I just purchased a sandblast cabinet for the purpose of cleaning parts etc. I was wondering what advice other members might be able to give me on blasting techniques, types of blasting material to use for different jobs, appropriate air pressure and any specific do's & don'ts.
Thanks
Gerry

 

Try checking out this site, it is one of many that explains various media uses.

www.kramerindustriesonline.com/blasting-media


Just make sure your compressor has enough CFM to run a blast cabinet. If not, your compressor will be running constantly and that is not good.

 

I use a blasting media called Black Magic. It is a fairly mild media and works well for blasting all metal parts. It leaves a nice matt finish that holds paint well. You can get it at you local auto paint store. Price is around $18.00 for a 100 pound bag.
Roy

 

I use glass beads and adjust my pressure from 40 psi when doing aluminum to 90-125 psi when cleaning steel. The glass bead is less aggressive and sometimes can take longer but I have always been very satisfied with the results.

 

gerry, i see you live in colorado, i live in cal. if at all possible mount your blast cabinet outside the garage. blast media will ALWAYS escape from the cabinet and if it's in the garage the blast media will contaminate other stuff. i built a shelf outside mounted to the exterior wall of the garage at a comfortable hight to avoid the contamination issue, in bad weather or when not in use i just cover it with a tarp. all has been good for 2+ years now.

as far as compressor/pressures go, blast at full pressure. i have a 60 gal. 7 HP compressor and the blast cabinet will slightly run away from that. i blast for about 10 minutes then take a few minute break to allow the compressor to catch up and cool down.

i don't use sand as a blast media in my cabinet, i have a pressure sandblaster for that. the 2 medias i use in my cabinet are glass beads and aluminum oxide. the glass bead are for fine cleaning on small or delicate parts but it is kind of slow. the aluminum oxide will clean about 5X faster than glass beads and i use that a lot. both glass beads and aluminum oxide can be bought at harbor freight if you have one near you.

if your blaster seems to quit working check the ceramic tip in the gun, when the air comes through the tip the moisture in the compressed air can condence and plug the ceramic tip up. i had this problem sometimes when i first started. now when i am blasting i always take the ceramic tip out when i stop and lay it in the sunlight to warm it up--no more problem.

 

Thanks everyone for the advice. I really appreciate the help.
Gerry

 

check out tptools.com and eastwood.com for abrasive blasting stuff too. And don't use sand. No matter what.

hook up a shop vac and to the cabinet. just change the filters regularly. it really helps keep the cabinet clear so you can see what you are doing. or they have a dust collector at harbor freight. just type in keyword "abrasive" and you'll see it.

I hooked up an extra couple lights (similar to the kits on tptools but cheaper just buying the pieces at home depot) because you can't have too much light in the cabinet. And I also hooked up a vibrator motor (NO, not THAT kind of vibrator motor - again, similar to the one on tptools but I found the Dayton motor on ebay for $10) to the funnel part of my cabinet to keep the abrasive moving down to the pickup.

Read up on the types of media and the materials to use it on. For example, if you use glass beads or anything aggressive on smooth cast aluminum surfaces, it'll take the smooth "skin" right off and leave a textured finish which isn't right for restored pieces. There are walnut shells, plastic beads, and other media for different materials.

Oh, and a good moisture separator. Particularly if you are running a smallish compressor which really heats up the air. Get a decent size compressor. You can't have a compressor with too many CFM's when blasting. My little 30 gallon Craftsman with 2.5 hp hates me and just runs non-stop if I do a lot of blasting.

Oh, and get yourself a stool if you have a bunch of pieces to blast. They are always too short and kill my back!

 

check out the cyclones on this site
http://www.clearvuecyclones.com/index.htm

I use there mini cv106 mounted to a drum. It works like a charm. keeps my cabinet dust free during blasting and captures most before it gets to the vaccum filter. This was one of the best additions to my Blast cabinet and I use it on everything else also.

 

If it is a siphon/hopper feed, they can plug now and then. I leave a rag in the cabinet, then use it now and then to plug the nozzle and force air into the hopper and stirs up the media.

Big nasty rusty parts I use coal slag. The hopper has a trap door, and I can change media in a matter of minutes.

Glass beads for everything else.

Mark

 

My TIP blast cabinet has a plexiglass window in the top lid that will eventually get clouded by the blast media bouncing off of parts being blasted. I tried putting clear plastic under the window but that also became cloudy rather quickly so I attached a piece of 1/4" plate glass under the window and that seems to last much, much longer. I suppose a thinner glass would work, but I happen to have a good supply of 1/4" plate glass.

Charles

 

I found that you can take the hose and gun out of the cage and connect it to the ir , stick the tube in a cleasn bucket of sand and it works great. Just keep the ttrash out of the sand and keep it dry. You could sand blast an entire frame like this. Sounds crazy, but it works. Use on any type of metal or fiberglass. Just hjold the nozzle a distance away from the fiberglass.

 

Gerry,

Aluminum oxide (AO); is more expensive at 30-40 bucks for a 5 gal container of 80 grit. I've been blasting for 35 years. The black stuff, one guy talks about is referred to as "coal slag." It's cheap for sure compared to glass bead or aluminum oxide, but when the media breaks up upon impact, the residue dust is much more than aluminum oxide or glass bead. So, you need a cabinet that you can attach a filtering system to, or all that dust will contaminate the good media left in the cabinet for re-use. I first hooked up a shop vac and it actually worked pretty good to shoot the dusty air outside under the garage door. This kept the cabinet from getting so dusty that I couldn't see what I was blasting! I now have a huge filtering system, so dust is at a minimum.

