I don’t go to the gym to workout. I use a duffel bag in which I add weights. As mentioned before for biceps for example I am lifting 40 KG kilograms (not LBS but kilograms). I lift this with one hand for 12 reps to failure. I wouldn’t call that weak and I am not small. By that I mean I look muscular. At my heaviest, 6 years ago I was using 50 KG. For legs and chest I put the bag on my back and do squats and pushups.
Also as far as I know building muscle doesn’t have anything to do with lifting to failure. But rather with the application of progresssive overload: increasing load, reps, sets or frequency over time.
Also I am natural. Not on any drugs of any kind. Not even flu medecine. My goal is bodybuilding not strongman, weight lifting or power lifting.