Learn me sandblasting media please

Ok, as part of the grand shop reorganization/finishing, I just assembled a sand blasting cabinet that I've had in a box for a while.  Apparently a long enough while that the hoses for the air and the media pickup have gotten too hard to flex.  As I go to buy some more hose tomorrow, I realize that I have no idea of what media to get.  The instructions say to use no more than 10 lbs, so if I get the wrong thing, I'm not too bad off I reckon, but let's shoot for the right thing.  I'm primarily planning on blasting rusty car parts, don't reckon it will be anything too fragile, but don't want to set the phasers for kill either.  Getting cross-eyed reading about glass beads, crushed glass, aluminum oxide, walnut shells, corn cobs(???).  I want to be able to clean rusty stuff to either paint or weld.  What recommends the hive?

I used crushed glass for just about everything.

I have a bag of glass bead that gives a nicer finish, but I rarely use it.

I bought some blag slag something or other to do some cast manifolds as I had heard it was aggressive, but I wasn't impressed with the results.

I used crushed glass.

Wear a mask - crushed glass is not good for your lungs.  Neither is sand.  Or really anything.

For cleaning metal of paint or for welding either Aluminum oxide or "Black Beauty" is good.

Black Beauty is a brand name for steel slag, a by product.

There's also Black Diamond brand.

I can get the black media at my local home supply store.

For cleaning metal or light rust removal I prefer glass bead..

It leaves a smoother finish, depending on the pressure you use to blast it with.

Crushed glass is more abrasive then bead.

Walnut shells or corn cob is best used on items made of soft metals, such as copper, brass, etc.

jimbbski said:

For cleaning metal of paint or for welding either Aluminum oxide or "Black Beauty" is good.

Black Beauty is a brand name for steel slag, a by product.

There's also Black Diamond brand.

I can get the black media at my local home supply store.

For cleaning metal or light rust removal I prefer glass bead..

It leaves a smoother finish, depending on the pressure you use to blast it with.

Crushed glass is more abrasive then bead.

Walnut shells or corn cob is best used on items made of soft metals, such as copper, brass, etc.

 

 

Is it steel slag?  I thought it was coal byproduct.  I got mine at Tractor Supply.  Anyway it works great.  I got the big 'pressure vessel' from HF.  Aside from a few Chinese quality issues it's a solid piece. I can't believe what it will do to a weathered old oak board. Makes it look show quality.  I found that purely by accident.

Ok, I see the Black Diamond at Tractor Supply, hard to go wrong at $10/25 lb. bag.  For cleaning things like alternator brackets, motor mounts, etc., should I get fine or medium?  Thanks everyone!

If you have a new cabinet before starting to put media in or start blasting I would take the time to silicone all the joints of the sheet metal. A cabinet I had leaked like crazy and other have told me they had the same problem. There are probably alternatives to using silicone but it was what I had on hand. Easier to do when new and clean.

Thanks for the advice pirate!  There is a foam seal around the bottom, but nothing on the sides.  I'll get some caulk & seal it up before starting.  This is one of the reasons I love coming here for info, somebody else has been there, done that :) 

In reply to A 401 CJ :

What I've read is that it's a by product of the steel making process. Part of that is truning coal into coke. Slag; which is impurities that tend to float on top of molten steel is drawn off and then use by  some media manfacturers.  I live in a area where they still make steel and this slag is easy to get so it gets used.

I researched this recently.  I concluded that glass bead was the best overall for a cabinet (vs. outdoor work).  It's about a 'medium' for aggressiveness, but the biggest advantage is that it lasts a lot longer.  The other hard media (crushed glass, slag, etc.) are recommended for 1-2 uses before it doesn't work as well from lack of sharp corners and/or breaks down to smaller pieces.  Glass bead is described as being effective for much longer, like 20-40 times, though I can't remember where that came from.  Outdoor pressure-pot work, you're not going to recycle the media very much compared to a cabinet where it's constantly recycled.  

Having said that, I ran low on glass bead that had been in the cabinet for years (ultimately does break down with use and you loose some everytime you remove a part) and bought some fine slag because that's what they have at Tractor Supply, and it was quite effective.  The really coarse slag I had on hand would plug up the feed mechanism, so I wouldn't recommend that at all.

