New Diatom Project

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Charles
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New Diatom Project

#1 Post by Charles » Sat May 23, 2020 11:10 pm

I bought on eBay and have received diatomite from three US locations: Basalt, Nevada; Monterey, Calif; and Santa Monica, Calif. I will document from start to finish, processing these from raw diatomite to the finished type slide. First, the samples, The 5ml tube, I fill half way with diatomite and rest with distilled water to perform a series of freeze and thaw to break the material into a slurry:

Basalt, Nevada, Packaging, raw material, raw strew slide, material in a 5ml tube with distilled water:
Balsalt, Nevada Diatomite2.jpg
Balsalt, Nevada Diatomite2.jpg (98.06 KiB) Viewed 195 times
Raw strew slide:
Nevada Uncleaned Strew.jpg
Nevada Uncleaned Strew.jpg (137.5 KiB) Viewed 195 times
Uncleaned Strew Slide showing forms from the strew:
Nevada Uncleaned.jpg
Nevada Uncleaned.jpg (68.57 KiB) Viewed 195 times

Charles
Posts: 1173
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Re: New Diatom Project

#2 Post by Charles » Sat May 23, 2020 11:17 pm

Here is the diatomite from Monterey, California:
Monterey, CA Diatomite.jpg
Monterey, CA Diatomite.jpg (122.98 KiB) Viewed 189 times
Uncleaned strew:
Monteray CA Uncleaned Strew.jpg
Monteray CA Uncleaned Strew.jpg (182.88 KiB) Viewed 189 times
Diatoms from raw strew:
Monteray CA Uncleaned.jpg
Monteray CA Uncleaned.jpg (69.38 KiB) Viewed 189 times

Charles
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Re: New Diatom Project

#3 Post by Charles » Sat May 23, 2020 11:20 pm

Diatomite from Santa Monica, California:
Santa Monica, CA Diatomite.jpg
Santa Monica, CA Diatomite.jpg (107.77 KiB) Viewed 189 times
Raw Uncleaned Strew slide:
Santa Monica Uncleaned Strew.jpg
Santa Monica Uncleaned Strew.jpg (142.88 KiB) Viewed 189 times
Diatoms from Raw Strew slide:
Santa Monica Uncleaned.jpg
Santa Monica Uncleaned.jpg (69.02 KiB) Viewed 189 times

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KurtM
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Re: New Diatom Project

#4 Post by KurtM » Sun May 24, 2020 12:07 am

I will document from start to finish, processing these from raw diatomite to the finished type slide.
Most excellent! I am already very much looking forward to each and every installment!
Cheers,
Kurt Maurer
League City, Texas
email: ngc704(at)aol(dot)com
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Hobbyst46
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Re: New Diatom Project

#5 Post by Hobbyst46 » Sun May 24, 2020 10:11 am

Very appealing post.
How many freeze/thaw cycles produced the raw strew slides shown above ?
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

Charles
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Re: New Diatom Project

#6 Post by Charles » Sun May 24, 2020 12:49 pm

Thank you Kurt and Doron for your interest.
Hobbyst46 wrote:
Sun May 24, 2020 10:11 am
How many freeze/thaw cycles produced the raw strew slides shown above ?
The sample from the strew slide had not gone through the freeze/thaw cycle yet. The raw strew slide was made from the powder in the packaging mixed with a few drops of water on the slide. The raw diatomite is a bit crumbly. The whiter the material, the more crumbly it is. It should take between 15-20 freeze/thaw cycles to get the diatomite into a slurry.

The purpose of the raw strew slides was so I could see what to expect from each sample. It looks like the Nevada sample came from fresh water since it is predominately fresh water species and they are well distributed in the diatomite. The least promising is the Monterey sample but you never know until they have been cleaned and condensed.

The seller said he sold quite a bit to Stefano Barone of the Diatom Shop, and I see he is currently selling some nice diatoms from the Santa Monica deposit.

Wes
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Re: New Diatom Project

#7 Post by Wes » Mon May 25, 2020 6:04 am

I like your project.

From previous threads you linked to in my Oamaru post it looked like you are using Zrax and Klaus Kemp's adhesive. From what I read it seems like Zrax (which is probably just good grade Naphrax based on IR spectra) bubbles a lot less than Pleurax. I suspect the pleurax bubbling that some people report might be related to the higher vapour pressure of isopropanol vs toluene (pleurax vs zrax/naphrax solvents resp.).

Anyone care to share their experience with different mounting media and adhesives? What works well for you and such..

Hobbyst46
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Joined: Mon Aug 21, 2017 9:02 pm

Re: New Diatom Project

#8 Post by Hobbyst46 » Mon May 25, 2020 6:41 am

Wes wrote:
Mon May 25, 2020 6:04 am
I like your project.

