# Kobalt Backpack Sprayer- nozzle upgrade



## spraying_and_praying (Feb 24, 2021)

Hello Lawn Forum! I'm a new member here on this forum, and this is my first post. I'm relatively new to lawn care, and trying to learn how to improve my cool season lawn. I just bought a Kobalt battery backpack sprayer(4 gal, 40v, up to 70psi):

https://www.lowes.com/pd/Kobalt-Kobalt-40V-BP-Sprayer-2-0-Kit/5001554497

I assembled it and tried it out, and it seems to work properly. But I attached the fan tip that came with the unit, and timed the amount of liquid sprayed, and after three tests, I averaged 48oz per minute. That translates to 2 min, 40 sec per gallon. So using the standard of 1 gal covers 1000 sq ft, that would be an incredibly slow walking rate. I've been following Allyn Hane (and others) on YouTube, and he recommended aiming for 1 gallon per minute. I plan to use my backpack sprayer for the N-Ext Bio-Stimulant pack, and weed control this season.

So all that said, I'm really confused on how to choose spray tips for my backpack sprayer, and what adapters I will need to make them work with my unit (if I need any at all?!?). Frankly, I'm still trying to wrap my head around how to spray my lawn properly in the first place. If anyone can help with advice on upgrading my new sprayer with better nozzles (or other helpful upgrades) that would make spraying better, it would be greatly appreciated. Thanks in advance!


----------



## Automate (Aug 14, 2020)

Why do you think 1000 sq ft in 2 min. 40 sec is so "incredibly slow".? This is square feet not linear feet so it takes a while to walk back and forth. So with 18700 sq ft it would take 50 minutes to do the whole yard if you didn't have to take time to refill.

With your 18700 sq ft at 1 gal per 1000 sq ft and a 4 gal tank means you will have to refill your back pack 5 times.


----------



## UltimateLawn (Sep 25, 2020)

@spraying_and_praying, So I've been through your journey in recent months. Here are some thoughts...

1. Fill the tank with a first fill of water. Walk across the entire square footage you are targeting the tank to spray. In my example I either do a single 4 gallon or 2ea 4 gallon tanks depending upon how much dilution of the active chemical I want. More tanks...more dilution. Fewer tanks...fewer dilution. When I did this timing on my 5,000 ft2 I ended up around 12 minutes total. Remember...time and walking speed are the things that you either can't control or are reflective of how fast you want to walk. Everyone will be a little different here. I end up at 2 minutes 24 seconds to spray 1,000 ft2. I would also recommend that after you time yourself on that error-free walk, add an additional 10% of time. Sometimes the walk might be a little slower or faster, and having a little buffer in the tank helps to ensure that everything gets touched. From my testing and depending upon the purpose of the chemical, I'll re-cover any areas that I felt may not have gotten good coverage on the first pass.

2. The Lawn Care Nut has a lot of great advice, but I keep hearing him and some of the other YouTubers saying "you need to mix 1 gallon for each 1,000 ft2". They typically add that this makes it easier. In my opinion not really. Your mindset only needs to be on what the chem label says. It is almost always an amount of chemical based on 1,000 ft2 or on an acre (43,560 ft2). Do not be too overly concerned about it being 1 or 20 gallons. You are targeting a specific chemical amount for the square footage - not really water.

3. Give a thought to what type of chem application you are doing. Some chems work best with a foliar/leaf applications while others are more targeted for soil applications. Each of these will require a different type of tip configuration and it is fairly easy to say that foliar applications are often smaller particles of water so typically at a given pressure this will mean less water will be sprayed. Many chems have the concept of a minimum dilution rate. For example a 7 to 1 means 7 parts water and 1 part chem, so the chem mix amount needs to be at least 1/8 of the total volume.

4. Spray tip calibration is important before you spray. Generally speaking the same tank, the same pump and the same tip should spray out at the amount you would like to support your walking speed. However, sometimes chemical mixes may have different characteristics. Some are too thick for a mist foliar spray. Other mixes may have characteristics that affect the flow rate. Take the time to measure the flow rate before you walk out with a new mix.

