using AIR ERASER to clean 3D prints.... TERRIFIC

[Chris333]

Don't for get your 20% off Harbor Freight coupon 

[Cajonpassfan]

Well, the winner is Harbor Freight, it looks identical to the other kits as far as I can tell. And I got my six bucks off and a free LED light. Thanks @Chris333!
Can’t wait to try it out!
Otto

[peteski]

Make sure that you can buy spare nozzles - they do get worn (etched by the blasting media).  But I suppose at twenty bucks, you can just get a new air eraser.

[Chris333]

I dropped mine once and broke of the pipe where the cup joins to. I just bought another one.

You know our local Harbor Freight only give out those LED pucks for free now and they never have any in the store. I feel so cheated. 

[Dirk Jan Blikkendaal]

Otto,

The top one is the one I have/use. It looks like quality not top notch........ but it does the job perfectly.
It clogs every now and then but you can remove the tip by hand (rubber gasket inside) and clean with a .375 mm Tichy phosphor bronze rod.
I leave that rod inside my "blasting box" and this procedure takes a few secconds only.
One advice: buy extra alu oxide but EXACTLY the same brand. You have to refill the eraser quite often (can do only 1 shell per filling)
I got 1 kilo extra for € 2,99 = $ 3.50 about.
This eraser using quite fine alu oxide. Added advantage: no damage to detail.
You HAVE TO use a blasting box (see my picture previous post or Peteski) because the grit flies everywhere.
The extra advantage of this box is that you can easily collect and reuse the blasting oxide + no almost risk of moisture into the stuff.

I am so satisfied, I am almost at the point of redoing my older Shapeways 3D shells, stripping them and repainting/redecalling.

Good luck!

PS regarding the question how I got the idea......its really Lou Bourdages in a recent post on his FB group. He used the thing to remove decalling from cars while leaving the paint unharmed.......

[Cajonpassfan]

Well thanks,
but sometimes nothing seems easy. I’ve tried both baking soda and the aluminum oxide that came with the unit and can’t get the flow of material right...it seems only very little comes out before nothing but air comes out. I’ve  cleared the tip numerous times, and had the pressure up to 70 psi and as low as 25, tried a full range of adjustments on the top of the cup with no success. The only thing I can think of is moisture getting into the line, so I need to get get a moisture trap (here in dry SoCal I’ve never felt the need for it just airbrushing and never had a problem). If I’m missing something, please advise.
Regards,
Otto

[Dirk Jan Blikkendaal]

Hi Otto,

That sounds different from my experiences....  The only problem I get is clogging in the tip every now and then. But then first the air flow goes down and then stops completely. I gues thats coming from some larger particles blocking the exit/tip. As long as the air comes out of the tip the alu oxide comes out in my experience. I havent tried baking soda. The alu oxide coming with my eraser is quite fine and very dry.
The problem is I can not/hardly see/feel the oxide coming out..... so I frequently refill the cup (after 1 larger N scale object - a loco shell - or 2 smaller ones).
I set the air between 50-60 psi and I certainly employ moisture traps..... I my case even 2 because thats the way I connect the eraser the easiest way: on the exit of my normal airbrush moisture trap and the one in the airline of the eraser. Cannot tell about SouCal but overhere thats better I presume. I turn/open the top screw only a little bit.
Looking through the plastic of the box is not the best way to see what the results are, so I have to check my work after I open the lid again and for sure sometimes I need te redo certain spots.
One more thing: hold the tip very close to your object........ 1 cm is max. It takes a lot more strokes up/down and left/right than the regular airbrush.
Let me know what happens, good luck!

[Lemosteam]

Otto, you really need two moisture traps, one at the pressure valve connection and an inline one.  I stated this in the Facebook post as well.

Also note that there is a needle valve screw on the top of the cap where you add the abrasive, this is a shutoff valve.  Make sure that is not closed tight, the hole at the top of to post in the middle is where the air draws in the abrasive.

[Cajonpassfan]

Thanks guys, that’s the next step. TWO traps?!
I need to go find some that fit my system, HF doesn’t carry anything appropriate.
Otto

[MK]

Otto, Home Depot has a lot of air compressor accessories.  I'm assuming Lowes too.

[Cajonpassfan]

Had a bit of a setback. Dang, this is a tough hobby....Now the compressor-to-air tank hose went bad
Leaking all over the place. My loud and expressive comments made my wife wonder why I’m still in this hobby😬
Spent a good part of the day driving around to ACE, Home Depot, ToolsAreUs, and Harbor Freight to find replacement parts (imagine, they’d rather sell you a new $300 setup than a two-dollar coupling!, I’m shocked I tell you).
Anyway, I got the compressor working, but ran out of time to try the new and exciting “Dirk tool” 😁
Time to take my sweet lovely wife to dinner😎
Maybe tomorrow...
Otto

[Cajonpassfan]

Finally had a chance to play around with the Eraser today. I learned it takes lots of practice, among other things.

I now have two moisture traps, kind of a suspenders and a belt situation, but it works and I have very little clogging now. Before tackling one of Dirk’s parts, I decided to practice on some old Red Caboose late ice era reefer shells.
(They have exquisitely rendered sides, see first photo, beautiful finish, correct lettering styles, but inexplicably undersized logos and slogans. I don’t know what they were thinking It would be nice if whoever owns these now would rerun them with correct lettering and perhaps correct new ends).

Frankly, I do not understand how this tool can be used inside a plastic box. I’m having enough trouble observing the work even without a view barrier, because so little material comes out of the nozzle as to make it virtually invisible.

I took it outside as I’m fortunate to have a covered outdoor work bench for painting and such. Today was a breezy day which makes for quick dispersal but I donned a mask and and an Optivisor, and did the work with my face close up. Even so, hard to see anything, other than the lettering fading and disappearing. Using the Aluminum Oxide left dark “smudges” on the orange background (and frankly made me uncomfortable about maybe breathing the stuff) so I switched to baking soda. For this purpose, the baking soda seems to work fine, with the tip quite close to the work. The top car in the pic below was done with the abrasive, the lower two with baking soda at about 45 PSI. I also tried a couple of Dirk’s parts, but I think maybe these were painted? already so can’t compare with and unprepared print...

I have a ways to go to master this new tool but the results are encouraging so far. Thanks guys for the valuable advice!
To be continued, I’m sure...
Otto

[Chris333]

Unscrewing the top knob makes more grit come out and work faster. I find the cup needs to always be full to work well.

[Cajonpassfan]

Unscrewing the top knob makes more grit come out and work faster. I find the cup needs to always be full to work well.

Thanks Chris, good suggestion: keep the cup close to full.
Next time...
Otto

[Dirk Jan Blikkendaal]

Hi Otto,

Glad it works. Good to know the baking soda leaves no traces. The alu grit is probably just a little more aggresive which is ok for the 3d print cleaning in my opinion (I simply wash the prints and most of the gray haze is gone bythen).
The shell parts you are showing are cast grey resin..... I am afraid the eraser will not improve them very much...... All my original 3d printed masters are eraser treated and a lot better by now...... .When I have to make new master moulds I will employ these of course.
I wish I had known this trick before I started www.atsfnscalemodels.com..........