AO outlasts all of the above that all these good folks have mentioned. I can reuse aluminum oxide at least 20 times from my calculations and that is blasting out of the gun at 125 PSI. It does leave a film on the metal, unlike glass bead leaves very little film residue.

Now no matter what you use, you have filter out all of the water out of the line prior to the air reaching the gun, or you will have lots of problems with the gun clogging. Use two to three filters if you want to get out all the water. This all depends upon how much humidity you have in the air. If you have lots of humidity, and the luxury of a/c in your garage, then the air that is sucked in by the compressor wil be drier. A compressor with a larger tank for reserve air will help immensely for volume of air and will keep your motor from working full speed all the time.

It will pay to spend more for a better planned system, rather than go cheap which will cause you to cuss quite a bit!!!

I went cheap the first time and regretted it. I now have an Ingersol Rand rotary compressor with a drier. And man, is life ever good with that beast!!! The air is totally dry in the 80 gal storage tank; Expensive, but the jobs I have done paid for it in no time.

Happy blasting!

Jim

 

1. Don't use sand. It will kill you. Slowly. See Post Script.

2. Glass bead is an all purpose media. Don't set your pressure above 60 p.s.i. or it will pulverize quickly and you will be out $40.00 for a 50# bag.

3. Crushed glass is a cheap alternative to sand. It is made from crushed bottles and glass jars. Only problem is, they don't remove the labels before they crush them, so the paper gets ground up with the glass and clogs the nozzle. Filter the media before using it.

4. Aluminum Oxide is a very fast cutting media, not cheap but it lasts a long time.

5.Walnut shells are worthless with small home workshop equipment. You need a gazillion c.f.m. compressor to make it work. It smells nice, though. It also leaves Walnut oil on the surface, and I believe the oil can impregnate fiberglass.

6.Plastic media is great for fiberglass but you need a huge compressor and it is expensive.


7. Soda blasting is another alternative, but be carefull that you remove all the residue.




Post Script: From The Workers Compensation Board Of British Columbia, Canada.


A variety of materials may be used in many of the same applications as silica sand in abrasive blasting. Employers are expected to switch to these products when practicable. "When practicable" means when an alternative product is available which can be used to perform the job. If an employer decides to continue to use silica sand, then the employer must demonstrate why an alternative is not practicable. An example may be on a job bid before April 15,1998, but not started until April 15,1998, and silica sand was specified in the bid.
The use of crystalline silica was prohibited in Great Britain in 1950 and in other European countries in 1966. Since 1974 the National Institute of Occupational Safety and Health (NIOSH) in the United States has recommended that silica sand be prohibited as an abrasive blasting material.
Workers' exposure to crystalline silica must be kept as low as reasonably achievable (ALARA) below the exposure limits in Table 5-4 in the Occupational Health and Safety Regulations.




ps/ps. Banned in Great Britain in 1950. 10 years ago I was blasting with sand unaware of the consequences. Nice to know that the government is looking out for me. In the city where I live, stores have to keep cigarettes behind closed doors becuase they fear that children will see a package of cigarettes and get the urge to light one up. Yet, they are still allowed to view alcohol.

 

hey buns, a couple of questions on that gizillion CFM compressor:
how much does it cost???
how big is it, will i have any room left in the garage??
will i get sucked into the intake port???
how many thousands of volts service do i need to run it??
.
.
.
that is all...

 

not good advice. if the health concerns weren't enough to steer you clear of this method, the sand that was used wasn't regular playground sand. It had been sifted to a consistent grain size so the media removed material evenly and consistently.

Sand may be cheaper on the wallet now, just be prepared to pay with your life later on.

 

Depends on your situation. There are several options.

Portable:




Horizontal:




Vertical:

 

I also use glass bead 80 grit. Works well for cleaning most everything without damage.

!!!! Caution should be used with aluminum oxide as I recall this is also a dangerous material if breathed !! (Just going from memory so maybe others can confirm or not)

 

Good point! Caution should be used with all blasting media. You don't want to inhale the dust from anything you blast with. Even if it isn't necessarily toxic or harmful, you are still coating your lungs with the dust. Drywall dust isn't said to cause any particularly dangerous conditions, but I still don't want it all down in my lungs. The dust will be carrying particles of whatever you are blasting off the parts. So if it is painted or rusty, those particles are in the air you breathe. And I've read warnings about blasting old cadmium plated parts in that the cadmium can be toxic if inhaled too. I do use a vacuum and filter on my cabinet, but I also use ear protection and a dust mask. The dust mask is always really dirty after a couple uses even with the steps I take.

 

Check these out:

http://www.eatoncompressor.com/page/page/2499974.htm

http://www.northerntool.com/webapp/w...6970_87+771255

 

I have blasted with plain white Play Sand many of times but wear a mask or respirator when doing so. Just curious. If someone wears a respirator why would sand for as cheap as it is be a problem? Sand is all I ever saw people use since years back when blasting a frame or other large object. I used it to blast my snow plow blade. For a blasting cabinet I can see other more expensive media being use as it is self contained and used over and over again.