Temp control success

[davidpretorius]

Hi all,

after Birds fantastic introduction to temp control for us all, I went looking for a temp monitor we had from when our 5yr was a baby.

I found it and it was as I remembered it. It has two sensors, for outside and inside. The theory being you stick one sensor to the window for outside temp and the main display has its own sensor for inside.

Guess what, the outside sensor still had the sticker on it, so it is now proudly stuck to the side of the mirror. This sensor has about 1.5 m of cable back to the main sensor/display and it also has a stcky back. It is now mounted next to the eyepiece holder.

I can now monitor the temp of the mirror and the ambient temp.

I will visit the chemist where we bought it 5 yrs ago and try and find a price for you guys.

As you can tell, i am very happy!!!!

[asimov]

Sounds cool Davo!!

[davidpretorius]

yup have the scope outside cooling as we speak. I have adjusted the primary screws and collimated with my cheshire. I will star test to finish off and even if it is raining, i will image saturn at 4am after the alarm wakes me at 3.29am.

Does anyone want to know the tempertaure, they started off at 18.5 and 18.5 about 10mins ago!!!!

[davidpretorius]

mirror 15.5
ambient 12.5

after 15mins

[asimov]

Yes! This is what happens...the mirror can't keep up with the falling air temp. Once the air temp stabilises, I'll be REAL interested to know how long the mirror takes to catch up! I'll give my eye teeth for one of those sensor units toooooo!

[davidpretorius]

i know you can go silly with the first born and spend heaps, but I would like too think it was not a lot of $$$ I will check tomorrow!

[janoskiss]

Wow Dave, that is too easy! Please let us know how it goes. I'm very interested.

[asimov]

Do you use a fan Dave or do U have to wait for the mirror to reach ambient 'naturally'?

[davidpretorius]

right on the 1/2 hr

mirror 15.0
ambient 14.3

[davidpretorius]

i prefer the natural method.


actually, the 10" from andrews went to including a fan about 2 hrs after mine left his shop!!!

[davidpretorius]

50 minutes

mirror 14.2
ambient 12.9

[slice of heaven]

Good one Dave :thumbsup:

[RAJAH235]

I can see a fan being installed. :D L.

[davidpretorius]

80 mins

mirror 12.3
ambient 11.5

[bird]

Nice one DP.

Something to be careful of - you need to insulate the back of the sensor on the mirror so that it doesn't come in contact with the air, otherwise it'll end up reading part mirror and part air temp.

It's easy to do - just find some waste styrofoam from a parcel and cut out a cap to stick over the mirror sensor.

Weather looks clear here too, and I have my alarm set for 3am, maybe we'll be imaging at the same time ?

Bird

[janoskiss]

Davo, your numbers so far are telling a similar story to Bird's detailed graphs. The temperature is dropping and the mirror just cannot keep up; lagging by around 1 degree.

[davidpretorius]

100 minutes

mirror 12.3
ambient 9.5

[davidpretorius]

if i only have two sensors, is it a good thing to try and measure mirror and tube air temps???

or should i just stick to purely mirror?

[bird]

Buy another baby monitor, then you'll have the 4 sensors :-)

You'll find the difference between tube temp and air temp very amusing, and you really do need 2 sensors on the mirror to get an accurate picture of what it's doing, one in the middle of the back and the other on the side up close to the aluminised front surface.

Bird

[bird]

Interesting to watch your temps - ambient dropped 2 degrees in the 20 mins from 80 to 100, but the mirror stayed at 12.5

If you're near the scope, watch out that you're not warming up one of the sensors. I've done that a few times by accident.

Bird

[janoskiss]

It's nothing but clouds over here so I'm watching this thread with interest. Dave, I am recording your data as you're posting it. Here's a plot of the data so far.

[davidpretorius]

140 minutes

mirror 11.1
ambient 7.5

[davidpretorius]

seeing is improving, temp dropping, moon rising. Transparency is beautiful.
Had a lovely look at orion. Collimation is very good -> 5 stars in the trap. SMC showed up lots of clusters and detail tonight. LMC, started at tarantula and literally followed a ribbon of nebula and features.


Hopefully 3.29am alarm works, temps will have stabilized and saturn will be beckoning.

Catch you all in 3 hours!!!

[davidpretorius]

if the price is right at the chemist then yes i will buy another.

