two machines at 4gpm or one at 8gpm?

[Windows R Us]

We currently run two direct drive 4gpm cold water machines at one time on most jobs. These machines have been very unreliable. They have Honda GX390 engines and AR/General pumps.

I'm sick and tired of them breaking all the time and am considering getting new equipment and setting up our trailer with hose reels. Would it be better to get two 4gpm belt drive machines or one 8gpm hot water machine. We do mainly residential siding, concrete and stone.

Could one expect to get 8gpm out of most residential hose hook ups?

 

[Mark]

In most cases one operator with
8 GPM can outclean two guys with
4 gpm machines doing flatwork.

You should have a water tank to
draw your water from.

 

[DAFF]

A 8GPM machine will do the trick (cold water). As for the steam hot washing you need temp not voume to do the work. For this a 3.5 -5.5 GPM will be more than you need. With the price of fuel you do not need to heat up 8gpm in order to wash. Simpilly have the 8gpm unit do most of the work and the hot unit for the touch ups.

In a perfect world you can order two high quality 5.5GPM units (cold) and one hot box. Using quick connects you could have a 11GPM unit or two wands at 5.5GPM cold or one hot or one cold. Hot boxes are the way to go expecially due to the fact when versatility is key. Plus they don't need to be on all the time like the skid mount units. To think even with a complete breakdown you will still have a machine up and running. Finally this way might be cheaper to price rather than a 8GPM hot unit.

Good luck

DAFF

 

[DAFF]

Sorry, you will require at least a 300Gal tank. Hose hook ups at these volumes are asking for issues.

DAFF

 

[Henry Bockman]

I'd suggest the 8gpm machine, if you don't need hot water just turn off the burner. More water volume will allow you to work much faster, expecially with heat.

Almost all of my machines are high volume units and I generally run them with small tanks.

I have a 6gpm cold water unit mounted in a van with a 30 gallon float tank.
A 5.5 gpm hot water unit with a 225 gallon tank on a trailer.
A 8gpm black knight hot water pressure washer with a 200 gallon float tank
and a 12 gpm hot water unit with a 200 gallon float tank.

In a couple of months I'm going to mount my 8 and 12 on a new trailer with a 325 gallon float tank for some commercial jobs I'm doing. I'll tow it with a ford350 pickup truck I just got that has an 8gpm unit in the back. I'll be able to run 3 high volume lines or 6 lines from the one rig.

 

[Windows R Us]

Those sound like good setups. I don't want to haul a lot of water around, especially with fuel cost here in Hawaii. I like the idea of a 30 gallon float tank. Do you guys think 8pm is overkill for what we're doing, or the more gpm the better!

Thanks,
Chris

 

[Henry Bockman]

For me, power washing is all about speed. The faster I can apply a good cleaner and let it work, then rinse it off, the happier I am. We can clean most houses in about an hour with one of our machines.

 

[BigChief]

Perfect world

I'm with Daff on this one. If I had to start all over again, I'd run two 5.5/3500 machines; LOTS of flexibility.

 

[Windows R Us]

Big Chief - What set-up do you have now that you would prefer two 5.5s instead?

 

[Windows R Us]

So theoretically, I could get my two 4gpm direct drives running well, connect them together, throw a hotbox on and have 8gpm, 3500psi and hot water. Then all I would need is higher rated hoses, guns, and reels. Sound right?

 

[john orr]

So theoretically, I could get my two 4gpm direct drives running well, connect them together, throw a hotbox on and have 8gpm, 3500psi and hot water. Then all I would need is higher rated hoses, guns, and reels. Sound right?

As I see it, the biggest problem you will have is supply. Two machines drawing 4 gpm at the same time would be a problem at some homes I do. (99% residential with 8 gpm/3000psi.) Many times, a customers city water supply will not keep up with 8 gpm, so I usually carry 75 or so gallons in my 300 gal tank as a buffer. If the flow is low, I will allow the tank to fill while I get set-up. Sometimes, you have to give it quite a head start.

In fact, insufficient water supply may be the reason you are having problems with your machines now. Starving a pw is never good for it. Direct drive pumps, because they are spinning at the same speed as the engine (3400 or so RPM) don't pull water too well. They need the supply pushed. Belt or gear drive pumps spin at 1/2 engine speed, so they will draw much better - either from a hose bib or a tank.

Having said all that, to answer you question directly, most likely, your guns/hoses and reels are rated to 8 gpm. The psi does not change, only (!) the volume.

 

[DAFF]

Myself I would look into the belt drive cold water systems. The direst drive units are good but they seem to have a short life expecially decause people use them at 120% capacity. Gpm is key and the size of the pump is directly related to longevity. If you went with the 5.5 GPM it will make your operation way more flexable. Or run the 5.5 with a 4.0GPM each on thier own unloader and return line and T them together on the outlet side of the unloader with quick connects. Use the 5.5 for rinsing and the 4.0 for chem application and/or heat. put them together for some good cleaning fun!!

If you are trying to get the 8GPM you want I would stay with the 200Gal reserve tank at a min. This will give you 25 min of wash time with no hook up. With a hook up you might get 35-40 before you got low in the water department.

Good luck and shop frugally. What is the going rate for a 10.5 GPM skid mounted unit vs a three piece unit running all the pieces individually.

DAFF

 

[BigChief]

my rig

Big Chief - What set-up do you have now that you would prefer two 5.5s instead?

Sorry it took so long to reply.

I started with a Mi-T-M 3505 (which I bought used) and it just didn't sling enough water (4.7 gpm) to get the job done in a satisfactory amount of time. I purchased a BCE HydroMax from Randy and Brian in Georgia which I am very pleased with. I'm shooting 7.5 gpm at 3600 psi through a Mosmatic 21". I still use the Mi-T-M for curb work and rinsing. Future plans include upgrading the pump on the Mi-T-M to 5.6 gpm/3500 psi and replacing the unloader to match--- possibly a KZ-1 flow-type. The 20hp Kohler on the Mi-T-M should handle it fine. Haven't finished all of my research on that yet.

In the meantime, I'm thinking that rigging the Mi-T-M unloader to bypass into the tank instead of the pump will help some with my fluctuating pressure problems.