DIY Vacuum Purging Chamber

[jump117]

 

[Gray Wolf]

Just wanted to drop back into this thread and mention my results with the "Best Value Vac" chamber from ebay (http://www.ebay.com/itm/3-Gallon-Va...381&pid=100012&prg=7787&rk=3&sd=221224476283&)

Was working great for a while but lately seems to be losing vac pressure after maybe an hour. The neoprene gasket is noticeably thinner than when I first got it. It seems many hours under vac has compressed it and this is possible leading to seal that is not 100%. I have contacted the seller to see if there is a good way to replace or modify the gasket to improve the seal.

Any ideas here?

Paramount Supply will cut you a new gasket. We use Viton instead of neoprene for this application, but either should work.

You might try a harder durometer material, to keep it from thinning under vacuum.

A thin film of vacuum grease on the gasket may help seal.

 

[Gray Wolf]

View Image

In the 60's we were using hemispherical acrylic inert atmosphere weld chambers to weld exotic alloys and we got the bright idea of reducing our argon consumption by pre-vacuuming the atmosphere out of the chambers using a vacuum cleaner, before back filling with argon.

It worked slick, until one of he welders got the bright idea of bringing a venturi vacuum from home, to see if it would work better.

It did and the implosion gave him permanent ear damage, even after some expensive surgeries.

 

[SkyHighLer]

Reptile heat mats, I got mine from ebay,
"Heat-Sprout Seedling Heat Mat Germination Propagation Sprouting | 4 Sizes"
http://www.ebay.com/itm/Heat-Sprout...t=LH_DefaultDomain_0&var=&hash=item84bef39491
I use two, 11" x 1' without dimmer mats, stacked, and turned ninety degrees from each other. I was plugging them into a 'cheap wall light dimmer in a box,' but added a thermostat and now wouldn't do without it! The thermostat is a DorkFood DSV,
http://www.dorkfood.com/dp/B0088OTON4#specifications
http://www.amazon.com/DorkFood-DSV-...=UTF8&qid=1377629266&sr=8-1&keywords=dorkfood

 

[Gray Wolf]

Reptile heat mats, I got mine from ebay,
"Heat-Sprout Seedling Heat Mat Germination Propagation Sprouting | 4 Sizes"
I use two, 11" x 1' without dimmer mats, stacked, and turned ninety degrees from each other. I was plugging them into a 'cheap wall light dimmer in a box,' but added a thermostat and now wouldn't do without it! The thermostat is a DorkFoods DSV (the generic for this device is a Ranco ETC.)

Hi Skyhighler! Thanks for the reptile mat idea on forum X!

 

[SkyHighLer]

Hi Skyhighler! Thanks for the reptile mat idea on forum X!

I'm curious what the industrial grade wire wound silicone heat mats cost...I also saw etched element replacements for the wire wounds, $$$...

Here is a link to positively identify the product I've tested and use, and to separate the wired mats from the DIY offerings by the same vendor:
http://www.ebay.com/itm/Heat-Sprout...t=LH_DefaultDomain_0&var=&hash=item84bef39491

To wire the mats yourself (the DIY version from the vendor) requires perfect crimps as there is no strain relief other than the mastic tape. Among many other occupations I was an A level mechanical/electrical assembler and getting a solid crimp I would trust my life on (this mat is used under my evaporating dish) took some effort. A bench vise is probably best for clamping the connector to the mat, and the mastic tape is Scotch 2228 (I bought a roll, awesome product, they need to start carrying it at hardware stores.)

 

[SkyHighLer]

Using two, stacked, low wattage (20 watts each,) thin film, heat mats with either a light dimmer, variac, or PID microprocessor thermostat works well and is inexpensive, but I ordered a couple of industrial heat mats to test out for those needing a more robust heat source. I was warned by one vendor that none of these higher wattage mats can be run at full power in free air, so my round stock pot on a square mat with the corners exposed would be a no no. Well see...I ordered a low wattage 12" x 12" square 180 watter for about $100, a 12" round 360 watter for about $75
http://www.oemheaters.com/p-3717-silicone-heating-blanket-12-x-12-180w.aspx
http://www.omega.com/pptst/SRFR_SRFG.html

PID thermostats can obtained from ebay or Amazon for as little as $20-$35, and if you can replace a wall switch you can probably wire a PID controller.

Neither of the mats have shipped yet, give me a week or two to report back...

 

[SkyHighLer]

I tried out two silicone heaters in conjunction with the Dorkfood DSV temperature controller.

