extender fluid

[carlshearer]

i keep reading about diamond extender fluid in faceting but i am having trouble finding out what it is and what its role is.
i am wondering if anyone can clarify this for me

[Alan Balmer]

I don’t know where the name comes from. A machinist might call it cutting oil. It helps disperse the diamond, lubricates, and helps swarf removal. Diamond is traditionally used with a light oil. Many people use WD-40, but I’ve heard of trombone oil, silicone/teflon grease, or even nut oils being used.

There are ways to make diamond water-friendly, as in the Gearloose water-based Diastiks. They work fine with just water, though you can use a fluid which helps the lap stay damp, and actually absorbs water from the air.

[carlshearer]

Thanks Alan. I use oil when polishing with 50 k diamond on my batt lap. I am aware of all of the functions of the oil that you describe (lubrication, award removal and cooling).
I guess u have been confused by the term diamond extender and its implications/significance when I see it referred to. So, thanks for clarifying
I do find it interesting and confusing that none of the references I see to “diamond “extender” actually identify the nature/identity/role if the extender fluid

[Alan Balmer]

Yep. That’s because they want you to think it’s something magical that you should pay extra for 🙂

[QuailRiver]

I believe the term “diamond extender” originated with the use of diamond paste. Diamond paste is a diamond and grease compound that used to be popularly used on canvas and resin pads/belts, and on wooden or composition spool polishers, and on Crystalite “Star Laps”, etc.. It was used mostly in pre-polishing and polishing cabs but was also used some in faceting with laps like the old phenolic laps. The “diamond extender” fluid was/is just lite oil used to thin the grease in the diamond paste which allowed the diamond paste to be spread more easily and evenly. Crystalite used to sell a diamond paste kit that had several syringes of color coded (by mesh) diamond pastes and a bottle of their trade marked diamond extender called Crystalube which was a silicon oil product. But many thin oils can be substituted. In addition to the ones Alan mentioned a lot of folks used to use sewing machine oil.

Larry Cashatt

[Alan Balmer]

I believe the term “diamond extender” originated with the use of diamond paste.

I’ll bet you’re right. The term makes sense in that context.

[gemmakermz]

hi i used to work for crystalite/pacific test specialties in the 70’s when we pioneered the making of the plated metal bonded diamond wheel. i used to make the flat faceting and cabbing flat wheels at the factory and later demo’ing the products with the boss at the show all over u.s.a. .. we put out the crystallub he was talking about that was used on the pads to lub and remove cuttings. it was a 30 weight silicone oil then but later mineral oil was added to it. mineral oil will do the job too. i’m using a gallon jug of mineral oil i got from a farm supply labeled as a laxative for farm animals and it works extremely well for the pads,laps and my trim saws. however my preference for facet polishing is a pure tin layered lap (not scored in any way) with 50,000 diamond powder. run lap very slow so’s to not sling everything off, with very slow water drip to make a thin wet mud of the diamond powder. i find this polishes just about everything. i have an 8″ and 6″ i’ve been using for 40 yrs and still work fine. one might try and use the same procedure on a phenolic lap too. i’m not a happy user of oils in faceting, it makes it difficult to see if you have a polish as oil fills scratches. clean stones before un-dopping to check. i find useing the diamond powder much better than the compound which is greasy . i get my diamond powder off of Ebay for about $15 for 5 grams=25ct and does a lot of stones. i’ve found very slow speed and the diamond mud work fine.

[carlshearer]

thanks everyone, very helpful and interesting discussion

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