Bird advised it, my wife will understand!!!!

[janoskiss]

..

[bird]

clouded over here :-(

Bird

[davidpretorius]

4.15am:

clouds = no go!

mirror:5.9
ambient 3.3

it was quite chilly

[iceman]

I got up at 3:30am too, but clouds :(

[davidpretorius]

8.08am:

in the garage downstairs. I will be most interested that when the temp has stabilized during the day, that the two sensors show the same. Both showed the same temp before attaching to the mirror.

mirror:14.3
ambient 15.0

[slice of heaven]

Definitely. Hook 1 or 2 fans from a computer up Dave to cool your scope. Steve's graph clearly shows there's no way the 'natural' cooling method will keep up.
It' a nice little excercise you've started on :thumbsup:

[davidpretorius]

asi has sent me a great article on how to blow air across the mirror, so guess who has some reading to do!!!!!

[slice of heaven]

There was a great thread on CN about cooling reflectors. It was a top thread to follow,lots of useful ideas. I think it was where I first read of Birds cooling setup.
It might have been 'Reflectors v Refractors'

[acropolite]

Interesting stuff Dave, does the Temp monitor log with time or were you running outside to check each time. If logging is not impostant DSE and Tandy have heaps of inexpensive dual sensor indoor/outdoor thermometers most of which would suit the task admirably. I think some even come with inbuily hygrometer, moisture content may be interesting to factor in. I would imagine that the mirror cooling lag scenario would be even worse with SCT's . :confuse3:

[davidpretorius]

i was running outside!!

i am going into town today to look at DSE and the local chemist

[iceman]

Look forward to hearing what you find Dave!

[bird]

DP, might be worth checking how accurate those temp sensors are, maybe with a glass of water and a normal accurate thermometer. Start with warm water and see if the electronic thermomenter agrees with the "normal" one as it cools.

regards, Bird

[davidpretorius]

the old physics 101 question: "accurate or precise"

am i wanting to know the exact temp, or that they can equalise as a group?

9.35am:

mirror:15.3
ambient 15.6

[bird]

Probably comes to about the same thing - if you're going to try and equalise them all to the same value.

They're probably using the same $5 digital sensors in my kit...

Bird

[janoskiss]

I just checked Jaycar's website. They've got lots of dual in/outdoor thermometers, from $20. Just not sure how suitable the sensors are for attaching to the mirror...

[davidpretorius]

http://www.jaycar.com.au/productResults.asp?whichpage=4&pagesize=10&keywords=temperature&CATID=&SUBCATID=&form=KEYWORD&SPECIAL=&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=

QM6326 looks good, but as you say, attaching to the mirror looks interesting.

The baby one had a sticky pad on one side of the sensor which made it easy

[iceman]

Is it actually measuring the temperature of the mirror, or the temperature of the air just near the mirror?

[Starkler]

Whats needed is a small sensor of low thermal mass that can be thermally coupled to the mirror whilst insulated from direct air contact.

Birds sensors are tiny beasts the size of a small transistor and mentions insulating them from the air with polystyrene.

[davidpretorius]

I am going to take some pictures today.

It is stuck to the side of the mirror near the top. Bird has suggested i put some styrofoam over the back of the sensor to make sure it is measuring the mirror.

[Starkler]

I dont think the actual read out temperature matters, just that both sensors accurately track each other over a wide range.
Yep a glass of warm water placed in the fridge should do it.

As for thermally coupling the sensor to the mirror, a small amount of heat sink paste will help. Its horrible messy stuff to deal with though.

[bird]

Geoff, that's what I did - I was a bit paranoid about making sure the temp sensor was reading the right thing, so I put a small smear of thermal paste between it and the mirror and made sure the back of the sensor is completely insulated from the air. Styrofoam cap, thoroughly glued on with 5 minute araldite :-)

It's the only way to be sure.

Bird

[bird]

btw I mounted the sensor on it's own small connector so I could plug and unplug it without having to remove the sensor. You can see some pics of this on my website here:

http://www.acquerra.com.au/astro/equipment/temp-logger/

That way I can be sure that the sensor is firmly attached.

