Sandblasting and media info

[Patrick Walsh]

Hi all wondering if anyone here had experience with sandblasting equipment.

I have access to a cabinet that recirculates the media and everything needed. The equipment is not setup and I’m pretty much on my own to figure out how to set it up. Im sure that should not be to hard but any advise offered would be appreciated.

I know to wear proper breathing apparatus even with the cabinet when working with glass bead or crushed glass. I also know to tape off all machined and working parts or they will get ruined.

Mostly what I don’t know is what is the appropriate media to strip all the pain of cast iron parts vrs aluminum parts vrs knurled parts yada yada yada.

Any insight appreciated.

[Steve Eure]

I can't help you on the media, but my wife uses a blasting cabinet with some of her artwork. A couple things to consider. First is dust extraction. Those cabinets get dusty in a hurry and it gets impossible to see your work. Second is a good light inside for the same reason. My wife uses a magnetic based florescent light on the outside of the glass panel that helps but not perfect.

[Carl Beckett]

The biggest impact on sand blasting is AIR. You need at least a 5hp compressor that puts out high air volume.

For most metal processing use 'black beauty' blasting grit. Pretty coarse/aggressive, but sounds like what you need. For fine detailed work a glass bead is better. And for very sensitive work walnut shells.

The biggest thing though is air. And 'dry' air, else the moisture makes the sand sticky and the siphon doesnt pull well.

[John K Jordan]

I've used the silicon carbide grit. For a finer grit I got the stuff used for blast cleaning spark plugs, found at the Auto Parts store. (I used it for etching artwork onto clear glass.) I haven't tried the glass beads. For specific materials, I'd try to find some junk pieces and test. Maybe ask a fab shop.

I assume you've already done a web search but if not, Google seems happy to provide reading material:
https://www.pittsburghsprayequip.com/2018/02/27/sandblasting-aluminum-complete-guide/
http://www.yourepair.com/205/sandblasting-metal-to-remove-rust-or-paint.html
https://www.kramerindustriesonline.com/resources/blasting-media-selection-guide/
https://www.graco.com/us/en/contractor/solutions/articles/how-to-choose-the-right-blasting-abrasive.html
https://www.sharrettsplating.com/blog/7-tips-for-choosing-abrasive-blasting-media/



Hi all wondering if anyone here had experience with sandblasting equipment.

I have access to a cabinet that recirculates the media and everything needed. The equipment is not setup and I’m pretty much on my own to figure out how to set it up. Im sure that should not be to hard but any advise offered would be appreciated.

I know to wear proper breathing apparatus even with the cabinet when working with glass bead or crushed glass. I also know to tape off all machined and working parts or they will get ruined.

Mostly what I don’t know is what is the appropriate media to strip all the pain of cast iron parts vrs aluminum parts vrs knurled parts yada yada yada.

Any insight appreciated.

[Patrick Walsh]

Thanks guys.

Yes I found those links. I the. Figured why not ask and see if I could find some sedond ha f first hand opinions from others of whom maybe I had seen a thing or two they had done prior as a point of reference.

As suggested I will run test samples of everything. I also watched a couple videos and read the above articles suggesting light and vacuume. I could be wrong but I feel like the cabinet I have access to recirculates the media. In this case I wonder if that is the same as a vacuum. I would kinda think so being how else does it get pulled out of the cabinet eat other than a constant suction?


I've used the silicon carbide grit. For a finer grit I got the stuff used for blast cleaning spark plugs, found at the Auto Parts store. (I used it for etching artwork onto clear glass.) I haven't tried the glass beads. For specific materials, I'd try to find some junk pieces and test. Maybe ask a fab shop.

I assume you've already done a web search but if not, Google seems happy to provide reading material:
https://www.pittsburghsprayequip.com/2018/02/27/sandblasting-aluminum-complete-guide/
http://www.yourepair.com/205/sandblasting-metal-to-remove-rust-or-paint.html
https://www.kramerindustriesonline.com/resources/blasting-media-selection-guide/
https://www.graco.com/us/en/contractor/solutions/articles/how-to-choose-the-right-blasting-abrasive.html
https://www.sharrettsplating.com/blog/7-tips-for-choosing-abrasive-blasting-media/

[Lisa Starr]

We keep a rugged crushed glass (Scat Blast) in our cabinet 99% of the time. It is a good "all purpose" media that we use for everything from zinc die castings to stainless steel parts. We purchase ours from TIP Tools in Canton, OH. They are a good source for lots of blasting related stuff.