From previous threads you linked to in my Oamaru post it looked like you are using Zrax and Klaus Kemp's adhesive. From what I read it seems like Zrax (which is probably just good grade Naphrax based on IR spectra) bubbles a lot less than Pleurax. I suspect the pleurax bubbling that some people report might be related to the higher vapour pressure of isopropanol vs toluene (pleurax vs zrax/naphrax solvents resp.).

Anyone care to share their experience with different mounting media and adhesives? What works well for you and such..
I can only testify for Pleurax. The manufacturer's instructions are to heat the slide very slowly until it reaches the target temperature. Indeed, rapid heating causes intensive bubbling upon evaporation of the IPA. Upon gradual heating, bubbling is less fierce and a fairly uniform layer of mountant spreads between the slide and coverslip. It is possible to avoid temperature overshoot.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

Wes
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Joined: Sat Mar 09, 2019 12:58 pm

Re: New Diatom Project

#9 Post by Wes » Mon May 25, 2020 7:00 am

Hobbyst46 wrote:
Mon May 25, 2020 6:41 am
Wes wrote:
Mon May 25, 2020 6:04 am
I like your project.

From previous threads you linked to in my Oamaru post it looked like you are using Zrax and Klaus Kemp's adhesive. From what I read it seems like Zrax (which is probably just good grade Naphrax based on IR spectra) bubbles a lot less than Pleurax. I suspect the pleurax bubbling that some people report might be related to the higher vapour pressure of isopropanol vs toluene (pleurax vs zrax/naphrax solvents resp.).

Anyone care to share their experience with different mounting media and adhesives? What works well for you and such..
I can only testify for Pleurax. The manufacturer's instructions are to heat the slide very slowly until it reaches the target temperature. Indeed, rapid heating causes intensive bubbling upon evaporation of the IPA. Upon gradual heating, bubbling is less fierce and a fairly uniform layer of mountant spreads between the slide and coverslip. It is possible to avoid temperature overshoot.
What is the target temperature?

Hobbyst46
Posts: 2574
Joined: Mon Aug 21, 2017 9:02 pm

Re: New Diatom Project

#10 Post by Hobbyst46 » Mon May 25, 2020 10:36 am

As far as I remember, heating the Pleurax mounted slide should be a slow ramp until about 180C, then 15 minutes at 180C.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

MicroBob
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Location: Northern Germany

Re: New Diatom Project

#11 Post by MicroBob » Mon May 25, 2020 11:40 am

Hi together,
right before Cornona I prepared a group meeting on diatom strew slide making. The aim was to do a bit slide production from selected really nice material so everybody has some slides to take home. For this I built a small heat plate that heats a round cover slip which is then picked up with a pre warmed slide.
In my experiments in the preparation I had some cases where I didn't heat the slide enough to the warm Pleurax to spread fully. In these cases I warmed the cover slips a bit with a cigarette lighter (blue flame version). Here I recognized that in some cases "particles" formed in the mountant reducing the value of the slides considerably. The particles were visible by plain eye as a kind of misty look of the mountant. I haven't checked this in detail but there seems to be a temperature limit that has to adhered to.

Pleurax diatom slide mounting works best upside down in my opinion:
- Cover slip with diatoms (powder can just be shoveled on, spread itself later)
- drop of Isopropanol
- 1-2 drops of Pleurax
- put coverslip on pre heated heat plate (180°C in my case)
- pick up cover slip with pre heated slide (montant spreads well)
- let cool upside down with no pressure on cover slip

I would like to check the "particles" problem first and then show my new equipment and process, will takes some time.

Bob

Charles
Posts: 1173
Joined: Mon Mar 02, 2015 11:55 pm

Re: New Diatom Project

#12 Post by Charles » Mon May 25, 2020 1:49 pm

Wes wrote:
Mon May 25, 2020 6:04 am
I like your project.

From previous threads you linked to in my Oamaru post it looked like you are using Zrax and Klaus Kemp's adhesive. From what I read it seems like Zrax (which is probably just good grade Naphrax based on IR spectra) bubbles a lot less than Pleurax. I suspect the pleurax bubbling that some people report might be related to the higher vapour pressure of isopropanol vs toluene (pleurax vs zrax/naphrax solvents resp.).

Anyone care to share their experience with different mounting media and adhesives? What works well for you and such..
I do use Zrax, which uses Toluene as the solvent and it also bubbles violently when heated. I think any solvent will bubble a lot when heated to drive off the solvent. I also have Naphrax and Pleurax and will test each.

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