't think it's just because I live in Wisconsin.

Send the whole mold back to them and see what it costs to replace it. You may be surprised how they respond to that. They are an absolutely awesome American company when it comes to customer service, and I could list so many personal examples of it that the list would bore you.

At WORST, you'll end up buying a new mold, which isn't the end of the world.

Just my $.02 putting in a good word for a great company.

8mmFan

[Bazoo]

If you want to plug the sprue hole I have an idea. Never done it, but thinking about it a minute. You could find a bugle head screw whos head fits in the sprue hole just a touch below the top of the sprue plate. Cut the head off the screw so that the shank doesnt protrude through the sprue plate. Then put the head in the sprue hole, and peen the sides of the hole over in a couple spots.

[NyFirefighter357]

https://www.jbweld.com/products/j-b-extremeheat good to 2,400F

Great For:
Exhaust Manifolds
Tail Pipes
Mufflers
Engine Blocks
Duct Work
Heat Exchange Units
Fire Box / Fire Place
Outdoor Grills

[dale2242]

I repaired a crack in my homemade wood stove in my shop with the JB that NyFirefighter357 recommends.
It has held for a few months.

[jimkim]

Now there is a thought drill 2 holes at an angle to form a vee in on sides bad cavity and fill with lead when mould is hot. this creates a mechanical lock to hold bullet in. would mean only spure would fill and provide added alignment to the blocks.I like this, OR lap OR drill OR bore that cavity out, and make it into something useful.

Sent from my VS880 using Tapatalk

[Gohon]

Lee 6-bangers wear an aluminium sprueplate so welding is pretty much of.

None of mine do...

[Dusty Bannister]

All the Lee six hole plates are anodized aluminum plates. Only the one and two hole plates are steel. Did you replace them with after market?

[Gohon]

No I didn't replace them and on closer inspection it seems you may be right. That's what I get for assuming something without checking. However, I've had no problem with them and see no need to replace them at this point.