We have an old hot tub on our deck. One of several issues with it is that mice have been tunneling in the foam insulation that resides between that tub and the wooden frame.

I've shop-vacced out as much of the debris as I could and now I would like to fill in all these tunnels and voids (some up to several inches in diameter), but whenever I read the instructions on cans of spray-foam insulation (like Great Stuff and Touch n' Foam) they state that they are for filling cracks and small gaps and will not cure properly in enclosed spaces (even the Great Stuff "big gap filler"). On the other hand, the kind of spray foam used to fill walls and rafters seems like overkill and much too difficult for a small DIY project.

Is there an appropriate product to use for this job? Is the best solution just to use the Great Stuff and hope for the best?. I could probably fill the larger, easily accessible voids in layers, but for the tunnels, it would be nice to just spray something in there and have it fill the thing up. The gap between the frame ranges between about 3 and 6 inches. I think the tunnels really snake around in there.

Thanks.

-J

On Tue, 2 Sep 2014 10:08:42 -0700 (PDT), J wrote:

We have an old hot tub on our deck. One of several issues with it is that mice have been tunneling in the foam insulation that resides between that tub and the wooden frame.

I've shop-vacced out as much of the debris as I could and now I would like to fill in all these tunnels and voids (some up to several inches in diameter), but whenever I read the instructions on cans of spray-foam insulation (like Great Stuff and Touch n' Foam) they state that they are for filling cracks and small gaps and will not cure properly in enclosed spaces (even the Great Stuff "big gap filler"). On the other hand, the kind of spray foam used to fill walls and rafters seems like overkill and much too difficult for a small DIY project.

Is there an appropriate product to use for this job? Is the best solution just to use the Great Stuff and hope for the best?. I could probably fill the larger, easily accessible voids in layers, but for the tunnels, it would be nice to just spray something in there and have it fill the thing up. The gap between the frame ranges between about 3 and 6 inches. I think the tunnels really snake around in there.

Thanks.

-J

The Great Stuff comes in various types of expansion formulas. Low
expanding (around door & window frames) to high expansion for larger
cavities.

I've used high expansion to fill cavities the size of a couple of
gallons. I layered it, allowed that to expand, and then another layer
- used about two cans. Trimmed with a utility knife anything that
exceeded the cavity.

Each end of our "cat bench" is hollow, roaches invaded the space for
shelter. Great Stuff high expansion foam eliminated the problem.

Sample Pic:

http://reelnetandtwine.com/store/images/BEN31.jpg

Can you post photos on a free site with a link back here?

The Great Stuff comes in various types of expansion formulas. Low

expanding (around door & window frames) to high expansion for larger

cavities.



I've used high expansion to fill cavities the size of a couple of

gallons. I layered it, allowed that to expand, and then another layer

- used about two cans. Trimmed with a utility knife anything that

exceeded the cavity.



That seems good. I was looking at the stuff specifically for "larger cavities" but even that claims that it will not cure properly if there is no air. I'm not too worried about the easily accessible spaces - it's more the tunnels that I can't see where they go. I can't see how I could possibly layer the foam in the tunnels - especially when they start out going in and up. But maybe it's not too critical if the foam in the tunnels doesn't cure properly as long as it cures at the exit points.

I'll see if I can post a pic later.

Thanks.

-J


Each end of our "cat bench" is hollow, roaches invaded the space for

shelter. Great Stuff high expansion foam eliminated the problem.



Sample Pic:



http://reelnetandtwine.com/store/images/BEN31.jpg



Can you post photos on a free site with a link back here?

On Tuesday, September 2, 2014 1:45:41 PM UTC-4, J wrote:




The Great Stuff comes in various types of expansion formulas. Low



expanding (around door & window frames) to high expansion for larger



cavities.







I've used high expansion to fill cavities the size of a couple of



gallons. I layered it, allowed that to expand, and then another layer



- used about two cans. Trimmed with a utility knife anything that



exceeded the cavity.







