Blast Cabinet Metering Valve: Harbor Freight Sandblaster Upgrade. Improve flow!

Description

Upgrading your siphon tube abrasive blasting cabinet to a gravity assisted metering valve setup is one of the best mods you can make. Tired of surging, inconsistent media flow and struggling with a subpar siphon blast tube? This is the upgrade for you! This durable, affordable DIY abrasive blast cabinet metering valve allows you to upgrade at a great price The metal construction and easy to use full 3/8” air inlet valve offer significant improvement over the bad stock siphon tube design. A drain plug allows easy media changes. Features: easy install instructions provided. Beveled internal edges for better flow at hose connection. Rust preventative coating. Sealed threads. Use 1/2" ID blast hose.(Customizable) Easy toolless adjustment. Click or tap “See full description” below for more info
Affordable Low Cost DIY Harbor Freight Blast Cabinet Metering Valve
Huge improvement over the horrible stock siphon tube design: Better, faster blasting with less media. (Even with the stock gun!)
Affordable
Durable: Constructed with heavy duty metal components
More Free Flowing Design: Media Flows more freely and rapidly
Tool Free Adjustment:  Adjust inlet airflow in seconds with just a finger or two. No tools required!
Valve comes assembled and ready to install
Clear rust preventative coating applied
Sealed threaded connections
Easy to install with clear instructions provided.
Installs on Harbor Freight and similar economical blast cabinets featuring a hinged media dump door
Removable Metal Drain Plug: Allows easy media changes without disturbing the hopper door.
Full size 3/8" air inlet valve for better air flow
Custom beveled internal edges at hose connection improve media flow.
Ready for use with 1/2" ID hose but that can be changed if need be.
Your purchase includes a blast cabinet metering valve similar to the one pictured and printed installation instructions.
Need a kit with blast siphon hose included? Want slightly better flow and a better price? Check out all of my other listings!
https://www.ebay.com/sch/dcmimpala/m.html
Improved Flow and Better Blasting Performance:
Converting the horrible stock siphon tube to a gravity fed metering valve setup like this greatly improves media delivery. When properly setup and adjusted, you'll significantly reduce or eliminate issues such as poor media delivery, surging etc. No more constant banging around or moving the siphon tube to get media flowing again!
I even take a few extra minutes to mill/machine a beveled edge inside the valve at the hose connection. This smooths the transition between the brass hose connection and steel and reduces the sharp square edges that collect media and slightly impede flow. Every little bit helps! In my experience, the
result of all this is improved flow that
equates to better blasting performance.
Additional Details:
Use with multiple media types.
Measures approximately 6.75" tall x 8.2'' l
ong x 1.75" wide
Ready for 1/2" ID blast media tubing. If you need it set up for a different hose size please inquire before purchasing. I may be able to accommodate your needs and I can let you know the price difference if any.
Affordable:
I've priced this so it isn't even worth your time to run around attempting to build one on your own. In fact, if you don't have a couple of the specialized tools necessary you'd likely end up paying more than I'm charging here.
Saving money is great, but when you save money and time
and
get better performance that makes it even sweeter! In my experience this blast cabinet metering valve performs just as well, if not better, than the fancy die cast aluminum ones that are much more expensive.
Durable:
I build this blast cabinet metering valve with all major construction being metal components.
Sealed Connections:
All threaded connections are sealed with thread sealant and/or pipe sealant tape to prevent leaks and for peace of mind.
Sealing the threaded connections actually isn't necessary but I do it anyway for added security and piece of mind. This sandblaster metering valve operates on a suction or negative pressure principal and is typically under very low pressure. Air rushing through the gun pulls air into the air inlet valve and media through the metering valve. Basically air is trying to get into the pipe more than the sand or media is trying to get out.
Rust Preventative Coating:
I spray all steel components with a permanent rust preventative coating to prevent rust and corrosion. These pieces typically have no coating from the factory and can actually rust and corrode without out some protection, especially in humid environments. I spray your valve with a clear, hard protective coating to reduce or eliminate exterior corrosion and rust.