Bird

[davidpretorius]

ok off to town with the girls, just dad and the daughters, so i will be able to dictate where we go ie Dork Smith!! How hard can it be to organise a 5yr and 2 yr old. Gee they are taking a long time in the bathroom!!!

right, i am in charge, i am in charge, no toy shops, junk food and the other banned items on the list the wife gave me

[bird]

Hmm, 5yr old, 2yr old and DP... pick the child in this group.

[davidpretorius]

?????

oh ok you are right!!!

got it at DSE for $30, have got the digital camera so I will go downstairs and mount it out and take some piccies

[davidpretorius]

Pictures of the two.


The original old white one and the duck smith digitor for $30.

I now have one on the mirror, one sitting lazy in the tube, two measuring ambient.

[bird]

Hmm. "Temp Alert, Dual Thermo"... I've got one of those exact units sitting on the shelf here in front of me. I wonder if I bought it last year before I decided to build the Beast? I can't remember...

Bird

[davidpretorius]

Temp chart starting at 17:45 every 15 minutes

[bird]

You're doing these by hand I guess...you're going to have a busy night :-)

It's clear around here, but a bit windy - still, I'll stay up and keep you company and maybe it'll stay clear and I can have a shot at Saturn in the morning.

Bird

[bird]

Question - have you put thermal paste between the sensor and the mirror, or added an insulating cap over the sensor?

[davidpretorius]

yup by hand, I will give these a good go and then invest in an automated thing.

I am liking the idea of sucking the air sideways off the mirror?

very nice here again, so will give saturn another shot!

[davidpretorius]

no, just stuck it with the sticky base. i also have not insulated, but the other one "tube" is near the mirror one and just loose, so i hope to get an idea if the mirror is dominating the mirror sensor.

I will be doing a more professional job later once i get the sensors like yours.


oops 15 minutes up, go and check again

[bird]

Looking good Houston

[davidpretorius]

update

[bird]

The mirror sensor is following the tube temp very closely, I'd be a little suspicious that it's reading a combination of mirror and ambient.

We'll see if it's any different after you've made those changes to it.

[davidpretorius]

when the tube was removed, both sensors settled to the same temp. I still think that the mirror cooling is still the major factor on that sensor otherwise they would be cooling at the same rate and value, would this be right?

[bird]

Yes, it's certainly a factor, but I wonder if it's reading the average of ambient + mirror or something like that, if it's not completely insulated from ambient.

That would help explain the rapid drop in the mirror reading, which seems a bit faster than it ought to be.

Bird

[davidpretorius]

updatescope is pointing directly up, i will now point it down at roughly a 45 degree angle.

I thought that hot air would rise, but maybe air needs to come in and out of the top opening

[davidpretorius]

ok, test done for now! Bed now otherwise no getting up for saturn.

Not sure if the mirror is now falling quicker due the scope being on its side, or the ambient is going thru another drop.

Put it this way, 1 month ago, I would have well and truly thought I would be right to go having left the scope out since 6 oclock. There is still a 1.5 degree difference after all this time, due to falling temps and the mirror not being able to expel that heat quick enough!!!

I think it is pretty straight forward guys and girls. A fan must be tested to see if it can right the situation.

In summer in tassie, this situation of being at 20 degrees at 6pm is common and 10 degrees nights or less are also common. I would say that over this extreme of temps after the sun goes down, a 10" dob mirror will not reach ambient temp for at least 1-2 hours after the ambient temp has settled. Most probably in the early hours of the morning.

More data is needed, but this little experiment has been well worth the effort.

Now, please no clouds for saturn!!!!!

Sweet Dreams

Remember $30 for the dual temp sensor from duck smuth. I am going to be recommending to all noobies from now on!

[bird]

Good luck DP, nothing but clouds here

[Robert_T]

Hi David, probably a question more for Bird (feel free to chime in here Anthony) but I'm wondering how close the mirror's temperature needs to be to ambient to achieve good imaging. I must confess to occasional lapses of "near enough is good enough" thinking :P, and wondered whether there is a point of "diminishing returns" in image quality gains as one approaches thermal equilibrium between mirror and air - I guess what I'm getting at is how much the last 1deg and then the last 0.5deg etc is worth pursuing in terms of improved imaging (subjective as this is).

Would I be right in thinking that like most things (eg use of raw mode etc) to squeeze that little bit extra from our imaging depends on no other weak links being present such as poor seeing etc?

cheers,

[bird]

Robert, if you've got broadband and don't mind downloading some 3Mb avi video files, then I can show you the answer to your question.