That seems good. I was looking at the stuff specifically for "larger cavities" but even that claims that it will not cure properly if there is no air. I'm not too worried about the easily accessible spaces - it's more the tunnels that I can't see where they go. I can't see how I could possibly layer the foam in the tunnels - especially when they start out going in and up. But maybe it's not too critical if the foam in the tunnels doesn't cure properly as long as it cures at the exit points.


The issue may be in the details, ie what is an "enclosed space, no air, etc..
I think those foams rely on moisture in the air to cure, if I'm not mistaken.

J wrote:
We have an old hot tub on our deck. One of several issues with it is
that mice have been tunneling in the foam insulation that resides
between that tub and the wooden frame.

I've shop-vacced out as much of the debris as I could and now I would
like to fill in all these tunnels and voids (some up to several
inches in diameter), but whenever I read the instructions on cans of
spray-foam insulation (like Great Stuff and Touch n' Foam) they state
that they are for filling cracks and small gaps and will not cure
properly in enclosed spaces (even the Great Stuff "big gap filler").
On the other hand, the kind of spray foam used to fill walls and
rafters seems like overkill and much too difficult for a small DIY
project.

Is there an appropriate product to use for this job? Is the best
solution just to use the Great Stuff and hope for the best?. I could
probably fill the larger, easily accessible voids in layers, but for
the tunnels, it would be nice to just spray something in there and
have it fill the thing up. The gap between the frame ranges between
about 3 and 6 inches. I think the tunnels really snake around in
there.


Check out 2 part expanding foam.
https://www.google.com/search?q=t2+p...expanding+foam

On Tue, 2 Sep 2014 10:52:19 -0700 (PDT), trader_4
wrote:

On Tuesday, September 2, 2014 1:45:41 PM UTC-4, J wrote:




The Great Stuff comes in various types of expansion formulas. Low



expanding (around door & window frames) to high expansion for larger



cavities.







I've used high expansion to fill cavities the size of a couple of



gallons. I layered it, allowed that to expand, and then another layer



- used about two cans. Trimmed with a utility knife anything that



exceeded the cavity.







That seems good. I was looking at the stuff specifically for "larger cavities" but even that claims that it will not cure properly if there is no air. I'm not too worried about the easily accessible spaces - it's more the tunnels that I can't see where they go. I can't see how I could possibly layer the foam in the tunnels - especially when they start out going in and up. But maybe it's not too critical if the foam in the tunnels doesn't cure properly as long as it cures at the exit points.


The issue may be in the details, ie what is an "enclosed space, no air, etc.
I think those foams rely on moisture in the air to cure, if I'm not mistaken.
So, if you really put it in something that is totally airtight, I can see
that being a problem. But I bet the area around a spa tub doesn't meet
their meaning of airtight. I think enough air is going to get to it so that
it will cure.

IIRC the can mentions temperature; not sure about moisture. They work
best at the recommended temperatures. (like many products)

On Tue, 2 Sep 2014 11:25:42 -0700, "Bob F"
wrote:

Check out 2 part expanding foam.
https://www.google.com/search?q=t2+p...expanding+foam


Some of those speak of "liquid" and "pouring" when mixed. Likely not
what the OP needs, when a spray foam will work.

The issue may be in the details, ie what is an "enclosed space, no air, etc.
I think those foams rely on moisture in the air to cure, if I'm not mistaken.
So, if you really put it in something that is totally airtight, I can see
that being a problem. But I bet the area around a spa tub doesn't meet
their meaning of airtight. I think enough air is going to get to it so that
it will cure.

Precisely. I'm sure that for any "surface" area (within an inch or so) it should be fine. It's just that I think there will still be plenty of tunnel spaces (surrounded by the previous foam, which should be air-tight) that will probably not get the necessary air for good curing. But upon reflection and reading the responses, I think the Great Stuff "big gap filler" will be good enough, even if not perfect.

Thanks all.

P.S. I think the 2 part expanding foam mentioned by Bob F. would probably be too difficult to get into place for this scenario - though the foam itself would probably work better.

"J" wrote in message
...

We have an old hot tub on our deck. One of several issues with it is that
mice have been tunneling in the foam insulation that resides between that
tub and the wooden frame.

