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Gadgets, Gizmos, and Dohickeys => Tool Talk => Topic started by: 55fossil on January 31, 2018, 07:06:03 PM

Title: specific gravity tester, buy or build ???
Post by: 55fossil on January 31, 2018, 07:06:03 PM
    I have a lot of Jade and some maybe Jade that I wish to test. I do not mind buying a Specific Gravity Test unit if I know it is correct for the job. Building one is a second option. I am open to any suggestions or You Tube postings if it will help in my decision.
    I also want to make sure I get the correct size tester.
    Duh;  There is also the need to know what size scale it will work with. The advertisements I have seen do not tell you what type or size scale they use with their tester. For all I know it is 3 x 2 inches. I have some scales somewhere and would prefer to find a test unit that will work with one of the small scales I have.  thanks,  Neal
Title: Re: specific gravity tester, buy or build ???
Post by: gemfeller on January 31, 2018, 09:10:35 PM
A lot depends on the size of the items you want to test, and the size of your scale.  You might check Mineralab for options:  http://www.mineralab.com/SpecificGravity/

I have a brand new Universal S.G. Kit from them that I ordered just before the scale I wanted to use gave out.  It won't work with my new scale.  If it fits your needs maybe we can work out a deal.  PM me for questions and details.
Title: Re: specific gravity tester, buy or build ???
Post by: Slabbercabber on February 01, 2018, 05:30:38 AM
The method for this was discussed recently.  Weigh a container with water, suspend the sample and weigh again.  The difference gives the weight of water displaced.  Lower the sample to the bottom to get the the weight of water and sample water and sample.  Divide weight of sample by weight of displaced water to get density.  Any scale and container you can put together will work.
Title: Re: specific gravity tester, buy or build ???
Post by: Jhon P on February 01, 2018, 07:28:27 AM
You just need an accurate scale that is big enough
To weigh the container and the stone you are testing
Everything else you will have. A plastic cup or bowl
To hold the water and a string or wire or tweezers to suspend
The stone in the water. There are videos on the internet
That gives you all the instructions. This method is close
enough for most. Unless you are a needing a very accurate
Measurement.
Title: Re: specific gravity tester, buy or build ???
Post by: 55fossil on February 01, 2018, 07:45:08 AM
   Thanks for the replies, all are helpful. Yes, I understand the concept and can do it. I am looking for recommendations on a test unit I can purchase. I do not want to end up with Gemfeller's scenario and buy a unit that does not work for my needs. The advertisements are not very good in detailing size of unit or material that can be tested.
Title: Re: specific gravity tester, buy or build ???
Post by: Khaya gems on February 02, 2018, 11:21:17 AM
Hi Neal
I was watching a video YouTube that shows practically  how to make the setup. It's on a channel called Cody's lab.
https://youtu.be/iJPjFddLOxo
I use the same system and it's pretty spot on.
Title: Re: specific gravity tester, buy or build ???
Post by: 55fossil on February 02, 2018, 08:39:26 PM
    Yep, looks like I will have to just do it the simple way.  thanks
Title: Re: specific gravity tester, buy or build ???
Post by: finegemdesigns on February 02, 2018, 11:02:52 PM
http://www.zbestvalue.com/testspecificgravity.htm
Title: Re: specific gravity tester, buy or build ???
Post by: 55fossil on February 03, 2018, 09:12:04 AM
  Nice connection. That is a good and easy setup for weighing larger material. Soon as I get my hay shed built I will start on a similar test jig, maybe a bit smaller. The page that shows how to compute Specific Gravity will get laminated and stuck on my wall by the scale.

This is a good reference for others who may be interested in testing specific gravity.   thanks,  Neal
Title: Re: specific gravity tester, buy or build ???
Post by: finegemdesigns on February 03, 2018, 05:06:12 PM
No prob glad to help.

 :glasses9: