What's the minimum psi for a foam cannon?

My folks had a Generac 2100 CP electric power washer laying around unused so I snagged it. It's 1150 psi. Has anyone used a foam cannon with that low of a pressure? Is this one powerful enough to get good foam or do I need more pressure?

 

Pressure washer specs are kind of bogus anyway and it relates more to the nozzle that you'd never use on the paint. Foam cannons usually have an "orifice" that can be swapped out depending on the pressure. I think it's 1.25mm for gas or more powerful electrics. Most other electrics need a 1.1mm orifice. By default some foam cannons come with the larger orifice so try to find one that includes the smaller orifice or has it already installed.

Otherwise if 1150 psi is true, that is more than adequate for car washing.

 

Using a foam canon is not just about the PSI. PSI is important, but it's also about the soap, how much soap you use, the size of the oriface in the canon, etc. There's a lot of variables to consider. There really isn't any magical answer to what to use, how much to use, etc., you have to experiment a bit to find what works best for your specific equipment set up.

Not all soaps will work well in foam canon's, and not all foam canon soaps are great for contact washes either.

My electric pressure washer states it can produce up to 2100 PSI. To get the most foam out of it that I can, I put a smaller oriface in the canon to increase the pressure, use about 3 oz. of soap in the tank, and fill it up with HOT water. Using hot water will increase the volumn of foam your equipment will make.

There's a ton of great auto detailing videos about this specific subject on You Tube, and if this is someting you are just getting into, I would suggest you spend some time watching some of them. It will save you a bunch of time and money.

Here's a list of some of the detailers I follow on You Tube:
Apex Detail - https://www.youtube.com/channel/UCqZOhpSAihtUBnebhY_ro_Q
Pan The Organizer - https://www.youtube.com/channel/UCE0kcuDlwjfP2982jVH6WkQ
Forensic Detailing - https://www.youtube.com/channel/UC_4lRohBzY20wjsFGWS0Jzg
Miranda Detailing - https://www.youtube.com/user/Mirandadetailing/videos

 

Water hardness also plays a big role on how thick a foam you can produce.

 

Try and see. When foam cannons first came out I tried several smaller pressure washers and couldn't get good foam until I stepped up to a 3100PSI gas pressure washer. That was before you could get smaller 1.1 orifaces. Now, part of me wants to go back to an electric unit for quiet and ease.

I recommend getting a name brand foam cannon so you can get parts. That's why I had to get a new one last year as I was unable to get parts for my old one.

 

I have a trinova foam cannon, running off of a 500PSI cordless pressure washer, and it makes foam well.