First build attempt - Fresh water/wash down tank - Looking for input.

[ralphsmithiii]

I completed my first attempt at building a simple fresh water/wash down tank that's main purpose is to hopefully reduce my boat cleaning time at the end of my trips. Currently, I pull the boat out, take it to dry storage and spend an hour or so cleaning it. Then it needs to sometimes sit a day uncovered to dry which mean I go back the next day and cover it. That's not a huge deal as the storage is 1 mile from my home.

However...

I thought if I could take the boat out and while the salt water is still "fresh" (if that's a thing) and clean the boat at the docks, I could tackle that problem plus it'll be dry on the 30-45 minutes trip back to storage. I could then save a ton of time plus an extra trip to cover it.

During black friday I picked up a 4.0gpm/60psi wash down kit from West Marine for 50% off (199 down to $99). I bought a 16 gallon tank from Northern Tools (similar tank used by The Spray Kit). Bought a few feet of 3/4 hose based on the pump nozzle sizes and a 10ft 12v cig lighter cable to power it. It's not 100% complete but so far it looks promising.

What I'm looking input on is the hosing. I'm not 100% sure if the way I have it done is "optimum" for water pressure. I'd like a cleaner look with more elbows and such. The pressure is decent and I think it'll suit my needs OK. However, the nerd is me is wondering am I losing out because of using the 3/4 hose. Should there be a hard line directly into the tank versus drilling the existing hole bigger and showing a hose down into the tank, etc.. etc. I opted for the 4.0 gpm over the 3 and 5.0 gpm due to suggestions. When I think about washign down a 24ft AR240 I think, no way can 16 gallons do that. However, with a foam cannon and boat soap, some Salt Away, a wash mitt and brush AND being just right out of the water, I think 16 gallons will do the ticket. Worst case I can transfer everything to a bigger tank.

Please let me know if there's a better/more efficicent way to route the inlet hose. Again, its not sexy and I'll clean it up but it does the trick. Just really wondering if I can squeeze a little more pressure if I change up the 25ft supplied blue coil hose and/or change up the inlet into the tank hoses.

 

[ralphsmithiii]

Quick update:

This is round two. After thinking about the diameters of hose both inlet and outlet, I believe the pressure I'm going to see is mostly based on the actual pumps PSI/GPM. Sure, if your hose is too large or too small then the pump may not be able to keep up in some form or fashion (that is my speculation at least until someone else chimes in).

With that, I still wanted to clean up the install a bit and see if having a more direct line from pump to tank would help improve flow. So far I'm 90% happy with these results after a trip to Lowes. They didn't have a plastic/nylon 3/4 to 3/4 coupler or 90% elbow that would work so I grabbed this brass one to test it. I'll grab a more salt friendly one online and swap it out as needed. Flow seems a tad better but way more consistent when plugging the unit into power. The pump gets the water much faster due to not having to route the water so far into a 2ft+ rubber hose everytime it needs to build pressure.

Still open to any tweaks but this week if the weather permits, I'm going to give this a test run. Take the boat out for a bit in the gulf, pull it out, hit it with a foam cannon with some Salt Away + Meguiars boat soap, a section at a time. Take a wash mit (may be over kill). Switch to my adjustable sprayer and rinse it down. I'll do that in sections with a full 16 gallons of filtered Tampa tap water and see if it's enough to wash down the entire boat and possibly the trailer. If it is, then it'll be 100% success and I'll be one happy new boater. If not, then I believe it's a simple as buying a bigger tank, swapping the components and that'll be that. It's possible his may fit on the boat itself and I may check it just to see but from the back of my trunk it'll have plenty of reach with the included 35ft (I believe) coiled hose. If not, then well, more hose!

 

[ralphsmithiii]

Oh, I also threw some 3/8 plastic wire wire to protect the 12v cig lighter wiring. I bought a pack of 10 feet but the wire is around 15. I'll get some more to clean that up. Just need to determine if I need some way to manage the coiled hose or not.

 

[Dixie Highway]

If you really want to increase pump performance, I’d mount the pump low and put a bulkhead fitting in the bottom of the tank. Yes it will self prime at about 1’ high, but to be honest it will pump a lot more efficiently if you use a gravity/flooded suction. It does involve drilling a hole for a bulkhead fitting, but it shouldn’t be overly complicated.

 

[Wisefam22]

3/8 inch hose. It's what I and most pest control companies use from power rigs to treat houses.

 

[Wisefam22]

Put an elbow at bottom of intake and small piece of tub with holes all around it will suck up almost everything from the tank.

 

[Wisefam22]

From an every day use prospective I can treat with constant flow from my tank for 7-8 minutes and use 6-7gallons so you should be good. I'm not using max setting when doing that snd applying plenty of product to customers houses.

