TOPIC:

I am presented with a rare opportunity to acquire a media blaster and I am a complete novice at use of this equipment.  I am aware of the different types of media available but would like some input on what others have used and what I might expect...parts to be blasted include fuel tanks, fenders, stands, swing arms, and just about any metal piece on my bikes.  I look forward to your help.

I have been using SS media for years but I try not to blast too many large items that are painted. If I do I remove as much paint as I can. If I have large items that have been painted I take them to the local blaster and have them do it. I clean all my engine cases heads cylinders and small parts like calipers master cylinders with the SS media. I can clean the media if I need to. I have a std Harbor Frt cabinet that has been modified a bit. 
If you insist on blasting tanks, fender and such I would look at garnet media or coal slag. I have used both in the past.

I have developed my own process for cases

A friend of mine has three blasters.  One is a traditional sand blaster.  A second is for cleaning grunge off engines that haven't been cleaned for years.  He uses old silica beads in a dry blasting process to clean dirt, grease etc from pretty much anything.  It's also useful for stripping paint.  But it leaves engines with a dull finish, so the third blaster is a combination of clean silica beads mixed with water to give the clean shiny look like it was brand new.

Aluminum oxide grit is great for removing rust and paint off steel parts.  It can also be used for aluminum parts, but not delicate ones.  For aluminum, glass bead is better.  With fresh bead the aluminum comes out sort of shinny.  As the glass breaks down, or when using crushed glass, the finish on aluminum will be dullish.  Crushed glass is good for stripping paint as well, but it's slower than aluminum oxide.  Silicon Carbide is similar to AO.  I can't imagine restoring a bike without a media blaster and spray gun with good automotive paint or similar.

The problem with most of the media (at least for me) it creates a ton of dust. In a small shop it's not the best. I have a pretty good vacuum system which removes most of the particles that get blasted off the part. However if your using glass your going to vacuum up most of it as you use the cabinet. The SS media is heavy enough where I get only a small amount in the collector that is before the vacuum canister. I empty that once in a while and clean the media. I can actually see inside the cabinet while I'm blasting. Glass beads create so much dust as do other media that you can hardly see what your doing and it all gets caught in the vacuum and you really cant clean those beads. SS media is pretty expensive up front but I bought 25 lbs  of std and 25 lbs of conditioned maybe 14 years ago and have 90 % of it left. Some new and some cleaned which I reuse on parts that have more paint on them. I have done a lot of cases and other parts over the years. In the last 4 years I have done at least 8 restorations like below so the cabinet does get used. I blast a lower pressure maybe 50-60 psi . If your doing has tanks, fenders, frames and have a place outside where you can blast I would do those parts outside and not in a cabinet.. That's why I let those guys do my big parts.

Before you jump into the media, do you have the setup it needs? Such as big enough hose, compressor and such? Also, make sure you have good air/water separator. Otherwise, you going to have pretty wet media coming out from the gun. As for which/what media to use, you can always google it or go to places like Eastwood for a reference.

With that been said, I like to use both Aluminum Oxide and glass bead. I have both in 100, 180 and Oxide only, I believe it was 80 grit because I mostly use this stuff to remove paint from steel part. I have a small cabinet style blaster and I use it for both car and motorcycle. For car, I use it for engine parts, such as intake and such, just to take off the grimes Don't worry guys. I do have small parts cleaning bin as well so it usually go through several (yes, not couple) cleaning cycle. And finally, it will get blasted with air at the end.

One advice. If you decided to blast whatever part and want to keep the new alum. shine, clear coat it. I didn't do this on my bike and it is showing that nasty white powder again. Of course, bike has been sitting outside with just the cover, but I should've known.

You're going to have fun learning, soo many options. May i suggest if you're doing something like engine cases, calipers, general ruff and tumble parts. Start with media more aggressive, i use silica sand intended for sealcoat. I can get an 80lb bag for under 20USD. DON'T start with clean glass beads!! They have a tendency to "roll-up and blister" the aluminum. Aggressive removes and uniforms the texture. Results in that dull grey look but only then do you hit with fresh glass. Also those general purpose siphon tubes really need to be modified with an extra air correction elbow and tube to atmosphere. Keeps the media flowing without sputtering. Have fun and mask-up!  

asphalt900 wrote:

You're going to have fun learning, soo many options. May i suggest if you're doing something like engine cases, calipers, general ruff and tumble parts. Start with media more aggressive, i use silica sand intended for sealcoat. I can get an 80lb bag for under 20USD. DON'T start with clean glass beads!! They have a tendency to "roll-up and blister" the aluminum. Aggressive removes and uniforms the texture. Results in that dull grey look but only then do you hit with fresh glass. Also those general purpose siphon tubes really need to be modified with an extra air correction elbow and tube to atmosphere. Keeps the media flowing without sputtering. Have fun and mask-up!  

Not to go against Clay here, but if you use silica sand, you should wear a respirator.  Silica is bad stuff, or so people tell me.  That said, I've used it plenty of times, and I'm still here...

With fresh glass bead, my cabinet is almost dust free (good visibility).  It's after the glass breaks down, that the cloud storm starts.  I have a piece of clear plastic over the glass on the inside, and it lasts a couple of hours blasting time before it's all cloudy itself.  A pain in the butt to change, but necessary.

EXACTLY Ed!! That silica sand will lodge in one's lungs. Like you Ed, have been doing it for years but have been exposed the same scenario that somewhat duplicates it. Coming from 30yrs of saw-cutting concrete/asphalt, it's essentially the same by-product. Like you also mentioned, clean-new glass doesn't make a hint of dust initially. But..brakes down and there's the trail of dust.

I have this setup
 
   
Silica sand No. 1 grade. With the 3hp compreesor I get about 40 secs / min of blasting before I have to leave it to recharge
.
 
 

With the set up it's quite slow but also not too aggressive so ports can be masked with builders tape.
Whatever route you decide thorough cleansing afterwards is more important than anything else. With the sand I use warm very soapy water, rinse, repeat several times, airline then repeat.

Silicosis is a lung disease that was at one time very common in miners.  It is irreversable.  Once you've got it your lungs will never recover.  I was a miner for many years and there's nothing wrong with my lung.

To reinforce what HRM has posted:
When blasting with sand in the open, make sure you're using the right breathing protection (hood and filtered air supply) NOT just a dust mask!  Taking a shortcut "just once in a while" will result in permanent damage and you may end up lugging oxygen tanks around for the rest of your life.