Internal pipes coating robot

Hey guys!

I want to make a rotary spray painting mechanism for a coating robot. Lets say that is for pipes with diameters between 8-14 inches, and the surface to be coated is really small about 3-4 cm (welded seams). Considered already the next ideas:

  • Based on an airbrush concept, using small CO2 cartridges or propellant cans as air source. Here I am not sure if the pressure of those sources will be enough to complete the painting and the required wall thickness.
  • CO2 tank and a solenoid valve + regulator to decrease the pressure to desired levels, with possibility to use Arduino or Raspberry. Here had a confusion about how solenoid valve works, it requires electrical power to works, I would like to make the robot as compact as possible.
    Also need to be careful with CO2 and its temperature variation which can react in a negative way with coating epoxy.
  • There are simple coatings tools like this one clemcoindustries.com/products_showitem_clemco.php?item_id=325
    with a rotary head, so I wanted to automate the idea in a mobile robot, with automatic coating.
  • First idea was following the concept of this cordless Airless sprayer, graco.com/us/en/products/contractor/xforce-hd.html
    A motor, a pump, high pressure and possibility to use any kind of coatings. Here the problem is to adapt those components in a compact robot. (The pump)

Finally I don’t would like to use a regular compressor which are very noisy and big, even I can automate the existing tool, with mobility some sensors, lights etc. it will not be a big improvement.

Will be grateful for any comment to this post!
Thanks!

So what approach are you most comfortable with? We do not have anything commercial to offer you which can work off the shelf, so the approach can range from something entirely custom, to adapting an off the shelf robot frame and adding a custom sprayer, or adapting a commercial sprayer and creating a custom base. Do you have an idea of your budget? We do not know a lot about the internal pipe spraying industry or available products.