 

[ralphsmithiii]

3/8 inch hose. It's what I and most pest control companies use from power rigs to treat houses.

The kit came with 3/4 intlet/outlet. Should I see if I can find a 3/8 quick connect inlet/out to run the hose or get a reducer connected at the pump on both sides. I'm 3/8 at least on the inlet. The supplied coiled hose I believe is also 3/4 as well. Should I be looking for a 3/8 coiled hose as well?
@Wisefam22

 

[ralphsmithiii]

If you really want to increase pump performance, I’d mount the pump low and put a bulkhead fitting in the bottom of the tank. Yes it will self prime at about 1’ high, but to be honest it will pump a lot more efficiently if you use a gravity/flooded suction. It does involve drilling a hole for a bulkhead fitting, but it shouldn’t be overly complicated.

That sounds like it would definitely help. I'm surprised they put the mounting location at the top in that case but logically instead of having the pump to have to use power to suck up the water then expel it, gravity could do half of the lifting.

 

[ralphsmithiii]

Also, has anyone tested using a different type of hose, such as the expandable ones? I'm guessing the coiled versions has more rigidity which may aid in providing pressure but I have no data to back that up. I do like the idea of the expandable hoses being easy to store.

 

[Wisefam22]

The kit came with 3/4 intlet/outlet. Should I see if I can find a 3/8 quick connect inlet/out to run the hose or get a reducer connected at the pump on both sides. I'm 3/8 at least on the inlet. The supplied coiled hose I believe is also 3/4 as well. Should I be looking for a 3/8 coiled hose as well?
@Wisefam22

I'd just worry about the hose going out being 3/8 you could probably put small reducer last 2ft or so. That little bit will help provide extra pressure and not use it all as quickly.

 

[2kwik4u]

Definitely get the pump below the water line. Pumps increase pressure. The way it's mounted you are starting in the negative having to pull the water up. If you let gravity do the feed work, you'll get a bit more out the other side. Every 12in of height the pump has to "pull" the water up is worth about 0.4 psi of output pressure. A simple plywood base would work well and help the pump generate a bit more output pressure.

Where are you powering it from? Cigarette lighter in the truck? Looks like you are in a GM truck, I would guess most others have this as well though, I wonder what the fuse on +12V in the 8 prong trailer plug is rated for. Possibly pulling power from a closer source might decrease the voltage drop caused by the long cords. This might also help the pump run faster/more efficiently. Not sure if it would be an appreciable gain though. Depends on how well the power is getting to the pump now. If nothing else it might simplify cable management. Just a thought.

How is pressure vs volume for spraying down the boat? I've never rinsed away salt, so I'm curious if you're doing more showering, or need more "jet" action to blast things away. If just showering, then I would guess you're good with the outlet setup you have. If you need more pressure, drop the output line a size and that should help with pressure assuming the pump can keep up with the increased pressure change between intake and outlet. I would also perhaps try different nozzles to find it one works better than the other. I would expect an "old time" metal nozzle might work better in this application than the "gun style" you have there.

Keep in mind every change in direction, and every length of hose has an associated pressure drop. So fewer connections/bend/fittings and straighter tubing will flow better. Oddly enough there is also a relation to smoothness of the inside of the tube to flow rate, and a "semi-rough" interior surface will actually flow a little better than a completely smooth interior surface. So testing with a rubber hose instead of a silicone, or nylon might yield some improvements, but most likely won't be noticeable alone. Just a thought if you want to get crazy with the optimization

 

[ralphsmithiii]

Definitely get the pump below the water line. Pumps increase pressure. The way it's mounted you are starting in the negative having to pull the water up. If you let gravity do the feed work, you'll get a bit more out the other side. Every 12in of height the pump has to "pull" the water up is worth about 0.4 psi of output pressure. A simple plywood base would work well and help the pump generate a bit more output pressure.

Where are you powering it from? Cigarette lighter in the truck? Looks like you are in a GM truck, I would guess most others have this as well though, I wonder what the fuse on +12V in the 8 prong trailer plug is rated for. Possibly pulling power from a closer source might decrease the voltage drop caused by the long cords. This might also help the pump run faster/more efficiently. Not sure if it would be an appreciable gain though. Depends on how well the power is getting to the pump now. If nothing else it might simplify cable management. Just a thought.

How is pressure vs volume for spraying down the boat? I've never rinsed away salt, so I'm curious if you're doing more showering, or need more "jet" action to blast things away. If just showering, then I would guess you're good with the outlet setup you have. If you need more pressure, drop the output line a size and that should help with pressure assuming the pump can keep up with the increased pressure change between intake and outlet. I would also perhaps try different nozzles to find it one works better than the other. I would expect an "old time" metal nozzle might work better in this application than the "gun style" you have there.

