FMF - Friends of Minerals Forum, discussion and message board

[Jordi Fabre]

[Peter Megaw]

Depends on the job...small with precision...canned air (go industrial, the Biz Mart stuff sucks and teh cans freeze up quickly)...for big jobs a compressor...problem there is lubricants can put droplets of oil on stuff if equipment is overoiled. There are diaphram compressors used to drive airbrushes that work well for both...

[bugrock]

Jordi and Peter,

Dare we recommend a specific brand or brands of the canned air on this site?
If it's OK would appreciate that detail.

Also, if others have specific dust cleaning methods perhaps we can entertain
another thread. Even when specimens are in cabinets dust will happen but the worst
are those specimens you decide for one reason or another to place on the desk etc.
Not a great idea I admit as more than dust can accumulate. Of course one can always
wash each one with water from time to time.

Another potential subject is how to clean the really delicate minerals, those with fine
and especially hair-like xls. One dealer has suggested using careful immersion
in isopropyl (rubbing) alcohol. Have not tried that but what concentration of isopropyl
works best? Is 70% OK or should you use higher concentration?

Have one large rock from the Minnesota Iron Ranges covered in fine felt like manganese
mineral (like black Teddy Bear Fur) that is in storage. Really looks like a difficult case.
The previous owner kept it in the open in his office for decades and it really shows but
afraid to treat it in any way that will result in stripping the mineral away or washing it
down the drain.

[GneissWare]

I use a WD-40 Turbo Air Blower System (you can google). The specs say:

--9,000 RPM motor with an aerodynamically designed housing and impeller provides enough air velocity to blast away dust off of electronic components safely with out creating static electricity
--Outside air is drawn in though the intake vents and propelled out of the unit at approximately 30 mph

Sometimes they are on sale for about $13 US.

[Vinoterapia]

Actually, if you want to remove dust and the sample is suitable to be submerged in water, I believe that the best is to use an ultrasonic cleaner, just add a few drops of detergent and there you go. I have one of these appliances (2 liter capacity) and use it rather frequently.

Regards.

Jose Luis

[Peter Megaw]

I prefer not to get specimens wet unless they really need serious cleaning...especially sulfides and other potentially reactive species or specimens with less than stable matrix. Dry dust blows off pretty well with compressed air (I have two types...large cans that come from a wholesale electronics supplier and another that uses CO2 cylinders that drop into a special gun...the latter sounds a whole lot better than it is). I will try the WD-40 system.

Obviously, the pressure used needs to be compared to the fragility of the sample, but I find that for fragile stuff starting at arm's length I can gradually close in until the dust vanishes.

I would not use this for fine hair-like samples of any kind since the fibers will mat down permanently. I have successfully cleaned "rats-hair" psilomelane from Socorro New Mexico with a modified vacuum cleaner however. I took a paper cup, punched a hole in the middle of the bottom, put a soda-straw through the hole and taped it in place. Then I taped the paper cup over the end of the vacuum cleaner hose and put a 20cm length of lab tubing over the straw...giving me a powerful but very focussed mini-vacuum. Using the same far-to-near approach, I got to a distance where the dust and broken fibers came off, but not the attached fibers. It was a bit tedious but worth it. The technique also worked well for removing hairs snagged in some aurichalcites that a seller had carelessly left uncovered.

Keeping dust out is a related, but separate matter. To avoid "recycling" dust I always take the specimens outside of my mineral room to blow them off. I also have pretty good weather stripping on the door to keep dust from inflitrating...but it does. I also use a light coating of spray starch on gossanous matrix if it is excessively crumbly. It very nicely keeps tiny particles from sifting off the matrix over time...and addiing to the dust budget in the cases.

[Pete Richards]

[GneissWare]

It's single speed with 2 attachments -- one a 1/2" diameter nozzle and the other a brush with about a 2" opening. You can control it by moving it further from the target.

[Les Presmyk]

I agree with Peter Megaw. If the crystals are delicate enough, the weight of the fluid itself will cause the crystals to flatten. His method for cleaning with a vacuum cleaner is a good one but one cannot lose sight of what you are doing. Since Peter has suggested the technique, I will provide the caution.

There is a famous (or infamous) story of a California collector who was using his wife's vacuum cleaner to clean mine debris out from cyanotrichite specimens he had collected. He started correctly, holding the nozzle of the vacuum cleaner from a longer distance and gradually brought the nozzle closer and closer to the specimen to get as much of the crud out without sucking up crystals. That is, until he got close enough that the entire specimen was picked up. He was so intent on making sure he did not disturb the crystals, he forgot about holding the specimen down to keep it from being picked up by the force of the vacuum. I am not sure how successful he was in removing all of the dirt but he did leave a perfect ring of mashed cyanotrichite crystals in the specimen.

[Les Presmyk]

P.S. You can buy a set of attachments for shop vacuums that will allow you to do what Peter has described, if you consider yourself not handy enough to construct what Peter did.

[Jason]

WD-40 Turbo Air Blower System..will have to check that out

[Screenname]

I just use a dremel with a soft plastic bristle brush on a low speed, too high of speed will melt the brush and could damage the stone I use around 1/4 speed, I have the dremel stylus, speeds will vary depending on which one you own.