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Techniques for CollectorsMaking saw marks look natural

26th Jun 2015 23:40 UTCAnonymous User

Hello all!

Would you please help by offering ideas on how to make an area of a specimen that is cut with a saw disk look natural.

Please,note in your replies if this is an idea or an observation by experience-this is important,since a good idea should be used and compared/combined with already successful techniques.

Also,please try to describe/guess the disadvantages of each technique you may suggest.

Thank you all SO much in advance!

-Kostas.

27th Jun 2015 01:05 UTCSteven Kuitems

Air abrasion should work, you need to know the hardness

Of your specimen to determine which material

Glass beads, pumice, walnut shell, etc

Steve

27th Jun 2015 01:15 UTCAnonymous User

Stevens,

Thank you for your reply!

Air abrasion is a well-known technique,but with two disadvantages:

1-Could damage crystals,since there is little control on the powder shot

2-Will give a surface similar to polishing (only rougher...),which doesn't look natural enough.

So far,I find a pneumatic engraver the best way,but it also leaves marks behind.Is there any other way?

Thanks!

-Kostas.

28th Jun 2015 12:18 UTCRock Currier Expert

Usually small pneumatic hammer chisels are used. It is much easier to remove saw marks from softer material than from harder material. What is the rock or mineral that you cut away? Can we see a picture of it. For hard matrices with delicate crystals, the crystals may be at jeopardy from the vibrations of the equipment.

28th Jun 2015 20:56 UTCUwe Ludwig

In such a case I cut with a small cutting disc into the dispensable part of the matrix. I start from the edge and break the small matrix gill away. Then I set the next cut. It must not be parallel to the first cut. Then I break the next matrix plate away. I repeat than until the matrix part is small enough. At last I go with the cutter criss-cross over the backside to remove the traces of the cutting disc or I go carefully with a small hammer over the backside.

To avoid damages of the crystalls I fix the cutting machine and guide the specimen by my hands. I recomment to prodect your hands by gloves.

Rgds.

Uwe Ludwig

4th Jul 2015 01:17 UTCAnonymous User

Hello!

Please excuse my delay in reply!

Thanks a lot for the replies and the great recommendations!

Rock,I'm not talking about a specific specimen.This is the best method I know of so far.However,pneumatic hammers still leave some marks behind-in best cases those are small white spots(micro areas with internal cracking,which appears as white spots).

Uwe,your method is the method I used years ago,and works well,but it's very limited and certainly very risky,both for the specimen and your hands.I would recommend using a quality one handed rotary tool with a small diamond disc for cutting.If you don't need deep cutting into the rock,the small disc is much safer.I'm not sure if the glove will help or make it more dangerous,since,in case of an accident,the threads of the glove may block the tool,make you lose control of it and cause much more serious injury!

Please PM me with recommendations of companies of pneumatic engravers.

Thanks a lot!

-Kostas.

4th Jul 2015 12:17 UTCDennis McCoy

Have you attempted chemical etching?

4th Jul 2015 13:19 UTCWayne Corwin

Save time,,,,, Just don't cut it in the first place :-D

13th Jul 2015 08:11 UTCAnonymous User

Hello and please excuse my delay in reply!

1-Chemical etching:It is a way,but I really feel cutting is MUCH more natural than chemical etching.Cutting does not alter the species,while chemical etching does.The point here is to offer a more natural look to an already "natural" treatment,not replace it with an unnatural treatment.If I can't cut in the first place(a good example is removing Natrolite off Benitoite and/or Neptunite...cutting may damage the crystals),then,yes,I will pick chemical etching as a last resort and I will avoid full removal of the Natrolite,if I don't want to result with loose crystals.

2-Not cutting-Wayne,I know you were joking,but yes,I won't cut if I have this option.I would really love it if every piece comes with a perfect appearance after extraction and after some basic cleaning,but this rarely occurs...When a piece can become a masterpiece with proper trimming,I will do my best to offer to the specimen what it really deserves.Isn't that the reason we trim pieces,after all?

Thanks again,please continue to offer ideas!

-Kostas.

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