5. Calculate that walking time and # of tanks to derive how fast the flow rate needs to be. For my 5,000 ft2 and 12 minutes of walk time, I have to hit a 16 floz calibration target at 22.5 seconds on a single 4 gallon tank and 11.25 seconds on 2ea 4 gallon tanks.

6. I ended up giving up on the standard tips that came with my pump sprayer because they were either not consistent or simply created a poor quality spray pattern. Many of us have put in adapters for TeeJet tips. I ended up buying a variety of them for both foliar and soil applications and that seems to work across the variance of needs.

In summary, there is a lot going on here, but I find it a little fun in doing these calculations, then dropping chems down with pin point accuracy.


----------



## spraying_and_praying (Feb 24, 2021)

@UltimateLawn Thanks for the great perspective and advice. You are correct- I've noticed that many in the YouTube lawn community go with the standard 1 gal=1000 ft2. In my case, that would require a quite a number of refills in one application.

Doing some math on this, the N-Ext products say to go no stronger than a 7 to 1 dilution ratio. So in a 512 oz backpack sprayer, I could go with up to 64 oz of product and still be within the ratio. At 18,700 sq ft, that would be 56 oz of a single product of the bio-stimulant pack (they recommend 3oz per 1000 sq ft applied monthly during the growing season).

So, using my test calculation of 48 oz per minute, I would have 10 minutes and 40 seconds to empty the tank. At my lawn's size, that would be 18700 sq ft/ 10.6 minutes= 1764 square feet per minute, or about 34 seconds for every 1000 sq ft. That's really moving (though I have yet to try it)! But, I could cut the amount in about half (28 oz instead of 56), slow down and do one refill, and that would be about the 1 minute per 1000 sq ft rate (and at half the full rate of one product, I could combine one additional N-Ext product in one application and still be within the 7 to 1 ratio. Again, I would just need to make one stop halfway to fill back up).

Your idea of walking the entire yard with water to test is a great idea (after all this snow melts!). I could also stake out a 32x32 area and use that as a test area to get the feel for 1000 sq ft. I guess I need to get a feel for what is an appropriate walking speed, and how long it would take to get even coverage.


----------



## spraying_and_praying (Feb 24, 2021)

@Automate Thanks Automate. You are right, at 1000 sq ft per gallon, I would have to stop and refill a lot. I'm probably better off going with a dilution ratio that allows for fewer refills along an application.


----------



## spraying_and_praying (Feb 24, 2021)

This is the standard fan tip included with the sprayer. I know there are better quality tips available, but how do you know what will fit and what won't? Or what adapters might be needed to make a tip upgrade work? This backpack sprayer says its rated for "up to 70 psi" and runs on 40v. I keep going round and round with how to choose an upgraded tip. :?


----------



## Automate (Aug 14, 2020)

Someone else will give you specific tip recommendations. Just keep in mind the "up to 70 psi" only applies with zero or very little flow. The pump can not maintain 70 psi at typical spray flow rates, Most people operate somewhere between 20 and 40 psi. More expensive sprayers will have an adjustable pressure regulator so the pressure and therefore flow can be adjusted by just turning a knob.


----------



## spraying_and_praying (Feb 24, 2021)

Thanks! Good to know. This isn't an expensive sprayer, and only has two settings: on or off. I checked the manual for the specific psi rating, and it only says "up to 70 psi" for max psi. No listing for normal operating psi.

It does list "rated gallons per minute" at 0.5 GPM. Does that help to determine the flow rate?

Seems very vague, but I'm hopeful that somehow someone here can help work out the best nozzle(s) for my purposes (N-Ext Bio-stimulants and weed control). I think I'll need to buy adapters as well, but I'm not sure.


----------



## Automate (Aug 14, 2020)

Your measured 48 oz /min => 0.375 GPM (gallons per minute) so the fan nozzle is a bit more restrictive. than the rated 0.5. Maybe one of the other nozzles that came with the sprayer will have higher GPM but may not have the best spray pattern.

