5000 psi or 4000 psi?

[Parker]

I am going to be taking on a few new accounts with some serious carbon build-up in the systems. Hard carbon build up is nothing new to me as some of my biggest accounts use char-broilers so carbon and char are just part of the job. However, I am charging these new accounts an initial cleaning charge which will be funding some new equipment for myself. We have always used between 3-4 gpm/3000-4000 psi pressure washers which never removes all the carbon, hence the scrapers, grinders, and elbow grease.

So here is my question for those of you who also have extensive experience with carbon built-up systems: Which of the following would you purchase?

A. Purchase a 4 gpm/4000 psi heated pressure washer and use a sand blasting carbide kit with it.

B. Purchase a 5gpm/5000 psi heated pressure washer-(not compatible with a wet sandblasting kit.)

So- 4000 psi with sand or 5000 psi with no sand? I have used wet sand blasting kits before and the results are slow but effective. Sand kit is very touchy though (don't get that tip wet!) Have any of you used 5000 psi on a hood system? Is it any more efffective than using 4000 psi and worth the difference in cost? GPM's are a non issue for me since our barrels are configured with an automatic pump out system (no over-flowing barrells!)

I cannot avoid the hardcore hand scraping, grinding, chiseling elbow grease work its going to take to clean these neglected systems, but if I can use the proper machines to their utmost effeciency, maybe I can save a few cuts and bruises on my hands!

 

[safeclean]

Parker I can't comment on the wet sand blast kit on a 4000psi machine versus a 5000 psi machine,since I have never used a wet sandblast attachment.But this is something you might want to look at in a worst case scenario for carbon buildup.Chimney sweeps use them to remove heavy creosote buildup in chimneys. www.rokleen.com. They attach to rods that snap together and you lower it into the flue then attach to a cordless drill and the spinning chains or poly whips spin and take off the carbon or creosote,so you can pressure wash it(ducts,not chimneys).I have not used it in a kitchen exhaust yet,but I have used it in chimneys,with a chimney vacuum at the bottom of the fireplace opening with the fireplace tarped off.
Jim

 

[John B]

Buy a $ 3.00 Razor Blade Scraper and alot of single edge razor blades and scrape first.. I do this with all my Burger Kings.. works great .. then set up the accounts where they do not get so nasty.. and lifes a breeze.. when I got Burger kings it took 7 hours for there initial cleaning .... now I do them every 2 or 3 months and it takes 2 1/2 hours...

Hey but what do I Know _______________________________

 

[mbryan]

I would say the same thing as John. Scrape scrape scrape. I would rather spend an extra hour scraping than try to clean up the mess a pressure washer would make trying to get the same stuff off. That tool Jim meantioned looks pretty cool. I would like to see if that works on grease.

 

[Ron Musgraves]

anything over 4 is considered Ultra high pressure, I believe cali has regs on this as well as OSHA.

My understanding you need a license.

 

[mbryan]

I think Ron is right. It gets in to the realm of "water blasting".

 

[Dave Olson]

Hello Parker,

We have sand blast, soda blast, and water blast equipment! I would not even consider using them in a kitchen exhaust system.

We scrape, apply a Potassium Hydroxide degreaser, rinse using 1500 psi 2 gpm up to 3000 psi 10 gpm equipment. And of course use hot 200 + degree rinse water. You must use a degreaser that will stay in contact with the surface or your gonna be spittin in the wind!

My couple cents,

Dave Olson

Ps: Don't buy either machine that you mentioned!

 

[Parker]

Dave,

Thanks for the input, I do appreciate it. However: Although 1500 psi is enough pressure for many of the restaurants we do, 3000-4000 psi certianly has its uses for speeding up work as well. We use variable pressure dual lance wands so we can adjust pressure as needed. There are times where all I need is 1000 psi and there are times when I need all the pressure I can get!.

We use sodium hydroxide for degreasing. I made what I call a "pre-spray tree" for chemical application. When I get to a job we do the hang, then I set up some piping that "branches" into the hood and flue and has ports where I can can attach nozzles. The tree then connects to a pump inside the barrell and pumps the chemical up the tree and to whatever nozzles I have attached. The chemical comes back down to the barrell and then is circulated back up through the system. This way I do not have to worry about dwell time and the hood cleans itself while I either prep another hood or get my equiment ready. This maximizes my pre-spray on dirty systems as I can let the "pre-spray tree" run for 20-30 minutes if I want too.

Then its time for the pressure and heat. I would cautiously use 5000 psi as I am sure you could cause some damage if not careful! I want to know if anyone has ever used 5000 psi on a hood system and what their experience was.

Finally its scrapers and grinders with wire wheels to finish the job. I have gotten incredible results with this process removing 95% carbon and char from horribly bad systems.

But, I am always looking for the extra advantage!

 

[Hoody1]

theres no need for that much psi

just do a lot of scraping, we use a 1500psi hot water machine, scraping is the key to cleaning hoods, more scraping, less washing.

 

[John B]

Cleaned another Burger king Last Night.. When you have carbon Build up Scrape .. Thats the key.. I can put 3000 @4Gpm at 210 Degress on this burnt on stuff and it does not move but I can Scrape it in about 45 minutes then wash..

 

[mbryan]

That hood looks beautiful John. I'll take your word for it that the duct came out pretty good, hard to tell from that angle.

 

[kmjt1021]

Parker, how about a pic of that system you decribed

 

[John B]

Sorry about the duct picture My damn camera only takes aboout 20 shots before the batteries play out... But I must be honest the duct looks good about 3 feet down but whoever put the fire system in this hood ran so much conduit and pipe thru the bottom half of the duct I was scared to clean it.. I talked to the owner and I believe he is going to let us put A new Pyro-Chem System in Next Month ... I will probably replace the ducting as well ... The bad thing about these Burger Kings is when I got them they had not been cleaned properly for like 3 years.. Every cleaning I get More and More Stuff off,, They only give me like 5 hours to work on them...
This owner has 8 Burger Kings that I clean every 2 months , He is happy with what the hoods are looking like, He pays within 2 weeks....Probably 2 more cleanings for each store and everything will be bare metal.. It's just hard to change 3 years of burnt on grease in a matter of a couple of 5 hour jobs... plus the maintenace man had a brilliant idea to tie the duct and return air holes in the vent hood and make them both exhaust .. Big problem is the return air is about 2" wide and goes all around the hood .. I have been scraping this and its getting pretty clean....... Duct work on these stores are 14x14 real small and a pain to reach down in , but we wre getting there..