Sandblast media choice

J

jforbush

Joined
Sep 29, 2007
Messages
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So I got a media blast cabinet and now want to blast knives to a satin finish. There seems to be a large amount of media choices so I would like to get input from the folks that are all ready doing this.

What media do you use to bead blast a knife to a satin finish?
What media do you use to blast a knife to (fill in the blank) finish?

Thanks in advance and I look forward to the responses.
 
I use a 60/40 mix of 80 Grit glass bead and 70 grit Aluminum oxide. I then go over it with some 0000 steel wool to smooth it out. That gives me a nice finish.

Whatever you do don't blast carbon steel with the same media as your stainless. Little pieces of the carbon steel will bond with your stainless and cause it to have rust spots.

I only blast stainless in my booth, The texture left on the blade would cause rust issues with the carbon steel anyway.
 
After messing with the different types of glass beads, I finally bought the more expensive silicon carbide and think it works much better on Ti framelocks.
 
outstanding thus far....... I have been running 120 grit alum oxide. Granger is the closest place to me (so I don't have to pay shipping) and they offer a few different glass bead options. I am not sure what I need to get......fine, med, course.....but they don't offer grit.....it is in micron's?????
 
glass spheres are more suitable IMO because the leave a very smoother surface rather than the alumin oxide that is more aggressive.
 
I have been using a coal slag abrasive called "Black Beauty", it is cheaper than aluminum oxide or silicon carbide and has a decent service life. It is a sharp, angular grit which gives a finish similar to these abrasives, overall it has worked well for me but I am wanting to get a smoother finish, the abraded finish does not clean very well.
I am going to try fine glass beads, I ordered some yesterday.
Whatever you are using to blast, you can "cut" or over-polish the finish with scotch-brite and get a somewhat smoother, more satin-ey finish that is still non-reflective and looks like it should absorb light scratches and wear pretty nicely. This seems like a good option for knives with kydex pants especially.
The more I read on this subject the more I think that a lot of the rust issues associated with bead blasting might stem as much from a very rough finish prior to blasting. It is pretty natural to want to stop grinding at a rough grit and go directly to blasting but the coarse scratches will remain under the finish, and if you imagine what happens when the beads bombard the edges of these scratches, it is no surprise that there are rust issues. I suspect a thorough 400 or 600 grit finish before blasting might help quite a bit with the rust.
 
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Justin..........thanks for the post......lot of good info there. Where do you get "black beauty"?
 
As far as the rust issue goes I was testing this the other day. I blasted a ESEE Izula with 120 grit alum oxide to remove the coating. Touched it bare handed on half of the blade and let it sit for two days. All the areas I touched the blade had rust forming. It was neat in a way because you could see my fingerprints! Went back and blasted it again and then applied Duracoat.
 
I was also curious about how to make this satin finish. I dont have a sand blaster so I was thinking a bit lower tech. I have also found that a random orbit sander at certain grits can do a decent job.

What I was thinking of is some sort of vibrating mechanism filled with sand, you know like those rock tumblers or something else that just vibrates sand or some media around with the blade for a few hours and viola!

Anyone know if that work?



Where do you get this media and where do you get duracoat?
 
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Here is the link for the Duracoat

http://www.lauerweaponry.com/

I am thinking about doing this as a part time job and earning extra money on the side. In addition to me teaching Concealed Weapons classes and selling ammo and media blasting gun parts.

Here is a link for a media tumbler. Not sure if it will do what you are looking for as I don't have one. I do have a brass polisher I use for reloading but not quite the same thing.

http://www.candmtopline.com/
 
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