Sandblasting

[hutchpipes]

So, I have been blasting with my new cabinet for a couple days now and things are going great. I'm really looking for a little more aggressive blast and can't figure out how to accomplish this. Here are my current settings.

120psi @ 17CFMs
Extra Fine 170-320 grit glass bead
#7 knozzle (tried the 4-6 too with worse results)




After 25 min in

[sandahlpipe]

What diameter is the hose/tubing from compressor to the cabinet? And what cabinet are you using?

[hutchpipes]

The hose is whatever size all the Lowes hoses are. They all looked the same diameter. I'm using a Eastwood benchtop.

[sandahlpipe]

The cfm is measuring the volume of air that gets through the opening at the compressor. Using a 3/8" of 1/4" hose restricts that airflow and reduces the volume your blast gun picks up. I ran 5/8" or 3/4" (can't remember offhand) all the way to the cabinet. The gun is the next variable I'd work on after increasing airflow to the gun.

[hutchpipes]

So you need to change the coupler plugs out to larger plugs too right?

[sandahlpipe]

Just use the largest feasible inner diameter. My cabinet took 3/4" so that's what I used. Also, cfm is higher at lower speeds, so you can set your regulator lower and see if that helps. Also, though it seems obvious, varying the distance and angle of the blast to the work piece makes a difference. There are a lot of variables with a blasting setup. Sometimes you just need some patience and experimentation as well.

[hutchpipes]

My cabinet may take some modification to get a bigger diameter into my cabinet but no big deal. I'm ordering some new hose and fittings now.

What gun and nozzle do you recommend?!

[baweaverpipes]

Hutch,
Please remember that not all briar blasts the same.
Rad and I talked about briar and how unpredictable it was quite often. Some pieces just melt away and other pieces, one's you know are going to blast easily, don't cooperate.
It's rare that I can look at a piece and predict that blasting will be easy and it will melt right off (the soft wood).
Blasting takes patience and there is a learning curve.

[hutchpipes]

Thank! I'll keep that in mind! Do y'all reuse media from your vacuum system? Mine has tiny particles of briar in it. Didn't know if that would clog my gun.

[sandahlpipe]

I save my media in a cyclone but haven't used it yet.

[baweaverpipes]

Thank! I'll keep that in mind! Do y'all reuse media from your vacuum system? Mine has tiny particles of briar in it. Didn't know if that would clog my gun.

Yes, but I have a separator.

[Sasquatch]

I think you have lots of air, and I think nothing will change if you switch all your hoses around.

Two things: one is that glass is not a real cutting medium, it's not aggressive. Second is that the particular block you are using is fairly tight in terms of rings. You won't get a real craggy blast out of that probably no matter what.

But I think you need something in your mixture to help you cut, and let the glass do the detail work, capiche?


This pipe




came out of the cabinet just ahead of this pipe




Very, very different pieces of wood.

[Ratimus]

Thank! I'll keep that in mind! Do y'all reuse media from your vacuum system? Mine has tiny particles of briar in it. Didn't know if that would clog my gun.

Dump everything into a bucket of water. The briar particles will float up to the top so you can skim them off.

[caskwith]

I think you have lots of air, and I think nothing will change if you switch all your hoses around.

Two things: one is that glass is not a real cutting medium, it's not aggressive. Second is that the particular block you are using is fairly tight in terms of rings. You won't get a real craggy blast out of that probably no matter what.

But I think you need something in your mixture to help you cut, and let the glass do the detail work, capiche?


This pipe




came out of the cabinet just ahead of this pipe




Very, very different pieces of wood.

What do you use for aggressiveness?

[hutchpipes]

Should I use a more course glass bead?

[W.Pastuch]

I don't use glass beads at all, tried it once, didn't work.
I get all the detail from fine corundum abrasive, finer=more detail.

[wdteipen]

I agree with Bruce. It looks like it's blasting fine and that that particular piece of briar didn't blast well. The reason I say that is that it appears to have blasted between the grain better than the ring grain. That happens sometimes, in my experience. Try it on a few different pipes and see if you get different results. You can also play around with the angle you're approaching the briar.

[Sasquatch]

What do you use for aggressiveness?

I tried Al/ox but these two pipes were glass with a little 120 Silicon Carbide in. I'm gonna try straight Si/Car at some point.

[N.Burnsworth]

There is a difference between glass abrasive and glass bead. Abrasives cut, bead will peen and soften things a bit. I use them both accordingly and get nice results. And like Bruce said, some blocks will be more difficult than others. I've worked on a stummel for several one hour sessions before at high pressure and didn't get the results I was hoping. Other times I've had to turn it down to 80 psi and adjust the angle of attack, and got great results in a half hour.