The inches of mercury will hardly show up on the gauges. I have tried them before but didn’t work out well 
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Here’s a note put together a few years ago about atmospheric pressures/vacuums:
for the relatively low pressures/vacuums that we are working with-----
It’s all based on the weight of the atmosphere on earth which is approx.
14.7 psi.
If we use a barometer to measure pressure or suction, we find that a columm on mercury 30 iches high (or 760 mm high if you like the metric system) represents this number.
Sometimes this 30" Hg (Mercury) point is refered to as “1 Bar” (One barometer).
In that system, 2 bar would be 29.4 psi, etc.
You could use a column of water for your barometer, but it would have to be about 32 feet high (or roughly 400 inches high) for the water to equal the weight of 30 inches of Mercury.
People in the natural gas delivery business sometimes use “ounces per square inch.
1 oz/sq.in = 1.73” water column, for instance.
Scientist sometimes like Pascals or kPa (a 1000 Pascals), since one Pascal is pretty small.
This list of conversions goes on an on,
See:
but we are generally interested in lower pressures or “suctions”. So that’s why we usually use the “Inches WC” (Inches,Water Column) gauges, sensors and U-tube manometers.
Table of presure readings. I don’t know about you, but I don’t need or want a pressure or vacuum gage that reads any higher than about 30"WC, and that’s only about 1 psi.
In fact, a lot of the pressures, both plus and minus, that I see are in the 1"WC to 6 0r 8"WC range.
Conv Factor 27.7
psi WC, Inches
0.25 6.925
0.5 13.85
1 27.7
2 55.4
3 83.1
4 110.8
5 138.5
6 166.2
7 193.9
8 221.6
9 249.3
10 277
11 304.7
12 332.4
13 360.1
14 387.8
14.7 407.19
Pete Stanaitis
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I have questain about coating my forge ceramic fiber blanket, what would be a good thickness of refractory cement too coat my blanket, Or should i use rididizor instead of shelling the blanket with refractory cement.
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I use ITC-100. Not cheap, but works well. It comes as a powder. You apply it with a paint brush, so it’s only about 1/16" thick, if that.
Some folks use “Satanite” which is a lot cheaper, but it doesn’t have the IR reflection characteristics of ITC-100.
Pete Stanaitis
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I got some shilp heat 3000 f refractory grade A ----85 % alumina/ wood that work as a thin coating thin down grease like consistancy. or a little thinner.? 1/16" thick or Thick;er/ or not work well.THANKS .
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Hi All,
This is what I have learned. Make full sized drawings of what you want to make first. It’s much easier to erase and redraw something on paper than it is to cut and reweld so many times.
Rindert
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You dont want too see my unit, it is in repair cut and reweld more times than i want too admit. , but its getting closer too complete in a few more weeks hopefully/ I gess i bought the wrong cement or morter/ too coat ceramic blanket/ unless i make the 12" diameter burn tube 16" long —at leiste 1/4" thick case around the ceramic blanket with the refractory cement. Then if i were too do that, it would take longer too heat up, maybe i wait and buy the IT-C 100 coating.Too keep the weight down, and warm up time faster,
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Any body got any good link too buy -ITC-100 coatings-- i need too coat a 12" by 16":long burn tube. You think a pint would coat this size tube area. Or how many pints, And do i need a rigidizer before useing ceramic coatings, THANKS
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I never thought about it being a powder. I thought it was a liquid so I was thinking it would dry up on my if I only used part of it. That is good to know.
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looking for tips on useing ITC–100 ceramic fiber coatings/ Questain is do i need ceramic blanket rigidizer before coating the fiber with the ITC-100 coating. Thanks in advance, to any one with real experiance with ceramic blanket sealers.
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Kevin it’s best to use some sort of rigidizer. Sodium silicate water glass is a good rigidizer. Otherwise you’ll pull away the wool when you spread the refractory. You can get water glass at a Home Depot or Menards whoever is your local hardware place.
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Thanks Much Cody for the experianced advise, and that reminded me i have some water glass i bought few years ago, and got side tracked in different direction on another project, If i can find it i think it was a box of powder form.THANKS + 10. Thanks.
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Re: ITC-100, “It comes as a powder”---- My mistake!!! It actually comes as a paste. I think its Satanite that comes as a powder.
I had thought that I had deleted that phrase before I pushed the “reply” button. Sorry!!
Anybody who is interested should go here to get the truth.
https://www.itccoatings.com/products-1
Pete Stanaitis
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Thanks for the info-- that tells me it can even be sprayed on or thinned a half container of water too one container of ITC-100 coating material. Or two parts material too one water. I think i will try some thinner water glass mix, and then after it drys , and or i heat it enough too harden the water glass, then coat the ITC-100 over the water glass stiffener.
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Is there a thread where readable scientific papers should go. I thought this one was interesting: Waste wood gasification in an allothermal gasifier
Rindert
Rindert,
I could not access the file from the link.
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I think I fixed the link. It downloads a file, m11078.pdf, to your computer.
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