Bead blasting : "how to" - PICS added post 24 -

[tino_ale]

Hi guys,

I have a 50L 2HP air compressor that I got for a decent price. Now I'm looking to do some bead blasting job, especially on titanium parts/flashlights :naughty:

My compressor will go up to 8 bars but will not restart untill the pressure drops down to 6 bars. So if I want a solid setting I can set manually the output from 0 to 6 bars.

Now what I need to know is the parameters to do some bead blasting on titanium :
- which media should I get (I would prefer the less toxic one)
- what pressure should I set on my compressor (I can set from 0 up to 6 bars)
- what distance to the part
- is there any specific method to blast a part, I mean do you just blast it randomly or is there a specific pattern to apply
- is there anything I should not do, or any "if I knew before..." kind of stuff

What I am looking for is a fine finish that does not errase machining details and crisp edges. It would be nice though if it could erase light scratches. I like the darker type of bead blasting, the one that is very soft and almost feels like rubber in your hand.

Last question : for small jobs (like A123 flashlights), can I do this outside in the grass or is it mandatory to get or make a cabinet? How messy does it get?

Thanks everyone, please share your skills!

 

[TranquillityBase]

Re: Bead blasting : looking for a "how to"

A small blasting cabinet would be the safest...

Cabinet make-up air suppy, and a good dust extraction vacuum system are key to safety...Consider any/all blast medias to be hazardous to your lungs, some more than others, but consider all to be harmful.

I found lower blast pressures to work fine, around 40/2.75bar to 60psi/4.13...

Silica sand produces a flat/matte dark grey finish, and glass beads media produces a satin silver/light grey finish.

 

[tino_ale]

Re: Bead blasting : looking for a "how to"

A small blasting cabinet would be the safest...

Cabinet make-up air suppy, and a good dust extraction vacuum system are key to safety...Consider any/all blast medias to be hazardous to your lungs, some more than others, but consider all to be harmful.

I found lower blast pressures to work fine, around 40/2.75bar to 60psi/4.13...

Silica sand produces a flat/matte dark grey finish, and glass beads media produces a satin silver/light grey finish.

Thanks TB!

Are blast media harmful only during blasting operation or should they be treated in a specific way even during storage?

Any other input for the other questions?

THANKS!

 

[precisionworks]

Re: Bead blasting : looking for a "how to"

Are blast media harmful only during blasting operation

The media itself is harmless, you can hold it in your hands with no effect. The problem is that air pressure accelerates the media to a high velocity, and the media fractures when it strikes the work - generating sub-micron particles that are easily inhaled. The particles are so tiny that they lodge in the deepest parts of the lung tissue, whey they can cause irreversible damage.

a good dust extraction vacuum system

+1

The blast cabinet (often available at farm supply stores for $100-$200) contains the dust and allows the vacuum to separate the dust from the media, which can be reused until it no longer produces the desired effect.

can I do this outside in the grass

You can, and I have, but it leaves a mess that's hard to clean up. Your wife will not be happy:mecry:

 

[G1K]

Re: Bead blasting : looking for a "how to"

I think HF sells a small counter top unit for $50 or so. As far as I know it does not have a dust extraction unit. A shop vac will work, but it'll kill the vac on short order. Also the typical shop vac filter will not get the smallest particles.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94917
This one is small but it's over $50. I remember seing one smaller in the store.

You'll be able to blast small parts fine with your compressor, it's not like you'll be blasting for hours on end. A typical flashlight body won't take too much time.

