Adjustable Density Expanding Foam
Two-part expanding foam, great for fin encapsulation, securing
noseweight, etc. Includes (2) 8-ounce bottles. Shelf life of
unopened product approx. 1 year from date on label.
By combining equal parts of A and B, the foam expands to about
10 times itís original liquid volume. The result is a 6 lb.
density (per cubic foot) rigid foam that is extremely strong
and still relatively light weight. This is perfect for filling
small spaces where the highest strength is required and weight
is not a real issue.
However, as the volumes increase, a lower density (higher
expansion ratio) may be desirable. With the increase of
volume, surface area also increases so strength and adhesion
are less of a factor. In larger volumes, weight may be the
over riding concern. Rather than stock several hard to get
foam densities, it is much easier to lower the density of a
high density foam as needed.
This type of polyurethane foam is highly reactive to small
amounts of water. Even the humidity in the air can slightly
alter the expansion ratios. The more moisture introduced into
the mix, the higher the expansion ratio. By purposefully
adding small amount of water to the mixture, we can adjust the
expansion (and density).
Most other brands of commercially available 2 part liquid foam
expand to about 20 times their original volume and are already
near the limit of usefulness. The foam is near itís lowest
density and strength. It cannot be adjusted down.
Our new Adjustable Density Foam starts as a denser foam that
can easily be adjust up using just a few drops of water.
Below is a photograph showing the results of adding various
amounts of water to the mixture of foam. The difference of
just adding one drop of water is dramatic. Keep in mind that
if you double the batch size, you will need to double the
water amount to achieve the same expansion ratio. A little
experimentation is highly recommended before actual use in
The Expanding Foam features are:
- Expands 10 to 25 times it`s liquid volume. (10x expansion
mixed in equal parts, adjustable to 25x with water)
- High temp formula. Perfect for fin root encapsulation.
- High adhesion rate.
- Two equal part (by volume) mix ratio.
- Does not need air contact to cure.
- Fast curing.
- Light weight.
- Easy to cut and sand. Very carvable.
- Great for strengthening thin wall nose cones or securing
Click here for a PDF file
showing how to use the foam. WARNING: Do not burn or use hot-
wire cutting methods on this or any other urethane based foam
product because toxic fumes will be released. (However, the
heat of a motor casing next to the foam is not a concern.)