[bongobat]

Hi everyone,

I am a member of a forum dedicated to low cost laser scanning: DAVID-Laserscanner Forum • Index page We use a webcam and a laser to create digital 3D models from real objects. A while back I was turned on to your site by a friend and have been visiting here on and off ever since. You guys do incredibly detailed work.

Recently I have given myself the task of scanning an insect. In particular a paper wasp (polistes fuscatus). For the scanner to work its best the object should be a light matte color. I painted my first specimen with a cheap matte white spray paint from walmart. You can see the results here: DAVID-Laserscanner Forum • View topic - Man vs Machine

I am not satisfied though. One of the problems was the paint itself masked the detail of the wasp's body. After asking this question in the Laserscanner forum and in an insect forum I have not quite gotten the answers I was looking for. I then remembered this site and the ingenius techniques you guys come up with to create your detailed models. I hope this is not too far off topic but my question is How would you paint a paper wasp to get a light matte finish yet preserve it's fine detail? Particularly what paint/dye and the technique?

Thanks,

Greg

[Don Garrett]

Greg, I'm a commercial artist detail freak by trade and looked at the pics on your forum. Very impressive. I don't usually paint bugs but I'll toss my few cents in hopes that it may help you out. First off....forget Wally World, you will not find anything that has the fine spray and coverage you are looking for. The only solution that comes to mind for work this delicate is an airbrush with a polished needle. Paasche is what I use although there are a few other quality units out there. Single stage units won't get the job for you so I would recommend a 2 stage internal mix. Use a "quality" airbrush water base paint suitable for paper, wood etc.
With a 2 stage brush (learning curve required) you can control the air/paint mixture from a thin pencil line to a broader "fine" spray pattern with one finger. Thin the air brush paint with water and spray using more air than paint.....properly applied in light coats you will be able to retain all the fine detail. You can purchase a Paashe for around a hundred bucks with several various size needles and accessories for around 100 bucks. You will also need a compressor or tank for air supply.

[Daytonatim]

LOL....well I guess Don and I were typing at the same time.


Hey Greg, how have you been? Man, you are really raising the bar on the David Laser scanner. Congradulations.

Let me introduce Greg to you guys. Greg is the person that helped me with the laser scanning of a couple of small scale car bodies a while back. He scanned a Watson and Kurtis roadster for me.

It sounds to me like your biggest problem is the thickness of paint. Spraypaint cans are notorious for putting out a lot of paint and laying down some pretty heavy coats. Do you have access to an airbrush? With an airbrush you have a lot better control of the amount of paint you are laying down.

If you do have an airbrush you can spray some of your spraypaint into a glass container, let it degass for a while, and then put it in your airbrush and lay the paint down in several very thin layers. This might preserve more of the body details.


Oh, Greg, I still do plan to take you up on your offer you made a while back. I just have to get through July, at which time things should settle down some for me.

Tim

[Don Garrett]

Greg, give Tim a yell, I just talked to him.

[bongobat]

Hi Guys,

Yes, Tim is the friend I refred to in my original post. and thanks Tim for the introduction

Looks like I am going to have to buy an airbrush. Okay so I also forgot to mention I am cheap I am not experienced with airbrushing so to start I thought about getting this: - Harbor Freight Tools - Quality Tools at the Lowest Prices I think this might at least get me comfortable with how these things work. Maybe it will be enough for just scan coating too? Has to be better than the spray can As I am still fighting line width and camera resoltuion anyway it should give me an idea if this is the right route. Thanks again Don and Tim I think I have come to the right place for advice

Tim my offer has no expiration date so anytime you are ready just shoot me an email.

thanks again

Greg

[Don Garrett]

Greg, at that price you can't go to far wrong...like you said, if you approach it as a starting point it looks good....30lbs of pressure may be a bit high for what you are trying to do, you don't want to blow the wings off the bug, hee, hee. For really thin mediums I usually run 20-25 but that depends....heck, grab one, get yourself a big piece of cardboard and start spraying...it becomes second nature after a while.

[Daytonatim]

I am not up on all the airbrush stuff like Don is, so I will ask a dumb question.

Is that a dual action brush in Greg's link?

I'll talk to you soon about that rescan Greg, thanks.

Tim

[hot ford coupe]

Hey Greg. It's great to meet another of Tims's friends. I was going to suggest trying the Tamiya gray primer. It lays down a lot thinner than some of the other preparations but I have to agree that nothing would be better than the airbrush treatment especially if you do a lot of scanning. For my money, the airbrush cannot be beaten. BTW, how did you get the wasp to stay still long enough to get a good portrait? Hee hee.

[Don Garrett]

Don't think so Tim...all those little knobs and thumbscrews look to me like you get what you dial in. A single action is just that...you adjust it as best as it'll let you and spray....these are fine for painting models and much better (in my mind)than spray cans but you can't do much other than spray your dialed in mix. With a double action if you push down the trigger button all you get is air.....the more you pull the trigger back while holding the button down the more paint is introduced into the air flow.....pull back, more paint. you can make one continuous line go from a pencil thin to a broad stroke in one pass simply with trigger control and the distance the airbrush is from the work surface. There is also an adjustment thumb screw that will let you preset the air/paint mix for fixed control just by pushing the button down.

Attached is a really basic free video just for giggles....it's only as difficult as you make it. The airbrush is a tool, once you get comfortable with it you'll wonder how you got by without one. The only drawbacks are cleaning if you work with it a lot and you can't skip the practice it requires to get comfortable. The mural I'm doing is a combination of hand painting and airbrush, that should give you an idea of how versatile a dual action is. When I get to the body on the 1/6th Willys I'll be painting a mural on the trunk using the same airbrush with a needle change.

airbrush-instructions | eHow Search

[mouppe]

Here is my 2 cents worth. Don't cheap out on the airbrush. I have an Iwata HP-C dual action gravity feed airbrush. You can get them on ebay new for $90 or so. The air compressor is more expensive around $200. Avoid canned air. Expensive and the flow is unreliable.

Regarding paint, I suggest you try airbrush-specific paints or lacquers before enamels. Airbrushes are a bugger to clean after using enamels.

Richard.

P.S. I should add that fixed pressure airbrushes do not allow you to vary the psi per paint. Alclad lacquers use a very low psi around 15, whereas airbrush paints can go up to around 45 psi.