[David Kumm]

To do any volume you usually want a pressure blast cabinet and lots of air. A 15-25 hp compressor is not overkill. You can do smaller jobs or work. slowly but then die grinders and wire wheels work about as fast with less hassle. Dave

[Bill Dufour]

Sand or silicon carbide requires breathing protection as well. To recirculate just use a syphon gun with a dip tube into the bottom of the cabinet. Harbor Fright actually sells some blasting media and gun parts. A pressure system will work about 2x faster then siphon.
Use a hepa filter if you use a vacuum cleaner. Shield view port and light with cheap disposable plastic covers like handiwrap or report covers from the office store.

[John K Jordan]

I could be wrong but I feel like the cabinet I have access to recirculates the media. In this case I wonder if that is the same as a vacuum.

Some use a vacuum, some simply have a hopper to collect and reuse.

[Patrick Walsh]

This is a pretty slick setup.

It’s my uncles whom restores antique cars. He purchased it moons ago and never used it.

It’s pretty slick I’ll get pictures Monday as it’s at work. There is a huge diamond plate case that holds two units. I guess one is a mobile unit and one is the unit to hook up to the cabinet that recirculates the media. In such a case will I still need a vacuum to keep the dust at bay so I can see what I’m doing?




Some use a vacuum, some simply have a hopper to collect and reuse.

[Ole Anderson]

Harbor Fright actually sells some blasting media and gun parts.

I was surprised at the variety of media that HF stocks.

[Wayne Lomman]

You can't successfully blast without dust collection and separation. It sounds like there is a reasonable chance you have that capability as there are 2 units. It will be interesting to see the pictures. Does it have a brand?

Our cabinet blaster users the dust extractor to provide the air flow for the separation of dust and blast medium. If you don't have dust extraction you can't see what you are doing, you lose efficiency rapidly and you end up with dust embedded in the surface of the object. The last one sounds impossible until you find out that grit leaves the nozzle at close to the speed of sound.

Choice of blast medium depends on what you want to achieve. Soft metal needs finer grit size. Thick paint needs coarser blast profile. Removing paint requires sharp angular grit. A smooth peened object requires shot or beads. We use garnet in the full size blast chamber as it is available in various grades and can be used on both ferrous and non ferrous substrates. It is fast cutting and recyclable. The cabinet blaster uses steel shot as we only use it for peening steel castings.

You are dead right about breathing protection. An air fed helmet is mandatory. Here it has been illegal to use silica media for about 40 years as silicosis was the common way for blasters to die. However, you need to protect yourself from all the unknown paints and other rubbish you are removing as well. Cheers

[Perry Holbrook]

I use a small siphon feed system for blasting holes in glass plate in a production process. I modified it for efficiency and worker comfort.

Install enough lighting to ensure you can see what you are doing.

Dust collection can be done with a simple shop vac, however some modification is necessary. Any shop vac that uses exhaust air to cool the motor will have a short life because the grit that doesn't get collected will go thru the motor, eating it alive. This can be avoided with a small cyclone mounted on a 5 gallon bucket between the cabinet and the vac. Mine has lasted for many years set up that way.

Provide clean make up air back into the cabinet. I did this with a filtered opening near the viewing window. If you do it right, the flow of fresh across the window will make for a clear view.

Hope this helps.

[Bruce Wrenn]

OP may want to post this in the metal working forum.

[Ed Labadie]

I use silica sand in my blast cabinet, it's hooked up to my 3hp dust gorilla for dust removal.
Got rid of all the 1/4" air hose and fittings. Replaced with 1/2" then plumbed it into my 100cfm IR gas powered compessor.

No problems anymore.

Ed

[Warren Lake]

besides the health issues silica sand is an inferior blast medium. If youve used sharp material and try silica again it just feels like tiny tennis balls.

[Wayne Lomman]

I use silica sand in my blast cabinet, it's hooked up to my 3hp dust gorilla for dust removal.
Got rid of all the 1/4" air hose and fittings. Replaced with 1/2" then plumbed it into my 100cfm IR gas powered compessor.