Personally I use glass beads on Ti

Ryan

 

[tino_ale]

Re: Bead blasting : looking for a "how to"

Personally I use glass beads on Ti

Ryan

Thanks for the info. Any picture of the result you get using glass beads in Ti? :naughty:

 

[McGizmo]

Re: Bead blasting : looking for a "how to"

I am no expert but I really like the system I ended up with even though it's a bit of a PITA to use. I purchased one of the bench top cabinets which I think is the only way to go. The vacuum that came with it sucked figuratively and not well, literally. It was also loud enough to wake the dead. I use a long hose connected to my Fein shop vacuum. The gun that came with the cabinet was also a real disappointment. I put a SpeedBlaster on short hose inside the cabinet which works so much better and I can always use the SpeedBlaster outside should the need arise. The SpeedBlaster with its integral hopper and gravity feed is a fantastic tool!! On a budget, one can use it outside and wear proper respirator and eye protection. I keep a small plastic cup in the cabinet and use it to scoop up the glas beads and refill the hopper of the SpeedBlaster.

I use glass beads exclusively. Early on, I tried some more agressive silica or was it aluminum oxide media (are they the same?). It imparted a darker gray finish like TB mentions. Looked cool until I went to anodize the Ti and discovered that the dark gray was embedded particles in the surface of the Ti and these particles precluded the anodizing from proceeding. IMHO, one should use glass beads if one plans to anodize and that is true for anodizing the aluminum as well as the Ti. The glass won't contaminate the surface as other medias can.

For small parts and multiples like the Ti pocket clips I blast, I found that a stainless steel screen type colandar was a quick and effective addition. I added a series of small stainless steel screws around the perimiter and through the mesh with nuts added to hold them in place. I hang the clips on the screws and the media not hitting the parts passes through the mesh of the colandar allowing for a clean flow from the gun.

 

[G1K]

Re: Bead blasting : looking for a "how to"

Thanks for the info. Any picture of the result you get using glass beads in Ti? :naughty:

Compare the three tritium pendents with a machined finish with the one ti part in the lower right with the bead blasted finish.

The bonus is the neat white sparks from the media as it abrades the ti

Ryan

 

[tino_ale]

Re: Bead blasting : looking for a "how to"

Thanks guys. Sounds like I need to source a small cabinet or maybe make one myself?

The cheapest stuff I've found in my country is this one (147 euros shipped). Looks okay and certainly good enought for what I'll be doing with it :

http://dema-france.eu/product_info.php?products_id=24

I don't know how good the gun will be though.

 

[TranquillityBase]

Re: Bead blasting : looking for a "how to"

Some good stuff 'here' tino

I'm still using the cardboard cabinet

 

[tino_ale]

Re: Bead blasting : looking for a "how to"

I have ordered the cabinet

Now, the gun included with the cabinet has 4 different ceramic settings : 4, 5, 6 and 7mm. Which setting do you advise me to use?

Besides, I've been looking for glass media with no luck so far. I understand there are different sizes, what size is suitable for applying a finish on titanium?

I can't wait to try this out, I have quite a bunch of stuff that I would rejuvenile using bead blasting. Also one thing that I would like to try is bead blasting a sapphire lens (no idea if it can be done)

 

[tx101]

Re: Bead blasting : looking for a "how to"

I have ordered the cabinet

Now, the gun included with the cabinet has 4 different ceramic settings : 4, 5, 6 and 7mm. Which setting do you advise me to use?

Besides, I've been looking for glass media with no luck so far. I understand there are different sizes, what size is suitable for applying a finish on titanium?

I can't wait to try this out, I have quite a bunch of stuff that I would rejuvenile using bead blasting. Also one thing that I would like to try is bead blasting a sapphire lens (no idea if it can be done)

Will you be offering a bead blasting service for us European CPFers

 

[tino_ale]

Re: Bead blasting : looking for a "how to"

Will you be offering a bead blasting service for us European CPFers

I do not have the compressor and cabinet at my home, they will be stored for me in a house, far away, and I go to this place only eratically (once every couple of months :mecry.
Given that I can hardly provide a "serious" service, but on a case by case basis, and if ridiculous process time is no problem, yes I can help
But first things first, I need to source the blast media, see if the provided gun works OK, then experiment a little and see how it turns out

 

[precisionworks]

Re: Bead blasting : looking for a "how to"

Try Cerablast for both ceramic & glass beads. I believe they are located in Germany.

http://www.cerablast.de/engl/index_engl.html

The website has some tech information, plus they have a tech line you can phone or email.

