I have been using a technique to weight my models so that the nose wheel on tricycle aircraft stays on the ground. I have not yet needed to use this technique on tail-draggers.   

Items needed for this process are some thin Cyanoacrylate (CA), some very fine bird shot used in the process of reloading shot gun shells, and a drill bit around 2x the diameter of the bird shot you select.  Keep in mind that the smaller the shot you can get, the more weight you can pack into a void. 

I am not a hunter, so I don't know what sized lead shot I have, but its REAL small (see photo above). So small that you almost cannot pick up one piece between your thumb and index finger if it's on a flat surface. This bird shot can be found at most hunting stores in the US ; other places in the world -- I dunno!?  I bought a 20 lb (9kg) bag and put it into a plastic ice cream container for storage as the bag falls over and the little lead balls go rolling everywhere. I think 20 lbs is probably a lifetime supply, unless you build 1/32 scale aircraft. If you decide to raid the ammo chest, be careful when disassembling shotgun shells. In fact, I wouldn’t recommend it at all. 

The thin CA you can find at any better hobby shop, but definitely get the thin stuff. 

Locate a void as far forward on the model as possible, preferably the nose, and drill a hole about twice the diameter of the lead shot. The hole can be on the underside of the aircraft so it is less noticeable later on. Make a "funnel" out of a 3” square of typing paper (see photo below) and place it into the hole, and pour in a little bit of lead shot. You will want to orient the void you are filling so that the lead shot and CA does not make its way into a wheel well or cockpit area, etc.

Once filled with a little bit of shot, place a few drops of thin CA into the hole and let it trickle down into the lead shot and shake it lightly. You may need to blow some air into the hole to clear the opening of CA for the next round of lead shot. If there's still a few pieces of shot rattling around, add a little more thin CA and shake gently. 

Keep building the shot and CA up in layers until the desired weight is achieved. You may drop a little CA accelerator in the hole as well. Putty over the hole, sand and finish.  

I have not had any problems with heat buildup while using this procedure.  

Best Regards,  

Jon 

Photos and text © 2004 by Jon Ruehle