No problems anymore.

Ed
Silica sand is outlawed as a blast medium even in the USA and has been for a long time. The devastating health effects of silicosis which results from respirable silica dust are far more rapid than asbestos disease and just as deadly. You don't have to be exposed to the dust for long either. Dust collection and breathing apparatus are not good enough controls hence the ban. Do yourself and those around you a favour and change to another medium. Sanitise your work area as well.

[Patrick Walsh]

I’m gonna get pictures of the setup Monday. Maybe that will help some guide me.

I know there is a bag of black beauty with the cabinet. I’ll probably start with that unless I’m told otherwise.

[Brian Holcombe]

I’ve only ever used glass beads, but only on aluminum parts. It works well, but you must be absolutely sure they’re completely cleared from the part before it’s put to use. Glass beads in a finished assembly will ruin it very rapidly.

In the machine shop we used a steel shot machine for smaller cast iron parts, like cylinder heads. We used it after baking them in a specialized oven to cook off any paint or grease. Aluminum parts were placed in a heated cleaning solution prior to glass beading.

Large cast iron parts were brushed by hand after cooking, they were neat and clean after the process and ready for new paint.

Media blasting the cabinet is a lot of effort for little reward, if the paint is not loose then remove all grease then sand and fill.

Its important that grease/oil be removed entirely. Paint does not adhere to greasy surfaces no matter what the manufacturer claims and blasting media will get stuck in anything greasy and load up the sprayer.

[Patrick Walsh]

So Brian would you be the “don’t sandblast corner”...

I have had more than one person tell me “sand and fill”.

My carpel tunnel likes the idea of sandblasting. I also like the idea of everything taken down to bare metal and any pitted on rust gone.


I’ve only ever used glass beads, but only on aluminum parts. It works well, but you must be absolutely sure they’re completely cleared from the part before it’s put to use. Glass beads in a finished assembly will ruin it very rapidly.

In the machine shop we used a steel shot machine for smaller cast iron parts, like cylinder heads. We used it after baking them in a specialized oven to cook off any paint or grease. Aluminum parts were placed in a heated cleaning solution prior to glass beading.

Large cast iron parts were brushed by hand after cooking, they were neat and clean after the process and ready for new paint.

Media blasting the cabinet is a lot of effort for little reward, if the paint is not loose then remove all grease then sand and fill.

Its important that grease/oil be removed entirely. Paint does not adhere to greasy surfaces no matter what the manufacturer claims and blasting media will get stuck in anything greasy and load up the sprayer.

[Brian Holcombe]

If the inside is intact and not rusty I wouldn’t. I might spot blast the rust. Blasting has a high risk of a piece of media destroying a finish machined surface after assembly or seizing a bolt. We limited blasting to small parts and cylinder heads because the media can be effectively cleared out. Big castings have lots of places for media to hide.

If you absolutely had to remove the current paint entirely, because it were flaking badly, I would bring it to a place with an industrial oven and bake the paint off, then spot blast rust. Otherwise I would use the current paint as a base filler then work from there.

[Patrick Walsh]

Hmm,

I really don’t know what I’m doing do I?

Ok so it’s not flaking like crazy. I’m sure a spot blast, sand prime, fill prime and a couple coats of paint will do.

Just sounded was more easy to me to blast all the paint off, prime, skim with bonds, sand off prime, coat spot bonds and prime then finish coat.


If the inside is intact and not rusty I wouldn’t. I might spot blast the rust. Blasting has a high risk of a piece of media destroying a finish machined surface after assembly or seizing a bolt. We limited blasting to small parts and cylinder heads because the media can be effectively cleared out. Big castings have lots of places for media to hide.

If you absolutely had to remove the current paint entirely, because it were flaking badly, I would bring it to a place with an industrial oven and bake the paint off, then spot blast rust. Otherwise I would use the current paint as a base filler then work from there.

[David Kumm]

Die grinders with various wire wheels and needle scalers do 90% of my work. When a small part has rust inside that I can't get to with the grinders, I drop it in a bucket of evaporust or esprit for a day. I also depend a lot on a 14" floor standing wire wheel and buffer. A benchtop 8" works too but not as well. Dave

[Patrick Walsh]

See I don’t have any of those tools.

I do have access to about 100hp of compressed air though and sandblasted and cabinet.

