This page will help you navigate the process of purchasing an industrial/commercial blast pot for your specific business needs.
A good blast pot should last you at least ten years. Cheap blast pots are cheap for a reason – and it’s not because they are looking out for your bottom line. Over the years, they will literally end up costing you thousands more in downtime, replacement parts, wasted abrasive, inefficient pressures, etc – than had you invested a few hundred dollars more on better components.
With nealy 50 years of industry experience, our goal is to give you all the information you need to make an informed decision to benefit your business. We trust the following information will help.
Home / Resources & Training / Blast Pots Buying Guide
Why the cheapest blast pot, is usually the most-costly choice!
In this article we’ll share our know-how on the most critical considerations when buying (or even renting) an industrial blast pot. This information is for professional sandblasters. Not hobbyists. The tips we’re providing are based on these upfront assumptions:
This pot is a professional tool to increase your productivity and profitability
You don’t want to pay more than you should.
If that describes you, we’re going to provide a checklist to help you select the perfect pot for your particular application. This article will save you lots of time, money, and headaches down the road. So, let’s jump right in.
Most people think that this is what you’re buying when you purchase a blast pot. It certainly appears to be a blast pot. But a blast pot is more than just a vessel holding your abrasive. It’s more than just a container.
If it were ONLY a vessel it would be very simple to buy the right pot. You’d compare size and price across the board – and simply choose the lowest price.
Here’s an analogy as to why that’s a bad strategy.
Let’s pretend you make your money as a taxi or uber driver. Would you buy this car from your local dealership? From a container perspective, it holds 4 passengers and it’s most likely the cheapest car on the market.
Of course you wouldn’t waste your money. That’s not a car – it’s a frame. It can’t even provide the most minimal outcome you need… which is movement and transportation.
Likewise, as a professional blaster, the most minimal outcome you need from your pot is not storage, but conveyance. The movement and transportation of abrasive from the vessel, into the hose and out the nozzle.
The perfect industrial blast pot will provide 3 key benefits:
Efficient Abrasive delivery
Low maintenance and repair costs
Pressure efficiency
These 3 benefits will determine your productivity, profitability, and ROI on the blast pot. And from here forward we’ll be discussing which blast pot features maximise each of these benefits.
But first – let’s just establish as TIP #1 this fundamental idea.
TIP #1
When pricing a blast pot, think of it as buying the valves and plumbing – more so than the vessel.
Just like a car, where the engine, transmission, and driveshaft determine speed, fuel efficiency, and future maintenance and repair… A blast pot’s results depend mostly on its valves and plumbing.
Size is important and we’ll discuss that in a moment, but your productivity and profitability are based on these metrics (3 Key Benefits) which are primarily the result of your valves and plumbing.
So with that being said, let’s focus on the number one valve to evaluate before making your purchase.
TIP#2
Focus on the abrasive metering valve.
The most important valve to consider is the abrasive metering valve. It can and will affect all three of these metrics (Efficient Abrasive delivery / Low maintenance and repair costs /Pressure efficiency) – and so therefore, pay attention to what is installed on the pot you buy – this may be the most critical choice for your success.
A really cheap blast pot costs less because it’ll have a really cheap metering valve. And a cheap metering valve will burn through your abrasive much faster.
Here are some fairly common conveyances of abrasive through blast pots per hour!
Garnet – 500 lbs / hour Slag – 1100 lbs / hour
A cheap metering valve – on its own can be expected to waste roughly 5% of the abrasive that flows through it.
So in one year’s time, operating these pots at 6hrs/day – this is the abrasive you can expect to waste by saving money with a cheap metering valve:
Garnet – 500lbs x 5% waste x 6 hours x 5 days per week x 52 weeks = 39,000 lbs wasted per year
Slag – 1100lbs x 5% waste x 6 hours x 5 days per week x 52 weeks = 85,000 lbs wasted per year
Those figures are per year… and your blast pot should be at least a ten year investment!
