Chipping With Air Eraser????

[marc_reusser]

I have been thinking about how to get certain wear, chipping, fading and weathering effects for my small scale boat project.....this reminded me of a discussion years ago with Chuck Doan who had tried sandblasting to age and grain his wood, and a recent discussion on the Terrrapin group re. etching the surface of certain materials with an "air eraser" to get better paint adhesion...........

Sunday I was wandering through my local "Harbor Freight" tool outlet, when I came across their "Air Eraser", on sale for $29 (Paasche also makes one that is around $60).....I couldn't resist. (the box also includes an air hose with moisture trap, a wrench, and a holder)



Just to see how the eraser functioned I decided to give it a quick test run (I had no specific look or effect in mind when I did these.....just playing around).  Instead of using the "sand" they sell for the eraser, I used common Arm & Hammer baking soda.

These are 3 pieces of scrap stripwood that were originally stained with silverwood, and painted with Tamiya acrylics (for scale, the middle board is about 5mm wide).




This is a 1/35 Opel Blitz cab roof, the white was painted over a layer of Dunkelgrau, and hairspray (this was a left-over test piece for experimenting with the hairspray method).




Another view of the entire cab roof.....on the green side you can see where the air eraser was used to fade/wear through the green paint which had been applied over the white (you can also see where I held it too long and the plastic base shows through)




...anyway....far from perfected...but maybe something to think about or possibly try as another tool in the weathering arsenal.

NOTE: When using this tool....do it outside...it's messy...and wear glasses.



Marc

[marc_reusser]

One interesting thing to point out on the last image of the roof. Note the difference in the chipping/wear effect. The white paint at the right was applied over a layer of hairspray, while the green was painted directly over the white (and the white under the green was agian over hairspray). You can see that the [aint over the hairspray has a different, more flakey, wear/chip while the paint-on-paint gives a more subtle faded transition/wear/chip.

On the picture with the wood, the effect will vary depending on how thick the layer of paint is. The top piece had the thickest application, and thus appears more peeling and flakey....the wide board had a fairly thin/washed coat this the wear pattern is different, and more paint stays in the grain.

The borrom piece had about a med amount of paint....but I used high pressure and wirked real close, as I wanted to see if what would happen......could one make the wood look rotten/decaying.

Marc

[Scratchman]

Marc , on the wood parts how long did the paint dry before you did the erasing?

Gordon Birrell 

[marc_reusser]

Gordon,

Those came out of my scrap box, so they were probably painted over a year ago.

Marc

[lab-dad]

AWESOME!!!!!!!!!!!!

what kind of pressure(s) were you using?

-Mj

[marc_reusser]

Marty,

I think it was around 50-55 lbs........I didnt really look too hard.


Marc

[chester]

I've had one of those for years but it sits in an unopened box. After seeing the results you have gotten Marc, I will be digging it out to experiment with. Thanks for the motivation. Some very nice effects.

[John McGuyer]

Cool effects. I'll have to look into one of those.

John

[marklayton]

I acquired an industrial bead blast cabinet some years ago.  It's been interesting experimenting with different media to achieve textures and paint wear.  Very fine glass beads will make a machined brass scale part look like it was sand-cast.  Walnut shells (yes, those are commercially available for cleaning delicate parts) will burnish painted surfaces making them look worn, but not worn through.  The only drawback to the cabinet is holding on to small parts with the heavy rubber gloves.  If I lose my grip, and the part can pass through the 1/2" holes of the cabinet's working surface, it gets sucked through the dust extraction blower's impeller.  They're often a bit worse for the wear!

Mark

[lab-dad]

I picked up one Saturday - mine was only $25.00!!!!


Can't wait to use it!
Thanks for the tip Marc.
-Marty

[chester]

Mark, when blasting small parts, tape a piece of woman's stocking over the exhaust to catch them when they go flying.

[John McGuyer]

The trick is to get the stocking off the woman. I'm sure Uncle Russ will help.

John

[RoughboyModelworks]

Ha ha... yeah 

I've had one of the Paasche units for years... great little tool. I've also been using a bead blast cabinet for many years. It's a great way to remove paint from previously painted brass models and prep finished models for new paint. I've also found it very useful for cleaning up 1:1 motorcycle parts for finishing or powder-coating though you do need a fairly high-capacity compressor to be productive. Can't imagine being without it in the shop now.

Paul

[marklayton]

Don't see many woman wearing stockings any more.  Slacks seem to be the uniform these days!   

With a 2 hp blower motor, the air flow is too great for a fine stocking, but Chester's suggestion got me thinking about lying a sheet of fine screen on top of the perforated work plate.  That will keep wee parts from falling through the plate to the bottom where the dust extraction hose connects.  I have a 25 hp air compressor to run the 175# pneumatic forging hammer, so feeding the blast cabinet is a cinch.  Can airbrush all evening without the compressor running once!

Mark

[John McGuyer]

I ordered one. $25 from Harbor Freight. Ordered three different kinds of media so I can experiment. I think it also might be good for cleaning up soldered parts.

John