Poor Man's Air Blaster

[cojo]

I owned 3 of the Paashe, eventually the brass orfice that has tiny holes in it at the bottom of the container gets the holes worn out and the adjusting screw at the top of the container gets destroyed and becomes immobile. But for the price you will likely get a 100 hours blasting from a Paasche. So it is a very inexpensive way to start air abrasion and the results are as good as seen here . Here is a phacops that was prepped with the Paashe

You definately need to build a blast cabinet and do something to filter the dust or you will be sorry.

I found the 22 gage dispensing tip(not sharp) to be the most usable with the Paashe. The pasche works fine with dolomite or baking soda in the 100 to 200 mesh range. At less than 100 mesh it will clog up but is easy to clear, just unscrew te nozzel and blow it out. I would set the flow as low as possible and use at 35 PSI. You need to use dry abrasive because the Paasche works by blowing the air up into a cloud that then gets pulled out the nozzel with the airflow. Tends to clump if it gets mositure. (Your compressor will put mositure into the media)

the picture is great! thats pretty similar to what i'm looking at doing, just a little more 3D. and it seems like an inexpensive way to begin abrasion. i will set up a cheap box like the one at the beginning of this thread. then if i enjoy it and it seems to work well i'll invest in some better, longer lasting equiptment. thats really interesting about the 22 gage tip. any reason in particular you didnt go sharper? anyway, thanks a ton for the info! the entire thread has been extremely helpful!

[Malcolmt]

Its hard to get sharp needles in Canada but the dispensing ones (blunt) are easy to get I have alll the gages just found as a general one the 22 gage worked best. For me the 22 gage worked better than just the nozzle on the paasche. as I do everything under a scope the extra reach of the needle is helpful. I use the 1/2 inch and 1 inch needles. The other needle that is very good is the pink 18 gage. Try an 18 , 20 and 22 then pick what you like best. here is a picture of a paasche with a needle on it .

I still from time to time use a dispensing needle on the end of my COMCO abrasion unit but the needle wears out very quickly on it. It gives me flexibility in reach and some different nozzle sizes that are a cheap throw away.The real nozzles for COMCO are carbide and cost $30 to $40 each plus shipping. .

[cojo]

that's comco for ya. if i end up liking the paasche, i'll look into getting something from them or crystal. and that 22 is alot smaller than i was imagining. was there any trick to getting the needle to fit into the pen or are they made to fit? and my last question (for now at least) is where are you getting the needles at? i'm sure it's different up there in canada but it there a brand name or a website youre sticking with??

again, thanks alot for the info! i spent the last 2 days reading up on air abrasion and learned more in the last hour than the rest combined.

[cojo]

and you run the 2 pens together so you can fill one with bicarbonae and the other with dolomite, correct?

[Malcolmt]

When I was actively using the Paasche's I had one filled with dolomite and one with baking soda, I also have a number of more expensive dental units including dual canister Vaniman clone built into a metal blast cabinet. I also have an ultraprecise dental hand unit that really only works well with aluminum oxide. These days I use the COMCO 95% of the time and only ever use one of the other units if I am trying to test a mixture on a fossil that plain dolomite is not cutting well. The COMCO works best when the container is 2/3ds full and that is probably a good 1/2 pound of material, so it is a bit of a pain to do test runs. I currently have the Vaniman clone filled with Canister 1 Baking soda and Canister 2 Dolomite with 10% aluminum oxide.

I got my dispensing needles off ebay. PM me if you want to know from whom . They were cheap and you can buy as an assortment in a bag or just the sizes you want. The two I definately used the most were 18 and 22 gage in both the 1/2 inch and 1 inch sizes . Anything longer is just too long. (Most of the time I would use the 1/2 inch size.) Don't forget I do everything magnified under a scope.

The dispensing needles do not naturally fit the Paasche. They have a proprietary twist loc system for syringes. The dispensing needle definately makes the Paasche unit more precise with less overspray.

