Repairing minor decoy damage

At the end of a hunt, I noticed a hen teal decoys was floating funny and had water on the inside.
Closer inspection revealed it had a small hole in it, possibly from being shot.

I knew I could easily repair this decoy because I have the material and experience, but I thought
other people might have decoys needing repair and don't know how to do it.  So I did this
web page to give instructions that hopefully can be followed by anyone.


The way I decided to repair this decoy was to fill the body cavity with 3 pound expanding foam, then cover the hole with a paintable acrylic latex caulk and paint the the repaired area.

There are 4 easy steps to completing this repair:

1.    Prepare the decoy by enlarging the hole and drying out the inside.

2.    Fill the interior cavity with expanding foam.

3.    Trim off the excess foam and apply the caulk.

4.    Paint the repaired area and test float the decoy.
Step 1--Preparing the decoy




I used a Dremel and a high speed cutter to enlarge the hole enough to allow the foam to be poured into the body
cavity.  This hole may be larger than what is needed to pour the foam in, but will allow for the excess expanding foam
to easily escape.  This step could also be done using a file or a drill bit.

Now is the time to drain all the water out of the inside of the decoy and allow it to dry out completely.
                                           

                                   




Having learned from doing a major repair that the 3 pound foam can push out the bottom of the decoy I secured a couple of scrap 1x2's to hold the bottom in place.  An elastic ankle support strap with a velcro closure is used to hold the 1x2's in place.  Anything that will withstand at least 5 pounds of pressure can be used to secure the wood. An elastic (Ace) bandage, a small belt, duct tape, athletic tap, several large cable ties, etc.  These 1x2's also turned out to be quite handy as handles when working with the decoy.
                                           








The final thing to do before filling the body cavity with foam is to apply a thin layer of wax to the outside of the decoy.  Any kind of car wax will work.  The wax will keep the foam from sticking to the plastic.  It's kind of like the old man said in The Karate Kid...."Wax on, Foam Off".  Allow the wax to dry before pouring the foam into the body cavity.







Step 2--Filling the body cavity with foam

This is the fun part of the repair.  No matter how many times I use it, I always enjoy watching the foam expand.

It is now time to get ready to pour the foam.  Always wear latex or vinyl gloves when handling this material.  A well ventilated area is suggested along with goggles.  Try not to get the foam on your skin or clothing. In addition to latex gloves you will also need some dixie cups and something disposable to stir the liquid foam.  I use those craft sticks that can be purchased at many stores.  It is also a good idea to put some newspaper or something that can be thrown away over your work area.


I have always used Smooth-On's FOAM-iT 3 pound rigid foam to fill the body cavities of plastic decoys. This is a 2 part liquid foam, measured 1 to 1 by volume and expands 10 times in volume when cured. The foam is strong enough to prevent the plastic from being easily crushed, but not so dense that it adds a lot of weight to the decoy. I am sure there are other brands of foam that would work just as well.

In order to know how much liquid to use, the volume of the cavity needs to be determined.  I showed how to do this on the first page.  We know that it will take about 1.25 oz of Part A & Part B (2.5 total oz) to make enough foam to fill the cavity.

This picture shows the 2 parts measured out, ready to be mixed and poured.  I use the high tech method of measuring in dixie cups to get the correct amount of foam. This style of dixie cup works best because it is fairly transparent and has many markings on it that can be used for measuring.  Each cup is 3 oz and I filled each one slightly less than half full.  When it comes time to combine them to make foam, I pour the thinner clear liquid into the thicker dark liquid. Don't pour these until you are ready to use them as the dark liquid will begin to leak through the cup after sitting for several minutes.


When you are ready to fill the body with foam, you will need to have everthing set up so you can work quickly.  Mix the liquids together and stir them well for about 15 seconds.  Pour the liquid into the hole in the decoy using the stir stick to get as much as possible out of the container.  Now hold the decoy so the liquid goes to the lowest part of the body, in this case the tail.  It should take about 2 minutes for the foam to expand to the point it is visible through the hole.  At this point you want to rotate the decoy so that the hole is the highest point and the foam can expand to the other parts of the cavity, turn it so the head is lower than the hole and then so that the breast area is filled. As the foam begins to expand to fill the cavity it will start to come out of the hole.  Hold the decoy in such a way the excess foam has as little contact with the outside of the decoy as possible.  Let the foam finish expanding, about 3-4 minutes and let it sit for at least an hour before handling it again.  Here is a series of pictures I took while the foam expanded, unfortunately the pictures do not show the rotation of the decoy very well.




One word of caution about using the foam.  If the weather is warm (over 80 degrees) the working time you have with the foam is substantially reduced.  At room temperatures the working time, the time before the liquid starts turning to foam, may be as long as 1.5 minutes but at 90 degrees or more the working time may be reduced to 45 seconds.  I have poured this foam in a building without air conditioning when it was 100 degrees outside and the total time from mixing the liquids to when the foam stopped expanding was 1 minute 20 seconds.  Believe me, I had to work very quickly to get the results I wanted.

Step 3--Trim excess and apply caulk






After the foam has quit expanding and become solid, carefully cut or break the excess foam.  It is best to leave a little extra sticking out of the hole.  This is how much I left on this one.














I used a dremel and a sanding disc to remove the excess foam and to make a slight indent in the foam in the body cavity.  This will give a good base for the caulk to adhere to.  Do not make this too deep, 1/4" is all you need.  This step could be done with a file, rasp, knife, drill attachment, etc. Clean the area very well, removing the burrs in the plastic shell of the body, any of the dust from grinding the foam and any wax from the outside of the decoy.









Now fill in the repaired area with a paintable acrylic latex caulk to seal the exposed foam and give a smooth paintable surface.  Try to make the repair blend in as much as possible.  Allow the caulk to completely cure before doing and touch up painting.


If I would be doing this for myself,  I would build a small clay dam around the hole and fill the area with liquid plastic instead of caulk.  When the plastic had cured I would file and sand the area down to match the rest of the body as closely as possible.  I can do this because I have this type of material on hand, but it is not worth buying the plastic to repair one or two decoys.



Step 4--Painting and testing





Once the caulk has cured, paint the repaired area with the a color that matches as close as possible. Your repair is now complete and the decoy is ready to be used again!!!!!  












Here is the repaired hen in my combination dog bath/decoy test tank/outdoor sink with a drake that has not had any repairs done to it.  The repaired hen floats the same and looks the same as before it needed repairing.  I will dunk the repaired decoy under water several times and look for air bubbles escaping at the place the repair was done.  If there are air bubble, the caulk did not completely seal to the plastic and water is getting inside.

If this happens, remove the caulking, hang the decoy upside down for several days so any water on the inside will dry and then try re-applying the caulk.  This hen did not leak.


The hen could use a new paint job as it is looking a little worse for wear, but that is not what I am trying to cover here.
Way to go.... your decoy is repaired!!!!!
The total time it took to repair this decoy, not including the time it takes for the foam or the caulk to cure was less than a half an hour.  My estimated cost of the repair was less than $2.00. This type of repair is very easy to do and relatively inexpensive.  If you do not have enough damaged decoys to justify buying the material yourself, get together with a few of your hunting buddies and do a group repair.  If you live close to me, let me know how many you have to repair and we can do them together.


I hope you have learned something here and now have the confidence to do your own repairs.  If you have any questions, please feel free to email me at  mucks_ducks@yahoo.com and I will get back to you as quickly as possible.