Keep in mind every change in direction, and every length of hose has an associated pressure drop. So fewer connections/bend/fittings and straighter tubing will flow better. Oddly enough there is also a relation to smoothness of the inside of the tube to flow rate, and a "semi-rough" interior surface will actually flow a little better than a completely smooth interior surface. So testing with a rubber hose instead of a silicone, or nylon might yield some improvements, but most likely won't be noticeable alone. Just a thought if you want to get crazy with the optimization

@2kwik4u Super helpful info as well, thanks a ton!

I made the suggestion to switch the outlet hose to 3/8ID and there may be a small increase in pressure. But, that's because I assumed the original hose was 3/4 whereas the connector was 3/4 but the ID was 5/8. So from 5/8 to 3/8 not as big of a difference than going from 3/4 down to 3/8. But, I got a custom 3/8 50ft rubber hose made locally that should last 20+ years as its made out of the same material I believe as some tires (Continental). That'll also give me a true 50ft versus the "35ft" coiled hose which might stretch to an actual 20ish.

With that, I can tell you that the cone setting on my current nozzle would do the trick for sure. It's by one of the two strongest settings and what I would use to rinse down the boat. The jet or stream setting is decent but not as strong as say a house connected line. But, it does shot 20 or so ft! The shower setting is borderline useless which I thought was odd but it would be good for say rinsing a person off. I'll be hopefully getting out on the water today and I'll be able to give this set a real trial run.

I'm not opposed to moving the pump down but before I go moving and cutting into the tank again I want to see if this current setup will do the trick. I am now also thinking that maybe a true spray "old time" metal one as you mentioned would be better and I'm going to pick one up now to test it since they are cheap.

I am powering it from the 12v cigarette lighter connector in my 2018 Silverado. If the tank wasn't so heavy with 16 gallons of water in it, I'd consider moving it to the back of the boat while rinsing and connecting it to the 12v source on the console. That I believe is rated at 20amps (it has 12awg for sure). The boat also has the 12v outlet in the port side rear wet storage compartment. I suppose I could test it with the truck running and connected as I didnt even think about possible voltage drop when connected to the truck and it turned off. But as it stands, I'm feeling pretty good it'll be plenty although I'm all for efficiency and doing things as "proper" as I can.

 

[Wisefam22]

I use mine every day on a 50gallon tank and its mounted on top.

I have it running to my battery and an on off switch at the pump.

Also have quick connects for wires so I dont have to have tank in truck when not working.

 

[Liveto99]

Use a three-quarter” hose right up to the nozzle that three eights inch hose is causing a lot of pressure drop, Friction loss. You can google it.

 

[the MfM]

Use a three-quarter” hose right up to the nozzle that three eights inch hose is causing a lot of pressure drop, Friction loss. You can google it.

Agreed, in general bigger diameter piping and as few fittings/pipe as possible is ideal.


But instead of trying to optimize the pipe/fittings for a likely minimal gain. I’d suggest using what you have and add one of those worx battery powered hand held pressure washers.

 

[haknslash]

I read the title and came in thinking he got a crack in his fresh water/shower tank

 

[ralphsmithiii]

I read the title and came in thinking he got a crack in his fresh water/shower tank

Hah! I just re-read the title and changed it because I would think the same...

 

[ralphsmithiii]

Agreed, in general bigger diameter piping and as few fittings/pipe as possible is ideal.


But instead of trying to optimize the pipe/fittings for a likely minimal gain. I’d suggest using what you have and add one of those worx battery powered hand held pressure washers.

Agreed, in general bigger diameter piping and as few fittings/pipe as possible is ideal.


But instead of trying to optimize the pipe/fittings for a likely minimal gain. I’d suggest using what you have and add one of those worx battery powered hand held pressure washers.

@the MfM I ended up with a 26 gallon tank (same shape) but instead of pulling water from the top, I ran a fitting straight from the drain plug to the 4.0gpm/60psi pump and thus making it gravity fed. It does seems to work a bit better and does the job but I am using a 50ft custom 3/8 hose which I'm not huge fan of due to it being a PITA to manage.

I'll switch back to a standard 3/4 hose but I never thought about looking at a portable/battery pressure washer. I'm familiar with the Worx brand and for the price of that pressure washer may be worth the shot. It seems to have some sketchy reviews on Amazon but ton of positives on Lowes. I'm betting its people who expect it to be a "real" pressure washer running on a 20v battery...

If it gets me more than what I have which a step or two below garden hose pressure and is portable then it may be the ticket. Looks I would just remove my current pump and run this unit straight to the fresh water tank...easy.

 

[the MfM]

I’m not all that familiar with the worx pressure washer but I think it can draw water from a bucket or be hooked to a pressurized garden hose? In which case I’d leave the pump you have and just add the worx.