"Liquid" foam?


MikeOwnby

MikeOwnby

Active Member
Having not been able to find coal loads for some of my coalporters, I'm perfectly content to make my own. I know that it needs a lightweight foam filler upon which WS coal or cinders can be added & glued like ballast. Correct so far, right? Or maybe not, so tell me if that's not valid.

Now, thing is I'm doing this in N-scale, and trying to cut down tiny filler blocks to fit just perfect in these little coalgons is going to be a right big pain in the rear. Is there any sort of liquid, maybe akin to window and door foam, but not nearly as aggressively expanding? Something that can be poured in to fill up the majority of the void without weighing the car down too much? Obviously with the talk of glue and liquid foam I'm *really* not worried about ever taking it back out and am fine with it being a permanent load. I'd just like something that isn't going to make me want to throw the car across the layout while shaving on bits of foam or balsa wood dozens of times after times after times...

Sorry if this has already been addressed, but all I was seeing in a search was HO scale and putting blocks of Styrofoam and/or balsa wood into them.
 
WAX
Fills the void, not very heavy, cheap
You can fill each car to a different level so they're not all exactly the same.
 
dlplost said:
WAX
Fills the void, not very heavy, cheap
You can fill each car to a different level so they're not all exactly the same.
Click to expand...

Interesting idea and you're right, it could make for a very realistic slight variation though I've noticed coal cars are loaded pretty uniformly. I think just my human error of piling on the "coal" on top of the filler might account for that much. You're right that wax is light, but in N-scale is that still going to be not too much weight? This actually brings up another point: Other than the pulling power needed, what are the negative effects of a piece of rolling stock that weighs too much? I've heard a number of cautions about overweight cars, but nobody has ever said exactly why that's a bad thing as far as them just running down the rails. Do they derail? Do they make other cars derail because they pull too much going around curves? My coalgons are problem children anyway, though none of my other rolling stock is. If they don't settle down once I put loads in them I'll have to see about replacing all the trucks. They're one of my few pieces that have metal wheels, so maybe that's an issue? I don't know.

On the other hand it just dawned on me (as far as weight) that I can also take OUT the original manufacturer weights, at least theoretically, so that might mean problem solved regardless. I've seen some that just can't be removed, but I think these might be okay in that regard. I'll check it out, and thank you very much for the suggestion.
 
Sirfoldalot said:
What about trimming down some foam, with scissors, to fit the cars ... Not styrofoam.
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It would still have to be very exactly cut, so I'm not sure it would have any advantage over Styrofoam. If it were too big at all it would tend to squeeze itself back out of the car, and if there were any gaps at all it would allow the "coal" to dribble down and leave funky spots. If nothing else comes up, though, at the very least it wouldn't be nearly as messy as having tiny bits of Styrofoam floating around and sticking to everything. Thanks.
 
I would try to come up with a way to make a mold and cast a form that would fit in the top of the cars. You could contour it to your desired model and glue a thin layer of model coal to it after painting them black.

Modern coal hoppers for unit trains are loaded by trains passing under a silo at a uniform speed and are weighed as they are loaded. This results in loads that have very little difference from one car to the next, especially after the train has traveled some distance. Prior to unit trains, hoppers were loaded by an operator controlling a car haul to move the string of hoppers as they were being filled. The cars were moved a few feet at a time as coal was loaded which resulted in varying contours. Some mines had the loading tracks on an incline and were moved by gravity as a worker rode the cars and released or set the brakes as needed. This also resulted in variations in the loads.

Another consideration is the size of coal being shipped. Almost all coal nowadays is very fine. In the not so distant past, different sizes were pretty common but small stoker coal was still the most popular. Lump coal was also shipped which consisted of different sizes mixed together sometimes ranging up to about eight inches in diameter.

Check out pictures of hoppers that are in the era and area that you are modeling to see the shapes and/or sizes you need.
 
I would suggest, rather than using the foam, cut a piece of basswood or balsa sheet to a good fit, seal (paint) with a slightly diluted white glue, allow to dry. If the cars have the angled supports in them, press the wood rectangles down onto them provided they leave about 3/16"- 1/4" of free gondola wall (if not cut them out and replace with a balsa block instead of the balsa sheet to allow that depth) and then fill up with your coal to your desired shape. Use the white glue/water mix as you would when ballasting track to fix it in place.
 
tootnkumin said:
I would suggest, rather than using the foam, cut a piece of basswood or balsa sheet to a good fit, seal (paint) with a slightly diluted white glue, allow to dry. If the cars have the angled supports in them, press the wood rectangles down onto them provided they leave about 3/16"- 1/4" of free gondola wall (if not cut them out and replace with a balsa block instead of the balsa sheet to allow that depth) and then fill up with your coal to your desired shape. Use the white glue/water mix as you would when ballasting track to fix it in place.
Click to expand...

