How to build a homemade sandblasting cabinet.
How to build a homemade sandblasting cabinet - By yours truly, Giovanni Smecca.
UPDATE: FRIDAY, DECEMBER 14th, 2012!
(Check the video at the bottom of the page for new updates and modifications that I highly recommend!)
If you've read my post about powder coating, which you probably haven't, since its not done yet, then you know that in order to successfully powder coat something, it must be properly prepped, and in almost every case, the part you want to coat must be stripped down to bare metal. The most effective, fun, exciting, dangerous, unhealthy, and generally guaranteed slaphappy way of doing this is by sandblasting. So grab yourself a cup of tea, a cup of coffee, a glass of milk, a pint of whiskey, an ice cold beer, a glass of water, a flagon of mead, some ovaltine, or whatever it is you drink, throw on your snuggie and buckle your seat belt because you're about to go on the ride of your life! (Not really...)
1. a blast of air or steam laden with sand, used to clean, grind,cut, or decorate hard surfaces, as of glass, stone, or metal.
2. the apparatus used to apply such a blast.
–verb (used with object), verb (used without object)
3. to clean, smooth, etc., with a sandblast.
So basically, sandblasting is sand mixed in with air blasted at high speeds. The sand does the same thing sand paper would do, minus the paper. Alright, so my description isn't the most detailed in the world, but most of you know enough about what sandblasting does to not need a description or explanation. Plus you're already on the internet so you shouldn't have much of a problem finding more information about it, right?
My buddy Jim down at the shop keeps saying Media Blast!, what the heck is he talking about??
Glad you asked. Sandblasting is probably the most commonly used term, but did you know that people also call it media blasting, abrasive blasting, grit blasting, shot blasting and probably a bunch of other stuff too? Personally, I call it abrasive blasting, since I never use sand, and will call it that from here on out.
The term "sandblasting" was most likely coined because the guy or girl who invented the process probably used sand. Honestly, I'm just taking a guess here. I'm too lazy to open a new tab in my browser and look up any real facts to back that statement up; although, you have to admit, it sounds good, doesn't it? Oh, and if i'm wrong, consider this an apology.
Nowadays there are many choices of synthetic, natural, unnatural, semi-synthetic, simi-natural, simi-unnatural, unnaturally synthetic and synthetically simi-natural medias to choose from, and most, if not all of these, are far superior and safer to use than normal sand. The main issue with regular sand is that the dust created from sand contains a high amount of silica, which inhaled over a period of time will cause a disease called silicosis. Silicosis is something you DON'T want to have. Trust me, or look it up if you don't believe me, or die if you don't want to look it up, but just remember that I gave you options.
Abrasive blasting can be used for all sorts fanciness from heavy duty stuff like blasting rust off of aircraft carriers to doing delicate work like etching things or even giving your jeans that "worn out" look that everyone loves. But just in case you were wondering, my main goal for blasting will be preparing miscellaneous parts for a fresh coat of paint or powder.
Whats with the "cabinet"?
Abrasive blasting can be done without a cabinet, and it probably is done more often without one; although again, I don't have any fancy charts or graphs, nor much ambition to Google what I just said, so you will have to take my word for it.
Blasting in an abrasive cabinet has its pros and cons like everything else on this planet, with maybe the exception of wining the lottery. For instance, an obvious pro is that its nowhere near as messy as blasting in your garage, which makes a lovely mess. Another benefit is that you can re-use the media over and over until it has reached its end of life. I'm not saying that you can't re-use media if you don't use a blasting cabinet, it's just a shit ton easier to reclaim the stuff when its contained.
An obvious disadvantage is that the size of your work is restricted by the physical size of your blasting cabinet, so no matter how hard you try, that 4x5 object won't fit into your 3x4 cabinet.
That being said said, I built my cabinet a little bit bigger than the biggest project on my horizon: the rebuild of my 1999 Suzuki DR 350 that was submerged in salt water for hours and hours during a hurricane that flooded my city, including my garage.
I'm not a genius, nor am I very inventive. I am just a guy motivated by the simple needs to blast my motorcycle frame down to bare metal. The easy route could have easily been to purchase a beautiful, professionally built, long lasting, warranted abrasive blasting cabinet by xyz inc, but what fun would that be? Also, I come from a long line of do it yourselves and I would be doing nothing more than shaming my forebears by taking the road most traveled and purchasing a shiny, brand new abrasive blasting cabinet. Ok, so maybe it helps that the same size cabinet as the one I'm building would have set me back almost 10 times the amount that I paid to make mine...