Hopefully you can now see how the cheapest price upfront, can easily become the costliest decision on the back-end. And that’s only calculating wasted abrasive.
More Hidden Costs Of a Cheap Abrasive Metering Valve
Burning through abrasive also results in your operators needing to stop and refill the pot more often. This refill process usually becomes an hourly 10-15 minute ritual of unproductive labor time – costing you money. In a ten hour day that’s almost 2 ½ hours of lost productivity.
Using extra abrasive will also mean more clean-up time – which you guessed it, costs you money
And finally, a cheap valve burning through abrasive will eventually require more replacement parts and maintenance – and this can realistically cost several thousand dollars per year. And if your metering valve were to break-down during your project for hours or even a day or more, what’s the value of that lost time?
Full Disclosure: We ONLY sell Axiom Schmidt blast pots. We’re not claiming they’re perfect, but from our nearly 50 years experience, they’re the best in the market. And maintenance and repair costs are just one of the reasons why.
Standard Metering Valve Maintenance Costs
A standard inlet/outlet blast pot from competing brands will require around $2000 worth of spare parts per year. Replacing these valves every 1.5-2 months is the industry norm.
Knock off pots that try and copy the Schmidt valves are longer lasting than the inlet/outlet competitors. However, due to the lower production quality, you are still spending about $1200/year on spare parts and replacement valves.
The lowest maintenance blast pots are the Schmidt brand. They have a few different metering valves and systems, all which average between $350-$500 per year in maintenance costs.
Your abrasive metering valve is the precision instrument on your blast pot. It’s worth the extra few hundred dollars up front.
Tip #3
Choose the Best Pressure Efficient System.
There are two styles of blast pots:
Pressure Release
Pressure-Hold
A pressure release system acts in the following manner. When the deadman attached to your blast hose is activated, it sends a signal to pressurise the pot and convey abrasive into the hose and out the nozzle. Each time you release the deadman, it signals the pot to release this pressure into the air. The critical thing to understand here is that the pot needs to re-pressurise each time you depress the deadman. Even if pressurisation only take a few seconds, you can imagine how much time is chipped away over the course of a day, week, or several weeks.
A pressure hold system, maintains pot pressure and doesn’t de-pressurise when you release the deadman. As soon as you depress the deadman trigger again, the blast hose is energized and the metering valve opens to release the flow of abrasive, in less than two seconds.
If you are doing blasting work that requires spot blasting, or constant stop/start moving about, you will save between 5-10% of your abrasive cost by using a pressure hold system. In fact, we recommend that all industrial blasters use pressure hold, its faster, and saves abrasive.
Okay, so what determines if the blast pot is pressure hold or pressure release? Surprise – it’s our old friend the abrasive metering valve. The valve you purchase even determines what style pot you’ll be using from here forward.
And in our experience, there are really only two reasons you should consider buying a pressure-release blast pot:
You have an automatic overhead feed of abrasive into the pot. Which means when the pot depressurises, gravity feeds abrasive into the vessel preventing those typical 10-15 minute labor breaks used refill the pot.
A pressure-release metering valve costs less than pressure-hold, so this may depend on your budget.
Pressure efficiency also depends on maintaining optimal pressure. Any restrictions will negatively affect your blasting speed. On a blast pot, a component that can choke this pressure is the bore piping. These come in different diameters. Here’s our advice… For an industrial blast pot you want a minimum of 1.25” piping. Make sure this is the minimum. If you are going to be blasting with a #7 or #8 blast nozzle, you want to upgrade this to 1.5” piping. This allows you to maximise your pressure, getting more done, faster.
And finally, with such a variety of pot sizes we would never say size doesn’t matter.
Tip #4
Choose the Right SIZE For 80% of Your Application Needs
There are two main considerations for choosing pot size.
Abrasive capacity
Portability
The size of the blast pot impacts how long the blast pot will last before you have to stop and refill your abrasive. Ideally, this would be sized to ensure refills are few and far between.