While I was at Snake Valley a few weeks ago I recorded several videos of Mars, some of them when the scope was out of equilibrium. I made a web page to show how much difference there is:

http://www.acquerra.com.au/personal/bird/astronomy/cooling/ballarat/

The short answer is, if you can get the mirror to within 0.5C of ambient then you'll be good to go.

regards, Bird

[davidpretorius]

thanks weather gods, littlest princess woke up crying , so daddy gave her a cuddle (they are so cute).

no clouds, i repeat huston, no clouds, you are green for go!!!

[davidpretorius]

Well got 300 odd frames of saturn to process. That is 9 flybys by saturn captured at 5fps and 7 secs at a time.


Temp seemed to settle. Did star tests on mag 0/1 stars and then finie tuned on mag 2/3 stars at high magnify. Went back to the trap and had a look and saw my my best view of 5 stars ever. So scope collimated as best as it has ever been, mirror temp about 1 degree away from ambient, so from a viewing point of view, I had nice pin point stars to look at.

Now..... i wonder how the saturn stuff will process!!!!

[iceman]

Great work DP, looking good. The temp sensors look good value at only $30, but I think i'd prefer to have something logging to my laptop so I might take a bit more time setting something up.

However I'm very impatient and don't have much time for long term projects atm so the $30 job might be the best way to get something happening quickly.

[matt]

nice work davo

very interesting.

[davidpretorius]

logging yes, i will be selling these ones & setting up something more permanent.

If you are impatient and don't own a fan?? I would be looking for a fan system very soon if you have temp swings like I do down here

[Starkler]

Dave, today I was thinking about stuff I have read recently on ota tube materials and supercooling of steel tubes.
Are you in a position to conduct a wee experiment?

Say one sensor measuring ambient and another the temp of the steel tube?
As the one side of a dob tube is always facing skyward perhaps a removable fabric/canvas/rubber drop cover can cure the supercooling blues :whistle:

[davidpretorius]

I will set that up now.

All fours (2 measuring ambient) were showing 19.5 as i got home.

so, one on mirror, one on tube (inside or outside)?????

[asimov]

In reference to that article I sent you Davo, you will note that Konus has adopted that technique in their reflectors.

I had an idea sometime ago about getting rid of that boundary layer, which I won't discuss here in case of ridicule! :lol:

[davidpretorius]

cmon , let us know. I am pulling apart a computer for the far tonight and hope not to drill holes in the wrong places!!!!

oops 7pm, better go and get some readings for geoff being a moddie and all!

[Starkler]

THe idea is to measure the temp of the metal of the OTA. Maybe outside is best with something over the sensor to keep air away. A small bit of clingwrap maybe?
Is the sky clear where you are this evening?

[davidpretorius]

clear as a bell.

i have started, but will wrapped a few lots of cling wrap around it.

At the moment it is staying the same temp as the ambient.

it is on the outside.

a' cling wrapping i will go

[bird]

A small cap of styrofoam over the sensor would likely be the best bet, lots of insulation so that the sensor is only reading what it's in contact with.

DP did you get some thermal paste today?

regards, Bird

[Starkler]

I look forward to seeing the results later :cool:

[davidpretorius]

no thermal paste yet.

ok sensor on metal, some styrofoam, to medical compression bandages and glad wrap,

ah yes my camera!!!

[davidpretorius]

my neighbours know i love my scope, but this must look ridiculous

[asimov]

Not as ridiculous as my setup last night!

[davidpretorius]

update

[bird]

Davo, thanks for the pic - you've certainly used a lot of gladwrap, I'm not sure what effect that's going to have, it might slow the cooling a bit if it's adding insulation around the mirror?

This is fun to watch.

Bird

[davidpretorius]

not as much fun as my neighbours are having.


i can't see why they are laughing so much at my telescope.

actually it is getting a bit chilly on the willy out here watching the temps change, so i better take my nude ass inside and get some clothes on!

[bird]

Hmm, I saw a thread elsewhere about snakes...

Bird

[bird]

I must be a sucker for punishment, but ti's clear tonight so far, so I'll have another go at Saturn in the morning. In the meantime I might organise for my temp measurements to be uploaded to my website, say every 15 mins. Not for any good reason, but it might be kinda fun to compare with Davos.

