Calculating Resin Volume for a River Pour

[Mr X]

I have a river which is about 4 or 5 feet long and varies between an estimated 2 to 7 inches width on my layout. I eventually plan to pour resin to make the water.

I am planning on four pours of resin each 1/8 inch deep. The two main questions that I have are:

One - How do I calculate the volume of the actual river bed so I know how much resin to mix and pour to make it 1/8 inch thick?

Two - Since the river goes off the side of layout at the beggining and the end of it how do I keep the resin from just leaking off the side of the layout?

Thank you
Mr X

[Flash Blackman]

I would just calculate the area and then multiply by the depth to get the volume. In the US, that gives you cubic inches or yards or whatever. Easier conversion using metric. Divide the area into simple shapes, calculate the area, and add them all up. That's what I would do for volume computation.

OTOH, just pour until you get what you want and then stop. You are going to do four pours anyway.

[Fotheringill]

One the last part of your question about leaking off-

Assume, ab initio, that you are going to pour about 1/8" of water.
At each end, affix a 1/4" high piece of balsa or whatever wood is handy. Make sure there are no pinholes or cracks. Fill the same in with wood putty and color the "dam" as if it were a continuation of the water course. When finished, poured and dried, just use an Exacto to cut off the overage and nobody but you will even know it is there.

[Hytec]

I agree with Flash...estimate the volume, then double it for the mix. Two things are solved by doubling: 1) your calculation probably will have errors due to unmeasurable nooks, crannies, etc., and you will hate yourself if you run short; and 2) you are going to throw away the residue anyway because it's hardening, so what's another ounce or two....it's not that expensive.

[L Lee Davis]

I concure with Flash and Haytec on figureing your pour. To block off each end you need four things 1. piece of plastic to fit opening, 2. Duct tape, 3. Armor-all and 4. caulking. Cover pour side of plastic with Armor-all and attach to layout with caulking. duct tape backside to layout. Make sure it is pressed fermily against layout with as tight a seal as possibable. Do your pour or pours let dry and remove. Wal-aigh! The polly will not stick to the Armor-all.

"Still Training After All These Years"

[Mr X]

Good advice from all.

Fotheringill - there will actually be 4 layers (four pours) of 1/8" thick material.

L Lee Davis - I have never done this before so forgive the dumb question but won't the heat from the resin curing melt or warp the plastic even if it were protected by the Armor All?

Just an FYI I am planning to do a couple of test runs on something smaller before I tackle such a big project.

Mr X

[L Lee Davis]

X man I use a perty heavy peice of plastic and I have never had any problems. After useing it for that it's not much good for anything else.

"Still Training After All These Years"

[Mr X]

L Lee Davis

I am guessing more than a piece of styrene? Do you mean something more along the lines of a plastic locomotive box top or a Tupperware container lid? Or even something sturdier than those? I guess more specifically what sort of piece of plastic do you use?

Mr X

[L Lee Davis]

Yes a plastic lid off the Tupper Ware stuff, the cheap kind not the better halfs stuff. You can get it at a Dollar General type store for a buck or two. I have also used .080 styrene it's a one shot deal though. I have a ton of it in the scrap ben.

"Still Training After All These Years"

[Mr X]

Just to make sure would like to see if we are speaking of the same stuff. I am looking at Polyester Resin water. Considering one of the following brands:

Castolite-SG - by Castolite Corp
Clear Cast - by American Handicrafts Company
Polyester Casting Resin - by Natcol
Chemco Casting Resin - Chemco

In the scenery book that explains how to do it, they say that it will warp and melt plastic. The author seems to say it will melt it pretty easily. I have never done this before so that is why I am here asking questions to make sure I get all the information before proceeding.

I think 'EnviroTex' is more of an expoxy? Perhaps it is more forgiving?

Any way I guess I have what I need to make an estimate. However the book is pretty attimate about being exact. I guess I can make little peices of card board and cover the river with a bunch of squares and rectangles then measure the volume from there. I just wondered if there was something easier to do or use?

Thank you for all the suggestions and help.

Mr X

[Fotheringill]

Try Famowood glossy sold in Home Depot. It is cheaper and works well. It is a two part epoxy.

[L Lee Davis]

Mr. X Just to clear the fog away I use Enviro Tex and A West systems almost exclusively and a scrap piece of plastic has worked well for me in all my pours. A scrap piece of masonite is another option to consider, tempered side in.

"Still Training After All These Years"