For example, if you are blasting a large tank, you don’t want to have to stop to refill ever, so you would want a bulk blaster, but if your budget and transport options don’t allow for that, you want the largest pot that will suit your needs.
Of course, you may be involved with a variety of blasting scenarios, and in that case our recommendation is to choose the pot that will work for 80% of your work. If you don’t have the right pot for a future project, you can always rent.
The other impact of size is portability. If you’re needing a blast pot set up that allows you to go up a man lift, of haul around it around in the back of a pick up, then a smaller size is what you need.
In a blast room situation, you want to size the pot, so the blaster can refill during normal breaks. If the blaster needs to break every 1.5 hours for a convenience break, get a pot that will last that long.
So that’s the best professional advice we can offer in this article. We hope it helps clarify a few issues and saves you time, money, and headaches down the road.
Understanding Mandatory Options
Option 1: Deadman Controls
The deadman controls have two primary functions:
Shut off the air supply
Shut off the abrasive entering that air supply
The reason it’s called a “deadman” is because it’s a safety system preventing a potentially dangerous or fatal accident. Should the blasting operator lose control or need to release their grip on the nozzle – the deadman shuts off the system so the dangerous air flow doesn’t whip the hose or spray abrasive upon them. The quicker this is done, the safer it is for your operators. The quicker this is done the less abrasive is wasted. The quicker this is done, the more efficient your system.
Option 2: Abrasive Metering Valve
The abrasive metering valve controls the flow of abrasive from the blast pot mixing it into the airflow that blasts the steel surface. Depending on which valve is attached to your pot, it will also determine whether your pot behaves as Pressure-Hold or Pressure-Release vessel. This valve also plays an important role in your deadman shut off.
It may surprise you that this valve is one of the most significant indicators of your efficiency and profit. This is one of the most important yet neglected considerations on the majority of jobsites we visit. It’s so important in fact – that if you’re a project manager looking to turn one dial to improve your team’s performance – we suggest researching this piece of equipment before buying your pot.
Option 3: Pressure Styles
Pressure Hold or Pressure Release?
Each of our standard blast machines has the option of having a pressure hold system or a pressure release.
Pressure Hold
A Pressure Hold blast pot simply means that when the blasting operator releases the deadman handle to stop blasting, abrasive and airflow cease traveling down the blast hose toward the nozzle. However, the blast pot itself remains fully pressurised and ready to send the air and abrasive once the deadman is reactivate. Retaining blast pot pressure reduces the amount of time needed to commence blasting – because the operator doesn’t need to wait for the entire pot to repressurise.
Pressure Release
A Pressure Release blast pot simply means that when the blasting operator releases the deadman handle to stop blasting, the pressure inside the pot that drives the air and abrasive is released into the surrounding atmosphere. This “depressurises” the blast pot completely. This depressurisation requires a bit more time to cut-off the flow of air and abrasive than a pot that retains pressure. Likewise, it takes a bit longer, once the operator reactivates the deadman, for the pressure to build in the pot to facilitate the flow of air and abrasive to the nozzle to resume blasting.
Pressure Hold Benefits
Safer and faster stop / start
Smoother start / stop
Reduces abrasive consumption and waste
Reduces moisture problems
Great for continual / high production blasting
Great for projects using lengthy hoses
Necessary to support 2 or more blasters
Pressure Release Benefits
Overhead Feed of Abrasive
This is great for set-ups that utilise an automatic overhead fee of abrasive into the blast pot when it’s depressurised.
Pressure Hold Disadvantages
Refill Breaks
A Pressure-Hold system requires temporary shut-down of blasting operations to refill the blast pot with abrasive
Pressure Release Disadvantages
Slower stop / start activation
These delays inhibit production and compromise safety
Typically wastes more abrasive
Invites moisture into the pot
Unable to serve more than 1 blaster
Frequently Asked Questions
What is the best Blast Pot for me to buy?
