| If you want to run an efficient mobile car wash | | | | Some of our units had dual hoses and dual wands for |
| business, there a few things you need to know. Not | | | | cleaning lots of cars on car lots, in this case we |
| long ago I was asked a very good question by just | | | | would bypass the coils, and divide the water, that |
| such a vehicle cleaning specialist. He wanted to know | | | | way each of the wands/guns got 2.25 gallons per |
| what pressure rating, PSI or pounds per square inch | | | | minute. But to maintain the right pressure you have |
| and what GPM (Gallons per Minute) would be the | | | | to swap out the tips at the end of the guns they |
| most efficient in his operations? Let's take a look at | | | | don't let as much water out. |
| this because this is a very important question. | | | | And after a while it gets fairly complicated, so you |
| We always chose the 4.5 gallons per minute, 10-12 hp | | | | need an operator that knows what they are doing, |
| skid units, later we went to 5 GPM and 17 HP, then | | | | and you can't lose the tips, which does happen with |
| many franchisees as they bought additional units for | | | | quick disconnects malfunctioning, bad O'rings |
| more industrial work went 3500 PSI and 22-25 HP. | | | | (remember the Space Shuttle) sometimes they pop |
| You see, if you are doing really big jobs you going to | | | | off, especially over time as the quick disconnect |
| need more water, giving you more cleaning units, and | | | | brass fittings fail, and even the stainless steel quick |
| they also operate hydro-twister type attachments | | | | disconnects don't last forever. |
| much better. For those you need 6 to 7 gallons per | | | | These are definitely wear-able parts, have spares |
| minute to really run optimum, and you can clean | | | | with you in your glove box or tool box, and o'rings, |
| concrete about as fast as you can walk, like mowing | | | | extra-tips, or "you'll be sorry later" guaranteed! No |
| a lawn with a professional grade lawn mower with | | | | one likes soggy socks and shoes when pressure |
| sharp blades and state-of-the-art technology. | | | | washing - be prepared, be USMC tough. |
| Nevertheless, when it comes to contract cleaning, it | | | | So, in summary; |
| is always an issue with water supply. If you have a | | | | If you're going to wash trucks go with 4.5 gallons per |
| big flat bed trailer with a 500 - 1000 gallon tank you | | | | minute and 3000 PSI with attended 12 hp skid unit on |
| can get away with using more gallons per minute. We | | | | a hot-water pressure washer. |
| had our units set up where we could take the 4.5 | | | | If you are going to just clean cars, go with a 5.0 hp |
| gallons per minute, adjust the system to put out only | | | | Honda motor with a general pump and do your work |
| two or 3 gallons per minute under 1500 PSI for clean | | | | at between 1500 and 2200 PSI - and look for water |
| cars, and then ramping it up to 3000 PSI at 4.5 | | | | volumes of 2.4 gallons per minute, 23 gallons per |
| gallons per minute when we are cleaning trucks. | | | | minute. |