As I've said before in my post about powder coating, let me warn you now that this is by no means a tutorial, how-to, or any other kind of guide meant to be duplicated or copied, simply due to the fact that this is the first time I've done this myself, and honestly I'm simply not the type of guy you want to follow if the ship we are on is sinking. Buuuuttt...if you are keen enough, you should be able to get the gist of things and might actually be able to successfully follow my flab jab and clamor without leaving this earth. But seriously, don't get pissed at me when you realize that I didn't mention dimensions, or any other "important details". I just create this junk as I go.
Building an abrasive blasting cabinet
If I haven't bored you by now, we can finally start talking about what you are here for.
The design you are about to read about is going to be 2' deep x 4' wide with a height of 38". A cabinet this size allows me to comfortably fit my 1999 Suzuki DR 350 frame and is a good size bigger than your standard $300-600 blasting cabinet.
While I was in the process of planning out my design for a base, I happened to glance over at a sturdy mobile bench that I built a while back. This thing would make a solid base for my blasting cabinet and it just so happens that the base is 2'x4' which is perfect. Of course the downfall now is that I have to build another bench... Oh well, at least that gives me another article to bore you with in the future. Heres what the bench looked like after a few modifications made so I can successfully "mount" the cabinet to it.
My design is pretty basic and some of you probably know a better way of doing this, but this concept came to mind first. What I did here was subtract the thickness of my plywood (1/2") from the outer edges of the base and screwed in 2x2s around the base using those measurements. This design will not only allow my cabinet something to screw into, but it will also allow the cabinet to be flush with the base. Another great feature is that when my cabinet is done, I will be able to unscrew it easily from the base and transfer it to another base (with a media chute) later. Whatever, It worked...
Like I just mentioned, my current design doesn't have the media "chute" that most blasting cabinets have which allows for the media to slide down a chute that resembles an upside down pyramid, although I do plan on adding that real soon, so check back!
A close up of the wood work shows how I built the extension of my bench to convert it into a base for my blasting cabinet. The distance from the 2x2 and the base edge is the exact thickness of the plywood being used. A time saving tip for this step would be to use scrap plywood to measure that distance instead of actually measuring it out. Oh, and don't forget to pre-drill any holes because the 2x2s split easily if you don't!
The back wall
Now that the base is built, and might actually work, the next step will be to start assembling the walls. I started with what I felt was the easiest cut to start with - the back wall. Its a basic square cut measuring 4' wide by 38" high. I put the DR frame on top of there just so I can get an idea of how things would fit. Even though I am just started, seeing this made me feel warm and fuzzy inside.
The left side wall
The construction of the wall is our first angled cut of the day so the difficulty raises a bit. I'm not a carpenter, so what I did to make things easy for me was to draw this panel out on my plywood. I marked the depth of the base (24"), the height for the glove panel (12"), the total height of the cabinet (38"), and the minimum depth I wanted my cabinet to be, which is also the ceiling depth (18"). With all of those dimensions drawn out, it leaves you with only one line left, which will be the angled face (26 11/16"). Your face will be different depending on how deep or shallow you want your ceiling to be. But be careful here and make sure you end up with an angle you will feel comfortable with.
An 18" ceiling gave me a nice, comfortable, ergonomically (in)correct angle.
I suck at explaining things, so maybe the photos will help.
The right side wall
The second wall can be created by doing the same thing as above, obviously, and now you can see that she is really starting to come together!
Pssst!..let me tell you a secret...
For those of you who are probably wondering how I am holding the plywood pieces together, lets just say I'm using a method probably not suggested by anyone who knows what they are doing. My method involves drilling through the piece of plywood being held in place into the plies of the other piece of plywood and screwing the pieces together accordingly. Don't even bother trying this without pre-drilling your holes because it would just split the plies apart and would not work at all.
Some of you might think it's a catastrophe waiting to happen and that I'm a complete moron for doing it, but if done right, trust me, I'll be able to jump up and down on top of the finished product. Videos will follow for any nonbelievers. Plus, the base of this cabinet is the only thing that will get any real stress or weight thrown at it.
A ceiling is a handy thing to have!