Link me a couple of the above mentioned tools and attachments if you don’t mind. Sounds like I should probably invest in them.

Remember I’m not a harbor freight fan lol..


Die grinders with various wire wheels and needle scalers do 90% of my work. When a small part has rust inside that I can't get to with the grinders, I drop it in a bucket of evaporust or esprit for a day. I also depend a lot on a 14" floor standing wire wheel and buffer. A benchtop 8" works too but not as well. Dave

[Warren Lake]

not sure what you plan to do, big stuff wont fit in a cabinet. Small stuff works great, sometimes getting grit into places is a concern. Ive never tried a scaler probably tried a die grinder a few times but sandblasting cuts into a fresh layer or metal and leaves you with good tooth, dont handle parts after with your hands and degrease stuff first if you are reusing medium. On the big scale say car frames cheaper medium is used and disposed of. As an example my 92 rotors before I had them turned. Ditzler Epoxy primer painted inside and out and the inside paint came off when they were turned. Sandblasting got into all the casing and the job will be as good as you paying attention. I loke the old flood light bulbs for light, they are super thick and produce heat, it helps dry the medium probably not much but it works in your favour.

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[David Kumm]

Ebay and CL are good sources for Mac Tools, Matco, Ingersol Rand, etc. You want the ones with larger capacity so they don't slow down when used. Usually 50-75 will get you a decent used one. You can usually tell if they have been abused. A good needle scaler is more like 100-150 unless you do the HF thing. Dave

[Patrick Walsh]

Big stuff I will setup for outside with the Portible tank. I’ll make myself a pop up bubbled in plastic roomer just go to town?

Brian and David have me double guessing the sandblater at all though at this point. Maybe I’ll start with a die grinder and needle scaler.

I also have access to baldor grinders and buffers and polishers that at least right now are setup to polish metals. They are the stand type and used to polish various car parts, normally brass, nickel and aluminum I think?






not sure what you plan to do, big stuff wont fit in a cabinet. Small stuff works great, sometimes getting grit into places is a concern. Ive never tried a scaler probably tried a die grinder a few times but sandblasting cuts into a fresh layer or metal and leaves you with good tooth, dont handle parts after with your hands and degrease stuff first if you are reusing medium. On the big scale say car frames cheaper medium is used and disposed of. As an example my 92 rotors before I had them turned. Ditzler Epoxy primer painted inside and out and the inside paint came off when they were turned. Sandblasting got into all the casing and the job will be as good as you paying attention. I loke the old flood light bulbs for light, they are super thick and produce heat, it helps dry the medium probably not much but it works in your favour.

397872 397871

[Warren Lake]

get yourself a drum like that and try those tools then show us the results and how long it takes you and all the places you cant get into.

[Patrick Walsh]

So this is what I have,

If better pictures are needed let me know. I took these in a rush just to have something to post I hopes it would help you all guide me.

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[Lisa Starr]

Patrick - That is the exact blast cabinet and dust collector unit we use in our home shop. Make sure you have the final filter that fits on the exhaust port of the dust collector. If you use Skat-Blast, as I posted earlier, you'll find that you have a good "all purpose" media that will allow you to do lots without changing the media. I'm attaching a pic of our set-up. If you need any other info, I'm happy to share our knowledge.
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[Alex Zeller]

I haven't tried it but I have seen others sandblast glass to etch patterns into it. I've even seen mirrors done where they blast away the back with reverse lettering and put a light behind it to make a sign. It seams a little more aggressive than acid etching but I suspect that's more a function of the media and pressure. It also seams more consistent than acid. By simply using a foam tape and an exacto knife they cut out the pattern. It needs to be thicker glass. I have a feeling that if I got into an artistic mood I could make some real nice cabinet doors with the glass.

[Warren Lake]

likely ive asked you what you are doing and maybe I missed you showing something. If you are doing dirty parts then a cheap medium would be fine and throw away. If you are doing clean parts or cleaning greasy ones you will be fine to reuse the medium depending on that it is, some are sharper than others and when they break down are still sharp just smaller from impact. If you use a pressure blaster more bang for your buck. If you use a sharper medium more cut. If you go too coarse then you have more texture to your surface you balance that out, car guys dont go too coarse depending on the finish going on whatever it is.