The Chapin 61800 backpack sprayer is easy to use and pump and offers solid pressure. Unfortunately, the harness could have been better and some users reported receiving a defective unit.
Pros:
- Easy to use and pump
Cons:
- Several quality issues (see below)

Note: Unfortunately, this is the only available video of this model – we apologize for its quality and the amount of marketing fluff. Also, the pressure regulator inside the tank was removed in 2014.
Large Tank, But Not Too Comfortable to Wear
Chapin 61800 is the brother of the more popular Chapin 61900. It offers a large 4-gallon tank as well (translucent so you can see the fluid level), with a 4" opening so you can fill it easily and without spilling chemicals.
When the tank is full, the unit becomes fairly heavy – so it’s advised to put it on a table first and get into the harness afterwards.
The shoulder straps are padded and provide a good weight distribution – but there are certainly more comfortable models out there.
Piston Pump with 60 PSI
The piston pump provides a solid pressure. You have to pump quite frequently but fortunately the pumping is smooth and really easy.
The pump handle can be attached to either side, depending on which hand you prefer. Only the storage can be a bit problematic due to the handle size – you probably would not want to remove it every time.
Viton seals provide good compatibility with chemicals and the sprayer uses a 3-stage filtration system to prevent clogging – there is a filter basket in the mount opening, a removable and cleanable filter in the tank and one more near the shut-off.
3 Different Nozzles
The wand works well, it’s long enough so you won’t have to bend over. The trigger has a very good response, the drip after releasing it is only minimal.
And to be able to use the sprayer for various tasks, the three common nozzles are included – a brass adjustment tip, fan spray and a poly cone.
Reported Problems
Unfortunately, several users reported defective products – a unit that did not work right from the start, started leaking or quit working after a few uses. While most customers were satisfied with their sprayer, the number of complaints is quite substantial.
Conclusion: The Chapin 61800 is a decent backpack sprayer, but there are simply better units available – more comfortable to wear and with less reported problems. So please check our most recommended models here.
>> Read more or buy the Chapin 61800 here
Specifications:
Frequently asked questions:
What is the difference between Chapin 61800 and 61900?
The 61900 features also a pressure gauge and (according to the users) it’s more comfortable to wear, has a better wand and the in-tank filter is easier to access.
Does it mix the liquid in the tank?
No – if you need a model equipped with an agitator, we would recommend you the Field King Professional.