Which equipment is best?

[davidwil]

Hello all,

I'm a real newbie . . . but I've read a lot of this board the last few days and it is a great resource! I'm almost committed to opening a PW business but I can't decide what equipment to buy. I'm convinced a hot-water setup with a high gpm is best and will make the work easier. But what do I need as far as psi goes? From what I've read, it seems that the majority use around 3000 psi in their businesses. What I was wondering is . . . what can I do with a 5000 psi that I can't do with a 3000 psi? I want to do this right and get good equipment and do good work, but I don't want to spend money unnecessarily.

As far as the type of work I expect . . . concrete, houses, trucks, fences, decks, etc . . . just about anything I can wash without climbing ladders!

Also, what equipment would you recommend? Thanks for any input that you can give!

David
W Tenn.

 

[oguard]

Well with 5000 PSI you can break glass, cut concrete, peel paint, dent metal, cut off your toes or take out an eye.

PSI is NOT what really cleans for you; it is FLOW (GPM).

At 5000 PSI you must wear ARMOUR over your complete body including a face shield supplemented by safety goggles and a hard hat. All of the components must be stainless steel rated at or above the pressure output of the system. These as well as the guns, wands, hoses, nozzles etcetera are MUCH more expensive than for 3000 PSI.

In almost every case 3000 PSI will handle your cleaning needs, often even less (check out the pressures used by deck cleaners).

Horsepower is directly related to FLOW. PSI is the easy part, just stick your thumb over the end of a garden hose to see the result.

Flow must be tempered by supply. Most municipal water supplies are hard pressed to give more than 6 GPM, rural wells often only 4 GPM. The practical limit is ~5 GPM without having a large water supply tank. Remember that flow is rated in Gallons per Minute; so 5 GPM will last ~65 minutes or less with a 325 gallon tank.

There are fairly valid "Rules of Thumb" that help in decision making. A common one is required HP..... [(Flow x Pressure)/ 1460] x 1.5 = gasoline engine HP.

There are other formulas that make the numbers dance but this one is close enough to reality to be useful.

Impact force, pounds = (Flow x square root of pressure) / 18.92. For example, and this blows away the so called validity of 'Cleaning Units' as a comparator;

1 GPM @ 4000 PSI = 3.34#
2 GPM @ 2000 PSI = 4.73#
4 GPM @ 1000 PSI = 6.69#

All of the above have 4000 'Cleaning Units' but the last one has the most impact to the surface you are cleaning. More water equals more soap on the surface faster with shorter time rinsing which equals more money per hour. Or to put it another way >GPM = <Time = > $$$

Oh, as to your 5000 PSI versus 3000 PSI, we will assume 4 GPM.

5000 PSI should require a minimum of 20HP and have an impact force of 14.95#. Oh, expect this unit to cost ~ $10,000.

3000 PSI should require a minimum of 13HP and have an impact force of 11.58#. Oh, expect this unit to cost ~ $5,000.

Is the extra impact force worth the extra cost and potential danger? Only you can decide.

Hope this helps? Cheers.

 

[davidwil]

Just the info I wanted

Oguard,

THANKS! You gave me just what I've been looking for. I didn't realize the degree of difference in 3000 and 5000 psi. I assumed that, since Sam's, Lowe's, etc sell 4000 psi units that a commercial application would need something higher. You also confirmed my understanding of the flow rate equaling shorter work time and effectiveness.

Any thoughts as to the best equipment for the money? I would like something that is easily serviced and extremely durable . . . you know . . . something that will last forever!

Thanks again,
David

 

[Mike Hughes]

Great post, Michael........as always.

David,

You won't need anything over 3000psi..........as a matter of fact, I rarely use over 2000 psi. Flow is of major importance, as mentioned above. No less then 4gpms............around 5 is good. I have 5.5, but that's not a huge difference.

Keep reading, searching the boards, and post any questions you may have!

 

[Jon Fife]

David,

send me an email, i'll try and help you out, i'm in Nashville

jfife81721@aol.com

jon

 

[Bill B]

Wanted to reiterate a couple of points Michael made. I use 3500 - 4000 psi machines (they are what I happen to need). Moving to a 5000 psi machine increases significantly the cost of accessories, for example hoses and fittings.

 

[Clean County]

If residential is your goal then 3.5 to 5gpm @3000psi Powerwasher should be more then enough.

If Commercial is the goal then 5gpm or higher @3000psi will do just nicely.

Also a good surface cleaning machine comes in handy for both Commercial/Residential cleaning.

As far as buying local compared to buying elsewhere such as online, I would try to get the best deal local if possible.

Either way if you buy elsewhere make try to find a good local pressurewashing place that can service you powerwasher if needed.

