I am working on getting a set of 4 Rivarossi passenger cars set up to run on my railroad: LL metal wheel sets, K-D coupler conversions, truck screws instead of plastic pins, etc.
I want to get them up to NMRA weight standards, meaning the 12" long cars need to weigh 7 ozs. There are some recesses in the bottom of the cars which are the insides of the under-car tanks, boxes, etc., a good location for additional weight.
These would be good locations for some lead. I have some moldable lead but not enough for all 4 cars. I also have a product which I think is low melting point metal, labelled ‘Cerro.’
Has anyone heard of this product? What is the best method for heating it? Is it safe to melt and pour into a plastic car? I sure would appreciate some guidance.
You can probably melt the Cerrro in a double boiler on the stove, I can’t remember exactly but I think the melting point is around 160. I don’t know about pouring it directly into a plastic car, but you can make a mold of the same size out of cardboard to pour it into until it cools.
Instead of trying to pour some molten metal into the slot, try forging a piece of lead to fit. I’ve done this many times. Simply cut off a decent sized piece of lead and pound it with a ball-peen hammer on an anvil to get the right shape. You can make it thinner, longer, etc. by rotating it and moving it around as you hit it. Cut off the excess when you’re done. If it’s not too thick you can cut it with tin snips. Use some glue like Goop to put it in place.
Wash your hands off when you’re done and all will be well.
Cerro is the name of the company. http://www.cerrometal.com/lowmelt.html. They make a number of low melting point alloys but its an expensive solution. Lead wheel weights would be much less expensive. Check with a tire dealer. You might be able to get a bucket full for little or no cash.
I use paintedlead weights I buy at the LHS. These are actually Automotive weights. Another option is to go to the local auto repair or tire store ans see if they have any used tire weights.
Best location for weight is right over the trucks. Weight in the middle is leveraged by the car length (simple physics) Car must be balanced in both directions. So, less weight is required at the ends than in the center.
Do they still use lead for fishing weights? Back when I was a kid, that’s what I used. I just pounded it into shape. Or are they afraid some fish will eat the weights and suffer from reduced intelligence?
You guys ever hear of a product called Temp-Low? It cost costs about $5 for 3 oz.
An easy way to add weight to any model, Temp-Low melts in hot water (158° to 190° F). It’s ideal for brass locos, as you just melt and pour in without fear of unsoldering detail. You can also make custom castings in cardboard, rubber or plaster molds. And it makes a great filler to support tubing while bending.
Those weights with the peal and stick ( 1/4 or 1/2 OZ) are the ones used to balance Mag wheels. I went to an automotive supply that deals wit the auto industry and bought a box. I think I payed about $30. It is a lifetime supply, about 5LBs +.
You can find them at LHS or flea markets at $1 or so each, my way its about 10 cents each strip. 1 1/4 oz per strip or less.
The warnings posted earlier are all valid. Be careful.
Dave
Micro Mark sells Type 160 Casting Metal. It melts at 160 degrees, but you need to be careful with certain plastics. Thickness of the part would be a factor too. You might want to try experimenting with a scrap part first. I would also freeze the part to be on the safe side.
You can also glue lead shot, used in reloading shot gun shells, into cavities. Available at most gun shops. Get the smallest size.
Thanks all of you for your responses. I think I will NOT use the melted lead for this model. I have a supply of the stick on 1/4 and 1/2 oz. A-line weights. I never thought of the mag wheel balancing weights as a cheaper solution. I will check into that.
Or you can use the cheapest weights available. Pennies. At $1.80 per pound they can’t be beat. So don’t say the government doesn’t do anything for you.
A couple of people have mentioned lead shot. You should always take precautions when handling lead of course, but shot is very good for filling in the recesses if you mix it up with a batch of epoxy. Simply mix the epoxy per directions and then mix in as much lead shot as you can and still get it to stick. While you do have to be careful not to get it where you don’t want it, but this can be used to fill up with weight where needed.
Mike Lehman
Urbana, IL
I use 3 or 4 strips of large diameter solid core solder held in place with hot melt glue or silicon sealant, and this works well for the underside. For the inside cavities, I use lead shot held in place with white glue. No heating is required with either method. No matter how low a temperature metal you use, there’s a high risk of melting plastic when it’s poured in.