Your blasting cabinet will not be much of a blasting cabinet if it doesn't have a ceiling, now would it? And what do you get when you draw out the overall length of your design by the top depth of your walls? You guessed it! The dimensions of your ceiling! See... building without plans isn't so hard after all!
My cabinet is 4' wide
My walls (the the top) are 18" deep
My ceiling dimensions = <answer>
If you guessed 4' x 18" than you win! If you guessed anything else, I win!
After the walls and ceiling come together, this thing really starts to look like a blasting cabinet, kind of.
NOTE: This is where you start to get excited and start rushing your cuts. I'm not one to say slow down and pay attention, after all, I am a measure once cut twice type of guy, but these steps require a pretty good amount of accuracy if you want your cabinet to look decent. Don't worry though, your favorite sealant can seal any ungodly cracks if you aren't that steady with a saw. I'm not.
The glove panel
Now it's time to cut the panel that will hold the gloves. My cabinet is pretty wide and will have 2 pairs of gloves (4 gloves, duh!). I mentioned earlier when cutting the walls that the glove panel will be 1'h and we already know that the width of the cabinet is 4' so what does that tell us our glove panel dimensions should be? If you guessed 1'h x 4'w than you win again!
After cutting 1x4 of plywood, I simply attached it the same way I've been attaching everything thus far. The result is a nice panel ready to be cut for glove clamp thingies. Also, that is me in the photo for anyone curious.
What was once faceless shall now be seen!
Moving forward, we make the cut for the "face" of this beast.
Following the build as you go mentailiy, I measured the last remaining panel and started cutting away. Everything would have worked out great except I didn't put much thought in seam where the face and the glove panel meet. These two pieces of wood didn't butt up against each other correctly at all. Patience is indeed a virtue. Lesson learned. Lets try again.
So, after rethinking things, I wasn't quite sure how to (properly) figure out the angle that I needed to set the saw to, and I wanted to learn. I'm no carpenter, and I am a better carpenter than I am math wizard, so I was stumped. I knew there were a few different tools that are used to find angles but I didn't have any, or so I thought.
After a short while, I looked closely at a tool I used a lot but never really looked closely at. My speed square! The speed square has a bunch of jibba jabba that I generally don't pay attention to because I've always used it to quickly square things up (hence it's name), but upon closer inspection (and watching a YouTube video) I quickly understood that it's also useful for finding angles! Who would of thought? Anyhow, after finding the angle with the speed square, I set my saw and made the cut again, and things were finally flush.
Egad! How am I suppose to see through that thing?!
Now we have some choices. Make the door, cut the window, or cut the glove holes. I chose to cut the window. You can choose my path or create your own path. This is your choice, so choose wisely.
If you chose to continue down my path, congratulations, our next cut is an easy one. This cut allows plenty of room for error because regardless of the size hole you cut, the glass will cover it, unless you already have glass cut, then you would have to cut your hole according to the glass size. The only thing you must do here is leave yourself an inch or so from any wall, ceiling and the glove panel.
What I did was took the measurement of what I knew my glass was going to be and subtracted an inch from all four sides. That gave me the dimensions for my viewing window.
Next, I marked the face with my level and cut it in place, but do remove yours if you if you feel uncomfortable or unsafe cutting it in place.
HANDY TIP: For cutting, you should probably use a jig saw for this, but I used a circular saw because I am impatient and awesome.
The entrance (what was suppose to be the door)
Cutting the door using my "build as you go" mentality almost bit me in the neck, because after I cut what at the time I thought would be used as the door, I realized it wouldn't work at all. The good news is that even now, I can't figure out a better way to build it than the way it turned out on accident. So now, what should have been the door, is the "entry way".
Measuring it out was simple. I just grabbed my level and held it flush with all 5 sides while marking the inside edge of the level. If you don't want to do that, or your level is too wide/narrow than just take off two inches or so around the perimeter of the side of your choice. This will leave plenty of room for the gasket(s) of your choice.
I chose to have my cabinet door on the right side because of where it will be located, but you can put your door on either side, or even both sides if you want.
You can see some light shining through due to my lack of circular saw skills, but nothing that a little sealant wont fix!
A (not so lovely) introduction to glass
This part was pretty exciting for me because I've never worked with glass before, and all I know about it is that it will cut you if you try to karate chop it, and it will mess you up if you swallow a bunch of it.
I was lucky enough to have scrap glass laying around, but there was one problem: most of it was regular old window style glass. Cheap glass like that just shatters and is too easy to break. This type of glass isn't good for this project.
