One company we clean owns around 200 trucks. They buy about half new and are always buying used trucks. I can tell which ones have been 2 stepped cause of the dull paint. IMO the acid (if used too strong) will dull the paint.
Another company we clean for only has 20 trucks. They had been cleaned by the same company for 4 years before us and that company 2 stepped always. The trucks were dull with no shine when we took over. In the last 5 years, this same company has bought 5 new trucks and we are the only company that has cleaned them. I use my detergent (single step) fairly strong and only brush them maybe every 4th or 5th cleaning and these trucks (with exception of scratches, etc. from use) still shine like they did new! Same Freightliner trucks as the dull ones. We have some trucks we have cleaned this way for over 10 years and they still shine and some that were dull 10 years ago and are still dull. Now I don't know that ALL the dull trucks we cleaned were 2 stepped, but most I do know were cleaned that way. Maybe the guys that cleaned them just aren't doing something right, but the trucks are dull!
Maybe it was the soap the others used that dulled the trucks in combination with the acid, but I use a very strong detergent (its strong enough to clean an engine with warm water in the winter)
On regular cleanings (weekly for the most part), we use 2 8gpm machines. One downstreams soap and other rinses. When the soap guy gets a few trucks ahead, he changes tips and rinses to let the other guy catch up. We can usually clean 10 -20 trucks per hour this way. We go back before moving the truck and brighten tanks and wheels the same way.
I do 2 step van trailers when they are bad, but all the ones that we have are older trailers and were dull when we started cleaning them.
Now I am not knocking anyones method, but that is just my experience. These dull trucks may be just results of a hack contractor, and not the fault of the acid used but I am not cleaning that way because of it. Also a single step with even some brushing is faster for me, maybe not everyone but for us it is.
We only clean 75-100 trucks/trailers per week. I could get a lot more to clean, but we do these and start Friday morning and only work till noon Saturday. Years ago, I would work all weekend but now with 3 kids I like to get most of my weekend off!! Also April- Oct. around here is race season (dirt stock cars) and my oldest son and I both race LOL