What I did with the Paasche was grind a very small amount off the sides of the paasche nozzle to make the needles fit better. It (Paasche) is a little too wide otherwise. However with the gluing and taping suggested next you may get away without grinding. I would then put a spot of cyano glue to keep the needle in place (when worn out it twists off easily with pliers). I would then wrap the seal with one or two wraps of plastic electricians tape pulled very tight.

Edited April 24, 2012 by Malcolmt

[cojo]

ya, when looking at the pictures with the syringe tips on, the lack of tape was definately a surprise. i found a guy on ebay with similar syringes but i'm not sure theyre the same so i'll pm you for confirmation. looks like i will have to find a supplier for the dolomite too. i ordered the paasche a few minutes ago so i'll upload pictures when i prep my first specimins. i'm way excited!! i'll be building a blast cab tomorrow. we'll see how ugly i can make it!!

[TOM BUCKLEY]

Keep in mind that you have precious little space between the specimen and the viewing glass. The top of the canister on the Paasche can bump against the glass when you're working. Very annoying. For awhile I was using a Rube Goldberg special that a friend made up for me. It allowed the Paasche to operated by foot and the Paasche unit was held in a vice outside the blasting box. I'm not talented enough to duplicate his system, but the same can be accomplished by buying a foot pedal.....~ $70.00. This does not eliminate the problem of the small canister.

My solution was to ask Santa for a Vaniman Solo unit....without the blast cabinet. Now I have a 1 qt. container. Their smallest tip is .026. I like to use a .018 from Comco. I found tubing that would squeeze over the Vaniman tip on one end and the COMCO threads on the other. Now I can use any COMCO tip. The piece of tubing is only 1" long.

I still use the Paasche but only when the ATH doesn't cut it. I figure out which abrasive to use with the Paasche and then load up the Vaniman.

Tom

[TOM BUCKLEY]

When I was actively using the Paasche's I had one filled with dolomite and one with baking soda, I also have a number of more expensive dental units including dual canister Vaniman clone built into a metal blast cabinet. I also have an ultraprecise dental hand unit that really only works well with aluminum oxide. These days I use the COMCO 95% of the time and only ever use one of the other units if I am trying to test a mixture on a fossil that plain dolomite is not cutting well. The COMCO works best when the container is 2/3ds full and that is probably a good 1/2 pound of material, so it is a bit of a pain to do test runs. I currently have the Vaniman clone filled with Canister 1 Baking soda and Canister 2 Dolomite with 10% aluminum oxide.

I got my dispensing needles off ebay. PM me if you want to know from whom . They were cheap and you can buy as an assortment in a bag or just the sizes you want. The two I definately used the most were 18 and 22 gage in both the 1/2 inch and 1 inch sizes . Anything longer is just too long. (Most of the time I would use the 1/2 inch size.) Don't forget I do everything magnified under a scope.

The dispensing needles do not naturally fit the Paasche. They have a proprietary twist loc system for syringes. The dispensing needle definately makes the Paasche unit more precise with less overspray.

What I did with the Paasche was grind a very small amount off the sides of the paasche nozzle to make the needles fit better. It (Paasche) is a little too wide otherwise. However with the gluing and taping suggested next you may get away without grinding. I would then put a spot of cyano glue to keep the needle in place (when worn out it twists off easily with pliers). I would then wrap the seal with one or two wraps of plastic electricians tape pulled very tight.

Malcolm,

Could you let me know where on eBay you purchased your needles? I can only find 11 unit lots of the same gauge. I'd really like to get a few needles of various sizes. Thanks.

Tom

[Malcolmt]

I don't generally like posting names of ebay suppliers generally but a few have asked me now. The company was CMLSUPPLY. If you search for the following you will find them

Dispensing Needle 18 ga 0.038id x 1/2" Tip Pink 50 PC

They sell variety packs and packs with just a single size. The only ones I ever reall used at all were 14,18, 20 and 22 mostly in the 1/2 inch length but did use the 18 a bit with the 1 inch length.

