Rigid Foam Two Pound Density
Polyurethane foam, 2 lb density. Also known as A-B foam. Mix two equal parts of Part A and Part B and compound will expand about 25 times to form a rigid mass of foam. Not the same as the spray foam you get at the hardware store. Doesn't form a consistent skin and not especially strong. Great for foam fill for watercraft. Water blown. A 12" x 12" x 12" block of this stuff will weigh about two pounds. A kit consists of two equal volumes of material. For example, a quart kit will contain one quart of part A and one quart of part B. The two gallons kit has a net weight of about 18 pounds. This means a kit of that size will yield about nine cublic feet under best conditions. No, you can not adjust the ratios between the A and B sides to change the density of the foam.

Rigid Foam Three Pound Density
Polyurethane foam, 3 lb density. Also known as A-B foam. Mix two equal parts of Part A and Part B and compound will expand about 20 times to form a rigid mass of foam. Not the same as the spray foam you get at the hardware store. Doesn't form a consistent skin. Stronger than the 2 pound stuff. Great for making foam armatures on which to sculpt. Water blown. A 12" x 12" x 12" block of this stuff will weigh about three pounds. A kit consists of two equal volumes of material. For example, a quart kit will contain one quart of part A and one quart of part B. Doesn't expand as much as the two pound kits so the material won't go as far. The two gallons kit has a net weight of about 18 pounds. This means a kit of that size will yield about six cublic feet under best conditions. No, you can not adjust the ratios between the A and B sides to change the density of the foam.

CAT #	Description	Price
RF3-16x2	Rigid Foam, 3#, 2 pints Kit *S*
RF3-32x2	Rigid Foam, 3#, 2 quarts Kit *S*
RF3-128x2	Rigid Foam, 3#, 2 gallons Kit *S*

Soft Polyurethane Foam
Polyurethane foam, about 3 1/2 lb density under ideal conditions. Also known as soft foam. Mix proportionate parts of Part A and Part B and compound will expand to form a soft mass of foam. The same kind of foam that you would find in a couch cushion. Forms a fair skin, great for filling masks, stunt props or body parts for display. Water blown. A 12" x 12" x 12" block of this stuff will weigh about three and 1/2 pounds. A kit consists of two unequal volumes of material. For example, a quart kit will contain one quart of Part B and about half of much of Part A. Rough mixing ratio is 63 parts of Part B to 37 parts of Part A. This is not a one to one mixture. An accurate gram scale is required.

CAT #	Description	Price
SF3-25	Soft Foam, 3.3#. 25 fl. oz. Kit *S*
SF3-50	Soft Foam, 3.3#. 50 fl. oz. Kit *S*
SF3-200	Soft Foam, 3.3#. 200 fl. oz. Kit *S*

Polyurethane Resin

Odorless Casting Resin or Plastic Casting Resin. Not completely odorless but is called that anyway. Mix two equal parts of Part A and Part B and compound will form a solid plastic in a few minutes. Great for artists who want to reproduce their own "Resin Kits." Works great in a silicone mold. Color is sort of a amberish, translucent white. Can be painted, but don't use a silicone mold release.

The 2 lb. rigid foam that we sell is used for boat floatation. There are some things that you need to know about it.

First, in order to comply with EPA standards the foam we sell today is different than the foam that was made prior to the year 2000. In the old days the foam was "blown" with a solvent, a solvent that hurt the ozone layer. Today the foam is "Blown" with water. The old stuff was more resilient and formed a nice skin. Today's stuff doesn't do that.

Next, you need to know that if you have standing water on top of this foam it will eventually seep in and water-log the foam. This is just a fact of life and there is nothing we can do about it. You will notice, after a few years that your floatation barrels will start to sink. The easy way to solve this is keep your gear in repair and dry dock your stuff during the winter.

Next, you need to know that this is not the same as Styrofoam (R) which is Expanded Poly Styrene. StyroFoam will melt when exposed to any kind of solvent such as spray paints. The 2 lb. foam that we carry will not do this. In fact, nothing seems to dissolve it. If you get it on your shoes, your skin or any thing with value it will stick and you'll never get it off.

Personally, if I need to protect something I use sheet plastic. Polypropylene to be exact. This is what plastic bags are made out of. If  I want to line the inside of a box I'll just use plain old clear packaging tape.

How Much do I need?

Excellent question. A two gallon kit of the stuff will have a net weight of about 18 lbs.. That means, when the stuff is expanded it will make at least 9 cubic feet of the expanded foam. That's supposed to be an expansion rate of 20 times the original volume, but don't hold me to that. Please go by the weight.

Calculating the amount you need is something you'll have to do. I'm not a math guy so I can't calculate the volume of a round barrel. Please do that yourself, if you call me and ask I will make a mistake.

Best Conditions

Use the foam under best conditions. That means the temperature of the product and the mold will be about 70 degrees Fahrenheit. If you use it on a hot summer day you will get more expansion than specified. Always do a little test to make sure everything is fine before proceeding. Be careful with your measurements. I recommend that you pour many small batches rather than one big one. If you pour a deep container the foam on the bottom will be compressed and have a different density that the stuff on the top. Watch your humidity, as the stuff will pick up water out of the air and change its characteristics.

*S* = Special Shipping Required.

This page originally posted: 09/30/2004
This page last updated: