Bead Blasting question

Leu Custom

Leu Custom

Joined
Jun 2, 2007
Messages
1,354
What is the ideal setup to bead blast blades? Any good recommendations on a good blast cabinet with a good gun that isn't gonna cost a gagillion dollars? How many HP Air compressor is needed to get an effective flow of air to the cabinet gun without it having to stop and refill and etc etc? Anyone know of any guns that only require 5CFM that aren't pieces of junk? Thanks!
 
Even this basic unit has a minimum of 5 CFM. You might need to up grade your air compressor to insure proper air delivery...
 
Probably far from ideal but my old bead blasting set up was a cardboard box with a piece of plexiglass on the top. Taped a trash bag to the plexiglass and let the bottom hang into the box with two holes in the bag to fit snug on my arms. The compressor was a small one on a bubble and the gun was purchased at the supply house where I got the glass beads. The gun had a hose that went into the box for a constant pick up. The whole shabang cost less the $100 but that was 15 years ago. Worked just fine for prep work on guns needing a matt finish before blueing.
 
Leu Custom said:
Thanks for the reply. Do you know of any that aren't Harbor Freight brand?
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Here is a TP blast chamber, but it shows 7 CFM being the minium... You might do a Google search and look for a small unit, but I think when you set the limit at 5 CFM you are going to have a hard time finding one...
 
So then idealy how many CFM do i want to get a nice good blasting job? The odd thing is i used to use the P.O.S. harbor freight gun that came with the unit (which eventually got a crack in the hose) but it would make a nice even satin finish and now i ordered one from some guy on ebay and it doesn't seem to do that anymore. The only thing that changed was I buffed the blades now with 400 grit compound first and it's like the beads are like skipping off the surface which doesn't create that nice gray satin look.
 
I've used a Harbor Frieght bead blast cabinet and a Hitachi EC12 nail gun compressor hooked up to a 25 gallon bladder tank for years and its just fine. I think I have, well, lets see, the cabinet was like $99 and some change to get it shipped, the compressor I bought used in a yard sale for $30 and the bladder tank was like $40 from a farm supply store. The media I get from wherever I see it local and cheap. Before the EC12 I had an old compressor my neighbor gave me hooked to it but it was so noisy I elected to get that one out of the shop.

I can't say I have any complaints about the HF gun or the cabinet, or the nozzles and how long they last either but I'm sure you could get any gun and use it in the cabinet or upgrade the hoses and everything.

STR
 
Leu Custom said:
So then idealy how many CFM do i want to get a nice good blasting job? The odd thing is i used to use the P.O.S. harbor freight gun that came with the unit (which eventually got a crack in the hose) but it would make a nice even satin finish and now i ordered one from some guy on ebay and it doesn't seem to do that anymore. The only thing that changed was I buffed the blades now with 400 grit compound first and it's like the beads are like skipping off the surface which doesn't create that nice gray satin look.
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Did you try boosting the air pressure? My old set up gave a nice frosted look to gun barrels at 40 pounds. I would imagine hard knife steel is going to take quite a bit more to get the peening action going.
 
Martin I have the large HF side door cabinet, with a dedicated shop vac, I upgraded the gun from msc. I also have the bench top model same type of set up, the big one requires 12cfm and the small one I cannot remember. They both seal well but when you open the door a small amout always makes it to the floor. I have seen the high dollor ones and they leak as well. I have been using both for over a year and I really can't complain. The truth is it does not matter if you use a shoe box its all in the gun so low cost cabnit high dollar gun equals good perfomance..less money

Edit: I shoot most all steels at around 80 psi with 70 grt AO or B60 zirblast ceramic

spencer
 
perhaps I boosted the air pressure too much? 110 PSI! and that doesn't seem to even really give that nice even look like I used to get. Back in the days before i'd blast, i'd use a scotch brite pad and some distilled white vinegar to get the black junk off...can't really call it scale as it didn't flake off, so whatever the rainbow color the steel would develop after heat treatment in a kiln with stainless steel foil. Now I just use a 10" inch JET Buffer and it removes all the black/rainbow decarb? off with just a few passes but when I go to blast the blade, it kinda comes out uneven looking tone. Anyone have an idea? The old blasting gun I used to use that came with the Harbor Freight cabinet had a much larger nozzle hole whereas i'd have to say this gun has ceramic nozzles with maybe only a 1/4" inch hole and the old broken one had probably a 1/2" inch hose. Every thing seemed to be either glued on very very tightly from the hose that went to the compressor so i just junked it when the hose cracked and now the gun i'm using pretty much everything comes apart from the pickup hose to the hose to the compressor. This is what they look like now. Am wondering if that is correct or not looking wise.

tanto.jpg
 
My HF gun has ceramic nozzles that you can get in different size exit holes.

I lose some powder but taping up the seams with duct tape fixed a lot of what was being blown out now and then depending on the angle that I hit stuff.

I typically bead blast a lot of stuff at 60 psi including G10 and Micarta and its not a bad finish at all. I work with a lot of titanium though which I've noticed is something I need to focus on hitting straight on rather than at an angle. I can see some shiny spots when I hit it at an angle and hitting it parallel seems to do the trick for reducing if not eliminating that. For blades and harder stuff I may turn it up a bit to 80 to 100 psi.

STR
 
STR,

I think you may have just turned a light on for me! I usually blasted my blades at angle as not to ding up the edges (sometimes I Blast them after they have been sharpened) and they have no secondary edge. I usually blast at a angle towards the blade edge and perhaps that is what is causing the unevenness! I shall try blasting straight on next time I do a blade! Hopefully that helps!
 
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