Looking further in the pile I came across a few sheets of tempered glass which would have been the perfect choice if the size was right, but once tempered glass is tempered, it can't be cut without special equipment.
My diamond in the rough was a sheet of "safety glass". Safety glass is a sheet of plastic (the "membrane") with sheets of glass glued to each side, like a sandwich. Its used in places where the risk of cutting yourself is pretty high, like in old automobile windows, or in glass doors. When broken, the glass just cracks and the plastic membrane in between would prevent it from actually coming apart into nice, sharp pieces, thus keeping your throat out of harms way. Seems perfect for my project! Now I just need to cut it to the proper size...
Cutting glass is a lot more fun than glass cutting you!
Now that I have my glass picked out, I need to cut it down to size. I knew of only one tool for cutting glass, so I went out to The Home Depot and picked one up. They had the basic tool by itself and one that came with snake oil. I bought the one with snake oil because I always fall for that trick. You'll want to use oil, any kind, to help keep glass particles from flying into your eyeballs and to keep the blade lubed up as well. Probably for other reasons too, who knows?
So now that I had the tool, the instructions say to score a perfectly straight line across a sheet of glass using the supplied cutting tool, then either tap the glass with the ball on the end of the tool or lift and drop the glass from a short distance while half is on your work area and the other half you want to break of is not. The piece should cleanly break off if done properly.
GLASS SCORING TIP OF THE DAY: You're only suppose to get one pass when scoring the glass, and apparently not suppose to go over the same line twice. I did, and the world didn't end.
The issue with the instructions is that my safety glass, unlike regular glass, consists of two pieces of glass glued to a piece of plastic. The instructed method of glass cutting would not work here.
The first step to solve this problem is a bit more obvious than the second step. We must score the glass at the exact same spot on both sides so both panes of glass will break at the same spot. I made this easy by clamping my level across the glass and using it as a guide for the tool, then repeating the process on the other side.
Using a mixture of the ball and a bit of the drop method I could clearly see that the glass was perfectly broken on both sides. But now the the plastic in the glass was preventing it from separating and the break in the glass is so thin that a piece of hair couldn't fit between. What the hell do I do now?
The not so obvious second step that I mentioned above was fire! (There is also a special chemical you can buy that is designed for dissolving the plastic membrane, but I jump at any chance I can to use fire!)
FUN FILLED FACTOID: A little bit of rubbing alcohol taken from ye ole medicine cabinet works wonders for cleaning out cuts, but did you know that it also works wonders separating pieces of safety glass? Yep! It melts right through that plastic membrane like butter!
DEATH ALERT: I suggest sweeping up any piles of sawdust before continuing. Also, if you die, I am sorry.
Lets continue, shall we?
Working one side at a time, pour the rubbing alcohol over the glass and set it ablaze. This will start to melt the plastic membrane. Pull your glass to the edge of your work area and let one half dangle off a bit so gravity helps with the separation, but watch out for the fire, it will burn you up if you allow it to. Also, don't let gravity get the best of you: make sure you hold the piece of glass dangling over the edge!
Flip the glass over and do the same thing again, but this time be careful because it will separate on you, and having a decent size piece of flaming glass come apart in your hands can be intimidating at best.
Repeat the whole process for the width (or length, depending on what you cut first,) and you should end up with the piece of glass that you need.
TIME SAVING TIP: Skip this entire section and go out and get a piece of glass cut for like seven dollars.
Installing the glass
So the next step here is to get this glass in place before I break it and have to cut another piece.
What I did was cut a few small pieces of scrap plywood to create makeshift mounts to keep the glass in place until adhesive cured; although, the temporary piece holding the glass will probably be left in, since they don't bother me at all, and seem to be giving the glass much more support than adhesive alone.
Here is a view from the other side:
Now would probably be a good idea to see if the DR frame fits, because if it didn't fit now, I would chainsaw this thing to death. Needless to say, everything is 400 times better than what I would have expected.
Looks good! Everything (important at least) seems to fit.
Catastrophe! Not really though...
When I came back to the garage to start on the door I noticed a crack in my glass! Guess I tightened the mount up a bit too much and it cracked when I walked away... Oh well, good thing its safety glass I guess...
The door is probably the most "complex" part of this whole build since it includes parts other than wood.
