The arms on my LEGO minifigures are loose. How can I repair these to remain in place when I move the arm to the location I want it to stay in?
You can replace the arm with a new one by carefully removing the old arm and snapping in a newer one. Please note that this should not be done too often, as the procedure will damage the connection and could even crack the torso.
LEGO never attempted the arms to be replaceable. It is not like snapping and unstapping bricks, however it can be done a couple of times with no ill side-effects.
In my experience the most times you can replace an arm on a minifigure without making the connection permanently damaged is 3. Maybe 4 times if you are lucky and you find an arm that is very tight.
Best is to take care of minifigures carefully. Constantly moving their joints will make those connection loose. If you are working on things like stop-motion videos where you are frequently adjusting the joints, it is best to use cheap minifigures. You can still play with more valuable minifigures, but it is best not to constantly move their arm around. Arms get loose faster than legs, so while you can put the minifigure in sitting, standing, running position many times before the joint will get loose, arms a a bit more delicate.
I have been experimenting to find the answer to this question, and today I have finally found it. I stumbled across a youtube vid of a child explaining his method, and mine was built off of his. His idea is to take labels, cut them into tiny pieces that are stuck onto the arm at the point where it connects into the torso. This works, all too well. Here's the problem. The arms get incredibly tight, as a result of there being too much pressure. This pressure slowly puts stress on the torso, and within weeks you will notice the modified figures busting open at the seem off the torso. This is generally on the sides, at the base, and it slowly cracks it's way up to the armpit permanently destroying your figures. I found this out the hard way when 10 of my superhero figures were destroyed. Still, I am thankful bcuz this lead to my discovery. Once the figures had been destroyed, I quickly removed the labels from all the others I had done, to stop them from suffering the same fate. What I realized was that once the arms had been doctored, after removing the label (I used small pieces of a cat hair roller, and I'd advise you use this bcuz I'm not sure labels are sticky enough) the arms retained Their clutch. This is a result of the stickiness staying with the arms after the sticky paper/cat roller material had been removed, but it feels like a perfect arm. The clutch is there, and you will not have to worry about the torso crackng. So now that you know, don't make the same mistake I did. This is what I would advise. 1.) Remove the loose arm. 2.) cut a small square off the cat roller. 3.) place It on the connected part of the loose arm. 4.)insert it Into a torso that you have double of, or don't care about. 5.) set it down, and wait an hour. 6.) remove the arm, take off the sticky paper. 7.) carefully inset arm back into the original torso. Now you have a perfect arm. It has amazing clutch, and best of all because the clutch comes from a sticky texture instead of immense pressure, your torsos will stay intact.