Large Scale Central

Casting parts in lead?

Modeling
#1

I am looking to make some parts. In particular I am looking to cast truck side frames. I am going to cast the bachmann 10 wheeler tender trucks because I have them and they don’t look to bad. Or I might make my own like I had wanted to do and then cast them. I know that people cast them in white metal or plastic but what about lead. I have lead and its is heavy which I think would be good for trucks. But is there some reason I shouldn’t use it. One concern I have is it being soft. I had thought on the trucks a steel or brass back with a place for the axle to ride in could be inserted into the mold and then have the lead pour around it. I am I just crazy for thinking this way. White is the difference between white metal and lead?

What about using lead detail parts? The same silicone rubber molds can be used for either plastic or lead. I am just thinking that using lead would add weight.

#2

IF you go that route, it would be better to set the bearings after casting, to get true running wheels. Soft metals in a loose mold can go any which way.

Injection molds are done under a set pressure, to help maintain uniformity…

Bad fumes and should wear gloves and don’t let anybody touch them until sealed in thick paint…

Keep the lead for weighting cars, it’s best property is weight, not fabrication.

John

#3

Thought you had lots of brass or bronze, or the like. Lead is for bullets and fishing weights. (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-laughing.gif)

#4

Why not resin cast? been some nice looking resin made sideframes shown on LSC and other forums.

#5

Well I will answer the last question first. Why lead instead of resin, because lead is heavy so was just figuring weight down low might be an advantage and had seen where there were ones cast in white metal.

Second question about bronze, Yes I do have an almost unlimited source of bronze and would very much like to cast them and the detail parts in bronze. I just don’t have nor do I very much want to invest in what it will take to do it. Lead is way easier to melt and pour.

I was just toying with the idea and John pretty much confirmed what I felt about it. to soft and unpredictable to make great castings. I figured if I was going to make silicone molds for resin casting and the same molds could be used for lead why not give it a shot.

I will save the lead for just adding weight where I can and cast the fun stuff in resin.

#6

Devon. Lead is to soft, and will deform easely. I use an English pewter that has a bit of silver added for hardness. Regular silicon molds will not handle the heat very well, and a high temp silicon needs to be used.

Is this what you have in mind?

That truck is a demo with a raw casting ( not cleaned up yet).

#7

Perhaps zinc instead of lead? Easy to cast, harder and less hazardous. Disclaimer: I’ve never cast anything save stones.

#8

Dave Taylor said:

Devon. Lead is to soft, and will deform easely. I use an English pewter that has a bit of silver added for hardness. Regular silicon molds will not handle the heat very well, and a high temp silicon needs to be used.

Is this what you have in mind?

That truck is a demo with a raw casting ( not cleaned up yet).

Yes David that is exactly what I was thinking. Is English Pewter the same thing as white metal or?? I figured lead would be to soft. I was aware of high temp silicone. I know that others at least in the fishing lure making have used regular silicone with great success but with that fine detail I would have used high temp. I may still do this in pewter/white metal.

how are you putting the bearings in? milling, then press fit? Epoxy?

#9

I will likely make the mold for these anyway no matter what route I go. It is something that I will need a bunch of since I will likely make most all of my cars.

So whether they are resin or metal I will need them.

David,

I notice you have three pour spouts. Are you pouring into one and using the others as a place for air to escape or do you pour in all three holes?

#10

Perhaps you want to use pewter?

http://hackaday.com/2015/05/31/from-scrap-to-sword-casting-pewter/#more-157496

#11

Yes Tom thanks to some great help from Dave T I have moved away from lead to pewter. He is walking me through his process for the trucks. I already have on order some pewter that is 92% tin 8% antimony which is supposed to be pretty strong and has a lower melt point than lead. I also am going to try a 60% tin 40% bismuth low melt alloy that if it doesn’t work for trucks can be used for detail parts.

#12

Ye Stupid phone double post

#13

And triple post

#14

Got the hiccoughs, again, Devon? (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-laughing.gif)

#15

Dave those are sharp trucks. I would like to cast my own , but am struggling with making the mold. Any pointers from you or anyone else?

#16

Travis, What kind of molding material are you using? For pewter you must use a high temp silicon made for pewter. I use one from a company in San Diego called “AeroMarine” It can handle the added temp, it is a much harder material then the rather common molding stuff, But it replicates a great deal of detail, and it will out last the softer stuff by a long way before the mold goes South. I’ve got probably 60-70 pours of pewter on that mold and no sign of deterioration yet.

I’ll help as best as I can, What seems to be you biggest down falling?

#17

Got a present in the mail today. Thanks Dave. LSC has the best members. Will to go to extra lengths to help a guy out.

#18

yippy two pounds of metal in my mailbox waiting for me to get home. 1# of 92% tin/8% antimony pewter and 1# of 60tin/40bismuth low melt. Hoping the low melt stuff works as it melts at only around 250-380 degrees-easy on molds. Dave T has warned it might be to brittle hence the petwer. I can always use the low melt for detail parts. I love experimentation. I am still waiting on the casting starter kit from Micromark. It has all the stuff to make molds and parts out of resin and will take the low temp metals. If I have to go to the pewter I will switch to high temp RTV. In addition to the trucks which are ready to mold I have a brake wheel and step I want to make molds of.

I can already see where this is going I wont get anything done because i will be making molds and casting anything and everything. The cat had better run and hide.

#19

hehe And all I’ve ever cast is stones

#20

OK So got the truck finished. These are poured in pewter. I made the two side frames and both bolsters. Then I clamped it all together which was a little tricky. I drilled a hole all the way through the two bolsters and side frames the right size hole to tap a #6 cap screw. Then I drilled through the bottom bolster and side frame big enough to let the cap screw slide in freely with no slop. I then tapped the top bolster to receive the #6 cap screw. It all goes together very nice. The wheel bearing holes are drilled big enough and deep enough for some slop so that things can move freely and not bind. The center hole for mounting to the pedestal is drilled for a little play on the pedestal. The bottom bolster is drill only big enough to allow the Allen wrench to be inserted. The pedestal on the car is a threaded nylon bushing that receives a #6 cap screw. The idea here if it works is once assembled the cap screw to mount the truck will be retained by the bottom bolster when the truck is removed. Then when it is to be mounted you can thread it in and tighten it through the hole in the bottom bolster. I have not mounted it yet. While the whole assembly of the truck and mounting it might be a bit complicated you don’t do it that often that it matters and I like the design.

Now there is concern about the bottom bolster. Dave T has suggested it might be to low and catch on things. While it will clear all the track and I am not sure what there would be to catch on; but not having experience running trains outdoors I did heed his concern and the way it is put together the bottom bolster is for show and can be eliminated no problem and shorter cap screws used to mount the top bolster. All told with the Bachmann metal wheels it weighs 8.8 oz. So the set will way a pound like I was hoping.

I still need to clean it up and paint it but here it is. I am not crazy with the spring detail and have since modified the blank and removed them and made a pocket for custom wire springs and will likely make another mold. I will make one more truck and use them like this and then pour a high temp mold sans springs. Also the bottom bolster is bent in the pictures but is straight now. The truck was not quite true and one wheel rode high. A simple bit of twisting the assembled truck brought it true. The video shows how smooth it rolls with just a slight push. Sorry for being sideways. All in all I am very happy with my first attempt to make a mold and cast anything. I have used commercial molds and lead for fishing tackle so not my first rodeo but from design to mold to completed project this is a first.

http://www.largescalecentral.com/folders/file/13