This can be done at any time after the ailerons are hinged to the wings. To balance the ailerons we’re going to pop rivet an aluminum tube weighted with lead. In the early days of the Bearhawk 4-Place, the plans called for a 3/4” O.D. thin wall aluminum tube. This tube diameter was later changed to 1” to improve the flight characteristics of the ailerons. If your ailerons were built to accommodate a ¾” tube, realize that you’ll really need to pack the entire tube full of lead in order to achieve the correct balance. If you are building with ailerons intended for the 1” tube, you will have plenty of air left in the tube at the balance point. Look at the nose ribs of the ailerons to see the hole where the tube goes. It will be positioned spanwise between the two hinges, but there are holes in the rest of the ribs so that you can slide the tube in. Most hardware stores will carry a 6061 aluminum tube with the right dimensions. You’ll want to put 5 pounds, 4 ounces of lead in that tube. You can add a little extra with plans to drill it out before covering, if you prefer.
Although you can go through an entire balancing process in which you suspend the aileron by thread and estimate the fabric and paint weight and then determine how much lead you’ll need (see Russ Erb’s CD), the range will always be between five pounds and five pounds, four ounces. Since overbalancing is better than under balancing, use five pounds four ounces as the target.
Pouring Lead (small tube only)
If you are building with a ¾” tube, the best method is probably to pour molten lead to fill the tube. The lead will cool as it is poured into the tube, which will introduce voids. Mitigate this by having a helper preheat the aluminum tube with a propane torch. This process is much more dangerous than it seems! Use a face shield and respirator, do it out doors, wear welding gloves and make sure no moisture is present as it will turn to steam and blow molten lead all around. Stand the tube up and either make a wood plug for the end or stick it slightly into the ground to seal it. Support the tube with some sort of structure up high, because once you start adding lead it will want to fall over and that will likely set the place on fire. Make sure the can or ladle you’re using has a narrow spout or make a funnel from aluminum flashing.

Because the tube is so long and you want the lead to keep flowing, rather than cool on the way down, carefully warm up the tube with your torch. Remember, it’s aluminum and easy to melt, so don’t get it too hot. Because there is no airspace in poured lead, there will be too much in the tube, so be prepared to drill some out. When the tube is full, slide it in place and pop rivet it with stainless rivets.
Using Lead Birdshot (preferred method for the larger tube)
If your plane uses the larger tube, you won’t want to mess with hot lead and the corresponding safety concerns. Instead, fill the tube with bird shot. Go down to your local gun store that sells reloading supplies and get the smallest lead shot they have. You want nothing bigger than 8 1/2 (the bigger the number the smaller the shot) and finer is better as there will be less air space in it. If you can find number 12 shot, great! make sure it is lead because some places sell steel shot, which isn’t heavy enough.
Although some builders have made up a paste of lead and epoxy, that is difficult to get down the tube and the epoxy takes up space. Instead, we’ll only use the paste on the ends, since the shot itself pours in like sand. First, rough up the inside of both ends of the tube with coarse abrasive, 60 grit or so, to give an epoxy plug something to hang on to later. Tape one end closed. Fill the tube with the lead shot up to about 3/4” from the end. Make sure to lightly pound the tube against the ground, so the shot settles into place. Then, make up a slurry of epoxy (JB Weld is good) and shot that is mostly lead shot (for weight) and fill the remaining space with it as a plug.
Before plugging up the other end, weigh the tube. It should be at least 5.0 pounds and a little heavier is better. Turn the tube over and remove a little shot to give enough room to form another epoxy/shot plug in place and you’re finished with this process Now, slide it in place.


Lead Wool
Yet another way of getting weight in there is stuffing the tube full of lead wool. This looks like steel wool, but it is lead and is available from McMaster-Carr. The method of installation involves nothing more than forming plugs that look like cocktail wienies out of the wool, dropping them in and compacting them with a steel rod. Then an epoxy plug is poured in the end the same as with the lead shot.
Lead wool “wienies” are formed really easily and tamped down are nearly solid.