That's what I was trying to avoid, actually, though it seems I may have to. I have 69 of these to do, and having to sit there and cut out so many pieces of wood or foam to fit is just going to be extremely tedious and un-fun. Was hoping there was a filler of some sort that wouldn't require all the cutting and fitting and so forth.
 
The is low expand foam on the market it will most likly expand past the edge of your. n scale car sotriming will be requered. You may be able to make a mold the foam will only epand to fill holes. You can find the low expand foam a any lowes and home depot you may also check out some chalking products thay are light weight and expand a little i would put paper in the car and then try the chalkif you go that way it will cut down on weight all styles will requere some cuting and size sorry no real short cuts
 
I've got about 40 HO cars to do, so have a similar task, fortunately I think I'll get away with the sheet balsa, pushed down onto the angle bracing, maybe you can get some balsa rectangular section that will at least give you the width and height near enough that will only require cutting to length. I would think the expanding foam is going to be impossible to control. Here's another idea, how about the sheet cushion foam of the right thickness, cut it up with scissors.
 
tootnkumin said:
I've got about 40 HO cars to do, so have a similar task, fortunately I think I'll get away with the sheet balsa, pushed down onto the angle bracing, maybe you can get some balsa rectangular section that will at least give you the width and height near enough that will only require cutting to length. I would think the expanding foam is going to be impossible to control. Here's another idea, how about the sheet cushion foam of the right thickness, cut it up with scissors.
Click to expand...

Oh yeah, the household "void filler" foam, even the so-called minimal expanding, is just way too messy and out of control to try on that small an item. And there's no way to clean it up short of acetone, and there goes your paint job. I did think about sheet foam, but wondered if it wouldn't eventually sag and possibly even eventually break if I didn't get it thick enough. And how thick is thick enough? Grr. That's why I was looking to fill the entire void if I was going to use foam. Oh well, looks like wood is probably my best bet in the end, I was just trying to be lazy. Like most things, once I cut a few and get a pattern set it'll probably be decently painless. Thanks for the input, though. I appreciate everyone's help and suggestions even when it doesn't let me be as lazy as I'd like :D
 
Would it work to make a master from wood then make a form to cast more? Like casting rocks. Maybe even cast the load surface.

Weight could even be added if necessary.
 
Richard V said:
Would it work to make a master from wood then make a form to cast more? Like casting rocks. Maybe even cast the load surface.

Weight could even be added if necessary.
Click to expand...

I've never cast anything to date, but this might be a good opportunity to try it. I wouldn't want to cast the load surface, though. A few of the gondolas do actually have coal loads right now, but they do look ridiculously toy-like. Even though I want the loads to be *mostly* uniform, a little variation and real grains of "coal" I think will look better. The molded-in-one-piece just don't look right to me. I have the same issue with my steam locos too, actually, and may end up modifying some of the tenders with a coating of cinder ballast rather than just the molded tender shell. For all the things in model railroading that do look toy-like and not real, for some reason the molded fake plastic coal is one of the things that bugs me the most. I have seen nicely realistic coal loads, but they're hard to find & expensive. Oh, did I forget to mention? I'm not only lazy but apparently also cheap :D
 
MikeOwnby said:
I'm not only lazy but apparently also cheap :D
Click to expand...

Ditto here. I think I've set myself a difficult task with some bulkhead log cars as well

1443987914sL4Qp0c1_zpsa20a0712.png


Trying to find twigs to represent these is proving daunting.

As far as making a mould for the gondola filler, that would be good so long as the cars have straight sides, if they turn in at the top edges as some seem to, could be a problem. If not the expandable foam could be used and any excess overflow sliced off before removing from the mould. The mould needs to be made, say, with fixed ends joined to the floor but with loose sides, otherwise getting the foam form out would present problems. Hold it all together for casting with an elastic band.
 
Try the Model Railroad Hobbyist issue #6. Mar/Apr 2010 Issue. There is a nice 2 page article on doing this very thing using pink foam on page 39, 40.
 
Thin styrene is easy to cut accurately, could that be the base of the load? Do you know anyone with a table saw to cut little squares of wood? You can also cut foam on the table saw which would give you cube shaped blocks to start with. Even a bandsaw with a fence would work for precisely cutting the blocks to fit the cars.
 
I agree that casting them is probably the easiest way. You only need to spend a lot of effort on the master. The rest are no-brainers. On a side note, this would be the perfect type of job for a CNC machine. Just design one load in the computer, copy paste it 60 times, and let your machine go to work. I gotta build one some day.

Steve S
 
Mike,
Although I model in HO I've been using volcanic cinders for loads, its real light (with weight's in full loads make weight) and it takes stain well. The best part its free! Here in CA. its used as a replacement for salt-sand but you can get the same stuff at the local hardware store just ask if they have any torn bags.

note; derailments do make a mess but it sure looks real:cool:!!! 3245.jpg Clean up is easy just take the wife's nylons and a shop vac!
 
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