Good to know about the life-cycle, thanks!

If you want to see what you are doing, put alight inside and add a vacuum cleaner to the system that sucks through a water trap.

I really like having a blast cabinet when it was working, but it was a pain to keep it so.

I have the Princess Auto equivalent of the Harbor Freight cabinet.  I added shields to the openings, and here is with two 100W LED bulbs (I later added two more):

I also added my own hookah pot, but it needs some more "cyclone vacuum" design happening.  You need to put it on wheels:

I recently Switched to this stuff: https://www.summitracing.com/parts/sum-913111

It works great, and gives a more satin sheen than the other Cheap Black media I had from Harbor Freight.

It is Snow white and reflective when new, so it brightens up and reflects the light off the bottom of the cabinet. It produces hardly any dust and tends to not clog the vacuum filter too quickly.  I also recommend using one of these in between the cabinet and the vac:https://www.amazon.com/Dustopper-High-Efficiency-Dust-Separator/dp/B0799QBX26

if you run straight into the vac you will be cleaning the filter every 2 minutes and 53 seconds.

Greg

Great advice everybody!  SkinnyG - it looks like you just bent some sheet metal and put over the exhaust in the cabinet?  Did you leave a filter inside the cabinet?  Mine is an old Speedway unit, with crappy instructions. It looked like it had the filter protruding into the cabinet?  I like the idea of more lights, the crappy little fluorescent is not going to do much in there.

Slantsix - do I still leave the filter on the cabinet, or just turn it into an exhaust port to the Dustopper and vacuum?  
 

Caulked the seams this evening, I'll take a pic tomorrow to show what I'm talking about with the exhaust filter. Thanks again everyone!
 

Mine came with no filter, I have not fitted one.  The shields are just bent sheet steel to slow down the exit of abrasive to the vacuum.  The fine dust disappears just fine.

In reply to HoserRacing :

I actually cut the filter out of mine as the original media I used made such a fine dust it clogged instantly.

I would try it with it on first and see how it goes. The dustopper does a nice job of separating all of the heavy stuff out, especially with the glass beads I am currently using.  I really just need to make a shield / baffle for the vac port on my cabinet but have chose to futz with other things currently.  I am not bothered by the no filter on there as on now - I just empty the 5 gallon bucket from the dustopper back into the cabinet and keep on blastin.

Greg

I added a Cyclone Separator to a 5 gal. plastic pail and run my vacuum though it.

I suck the dust out of the blast cabinet, thought the separator, and then into the vacuum.

The shop vac I use has both a large collection bag and a fine filter that stops whatever gets through the bag, but little does.

I wouldn't blast  indoors without a dust collections system.

I hope to get my system back up and running as I purchased a new air compressor.

This one is 60 gal. and two stage with 15+ CFM at 100 psi.

I'm adding an after cooler before the air enters the storage tank.

The air will exit the cylinders, go though a cooler attached to the pulley guard so air will be pulled through it,  then through two water traps, one with an air filter, all to remove the water before it goes into the storage tank.

I have the same cabinet as SkinnyG. I'm using the cheapest 50w outdoor LED floodlight  I could find on Amazon. It's incredibly bright. I also picked up a used indirect drive exhaust fan that is ducted through my shop wall to the outside. No dust in the shop and much quieter than a shop vac.

In reply to Wayslow :

I'd still use a separator to catch the larger dust and media before just blowing it out doors.

I would use an exhaust system too but I can't/don't want to punch a hole through my house wall to do it.

Plus I live in a cold part of the US so I like to keep the warm air inside.

Here are some pics.

Cheap hf blast cab that I got second hand.. welded 2 1/2" exhaust tubing to the side for the vacuum and a moisture separator inline at the air input.

20210127_174353 by Hyperpack, on Flickr

20210127_174356 by Hyperpack, on Flickr

20210127_174405 by Hyperpack, on Flickr

20210127_174410 by Hyperpack, on Flickr

20210127_174359 by Hyperpack, on Flickr

Greg