This is what I used for my door, all of it came from The Home Depot:
- Piano hinge (one long hinge)
- "Surface mount" latches
- Silicone gasket (was the only gasket material that said it was rated to seal out smoke)
The dimensions for the door are simple. Stand on the side of your cabinet, whichever side you cut the entry on, and measure the outside perimeter. Make that cut, and you have yourself a door. If everything works well, it should look like this:
Now we need to get the hinge on this thing. I attached my hinge to the inside of the door like so:
The next part would have been much easier with two people but I didn't have any help at the time so don't be discouraged if you don't have anyone to help either!
Now the door must be mounted to the cabinet. The other part of the hinge will be mounted to the back wall.
Once mounted, the door should open and close freely. If it doesn't, you screwed up.
Let me first start off by saying that I plan on using a better method of latching my door, but I couldn't think of anything else at the time.
What I used were "surface mount" latches. These were the only latches I could find that allowed my door to latch closed properly, although I really didn't look very hard. The satin nickel finish really classes everything up...
My current door design along with my current latching system didn't work out of the box... Like I said in the beginning, I just build I as go. A simple modification (scrap wood) allowed my latches to latch.
Here is the bottom latch. I plan on adding one more in between the two... Or just re-do the entire latch system itself...
Now the fun part! Its time to cut out the holes where the gloves will go. Instead of making my glove mounts out of PVC like a few people on the net, I just went ahead and purchased them from the same place I bought my gloves. The gloves and the glove mounts were by far the most expensive thing, but the quality really does makes up for it. The last thing most people want to do is to blast their hands off.
Cutting out the holes was pretty straight forward, and there wasn't much room for error. I drew a line across the cabinet about 3 inches up from the bottom of the base which gave me horizontal evenness across the cabinet for my gloves. Then I just marked where I wanted them to go and cut away. It came out just fine and feels pretty damn "ergonomic" to me...
Check the picture out in case you don't understand anything I am saying. Don't feel bad, after re-reading it, I don't.
After cutting all 4 holes, the next step was to screw in the glove mounts that I purchased. Needs no explanation, so I wont be explaining.
After all 4 glove mounts were installed, I installed the gloves by slipping them onto the mounts and tightening a clamp around them. The clamps came included with the glove mount kits that I purchased from tptools.com.
Here we can see all of the gloves installed. This setup gives me fairly comfortable access to pretty much every inch of the cabinet.
The (almost) finished project
So, we are finally at the end... It's not the best looking cabinet on the planet, but it works . I still need to paint it and drill out my vents and port for my dust collector, but this should be enough to get you started. Also in the works is redesigning the base for easier media collection because right now it just piles up and has to be scooped or vacuumed out, which slows me down. Stay tuned for updates on that.
P.S, You learn something new every day
In the process of finding media to blast, I came across something very interesting. Turns out "Black Magnum" coal slag is produced right here in my hometown! Who would have thought?
The fine folks at US Minerals were kind enough to give me 200lbs of their product for free, which, unfortunately to them worked out in my favor because the "Coarse" media didn't work regardless which nozzle I used. I ended up going back and payed for a couple of hundred pounds of "Fine" media, which is working out very well.
I was kind of bummed that the prices seemed to be the exact same as anywhere else. They were producing the stuff on the spot which seemed neat, and the entire property, including the parking lot, was literally covered in this stuff. It was everywhere. Oh well... It's still very convenient and cool that its produced here...I guess.
Does it blend?, I mean, does it work?
I think it works pretty damn good for something thrown together by a guy like myself...
Here are some examples including a short video of this baby in action. Oh, and by the way, I am using an Eastwood 200lb pressure blaster for those who are wondering.
Here is a before shot of what my DR350 handle bars look like...
Here is a video of me, blasting the bars with "Fine" black magnum coal slag.
Here is what the bars look like when I finished. I'd say that we have ourselves a working cabinet.
Hopefully this article was helpful, or offensive, or funny, or boring. Feel free to leave me a comment if you want to thank me, or curse me out!
UPDATE: FRIDAY, DECEMBER 14th, 2012!
Alright, hopefully that caught your eye before you run off and finish this build...
It's been almost two years since I finished this cabinet, and a lot has changed. Both with the cabinet, and my overall opinion on sandblasting in general. Although this time around, I decided to do a video update instead. I will try to fill this baby in with some more text and photos, but honestly I think it's already a bit much. So, here goes the video update. Enjoy it!