I had no issues dealing with them. Do not get any of the ones that are pure plastic without metal they are useless for this purpose. The dispensing needle does not fit over the nozzle of the Paasche very well. I ground the nozzle down a bit so it would fit better. I tack in place with a spot ot cyano glue and then I tape up with two wraps of plastic electrical tape pulled very tight. The whole thing will pull off the Paasche easily with a pair of pliers as the cyano gets quite brittle.

For general blasting the pink 18 gage (.0038 inch internal diameter) 1/2 inch long dispensing needle works best. The 22 gage 1/2 inch only with the 44 micron dolomite or other abrasives with small particle size. Aluminum oxide will wear out the needles but at the end of the day they are cheap and I believe much more precise with less overspray than the nozzle on the Paasche. (You do not take the original Paasche nozzle off). Note the 18 gage pretty much never clogs the 22 gage will clog if the powder flow is to high or the material has mositure in it.

Edited April 25, 2012 by Malcolmt

[TOM BUCKLEY]

Here is a pic of a Badger Air Abrader

It is possible to make your own custom orifice using the correct OD and ID of Tungsten Carbide tube. After that substitution is made; it will be the last piece needing replacement. After many hours of use I cannot even detect wear.

This sounds like I'm promoting Badger Air Abraders. I'm not. Just pointing out a tool that is out there. I am recommending that anyone new to prepping should try the inexpensive route before investing in a Crystal-Mark, Comco, SS White, Vaniman or whatever expensive system you have designs on. One should get the basics first. The expensive units do have features that make sense spending the extra money.

I've never seen THAT Badger air eraser. The only one I knew of looked just like the Paasche. This Badger has a 4oz. canister which is much larger than the Paasche at 20cc. Have you tried it with any of the lighter abrasives? Baking soda, dolomite, ATH.

Having the canister beneath the pencil also eliminates the problem of not having enough air space between the unit and the viewing glass.

Tom

Edited April 25, 2012 by TOM BUCKLEY

[TOM BUCKLEY]

OK. You are about to receive more information than you knew existed about non-shaker air abrasion.

Once you understand how the amount of powder delivered to the specimen is affected by various factors, it becomes clearer why some units work for us and others don't.

I recommend the diagrams as the verbiage is a bit hard to follow.

Enter at your own risk. :startle:

http://www.google.com/patents?id=5mnRAAAAEBAJ&printsec=abstract&zoom=4&source=gbs_overview_r&cad=0#v=onepage&q&f=false

http://www.google.com/patents?id=0neFAAAAEBAJ&printsec=abstract&zoom=4&source=gbs_overview_r&cad=0#v=onepage&q&f=false

[Malcolmt]

Tom, those patents are awesome finds. The first one explained for me much better than the second what we as fossillers need to know about the inner workings of air abrasion. BAsed on this I am going to try a copuple tweaks on one of my dental units as it seems that I can get better perturbation by reducing the size of the air input tube.

[cojo]

finished my blast box build!! A little heavier duty than the cardboard box with bags in it (brilliant!), but the same concept. It's built out of 1/2" plywood, has welding gloves installed in the front (extra far apart because at 6'6" I have a decent span) I have home depots sweet "bucket vac" installed, along with a Paasche air eraser and a filter intake for when the vac's on. I put weather stripping between all the wood and silicon-ed it after that and it is air tight. Possibly a little overkill but i didn't want to have to redo it for awhile. The viewing window is a 16"x20" picture frame and is removable for replacing. I will probably paint the inside with some sort of weather resistant paint in the near future, but other than that I believe it's finished!

Total cost (including generator): 160$

Edited April 27, 2012 by cojo

[cojo]

...and one more

special thanks to TOM for the idea.

MALCOMT for directing me and answering every little question and problem i had.

and MY FATHER for help with the build. twice as many hands are far more than twice as productive.

[cojo]

I have heard that regular arm and hammer baking soda will sometimes clog the paasche and other air pens via moisture or clumps etc. What's the best way to unclog the pens? Will sticking a needle up the nozzle cause damage? I don't know where exactly it's clogged but it's coming out much slower than it was several hours ago. There are airbrush cleaners at harbor freight. They look like tiny gun cleaning kits. I could get one of those. I still wouldn't know exactly what to do as I don't know where the clogs usually are. Any thoughts?

