I currently use the 12v Fatboy Bandit to clean roofs and a 100 gallon tank that I batch mix in. I am about to get a trailer and want to add a metering system (ProPortioner or a Dougenator). I hear that adding a metering system can restrict flow and this is why I am worried about adding it to my 7gpm 12v system. About 3 days ago someone posted in a Facebook group that he is using his 10gpm gas powered diaphragm pump with a Dougenator. I always heard that you could not do this because the bypass needs to go back to a tank which does not work for a metering system. They state that you can run the bypass back to the inlet of the pump enabling the use of a metering system. If this is true then isn’t this kind of a big deal? Gas powered diaphragm pumps can spray at over 10 gpm, are compact (compared to air and booster with generator) and i believe this would out perform and be more reliable than my current 12v pump. Has anyone else tried this successfully?
So a internal unloader? Sounds like a recipe for disaster to me. Seems like it would be easier to only let chems into the pump when you are on the gun. If I were designing a system like that, I would have a separate bypass tank that the pump draws from when the unloader is closed. The two problems that I see off that design off the bat are 1. Controlling which tank the pump pulls from and 2. The chems already in the pump would go into bypass tank so you would need to purge the tank at the end of the day/week + you cant run chems that would react badly to each other.
Prob a stupid idea, but if you could find a way to reliably switch witch line to draw from then it might be worth a shot.
All gas powered pumps have unloaders or bypass valves. Yes it will work if you redirect it back to the pumps intake. And a gas powered pump is one of the only pumps that using a proportioner is ok on .
Could you run into the same problems of pressure washers with the unloader hooked dirrectly into the intake? Seems like it would over heat before long.
Glad to hear. I cant tell you how many times i have heard that this isn’t possible. I’m pretty sure most don’t know this.
Yes you will run into many issues using that kind of system. That’s why there not common in this industry.
There goof for soft washing buildings and treating flatwork . I absolutely hated them on roofs to much volume on some roofs even at lower settings. There is a burst when you first pull the trigger like a pressure trapped unloader. And you have to be mindful of how long it’s in bypass even short periods turned very sudsy. To me it’s just the wrong tool for the job
Just because you can do it doesn’t mean you should. You won’t be doing people any favors by spreading that around. You’ll just cause more misery when more people by them with the intentions roof cleaning
Trust me, Im not the type to do it just because I can. It seems to be working well for the guy in the facebook group which had me confused because i haven’t heard of anyone else using one in this way. This is why I asked the question. After hearing what you have to say I think I will stick with my 12v and i may try to add a proportioner. If the flow is restricted too much then I may go to air or booster, but that’s only if a metering system is more efficient for me than batch mixing.
Hi Curtis,
Are you still looking to add a metering system to your setup? I have an option that won’t restrict the flow. Let me know if you would like more info.