 

[Vertigo Cycles]

Re: Bead blasting : looking for a "how to"

I use "Potters Quality" brand glass beads in their size called "AH". It's the finest bead they make and the original hue of the titanium is maintained while knocking down the shine of the part. Courser beads tend to make a very dull finish which I personally don't care for. Horses for courses. If you want an idea of what the finish looks like, go to Moots.com and check out their bicycle frames. They use the same size bead.

 

[tino_ale]

Re: Bead blasting : looking for a "how to"

Thanks for the info. Sure those bicycle Ti parts look good but I find they are still a little too "blight" in my taste. I am looking for a little more "deep" or darker look. The size you are refering to is 44-90 microns.

I have finally found a source for blass ball beads near my place. I will go for a size of 100-200 microns or maybe even 150-250 microns. Please advise if you have experience with this size of beads. :wave:

 

[tino_ale]

Re: Bead blasting : looking for a "how to"

I've got the glass bead SIZE is 106-212 microns, the most common size I was told, it should give good results on Ti.

Anyone knows if I can blast a sapphire lens or is it fundamentally impossible (glass bead agains sapphire lens)? I'd like to experiement a sapphire "diffuser".

 

[tino_ale]

Re: Bead blasting : looking for a "how to"

Ok no reply to my questions but I have news. And good news

I could get all I needed to make my first bead blasting jobs this week end and encountered great results.

Actually the surface finish I get on Ti is not what I was looking for in the first place (dark deep gray, rubber feel in the hand). Instead, the 100-200 microns glass beads gave me a very fine light satin finish.

Not what I was looking for, but seeing the result with my own eyes totally sold me on this type of finish. I would say the deep dark finish you get with agressive bead gives a stealth/rugged look, the fine finish I get with glass bead make my parts look like *very* expensive swiss watch parts :naughty:

I have blasted a few parts, also experimented on aluminium, easier to blast.

Pics will follow soon

I pushed the air pressure up to 4 bars otherwise I felt the titanium was resisting the beads and it took too long to apply a good and consistent finish.

Distance to the part doesn't seem to be such a critical parametter, I would say about 5-15 cm is a good range to start with.

It does NOT erase any machining details, crisp machining is not altered. It WILL erase micro scratches though :twothumbs.

The cabinet I got was, clearly, a low cost piece of equipment. It is even slightly leaking but the leak is very minimal and I intend to fix this next time I empty the sink. It is not well finished, not well built, rather crappy overall quality, but heck it does what I need it to do, so I don't complain more than this. If you have time and room to make your own cabinet, I think it's totally worth trying. Also, my compressor (typical 50L 2HP chinese compressor) started to leak it's oil, I returned it under garanty. Yes I've been having a blast doing this bead blasting stuff, but it was not thanks to all these crappy equipments and tools :green: I just hate when my tools fail


Bottom line is I've very pleased with the way it turned out, and I can tell you I'm not done playing with bead blasting.

 

[precisionworks]

Re: Bead blasting : looking for a "how to"

The cabinet I got was, clearly, a low cost piece of equipment. It is even slightly leaking

Like most things, there's no free lunch in a blast cabinet. At the $1000 USD level, they are heavily constructed and (sometimes) include the dust collector:

I'm very pleased with the way it turned out

That's the important part ... you can always upgrade the cabinet & dust extractor as funds allow. Bead blast is a nice addition to any shop.

 

[fludunlimited]

Re: Bead blasting : looking for a "how to"

here is somthing you can do with masking tape and your bead blaster.
just put masking tape on some wax paper and cut out.

scroll down to the bottom of this page to see the slideshow
http://fludunlimited.com/gallery1.aspx