[Malcolmt]

That my friend is awesome, great build with lots of room. What's is your final dimensions Looks like you have that bit of extra height I'm missing

for extra light I have one of those $9.99 fouresent 24" undershelf lights in mine

[Malcolmt]

All I do is I run an air line off the compressor and use one of those cheap shop blowing heads that mechanics use for blowing snarge. Have never needed to use a needlle. I have many quick connect couplers. Can hook up to 7 different tools at one time. I used to unscrew the nozzle head and container head on the paasche and empty out the abrasive blow everything clean (back blow the nozzle head) and then back to work. MAke sure you drain the moisture out of your compressor, there should be a drain valve at the bottom depending on the humidity it can build up fairly fast. If things slow down as you use it this is often because of mositure build up.

Airbrush cleaner will do you no good in my opinion.

Edited April 27, 2012 by Malcolmt

[cojo]

Malcomt, i'm going to go try that right now. And thank you! It's 36"x24"x14"h and it has enough room that I cant reach any of the sides. And i do still need to install a light or lights. I like the idea of having 2 coming from different directions so the shadows aren't so much of a problem. But i'm loving it so far!. I'll post some pix as soon as I finish something.

[TOM BUCKLEY]

Tom, those patents are awesome finds. The first one explained for me much better than the second what we as fossillers need to know about the inner workings of air abrasion. BAsed on this I am going to try a copuple tweaks on one of my dental units as it seems that I can get better perturbation by reducing the size of the air input tube.

I'm glad that you found them useful. I refer to them quite often.

Tom

[Malcolmt]

Interesting same dimensions as mine but with an extra few inches of height.... I like it.

For lighting I have the 24 inch florescent inside. Two florescent boom lamps above on the outside and the ring light on my scope (once the new one arrives the old one fried from overuse......) Can never have too much light......

Edited April 28, 2012 by Malcolmt

[Coco]

^{Very interesting subject. I have a question : is it preferable to have a light inside or outside of the box? I think that inside is better, but in that case I suppose that it is necessary to use lamps with leds to have some cold light (no possibility of making holes for the aeration and the cooling...).}

^Coco

[TOM BUCKLEY]

^{Very interesting subject. I have a question : is it preferable to have a light inside or outside of the box? I think that inside is better, but in that case I suppose that it is necessary to use lamps with leds to have some cold light (no possibility of making holes for the aeration and the cooling...).}

^Coco

I use an outside compact fluorescent light which was OK. I just put a halogen light inside the box. I'm amazed at the difference! That extra light makes working under the scope much more effective. Malcolm's right......you can't have too much light.

Although the halogen bulb gives off the most heat of any of the options, I have not had the need to vent the heat or provide aeration.

Tom

[Malcolmt]

I use inside and outside but right now with the ringlight on my scope broken I do not like the amount of light I am getting on my prep until it gets replaced. Takes forever for something to come from Hong Kong but is 1/2 tthe price of buying in Canada. I don't like heat so all my bulbs are non incandecent. I know others use halogen on a gooseneck inside the box and it is very effective at getting the light exactly where you want it.

[TOM BUCKLEY]

I use inside and outside but right now with the ringlight on my scope broken I do not like the amount of light I am getting on my prep until it gets replaced. Takes forever for something to come from Hong Kong but is 1/2 tthe price of buying in Canada. I don't like heat so all my bulbs are non incandecent. I know others use halogen on a gooseneck inside the box and it is very effective at getting the light exactly where you want it.

I wonder how an LED light would work? They are very bright, compact, and give off way less heat than a comparable wattage halogen. Antone have experience out there?

Tom

[Malcolmt]

The new microscope ring light I have on order is a 144 LED model. I suspect it will work just fine from the reviews I have read. Up here in Canada LED bulbs (that replace incandescent) of any brightness are prettty expensive.