Harbor Freight blast cabinet upgrades
Needed a blast cabinet for blasting some knife components. Here are some of the mods I did. I will add mods to this list as I add them.
Table of Contents
For the money, the blast cabinet from Harbor Freight (#68893) is a great value. I spent under $200 for both the cabinet and 80 grit glass media, using the usual 20% coupon you can get online.
We all know the reputation this thing has though. It’s well known this cabinet leaks media quite bad. This results in dust flying around your shop, and it makes visibility pretty bad inside the cabinet. Below is a compressed list of what I’ve modded so far.
This will get you up and running, there’s still a ton of mods that can be accomplished to really get some high end performance out of this thing. Down the line I will be upgrading the gun, and going to a media regulator / foot pedal.
To get started:
- Seal the cabinet with your choice of sealant(I went with silicon)
- Add an air regulator
- Install a standard outlet box for the new light and vacuum power
- Configure a dust collection system. Which includes, adding a vacuum, dust cyclone, hoses, and my sweet 3d printed adapters.
Item list – Affiliate links are included
- The cabinet: Model #68893
- Sealant (I bought 5x, only needed 3x)
- Caulking gun
- Light upgrade (I used one from Harbor freight, this one will work as well)
- Outlet box (Get this anywhere)
- Outlet plug, or plug and combo switch for said outlet box
- A 3 prong power cord that you can cut one end off of. So just cut an extension cord up.
- Air regulator (Get some air drying filters if you are not drying the air prior to the cabinet)
- Fittings for said air regular. (Everyone’s setup is different, I do recommend getting some 90 degree elbows though.
- Vacuum (Does not need to be high hp, just get a cheap one) I bought a Rigid from Home depot for $50. This one will work just as well.
- Some sort of dust regulator. I bought a Dust Stopper from Home Depot. The hose that comes with that is what I used to size the 3d printed adapter for the cabinet adapter. Any cyclone separator will work. You can even make your own for cheap following this video. Here’s an Amazon link to buy one if you’re lazy like myself.
- Required 3d prints for the baffle, and rear hose adapter. You kinda need a 3d printer for this step.. Worse comes to worse you can make the adapters out of PVC. Kinda lame though.
- Misc air fittings, grommets, knowledge of the dark arts, tools, ect.
1. When assembling the cabinet I highly recommend using some sort of sealer on every single joint. Both inside and out. The older cabinets came welded, so you didn’t need to worry as much. The newest version (SKU# 68893) is assembled via a ton of bolts and flat panels. There is gasket material on the major joints, but this has proven to be rather insufficient for sealing. The cabinet needs to be sealed to perform its best. This is a crucial step, ignoring this means you should just ignore all the other mods.
I used 100% silicon. I have heard that polyurethane may be a better option for straight blasting. The polyurethane is going to resist tearing more than the silicon. I do plan on converting my blaster over to a vapor blaster in the future, which requires the cabinet to also be water leak proof. So I took extra care to hit every joint. I recommend either clear, or black sealant.
Couple tips for sealing
- Seal the bottom basin before final assembly. It’s difficult to reach the inside joints when the basin is attached to the rest of the cabinet
- Buy a high quality caulking gun.
- After running your bead of sealant, take a popsicle stick or your finger and gently run it down the length of the joint in the sealant. This will force the sealant to spread over both edges of the joint and create a significant better seal.
- Silicon is easy to clean when dry. Just rub and peel it away. Be careful about peeling silicon that is attached to your sealed joints. You may end up pulling the seal off.
- I added sealant even over the factory joint that had the tape gasket.
- Clean up any loose sealant when done. Your gun will not be able to shoot a large chunk of sealant, which will cause it to clog.
Adding a regulator
This ones pretty self explanatory. You need to be able to regulate the PSI coming into the cabinet so you can fine tune how the gun is actually shooting the blast media. The glass media I am shooting has a wide range of applicable PSI. Something like 40 – 100PSI.
I found out that the regulator I did buy was not going to fit running straight out of the cabinet. I put a 90 degree fitting on it to cure that problem.
Its crucial to make sure the air entering the cabinet is as dry as you can get it. I recommend getting at least an air / water filter, and a desiccant filter. The closer to the cabinet hookup the better. Moister will kill the media and the gun quickly.
Outlet box and lights
Adding an outlet box makes controlling the new light and the vacuum system you’ll be installing a lot more easy.
- Mount the outlet box wherever you’d like. I chose the left side of the cabinet because that is closest to the light. I recommend using bolts and washers for this. You can use self tapping screws, but they may loosen up over time.
- Chop the female end of an extension cord off. Wire in the outlet box plugs like any normal household outlet using your new extension cord. Make sure its long enough, and properly rated for both the light and vacuum together. You may want to opt for a switch somewhere in here. Than you can just leave the vacuum on, and switch it off at the outlet.
- Climb inside your cabinet and mount the new light you’ll be using. Please make sure you have already run the plug for the light outside the cabinet before getting the order of operations backwards and cursing at the sky. If you’re planning on using a grommet around your lights cable, make sure that is also fitted before running the wires through the side of the cabinet. Make sure your lights cord is long enough to reach your new outlet box as well.
- Plug it in, and hope nothing explodes.
After all that fun stuff, here’s where the real results are at. (Sealing the cabinet was important too)
Using a vacuum and a dust cyclone will make this cabinet 10x better. You’ll be able to actually see, and your shop won’t look like the Sahara Desert.
The reason you want to use some sort of dust filtration before your vacuum is it will reduce the change interval on the vacuums filter. The dust cyclone will trap all the loose media before it hits the vacuum. Rearranging how the cabinet handles air will also aid in this. This will also reduce the amount of media carry out as well.
For some reason Harbor Freight decided that the left side opening was a great place for hooking up a vacuum. Problem with that is you end up shooting media right out of the cabinet. By switching from that left port, to using the one in the back, you can reduce media carry out.
- Download the two .stl’s for the adapters I have shown. The baffle will be secured inside over the left vent, and the hose adapter will be secured on the backside of the cabinet.
- Install the 3d printed baffle inside the cabinet. The gap goes towards the bottom. The baffle will fit over the factory hardware. I recommend leave the factory adapter attached. Use tape to secure the baffle in place. Use sealant around the edges of the baffle, making sure to not seal the bottom portion. Wait an hour, remove the tape, than seal where the tape was, again making sure not to seal the bottom.
- Take the 3d printed hose adapter which is sized for the hose that comes from the Home Depot Duststopper. That hose has an OD of 1.785″. If you wish, you can edit the 3d model to fit your hose. Follow the same steps from step 2, and seal the adapter over the rear opening in the cabinet. Make sure the factory grommet is not installed.
- With the side vent open, hook your dust collector to the rear adapter, and then the dust collector to your vacuum of choice.
- Plug everything in and bask in your hard work, or whatever you do after accomplishing something.