Installation:
Installation is simple. Detailed, easy to follow printed instructions are provided with your purchase. You simply remove the drop down door on the bottom of your blast cabinet and drill a hole to mount the gravity fed blast cabinet metering valve. Use the included threaded fitting to mount the valve to the door. Remount the door on the blast cabinet. Your blast media hose slips on the brass fitting at the end of the metering valve. Since you're converting from the siphon tube that was previously mounted inside the cabinet, you'll need to route the media hose from the outside of the cabinet to the blast gun on the inside. This is typically done by drilling an appropriately sized hole in the side of your cabinet and installing a rubber grommet or bushing in the cabinet wall. This seals around the hose and protects it from chafing. Secure the blast hose to the gun and you're ready to start blasting.
Please note, your purchase includes the sandblaster metering valve shown and printed instructions only. You need to supply your own blast cabinet media door from your cabinet, sand/media hose and grommet and any tools necessary for installation. Typical example of tools and equipment required: 1-1/4" diameter hole saw, drill, 1/2" ID blast media hose/tubing, grommet and necessary drill bits. You may need large channel locks, large pliers or a big adjustable wrench if you want to tighten the connection at the blast door snugly beyond hand tight.
Upgrade Your Siphon Tube Blast Cabinet to a Metering Valve:
The Single Best Siphon Feed Abrasive Blast Cabinet Upgrade You Can Make!
Holy cow! If you have a Harbor Freight or other economy blast cabinet that uses the horrible siphon tube feed design, do this upgrade NOW. Seriously. Those posts you've seen all over the internet claiming this is the best mod you can do are correct. I don't care if you you buy this design, the design without the drain plug or someone else's product all together. You will be much happier with a gravity fed metering valve setup. I know from personal experience.
I struggled with perfecting the siphon tube design for years. I was worried switching to a metering valve would be a mistake. The thought of drilling a couple holes in my blast cabinet and setting it up only to be disappointed kept me from doing this mod for years. Instead, I messed around and made double tube custom siphon tube designs. That all helped a little and I'm confident I had the siphon tube design the best it could be. The problem is you can only improve a terrible design so much. Over the years I've wasted countless hours making sure the stupid pickup tube stayed clear and had sand over it. The stock design requires more blast media in the hopper and most of the time it isn't where you need it. Blast for a few minutes and then you'll need to address something: a clog, surging, the pickup tube is sucking air and isn't fully covered etc. You end up with a blast hopper full of 20, 30 or 40 lbs of wasted media and you still can't get good performance. What a nightmare!
A metering valve essentially eliminates all of these issues.
How Does it Work?
All of these metering valves essentially eliminate the terrible siphon pickup tube inside the blast cabinet. You drill a hole in the door or hatch at the bottom of your blast cabinet and mount the metering valve there. Your blast media falls into the metering valve via gravity. A media suction hose is connected to the end of the metering valve and the other end to your blast gun. Gravity and the air flowing through the blast gun pull sand through the media hose. In addition, the air inlet valve allows for a rush of air flowing into the valve. That fresh air mixes with the media and improves flow and performance. This along with the shape and design of the metering valve and blast gun creates a sort of venturi effect that improves abrasive blasting performance dramatically over the stock siphon tube design.
Furthermore, adjusting the air inlet valve on the metering valve allows you to meter, or adjust, just how much sand blows through the gun. Allowing more or less air into the valve allows you to customize blast media flow. The result is much better performance and much longer blasting time compared to the siphon tube. Once you've dialed in the correct supply air pressure with the right position of the air inlet valve, you can blast for hours without issues like surging or no media coming out! Once you've dialed things in correctly, you'll experience better blasting, faster and with less media: even with the stock gun!
FAQ: Frequently Asked Questions
1. Is installation difficult?
No. Your valve comes assembled and ready to attach to your cabinet. Just drill your hole(s), mount the vavle and connect your hose. Most people can complete installation in 15 to 30 minutes. Easy to follow printed installation instructions are included. In the unlikely event you encounter any issues, just send me a message. I'll do my best to help!
2. What do I need to provide?
Only the metering valve and instructions are included with your purchase. You provide your existing blast cabinet media chute door, a 1-1/4" hole saw (or other means to cut a 1-1/4" diameter hole  in it), your choice of 1/2" hose for blast media, hose clamps, an appropriately sized grommet and drill bit, and some basic hand tools.
3. Does this only work on Harbor Freight sandblast cabinets?
No.