I've shop-vacced out as much of the debris as I could and now I would like
to fill in all these tunnels and voids (some up to several inches in
diameter), but whenever I read the instructions on cans of spray-foam
insulation (like Great Stuff and Touch n' Foam) they state that they are for
filling cracks and small gaps and will not cure properly in enclosed spaces
(even the Great Stuff "big gap filler"). On the other hand, the kind of
spray foam used to fill walls and rafters seems like overkill and much too
difficult for a small DIY project.

Is there an appropriate product to use for this job? Is the best solution
just to use the Great Stuff and hope for the best?. I could probably fill
the larger, easily accessible voids in layers, but for the tunnels, it would
be nice to just spray something in there and have it fill the thing up. The
gap between the frame ranges between about 3 and 6 inches. I think the
tunnels really snake around in there.

Thanks.

-J What ever you decide to use, cover that area with metal screen at
entrance and coat with same stuff so the mice cannot chew through it again.
The heaver wire gauge the better. WW

Those instructions need some explanation.

Great Stuff, and so far as I know all the other expanding "Polyurethane" foam caulks are in fact polyisocyanates. They react with the MOISTURE in the air to form a polyurea foam and CO2 gas. It's actually the CO2 gas that gets produced when the isocyanates react with moisture in the air that acts as a blowing gas to cause the foam to inflate and expand. So, if the foam is inflating / expanding, that means the chemical reaction with the moisture in the air has already occured. After that there's a drying process that happens as solvents evaporate from the foam, but so far as I now, those solvents can evaporate right through the foam just like solvent can evaporate right through a "wet" oil based paint film.

So, it's not really air that's the critical factor, it's the amount of humidity in the air. The foam won't work if there's no moisture in the air, and this can happen on really really cold days in winter (if you live where I live) when it's 40 degrees below Zero or colder and there is barely any humidity in the air. I guess what the instructions are getting at is that if access to a cavity is restricted, there might not be enough humidity in the cavity for all of the isocyanates injected to react.

If it wuz me, I would use any expanding foam, and I would go to any place that sells small tubing (like hydroponic garden shops) and get some flexible tubing that will fit over the nozzle of the can snugly. Cut that tubing to 18 inch lengths or so and insert the tubes into the tunnels. Inject the foam while pulling the tube outward to fill up that 18 inch of tunnel.

Both cured and uncured polyurethane foam can be cleaned off of most clothing with acetone. Acetone is commonly found in nail polish remover, but you can buy acetone by the quart or gallon at any paint or hardware store or home center. The only clothing that acetone will dissolve are acrylics which are typically found in KNIT touques, scarves and mittens. Any fabric whose label that says the garment is made of "Acrylic" will dissolve in acetone.

Keep plenty of newspaper around to throw the used pieces of tubing onto. Clean the nozzle with acetone if necessary after every injection of foam. Using an eye dropper helps to get the acetone into the nozzle and the outlet of the can. You can buy eye droppers at any pharmacy.

J wrote:
The issue may be in the details, ie what is an "enclosed space, no
air, etc. I think those foams rely on moisture in the air to cure,
if I'm not mistaken. So, if you really put it in something that is
totally airtight, I can see that being a problem. But I bet the
area around a spa tub doesn't meet their meaning of airtight. I
think enough air is going to get to it so that it will cure.

Precisely. I'm sure that for any "surface" area (within an inch or
so) it should be fine. It's just that I think there will still be
plenty of tunnel spaces (surrounded by the previous foam, which
should be air-tight) that will probably not get the necessary air for
good curing. But upon reflection and reading the responses, I think
the Great Stuff "big gap filler" will be good enough, even if not
perfect.

Thanks all.

P.S. I think the 2 part expanding foam mentioned by Bob F. would
probably be too difficult to get into place for this scenario -
though the foam itself would probably work better.

A syringe and connected plastic tube (straw?) should be able to do it fine, and
the 2 part foams are not going to have curing problems.

Any foam might cause problems with too much expansion if too much is used.