[drive surgeon]

what temp would be best to remove gum , graffiti etc,  im getting a hot washer which produces steam too when turn temp up and pressure down/

[Ian Rochester]

Gum can be removed with very low pressure steam, just enough to loosen it away then it can be scrapped or extracted off.

We have an Osprey Vega Plus 8 bar steamer, which is ideal for areas where there is lots of chewing gum.
 
Steam will not touch graffitti, you will need either a solvent based cleaner to break down the paint, or a very high pressure washer, ours is 4000 psi and it still struggles with some graffitti on certain surfaces.

[drive surgeon]

cheers lionheart

[Andy Foster]

If gum is outdoors I would use saturated steam at medium pressure to melt and blast away.
Steam has worked on 90% of graffiti jobs I have done, sometimes left with ghosting but a small amount of chemical will move that.  The other 10 percent, just use chemicals and steam (if the chemicals say it is OK to use heat of course.)

[drive surgeon]

so you dont need chemicals always to remove graffiti?   

[Andy Foster]

not always, no

[thewaterwizard]

 drive surgeon
   my hot box goes up to 120 havent had any jobs i cant do yet 
www. tensid.com  for graffiti chemicals i did there course
  a few years ago loads of info and good advice
  robin