Briskheat SRP12121 12" x 12" square, 180 watt (1.25 watts per square inch,) wire wound, fiberglass reinforced, silicone heat mat, about $99 plus shipping and handling.
http://www.briskheat.com/p-411-srl-srp-silicone-rubber-heating-blankets.aspx

Omegalux SRFR-12/2 12" round, 376.8 watt (2.5 watts per square inch,) etched foil, fiberglass reinforced, silicone heat mat, without adhesive backing, about $72 plus shipping and handling.
http://www.omega.com/pptst/SRFR_SRFG.html

Both worked fine and either is highly recommended, the round Omegalux remains under my vacuum chamber...

 

[SkyHighLer]

More pictures

 

[SkyHighLer]

Pictures of the square mat

 

[jump /injack]

GW, you had another one that you'd put together thats interesting using one of the Lil' Terp's/Mark111a 6" tanks and putting 1/2" acrylic [approx. Cost$] on top. What type of gasket did you use on that one and what did you use for the vacuum pump. Do you think that the same heating pad above would work?

 

[Gray Wolf]

GW, you had another one that you'd put together thats interesting using one of the Lil' Terp's/Mark111a 6" tanks and putting 1/2" acrylic [approx. Cost$] on top. What type of gasket did you use on that one and what did you use for the vacuum pump. Do you think that the same heating pad above would work?

I used the existing sanitary spool gasket and either our CPS VP6s, or our Robinair 15500.

I picked up several small remnant pieces of 1/2" Polycarbonate from Multi Craft Plastics for $2/lb.

I also made a lid for the Mk I & II Terpenator using the 1" Acrylic plate that I originally bought for the DIY vacuum chamber.

We are using one of the reptile heating pads that Skyhighler turned me on to, and it works well.

 

[j09]

GW have you done any testing on the air filters helping, and what filter do you recommend using for this application?

 

[Gray Wolf]

Haven't done much research on the subject yet, but cheap and easy is an air silencer/filter, with filter paper rubber banded over it.

http://www.ebay.com/itm/like/310269803306?lpid=82

 

[BagAppeal]

Hello
What do you think about emerging the vaacum chamber in water and using a sous vide water circulator instead of the traditional heating mat?
Something like this:
http://www.fusionchef.de/en/1_3_2_diamond_fusionchef.html

or this

http://www.amazon.com/Fusionchef-Stainless-Immersion-Circulator-Extendable/dp/B00BJOJ6OM

All the best

BagAppeal

 

[Gray Wolf]

Hello
What do you think about emerging the vaacum chamber in water and using a sous vide water circulator instead of the traditional heating mat?
Something like this:
http://www.fusionchef.de/en/1_3_2_diamond_fusionchef.html

or this

http://www.amazon.com/Fusionchef-Stainless-Immersion-Circulator-Extendable/dp/B00BJOJ6OM

All the best

BagAppeal

If you can keep it from floating, it should work well.

 

[BagAppeal]

I am assuming a large vaacum chamber, or weighting it down would do the job.Or could placing some bars above the chamber holding it down do good?

What is your input on a venturi vaacum aspirator, vs a vaacum pump.

"The aspirator works by means of the Venturi effect, using moving fluid to generate a vacuum. Water is directed through the top of the aspirator and discharged through the bottom tube. The vacuum line is on the side. This set contains everything you need to hook the aspirator to a standard faucet and safely support the glass apparatus.
Aspiration kit attains and holds a vacuum of 25-29" Hg within just a few seconds.
Source

All the best

BagAppeal

 

[neeee1]

More pictures

Hows that Thomas performance chamber holding up? Im looking to pick up an identical system (omega and thomas) but would like to know how the thomas is holding up before purchase. Thanks for your input!

 

[SkyHighLer]

Hows that Thomas performance chamber holding up? Im looking to pick up an identical system (omega and thomas) but would like to know how the thomas is holding up before purchase. Thanks for your input!

The Thomas Performance Parts chamber is holding up fine, but the Best Value Vacs look to me to be a slicker design.

Omega has low wattage 10" round silicone heaters in stock, which are probably the correct size for the three gallon aluminum stock pot vacuum chambers.

SRFR-10/2 In Stock $63.00 Round silicone rubber heater, 10 in. diameter, 2.5 W/in2 watt density, without PSA

http://www.omega.com/pptst/SRFR_SRFG.html

You need a low wattage twelve inch round silicone heater for a five gallon stock pot, and Omega seems to never have them in stock. Here's a direct source from China I checked out just so you guys wouldn't have to deal with Omega's aloof attitude,

https://www.icmag.com/ic/showthread.php?p=6429609#post6429609

 

[neeee1]

I'm going to start with a 3 gallon system so the 9" will be good, I'll be ordering that today and the dorkfood controller. Thanks for the response sky!!