Bird

[davidpretorius]

update from the nude scoper!

[davidpretorius]

bird looks like he is right again.

mirror and scope tube are neck and neck.

Although they are lagging more or less only 1 degree above ambient so far at the rate of 2 degrees an hour!

[davidpretorius]

well the mirror is saying it is cooler than the metal. I may have overdone the gladwrap and bandages.

i must say that the mirror has done well so far. ambient has dropped say 3 degrees in 2 hours = 1.5 degrees an hour and the mirror has been only .5 to 1 degree above that.

[bird]

Davo, looking at your graphs is very interesting.

I must say that I'm still dubious about your mirror reading though, I'm looking forward to your graph after you've got some thermal paste between the sensor and the glass, and covered the back of the sensor with styrofoam or something.

I'd bet that the mirror temp you're reading now is actually a combination of mirror and ambient, and your mirror is actually a bit warmer than you think.

If you look at your data, don't you think it's interesting how the mirror temp levelled off at about the 1:30 mark, just as the ambient also levelled off? That looks a bit sus to me... If the mirror was really cooling as fast as the earlier reading suggest then it should have kept on cooling down to ambient...

Bird

[davidpretorius]

yes, the mirror should keep cooling.


well the bandages are now off and i iam going to see in around 10 minutes and then another 15min, what that has done.

The ambient seems to be setlling as we speak, so i am keen to see what happens in next 25 minutes

[davidpretorius]

where would you buy thermal paste??

also the sensor is as big as my fingernail, so how big / thick should the styrofoam be in your opinion?

[Wombat_In_Space]

Dave I will send you a tube in the mail I have heaps of it.

[davidpretorius]

much appreciated young chap!!!

thanks,

ok off i go for the final reading, any guesses for the mirror now that the bandages have been gone for 1/2 hr?????

[bird]

D1ck Smith sells it, Jaycar also. Should cost just a couple of dollars for a tube that contains a lifetime supply. Beware - it has the magic property of getting on *everything* when you work with it...

What you want to achieve with the styrofoam is to make sure that no part of the sensor is in contact with the surrounding air. I'd cut a square (or circle) of styrofoam that was a few mm larger than your sensor and about 1cm thick, then carve out the right shape so that it fits neatly over your sensor and the edges of the styrofoam cap are down level with the mirror.

Then I'd use 5 min araldyte to glue that cap onto the sensor so that they are now a single unit. You can use tape or something to anchor it onto your mirror with a small smear of thermal paste between the sensor and the glass.

Here's the piccie of how I did this for my sensor, it's basically the same idea.. the big deal is that you can't see any part of the sensor itself, it's hidden under the styrofoam and that's the secret to getting trustworthy readings.

http://www.acquerra.com.au/personal/bird/astronomy/equipment/temp-logger/mirror-sensor2-2.jpg

cheers, Bird

[bird]

I'll be up at 1am for a weather check. Fingers crossed.

Bird

[davidpretorius]

thanks bird,


ok, all finished, temp seems to have settled at 11 ish
Dark blue / light blue are on the same unit, pink / yellow on the other.

All read 19.5 degree at around 6pm this evening.

dark blue and pink were less than an inch away from each other, dark blue is white in colour, pink is black.

the last half hour had the bandages and glad wrap off.

next step is to insulate the mirror sensor and get a fan down there to see if that makes a difference!

[Wombat_In_Space]

Ok it's ready to be posted tomorrow.

[bird]

Davo, where is your tube sensor (yellow) attached?

[davidpretorius]

it was on the outside of the tube on the metal, underneath the styrofoam piece, bandage and glad wrap. That was starklers experiment.

[bird]

Ok, that sounds like a good place for it. I was trying to figure out why the tube was reading warmer than everything else.

Now that I think about it, maybe the tube reading is good and the mirror temp reading is a couple of degrees too low. As the mirror cools it might be warming up the tube with no fans there to move the air away. Hard to see where else the heat is coming from to warm the tube up like that.

I guess we'll know in the next day or so :-)

Bird

[davidpretorius]

Next experiment is to test out the fan i have superglued to the middle of the mirror. I reckon that the secondary shadow should cover this area and wont affect my viewing.

Cloudy here today and no doubt tonight, so the temp drop wont be as dramatic, but i hope to test out the fan tonight.

