Footings

You can use some cardboard from a cereal box. Cut into strips of about 1/2 to 3/4 in width. (the height of your footing) Put a long piece of masking tape along one side of the cardboard strips.  This coating will give the mold some texture. Bend and tape the strips into small square or rectangular boxes. Set these on some wax paper and pour your plaster into each mold.  Eat the rest of the cereal while these set up

Just a thought to try.

Randy

Foam

Ice cube tray ?

Maybe you could use one as a rough mould, then carve the plaster to shape once it starts to set.

cheers

Steve

Styrene Sheet or ???

The footings and abutments for this trestle were scratchbuilt from .030" or .040" styrene sheet.  I already had the styrene sitting around, plus the solvent cement and paint, so the cost was next to nothing.

If you don't have regular styrene sheet hanging around, you could try left over kit parts or packaging, a plastic "for sale" sign, or other material from the scrap box.

Each footing has a square piece on top, and a trapezoid on each side.  They are hollow.  I don't remember the measurements for sure, but I think the top is four scale feet square.  The dimensions were guesstimated from photos of prototype WP bridges at Keddie and other locations.  After assembly, I sanded the corners smooth with some 150 grit sandpaper, which left a bit of texture, and sprayed them with Testors Model Master "Camouflage Gray."

Do you have access to a miter

Do you have access to a miter or table saw? Cut them from scrap wood. 

Could even do it by hand with some practice. 

There is another source...

You could go to your local computer guru shop and ask for a damaged keyboard or a really old PS2 type keyboard.  I'm not talking about Best Buy or Office Depot. I'm talking about the little hole in wall shop.  My local one has a lot of old computer junk for parts.

Den

I'd say no to computer keys

I think computer keys have a rather inaccurate profile for footings in HO.

If you don't have the styrene on hand to build the footings up that way (and this has the advantage that the footings can easily be glued to the bottom of the bridge tower corner beams) you might try making a mold from scraps of wood and casting basic footings in plaster of paris then use a mill file to smooth out the shape of the rough castings.

If you have access to a benchtop belt sander you should be able to the end of pieces of 1/2 x 1/2 wood stock into a footing shape. The belt sander should make this task go quickly.

Cheers,

Charlie

Molds

Of all the options, the easiest for me is probably going to be a mold. I just don't have access to styrene without driving 120 miles round trip or ordering some sheets mail order. I'd hate to pay shipping charges for just a bit of plastic and I don't have the funds right now for a bigger order. ( Although I'd love to order a huge order of stuff! )

The problem I keep thinking about is that I wish there was someway to make a reusable mold out of common stuff. The cereal box idea has merit as well as using wood for molds  but there I see having to make eight identical molds because I will likely tear them up getting the plaster casting free after it has set up.

Michael

Rob, how about the bottom dimension?

Do you know the bottom dimension off the top of your head? That would help me get the shape right. I thought some more about your suggestion of a plastic sign. That just might work pretty well.

Michael

Just a suggestion

Wood molds

I've used bits of wood to make molds for casting plaster. Coat the wood with cooking oil before pouring in the plaster to keep it from sticking to the wood.

A bandsaw (if you have access to one) works for "machining" plaster of paris (might not work so well for hydrocal).

If you have no train store nearby, do you have a model airplane store? Try explaining to them what you need and see what they suggest...

Charlie

Michaels, Jo-Ann, Target, Wal-Mart.

Your said a round trip is 120 miles away from a source for styrene but do you live way out in the middle of nowhere without any sort of craft or department store though? The suggestion of using a for sale sign from a department store or big home center like Home Depot or Menards would be exactly what you need. They are also made of styrene sheet and cost as little as 99 cents. 

Pretty much live in the boonies

On the shores of a lake and out in the country, just the way I like it. The 120 mile round trip is to Hobby Lobby. A traditional train or airplane store basically means a trip to Atlanta which is even farther away. The plastic sign from Wal-mart is doable though.  I'll either try to cut out and make a mold out of it or just make eight individual footings. The latter just sounds more time consuming. Thanks for the ideas guys.

Michael

A mold is going to be way way

A mold is going to be way way to go, if for nothing more then getting everyone the same size. 

Bridge Footings

Had the same problem, for multiple bridges. Make a master from a piece of wood. I used 1/2 sq balsa. I used modeling clay for the mold (pla-dough would probably also work). Work the clay til it is soft and thick enough for the height of your footing. Press the mold into the clay & carefully remove it. I just made the number of impressions I needed and poured plaster. Easy to get out of the mold & the material is reusable.

I've actually used this technique to mold several things. It's not fancy but it's cheap & works reasonably well for things that don't need lots of surface detail.

Good luck.

PKS , Espee over Donner

Dimensions

I'm just seeing this...  No I don't for sure, and the footings I made are buried so I don't have access to measure.  The measurement was probably something like 4 feet on the top, 12 feet high, and 8 feet on the bottom.  I matched to the angle of actual footings in some photos so was mostly concerned about making things look right with my existing model bridge parts as opposed to getting the dimensions exact.

An idea of my own....

Thanks Rob for the  guesstimate at the dimensions. That ought to be enough to get me going. Folks have been suggesting carving a master out of wood, either balsa or otherwise and then it hit me what might also work and is readily available anywhere. Soap!! That would work to make impressions in modeling clay with or to wrap foil around to form a mold. Or maybe I've been watching too many old prison movies where they carve guns from it??

Michael

Plaster

Make a simple box mold for some plaster.

Then cut the plaster with a razor saw to rough shape, then finish off with a file or sandpaper.

Ive done this with bridge piers and they turn out GREAT.

Its the same idea as making one out of wood but plaster is much easier to carve.

Mist the plaster lightly when

I over thought this.....

After hemming and hawing and much procrastination, I settled on making footings that span across the towers. In other words, two footings, two tower feet to a footing. There is a custom built bridge on the front of the kit box that uses these type and in my situation and scene, I feel they will look the best anyway. Since I freelance, I can just say that's what my railroad used. Tonight I whipped up the suggested "simple box mold" out of sign plastic and will do the final shaping with some sandpaper. Thanks again everyone for all of your suggestions,

Michael