Help! Home Prep Lab....

[John Papastathis]

I have been buying fairly rare fossils from a respected dealer that are nicely prepped but looking online I realize that both their aesthetic and monetary value would be greatly enhanced by further prep work. (Eg; spiny trilobites). I want to purchase an Aircribe and start a home lab but can't find info on what type of compressor I would need.

Any info would be greatly appreciated,

John

[Uncle Siphuncle]

John

First I would advise getting an ARO scribe or something smaller for delicate work as opposed to a Chicago Pneumatic or equivalent. I use a Craftsman 5 HP 20 gallon compressor that runs up to 125 PSI. You may not need that capacity for a scribe, but if you ever intend to get a microblaster you'll want the extra flow. One of the newer 150 PSI compressors might be even better. You can always dial the regulator down on a better compressor, but you can't dial up a light one if the capacity isn't there.

[John Papastathis]

John

First I would advise getting an ARO scribe or something smaller for delicate work as opposed to a Chicago Pneumatic or equivalent. I use a Craftsman 5 HP 20 gallon compressor that runs up to 125 PSI. You may not need that capacity for a scribe, but if you ever intend to get a microblaster you'll want the extra flow. One of the newer 150 PSI compressors might be even better. You can always dial the regulator down on a better compressor, but you can't dial up a light one if the capacity isn't there.

Thanks Dan,

Can you tell me where I can get one and what is the cost?

John

[RJB]

Hey John. I know two guys who prep almost exclusivly trilobites and they mostly use an air abrasive unit with both bicarb and dolomite media. Just a thought.

RB

[Roger]

I have been buying fairly rare fossils from a respected dealer that are nicely prepped but looking online I realize that both their aesthetic and monetary value would be greatly enhanced by further prep work. (Eg; spiny trilobites). I want to purchase an Aircribe and start a home lab but can't find info on what type of compressor I would need.

Any info would be greatly appreciated,

John

John

I concur with Dan - I have a portable (on wheels) Power Cable brand 2 gal electric compressor (1.2 HP and 3.3 cfm @ 90psi) that I can dial up to 150 psi. Besides prep work I have found it useful in airing lawn tractor tires, wheelbarrow tires after winter, blowing out the shop instead of sweeping etc. As for purchase, mine was purchased at The Home Depot, but Lowe's and Sears (Craftsman) would carry similar quality machines. Don't get duped into purchasing extra hose - I did and have never used it. I guess it would be good if there wasn't an electric outlet close to the situation requiring the compressor but I really haven't had that happen.

Now the difference between 2 gal and 5 gal compressors - I think is that you can use more air before the compressor kicks on; however I haven't found that to be a problem.

As for the air prepping tools - I just purchased a used Chicago Pneumatic and am learning to use it. I don't do any "fine" work with it yet. Oh btw - when my wife purchased it, the saleman did a fine job of "convincing" her that I also would need a complete set of air tools!! So I have a set of air drills, rachets, and hammers. . . . the only thing I've ever used out of the set is the blower!!!!

Roger

[crinus]

John

I have four different air scribes that I use. These tools are pictured below. Fourth from the left is a tool commonly called the Chicago Pneumatic. This tool is used for bulk removal of the rock. It should not be used near the fossil as its main function is to break off large pieces of rock. The first and third scribes are referred to as ARO tools. The names come from the original manufacturer of the tools and are carried over to clones of the same tools. The ARO is used for removal of rock near the fossil. There are modified versions of the ARO that have longer, girthier tips that help in reaching difficult spots. My main tool is the ARO with the standard tip (far left). It works well both in and out of the air abrasive box. When using a scribe in the box under a microscope, the longer tips are difficult to use due to the limited space and depth of field. The Micro Jack #3 (second from left) is for very fine work right next to the fossil specimen. I find it to be the least useful of all the scribes. Generally the ARO works well to a point and then I switch to the air abrasive unit. I do not recommend the Micro Jack #3 because the tips break very easily if you drop the tool. I have gone through 4 tips and have barely an hours use on the device. Miro Jack 4 or 5 are githier and may be better. You can find these tools as well as the ARO and Chicago Pneumatic clones at paleotools.com.

With any of these tools you will need compressed air. The Chicago Pneumatic and Micro Jacks DO NOT work below 100 psi. If you have a compressor that has a max pressure of 125 psi, that is fine BUT at what pressure does it kick back on to refill the tank. If it kicks back on at 90 psi you will have problems as I did. I did talk to a compressor rep and he did tell me how to adjust it so that it kicks back on at 100, but he also told me that it was illegal and dangerous because I have moved the entire scale higher. My max 125 compressor is now 135. I recommend buying the right compressor. The ARO tools do not seem to be a problem at the lower psi's.

Someone mentioned something about extra hose for the compressor. You actually may need it depending on where you place your compressor in relation to your work space. When the compressor is running it is very loud. I have my compressor in the garage and the work space is at the opposite end of the basement. I run the hose from the garage, through the wall, over my ceiling tile and down at the other end. At the other end you should have a regulator and moisture trap (especially if you are going to connect a air abrasive unit).

crinus