[iceman]

Nice Dave, how did you attach it?

Also, looks like your mirror needs a clean :)

[davidpretorius]

there is a little ledge at the base of where the clamps screw in. I glued it there.

I am going to move it around the other side because when i tilt the scope, it now hangs above the mirror. I am thinking that this is not good if the glue gives way. I have tried this superglue before and it comes away from metal with a solid tap with a chisel

The mirror is a bit dirty hee hee, but I will wait a fair while until i get the courage to clean. I have done an alright job with the cheapie ep's i have, but not a good enough job on the mirror.

[bird]

Cut a nice hole in the side of your tube and bolt it or suspend it with elastic?

[davidpretorius]

yup, if this size fan is sufficient, then it will be permanent as you say!

Do you think suck out the air or blow air??

A couple of vents on the other side can help feed the sucking.

Obviously drilling the tube means "Dave make sure you have done your homework".


A cover for the fan and vents would be handy to stop dust getting on my lovely clean mirror!

[bird]

Homework...mmm, there's always the Bird approach - "if it don't fit, drill more holes". :lol:

To be serious for a moment, I think the opinions are divided about where the fan should be - some people say on the back of the tube, and some say on the side of the tube like where you have it, or even down a bit so it's blowing/sucking partially onto the side of the mirror.

Where most people agree is that if you have a passive fan arrangement then you're better off sucking the hot air out of the tube. The computer case and power supply manufacturers worked that out many years ago.

Bird

[ving]

interesting stuff davo... cant wait to see the results from the fan :)

[ving]

your mirror clamps look very tight too davo...

[davidpretorius]

truly????

they are done up until i can just feel resistance and then a gentle baby turn.

Finger tight comes to mind, or that was what i have tried to do.

There is no astigmatism on a star test that i can detect??

[davidpretorius]

Started at 17:45, but the temp has started to drop, so i turned on fan at 18:45, so lets see what happens?

I will calculate from two nights ago, a rough lag factor and then we can compare.

[asimov]

Fan glued to mirror cell = vibration = ......?

[asimov]

Unless of course you intend not using it while your viewing?

[asimov]

I've experimented with fans sucking the layer off the mirror. It created a cyclonic effect in the OTA....the column of air in the OTA rotated as it was sucked down past the mirror, & you could see the effect at the eyepiece. Good stuff Dave, good to see your experiments.

[davidpretorius]

hmmmmm, not seeming to go as well as I thought.


two nights ago, ambient dropped at roughly 1.6 degrees an hour and the mirror dropped at 1.4.

tonight it is 1.76 degrees an hour and the mirror at 1.2 per hour

ok another hour and i will turn off the fan and see what happens.

My gut feel is sucking and vents on the other side!!!

[davidpretorius]

at 8pm, the scope went on its side

[bird]

??

[davidpretorius]

i had it vertical and thought that i would test if i had it horizontal, may speed up the mirror cooling and it seems to have worked,

[janoskiss]

Dave, I've been inspired by your efforts and I now take a digital thermometer outside with me when observing. It's just measuring ambient, but it gives a good indication of how well the scope will perform. Once the temperature does not change much more than about 1/2 degree in 1/2 hour, the views are getting good. :thumbsup:

The thermometer itself appears to be limited in relative accuracy to not much better than 1/2 degree. E.g., it can keep jump back and forth between say 12.2 and 12.7 degrees without displaying any values in between, but at other times it will show values between; like after I take it inside... The odd jumps and flat bits on your graphs might be due to inaccuracy in the measurements. :shrug:

[davidpretorius]

well she is improving, i have just moved the scope ready for some mars viewing (even mick pinner is getting the lpi out tonight!!!!!)

if i take a straight line average over the entire night, the mirror is cooling as quick as the ambient.
but since it went horizontal, it has been cooling faster!

[ving]

well thats interesting davo, horizontal hey... so the fan has made a big diference then would you say?

oh and bout the mirror clamps... they just look tight to me, but if they arent effecting you view it doesnt matter just leave it. :)
I do mine tight enough to touch the mirror and then about half a turn so the top rubber bit is still sitting flat.

[davidpretorius]

sort of.

I believe that i will cut a hole in the side and some vents in the other side and then suck air out.

That is the plan!

[ving]

cool :thumbsup:

/me waits for results...