 

[Mark]

Check out the All American Premier Series

Premier Series Contractors Corner

 

[Phoenix]

davidwil/ my lessons learned

David, Im another newbie, and I understood a little about pressure and flow at the onset, my dad was an engineer. These guys tell about PSI vs. GPM, and that really covers a lot, however if you keep looking at websites, you'll come upon some that preach "LOW pressure" thats not a bad idea either, and I have to admit, I started looking at the high end of the pressure spectrum, but was informed enough that I knew to look for flow (GPM) as well. After some thought on the matter, the low pressure approach, although not for every application, must be considered. If you're not familliar with using a high pressure machine, let me be one to warn you that you can do an incredible amount of damage with 3000 psi, FAST. If you are using more than 3000 psi, ya REALLY need to be careful! I had to laugh when I read that about cutting concrete and stuff, but thats pretty accurate. You can cause a lot of damage, and even kill someonewith 4000 psi.
Back to what I was aying about low perssure, and I think most of the folks here will ALL suggest that you start with lower pressure, and work your way up to where you need to be, this at least limits that possibility of damage, injury, and undue wear on your equipment.
If you are starting out with residential, as I am, there are a lot of applications that demand low pressure, like roofs, wood, and glass.
Pressure is just one part of the story, the right chemicals, time and flow cover more, and method has its own place in the process. I can't say enough about safety, but I dont want to forget to wish you well as others have done me!
Good Luck!

 

[Mike Hughes]

I almost never use anyting over 2000psi..........i use larger tips on my wands to lower the pressure. I use around 1200 psi on wood. Nonetheless, I still recommend you have a 3000psi machine...........so if you ever deem it necessary, it's there.

 

[P Austin]

Like Mike said, 1500-2000 psi is probably all that is needed, but is nice to have 3000-4000 psi just incase. There is also another reason for a slightly higher output machine. If say a 13 hp motor is pumping out 3000 psi at 4 gpm and next to it an identical machine is pumping out 1500 psi at 4 gpm, which one do you think will break down or fail first. A slightly higher rated machine will typically last longer than one maxed out all of the time. Many manufactures of the power washing machines, and other machines as well try to get the maximum amount of work with the least omount of cost; therfore, undersized pumps, motors, fittings, bearings, hoses etc results in premature failure.

I am a design engineer in the hydraulics industry, and this is one of the first thing our sales staff tells a customer. It is better to be a little over kill than to be under kill.

I personally bought a pressure washer from one of the home stores. got a decent deal for the price. 13hp honda, 3500 psi 4gpm cat pump with pressure control and down stream suction line etc. not a bad pressure washer for my second year in business, but there are several items and accessories that are less than high quality on the machine. If I plan to expand and grow my business, I know I will need a higher quality machine with a higher output. I think mike ore some one had talked about leasing equipment for a short time on a post some time last year. Perhaps this is a great way to get your feet wet, have good equipment, and decide what you actually need for your business.

well, I must be tired, for I am starting to ramble as usual. good luck with the equipment decision, just remember, research each and every purchace and weigh good -vs- bad prior to buying.

 

[T.A.M Mobile]

Well I have always felt that bigger is better and you can always turn it down. The more flow through (GPM) the faster you will clean. But you have to remember that for every 100 feet of hose that you have out there you loose 100 psi. I have some car lots that I service that have 300 cars on them and use 500 feet of hose. If you plan on cleaning concret with a large surface cleaner ( makes the work go fast and you can out-bid your competition ) . I would get a 3500 or 4000 psi machine with a high GPM flow. You can always buffer a slow water supply with a water tank. I have a 550 gal tank on my rig and in some cases use up to 700 feet of feeder hose to wash large fleets of trucks. I have 100 feet of high preasure hose off the reel and as I move the truck down the line the feeder hose comes off the reel. The point is better have to much machine than to little. At first you will think this BEAST you just purchased is to much but with a little skill it will soon seem a little small.

 

[Dave Olson]

Hello David,

We started out by buying out another fellow (1984). Got customers and equipment. Here is a picture of our primary pump as it looks today. The power-end is over 30 years old. We replaced the fluid-end including plungers 18 months ago. We ran the old fluid-end for 10 years. Cost to maintain this pump is less than $500 per year. I believe the reason this pump lasts so long is that it only runs at 485 rpm!

When we started in '84 this pump was using a 7.5 hp motor (electric). We are now using a 20 hp motor (electric) and the output is 3000 psi at almost 10 gpm.

We have always had high gpm equipment and have tried smaller pumps and was not satisfied with them.

We would not have been able to complete many of the projects that we have done without the higher volume.

Dave Olson

 

[davidwil]

Thanks! More advice wanted!

Hi all,

This BB is great! I appreciate all the responses to this thread. Each post has been extremely helpful and I'm thankful to each one who commented. I would really like your opinions on the setup that I have decided to go with in starting my business, but I will start a new thread to tell you about it. See "New equipment setup - advice wanted!"

Thanks again!
David Williams

 

[Dan Flynn]

Dave,

That is a sweet setup. I seen your stuff at the PWNA show in OHIO. That had to be 4 or 5 years ago.

 

[Dave Olson]

Thanks Dan, we like it!

Yes we took our Red truck to the PWNA conference in Columbus the fall of '98.

We have since rebuilt the back. Removed all of the equipment. Replaced the floor and crossmembers, walls, main water tank and boiler. Also added 24 volt switching for our pumps. Safer!

We started the upgrade of our equipment in early '96. I think we are done now. Spent a boat load of money but it sure works nice!

Here is a pic of how it looks now.

Dave Olson