I am trying to dye my wheel chair wheels from white to blue and or red.They are a obviously a SOLID nylon material (as opposed to a fabric like wool or cotton).And I am wondering if this would be possible w/ the all purpose dye.Would I need to boil them or use hot water?Should I prep them in any way?They are 24" and weigh about 5 lbs give or take.About how much dye would I need for a set?And is it even possible?Thank you so much for your time,

I have not dyed solid nylon myself, but I have heard of it many times. There are web sites detailing the dyeing of nylon discs and nylon lacrosse sticks. Some of these ideas may be useful to you.

Acid dye works well on nylon, and all-purpose dye includes acid dye as one of its components, so all-purpose dye can work. As far as the dye is concerned, the hotter the water, the better, but you do NOT want to risk deforming your wheels! I would be afraid to boil them. In general, nylon may do best below 185 degrees Fahrenheit.

You need to prepare the wheels by getting them as clean as possible, since any dirt or oil will repel the dye.

It is a lot easier to add more dye in a second process than to remove it. I doubt that you will be able to lighten the color at all after you have achieved it. You could try immersing the wheels just briefly in a dyebath made with hot water and one packet of all-purpose dye. Check the temperature of the dyebath, and the amount of water you dissolve a packet of dye in, and how many minutes you leave it in, so as to be able to reproduce it again for a second wheel. You might not want to simply reuse the dyebath for a second wheel, because the dyebath will be weaker after some of the dye has been used.

Pro Chemical & Dye <http://www.prochemical.com> sells specialized acid dyes that are just for nylon and wool, and they have an excellent technical department. Perhaps you should contact them for advice, and use the dye they recommend according to their instructions.