We believe that a Blast Pot is an investment, and we have to be straight up front that we only sell Schmidt Blast Pots, by Axxiom Manufacturing. We exclusively sell these because our experience has proven they are:
the best in the industry, and
use the least amount of Grit, and
have the lowest amount of maintenance.
Other brands are available. For example, the following:
Clemco Blast Pots. These are good if you have a jobsite where you need to wheel them around on a bumpy surface quite regularly. They often have a second set of wheels, which make them very maneuverable. However, we wouldn’t recommend them for production blasting because they use Air Valves which are very restrictive of pressure. It can often lead to a pressure drop quite quickly of 20-30 psi. The Valves also wear out very quickly and Clemco Blast Pots require around $2,000 worth of maintenance per year.
Marco Blast Pots: Marco copied the Schmidt Pot design, so you have a good balanced Pot. However, they included using Clemco Valves. These Valves also wear out quickly, have the similar pressure restrictions and require maintenance of $1,400-$1,600 per year.
Pirate Brand Blast Pots:
These are a good copy of Schmidt. However, in saving money, to be called a Pirate, they used cheaper materials in the Valves. This means we typically find a Pirate Brand Pot will use 10% more abrasive than a genuine Schmidt Pot. And you will need to do more maintenance on a Pirate Brand Pot than on a Schmidt Pot. Typical maintenance costs are $800-$1,000 per year.
To finish this up, Schmidt Blast Pots used the lowest amount of abrasive possible to do the job, have the least maintenance, and we estimate maintenance on a Schmidt Pot to be between $400 and $600 per year.
What is the warranty on a Schmidt Pot?
Schmidt Pots have come from the manufacturer with a 1-year full warranty for manufacturing defects, not wear and tear.
What is the common maintenance on a Blast Pot?
The most common maintenance on a Blast Pot is actually the accessories that go along with it. Like the Blast Hose, the Couplings, the Coupling Gaskets and the Nozzle Gasket. When it comes to the actual Blast Pot itself, on a Schmidt Style Blast Pot, the most common thing would be a Metering Valve, which doesn’t wear out that often, but that’s where you would need to maintain them. The only other maintenance item would be lubricating the air control Valve with a little bit of grease should the control Valve become sticky.
On a Clemco or Marco Pot style, you often have to replace an Abrasive Trap which sits in-between the exhaust outlet Valve. This abrasive trap is stated that it needs to be cleaned daily and wears out typically within 1 month.
What Causes Pressure Drop on a Blast Pot?
The most common cause of pressure drops in Blasting is using Air Valves, like an Auto Air Valve, or a Clemco Style inlet and outlet Valve System, which has restrictive ports.
The second most common reason for pressure drops, is using small piping in the Pusher Line of the Blast Pot.
The third most common and the most damaging, is using a small Air Hose to feed the Blast pot. Often contractors believe they can run their Blast Pot with a 3/4-inch Jack Hammer Hose or Chicago Line. However, this loses a lot of Pressure and is not recommended for anybody doing serious industrial Blasting. An Air Hose should be at a minimum 4 times the size of your Blast Nozzle. So, if you’re using a Nozzle that is half an inch, you should use at least a 2-inch Airline Supply Hose.
What does, “Choke the Pot” mean?
Choking the Pot is when an Operator has cocked the Ball Valve in-between the Air Inlet to the Blast Pot and the Metering Valve. But by cocking this Ball Valve, you are restricting the flow of the air which is going towards the Metering Valve and sending more into the Pot. This creates a differential pressure, which forces abrasive to come out of the Pot. The most common cause for abrasive getting stuck in a Pot is due to moisture. Moisture is the # 1 hidden enemy when it comes to saving abrasive on a jobsite. If you have any moisture, the abrasive will not flow freely through the abrasive Metering Valve and will cause the Blaster to have to choke the Pot. A simple way to overcome this is to install an Air Prep Moisture Removal System, which you can read about in this link.
We love to talk to customers and help them make the best decisions when purchasing equipment.
You can reach us via our Live Chat, Email, Phone, and Online Form.