The spray pattern is more important. Most people do not spray every weekend like cutting the grass. So if it takes a little extra time, its not that big a deal.


----------



## spraying_and_praying (Feb 24, 2021)

That makes sense! I didn't even think of that calculation, but that unit is putting down less than the rated 0.5 GPM with the included fan nozzle. So that being the case, how does that work with upgraded nozzles? Does the flow rate really matter when deciding on nozzles upgrades?

In other words, am I limited to just 0.5 GPM, or is the unit capable of more with the right nozzle? I would think a less restrictive nozzle could push more spray (meaning the nozzle is the determining factor in how much output the unit can produce). Or is the unit only capable of a sustained 0.5 GPM, so nozzles that hover around that rate are all I'd be capable of running?


----------



## Automate (Aug 14, 2020)

My guess is the 0.5 GPM is with almost no restriction. You could test by completely removing the nozzle and doing a timed catch test into a container. Any nozzle you use will reduce the flow from that maximum amount with no nozzle.


----------



## UltimateLawn (Sep 25, 2020)

From what I have measured, pressure varies too much...hard to count on it. In addition, I've seen large variances on TeeJet nozzles in terms of their published flow rates. Because pressure varies and the mix viscosity changes, what you think the nozzle will spray may not. That is why I ended up buying a number of TeeJet nozzles. One set for foliar applications (XR or AIXR series) and one set for soil applications (TurboJet series). Then I keep my walking speed the same and the variation in the mix is controlled to support that walking pace by going to the tip that supports the varieties of application type and chem mix.

Having so many wins and failures, we should put together a newbie guide to this if it does not exist.


----------



## spraying_and_praying (Feb 24, 2021)

I just tested with no nozzle. After 3-4 tests, it's pretty consistently pumping 0.75 GPM (96 oz per minute). So one of the included nozzles must be rated for the 0.5 GPM, and they use that as the rating on the sprayer. So this unit won't ever spray beyond 0.75 GPM (but realistically, always lower than that with any nozzle).

I'm interested in trying TeeJet nozzles, but are nozzles universal? And if not, how do I know what adapter(s) I need. That's where I'm stuck. I'm game to try the two nozzle setup (one for foliar, and one for soil apps). Can anyone make recommendations as to what I should try? I really appreciate all your help! Thank you!


----------



## spraying_and_praying (Feb 24, 2021)

As a follow-up, here are pics of my spray wand with the included fan nozzle assembly removed (has a male fitting, so a female fitting needed for the nozzle assembly). I'm trying to find a setup that has a bend (45 degree?) connection to the wand, and then the proper pieces for an upgraded nozzle. I see the Turbo FloodJet recommended in places (like the TF-VS5), but I would still need to find the other correct parts needed to make the nozzle work. :?


----------



## g-man (Jun 15, 2017)

UltimateLawn said:


> 2. The Lawn Care Nut has a lot of great advice, but I keep hearing him and some of the other YouTubers saying "you need to mix 1 gallon for each 1,000 ft2". They typically add that this makes it easier. In my opinion not really. Your mindset only needs to be on what the chem label says. It is almost always an amount of chemical based on 1,000 ft2 or on an acre (43,560 ft2). Do not be too overly concerned about it being 1 or 20 gallons. You are targeting a specific chemical amount for the square footage - not really water.


Most products need 1g/1000sqft to 2g/1000sqft. The amount of water does matter. If you do 20g/1000sqft, most of the water will rundown and be on the soil. If you intent a soil application, then yes it wont matter, but for a foliar it does matter. On the flip side a 0.25g/1000sqft could also be bad since there will be too few concentrated droplets.


----------



## g-man (Jun 15, 2017)

@spraying_and_praying the picture that shows the red nozzle, is that from your wand? If so, the red part will get replaced with a teejet nozzle and likely it will be a easy swap.

