Steam is actually the gaseous state of water or H2O. Ice is solid and water is liquid. In simple terms, steam is very hot water. As we all know hot water has lower surface tension that allows it "mix" with oil and grease. When mixed it is able to "carry" them away when washing. This might not be a very good scientific explanation but I hope I could get the point across. It is just like washing greasy dishes with hot water eases the washing. In fact, adding soap to water also lowers the surface tension. However newer detergents have other chemicals that help the cleaning process even better. Of course some harsh detergents could damage the surface that we are cleaning. If you feel that chemical based cleaners could harm your leather you could try steaming them.
To start off, we would need something that could give us steam. No, boiling kettle won't do.
If you happened to have a multipurpose home steam cleaner, it would be the best tool.
Yes something like the one shown above. However, if you feel that this a little too bulky, you could use a compact steam cleaner like the picture below.
If you do not have any of these, then a garment steamer could also work.
If you have none, then go get yourself any of these ;-)
Each of these has their pros and cons. The multipurpose steam cleaner, although bulky could generate dryer steam. When these steam cleaners generate steam, the steam that shoots out is not 100% steam (4 steam word in a sentence). There are some water droplets within them. Dryer steam has less water droplets compared to wet steam. So, steamed surface will not be "that" wet and will dry faster. I hope that make sense. Garment steamer is likely less powerful and might take a longer time to get the job done compared to those actual steam cleaners. On a steam cleaner, there is a pump that "shoots" the steam out but on a garment steamer, steam is released naturally.
Done with the tools. Let's get to work.
STOP! The leather seats should be thoroughly vacuumed before steam cleaning. Yes, see my earlier post.
Since I am cleaning leather, wet steam should be fine. So, I went with the compact steam cleaner. If I were to clean fabric upholstery, dry steam should be more proper to prevent over-wetting.
With the steam cleaner turned on and with the proper cleaner "head" attached, move the head in a straight line to clean a small section. Then quickly use a microfiber towel to wipe off the wet surface, lifting away dirt and grime that are "floated out" by the steam. Try not to let the surface dry before wiping off. The idea is to lift away dirt that is suspended on the hot wet surface. Do the same, section by section on the entire seat.
The microfiber towel should pick up all the dirt.
The picture below shows half a seat that has been cleaned.
Continue with the back rest and the entire seat and then on all other seats.
A cleaned leather should look matt and feel soft.
Once all the surfaces are cleaned and dry, protect them with leather care products. See my earlier post on complete interior care here.
Look at how dirty the cleaner head is after finishing all the seats. The microfiber attachment is supposed to be white.
Steam could be use to clean all interior surfaces. Just avoid areas with buttons and electronics components. Steam can also be used to clean engine bay but that is for another post.
That's all for this post.
Happy detailing.