This metering valve should work on any similar siphon tube style blast cabinet with a similar hinged bottom media hopper chute door.
I personally use this on the 40lb capacity, floor standing Harbor Freight blast cabinet (Item
#68893). It works great with that cabinet and many others. As long as you have a flat area at the bottom of your blaster hopper measuring 2" or more and enough room under your blaster to mount the valve you should be good to go. This blast cabinet metering valve can also work on many Eastwood, Jegs, Central Pneumatic, Dragway Tools, Princess Auto, Powerfist  and countless economical Chinese blast cabinets. If in doubt send me some photos or a description of your cabinet and measurements of the hopper door bottom and I'll do my best to advise!
4.  Will this work on a smaller bench top blast cabinet?
Not without modification to the cabinet and or the bench or table top. Most benchtop style blast cabinets don't have enough room below them if they are used sitting on a bench or table top. Accessing and adjusting the valve is difficult or impossible without cutting or drilling a hole in the benchtop for the valve to pass through. If your bench top blast cabinet is mounted to a cart or frame with room below you can usually make it work. I have made valves in the past that hang lower from the cabinet and allow for easier access to the valve. Contact me for details and pricing if you'd like me to create one for you. For a bench top style blaster without a hinged hopper door, I highly recommend upgrading to one of our metering valves with a drain plug to make emptying media much easier.
5.  Do I need to upgrade to a foot pedal?
No. You can use this metering valve with or without a foot pedal setup.
6.  Do I need to upgrade my blast gun?
No. This is still an amazing upgrade even if you're using the subpar quality stock gun that came with your cabinet. As long as your blast gun is in good condition and flowing air and media as intended, you don't need to upgrade. I'm still using the stock Harbor Freight blast gun because parts are dirt cheap and I can replace the entire gun for to if need be. That being said, a better gun makes this mod even better.
7. If a metering valve works so much better, why doesn't the manufacturer include one?
Cost. The main reason the economical Chinese blast cabinets don't include a metering valve is cost. It simply costs too much in materials and labor to make these additions in a hobby or entry level cabinet and keep the sale price low. Tossing in a cheap gun, tube and short section of hose is much cheaper and works "good enough" for blasting a few minutes here or there twice a year. Likewise, there's a reason the more expensive and better performing siphon blast cabinets do include a metering valve. They really DO work so much better.
8
. My blast media hose is bigger/smaller than 1/2". Can I still use this?
I'm happy to help customize this for your needs.
If you need a fitting for something other than 1/2" ID tubing feel free to contact me prior to purchase. I can probably make up a valve with the correct size fitting.
These are made for 1/2" media hose because that is the most common size. The size of blast media tubing you need depends on a variety of factors. The type and size of media you're using, blast nozzle orifice diameter, compressor size and output and more come into play.   Few non industrial blasters or hobbyists with siphon cabinets are blasting with larger than 1/2" or 5/8" media hose.
Some people running with a smaller than ideal compressor compensate by using a smaller blast nozzle orifice and stepping down to 3/8" blast media tubing. This helps slightly reduce air demand without significantly impacting blasting performance. I'm happy to move you down from 1/2" ID tubing fittings at your request. Please note pricing may be higher if I need to move you up to a fitting for larger hose.
Photos Are of Previously Purchased Items:
The listing photos shown are stock photos of previously sold items. Your purchase will look very similar, but minor differences are possible. At times I may use a slightly different valve for the inlet valve or fittings may look slightly different from those shown. The fit and function of the device will not be affected in any way.
Made by Hand - Scratches etc. are common and expected
These are made by hand using industrial parts. Some pieces may have minor scratches, tool marks from wrenches, clamps, tools etc. Some of the parts themselves arrive with minor surface imperfections before they are even put together.  Some scratches and tool marks are to be expected. No worries. I won't ship you anything that looks terrible and I definitely won't send something damaged to the point where it impacts fit, function or performance!
FREE SHIPPING:
Free shipping is valid for US Customers only. Free economy shipping will be via the carrier and service of my choosing. Slightly faster shipping may be offered for an additional fee. Please review shipping options at checkout.
Returns:
I generally don't accept returns on items that have been used, modified etc. In the event I do accept a return I can offer exchange or your money back. Return shipping costs are typically the responsibility of the buyer, unless I've made a mistake etc.