Teejets work best in the 40psi range. Too much pressure and they mist a lot. Mist is bad because it creates a cloud of product that can drift to areas you dont want them to. Ive killed some annua flowers with PGR drift. It will be good to figure out if you can lower the system pressure. I think Ryobi has a 70psi unit and I think I read that you can adjust it. Most of these sprayers are made by the same company with just a different brand name (eg. Kobalt).

Lastly, the advise someone gave you above is spot on. You need to fill it up with water and try to spray 1000sqft. Ideally mark a section of the driveway (20ft x 50ft) and spray it. See how long it take you, how much water it actually used (0.5g? 2g?) and see the pattern from your nozzle. This will help you see the overlap you need to have. Most teejet nozzles are designed for a 20in wide at 20in height. Real life practice will help you figure this out.


----------



## spraying_and_praying (Feb 24, 2021)

Hi g-man. Yes, that pic with the red nozzle is the included fan nozzle for this unit. I checked the instructions, and unfortunately, there is no adjustment to the psi level. So it appears the FloodJet nozzles are out. 

However, would the TeeJet AIXR series work? I'm thinking the AIXR1104VP or AIXR1105VP?

https://www.spraysmarter.com/teejet-aixr-air-induction-extended-range-spray-tip.html#85=901

Since the Kobalt produces up to 70psi pressure, that model nozzle can handle that pressure, and should be able to deliver the max liquid possible. The chart says at 60psi, the 1104VP puts out 0.49GPM, and the 1105VP puts out 0.61 GPM (and we know from my testing that unit max is 0.75 GPM with no nozzle). Any opinion as to which is better? (Or if I'm on the wrong track and there is a better option?)


----------



## g-man (Jun 15, 2017)

The AIXR110 is a great nozzle and I use it. I use the 04 (red) on my ~30psi sprayer and I get 1g/1000sqft at my walking speed. If you use the 04 at 70psi, it will output more water, so you will be above 1g/1000sqft. If you go with the 05, that's an even bigger opening, so even more gallons/1000sqft.

If you go with the 03 or 02, then it is more likely to get 1g/1000sqft.


----------



## kdxkid (Jun 8, 2020)

spraying_and_praying said:


> Hi g-man. Yes, that pic with the red nozzle is the included fan nozzle for this unit. I checked the instructions, and unfortunately, there is no adjustment to the psi level. So it appears the FloodJet nozzles are out.
> 
> However, would the TeeJet AIXR series work? I'm thinking the AIXR1104VP or AIXR1105VP?
> 
> ...


Did you ever figure this out? I'm looking to buy this or the chapin


----------



## spraying_and_praying (Feb 24, 2021)

No, never figured this out. I ended up returning the backpack sprayer to Lowe's and never purchased anything like it for this season. I have a little 2-gallon Sprayers Plus sprayer that's good enough for this season.

Personally, I would spend the money on a battery Sprayers Plus unit (or maybe the Chapin you mentioned). Yes, it's more pricey, but they both make great equipment that has more predictable spray pressure and wand accessories. If I end up buying one, that's the direction I plan to go in.


----------



## A3M0N (Mar 17, 2021)

I have the 4 gallon Kobalt sprayer. I didn't get T-Jet tips, but I picked up these tips from Tractor Supply (actually I'm pretty sure mine have metal inserts, but they're the same item). I'm not sure how they compare to T-Jet tips in size, but they didn't fit into the stock Kobalt sprayer cap. However, I already had a pump backpack sprayer from Harbor Freight whose cap fit both the Kobalt wand and Tractor Supply tip. I'm sure some light sanding would open up the cap enough to fit the tip.

I'm far from an expert, I've only been spraying products for this season. But this is what I have found, I hope it helps.


----------



## UltimateLawn (Sep 25, 2020)

I also have the 2-gallon Sprayers Plus sprayer and really like it for all sprays except for broadcast across my 5K ft².


----------



## mylawn2022 (9 mo ago)

Harbor freight has 4 gallon greenwood sprayer.the nozzle cap of this sprayer acommodates teejet and fits perfectly on kobalt 40v backpack sprayer wand. No need for adapter.


----------

