Practical DIY or modest cost Vapor Phase - does it exist yet?

[pisoiu]

I can predict they are way off the ideal reflow curve esp the soaking time at 160C and the final 230C time will be exceeded for the lower board and not met with the upper board or any shift depending in the actual movement of the boards and rise of the mist.

I am quite sure this will happen as long as there is air above the vapors.

[mrpackethead]

The answer is that you get a step function in the height of the vapour, if you ahve stacked boards,  if you have a 'static' system ( no moving parts ). 

A quick test, The vapour rises to the first board, then 'stops' as the board absorbs energy and then the vapour will start riseing again to the next board and so on and so on.  So yes, the 'curve' would be different for each board.   The time differnece depends on how big ( and how much energy it takes to heat ) the boards are.   

If you had a dynamic system ( boards being dropped into vapor )  and you had a big enough cloud.

At the price of a frying pan and $30 of control stuff, if you want to double up production, buy another frying pan. The currnet problem to solve is cooling.    Its easy enough to heat up the boards to a nice controlled curve, and do it repeatably, and not loose lots of galden.     The cooling side is much more difficult.


 

[mairo]

...     The cooling side is much more difficult.

How do they do it on a commercial machines? I think I have seen that the board tray is moving up and down on commercial ovens, I guess they lift the board of the galden once cooled and introduce cooling from the top? Can't you introduce CO2 into the system for cooling. Many ovens have CO2/Nitrogen inlets for rapid cooling.

[Kjelt]

How do they do it on a commercial machines? I think I have seen that the board tray is moving up and down on commercial ovens, I guess they lift the board of the galden once cooled and introduce cooling from the top? Can't you introduce CO2 into the system for cooling. Many ovens have CO2/Nitrogen inlets for rapid cooling.

Depends on the design. I have seen machines with seperate chamber where the board is transported to cool down, so it is lifted and then moved sidewards to a seperate room,
or it is lifted and a mechanical "lid" is moved to seal of the galden chamber and on top there are pipes around the walls with actively (compressor) cooled water flowing trough them.
I have not seen active air (fans) or that sort, probably to prevent that components get blown out of position before the solderpaste has cooled down enough.

[mrpackethead]

The moment you start adding vaccum and or board transport everything is much more complicated by a factor of ten. While not impossible I do think it’s out of scope for a simple low cost machine.

I have been testing some cooling methods and after quite a bit of trial and error the best solution so far with my electric frying pan is simply a decent fan that blows a lot of air from under the pan. It’s very simple.  With this I hit 3.8c/sec peak temp decrease.   This doesn’t hit the target of 6.   

[KaneTW]

Buy an (a couple) aluminum watercooler heatsink(s) from Aliexpress or your local machine shop and watercool it? That's what my plan was for my vapor phase oven.

[suj]

The shallow pan I bought is too shallow. It heats up fine but the lid leaks a lot of vapor. It seems like big stainless vessels are kind of hard to find, I need something that can fit a 450*350mm board.

Any ideas?

If you have not yet found one, try to use the catering container according to the EN631 Gastronorm standard. They are available in the normalized dimension 2/1 (length x width x depth: 650x530x200 mm), made of thin stainless steel and also lid are available for them. Sometimes, the lid have a silicone gasket. You should fit in <100 Euro. These containers are used by manufacturers of ultrasonic cleaners and imdes probably used it also for his "invention".

[KaneTW]

Oh, that's a good idea. Nice.

[mrpackethead]

The moment you start adding vaccum and or board transport everything is much more complicated by a factor of ten. While not impossible I do think it’s out of scope for a simple low cost machine.

I have been testing some cooling methods and after quite a bit of trial and error the best solution so far with my electric frying pan is simply a decent fan that blows a lot of air from under the pan. It’s very simple.  With this I hit 3.8c/sec peak temp decrease.   This doesn’t hit the target of 6.   

Removing the cover off the base, gets me to 5.1    Some extra heatsinks stuck to the side of the pan and a bigger fan might be enough.  THat will make build extremely easy.  Converting kitchen appliances to soldering ovens is a thing.

[gasmeter]

Hi Gastronorm's do work.

You need the 200mm deep ones and don't fit a sealed lid its not needed or it will blow off.
I simply fitted a swagelok bulkhead fitting in the lid. Then a tube up into the air to condense .
You get a lot of steam at first.

Make sure the tube has a decent bore though.

You can cool it down just with some decent power fans and if you can water cool the lid.

I have gone through several iterations from the flask (which worked amazingly well). To induction heating   huge catering  size pots (trying to work out what to do with them now ).
For home use the Gastronorm is by far the best choice in my opinion.
I had a lot of success with these.

I'm moving in a different direction now but every prototype I made would solder anything I put in it.
I used a metal screened can as a pcb stand on (mins lid) early tests and it soldered the entire can too using the solder in the corner overlap.

Its fun to play with but after every prototype test I weighed my Galden back into the bottle .

I've lost about 13g so far in the last 8 months transferring it between different test vessels from a 900g bottle.

I have also experimented with various types of heater , induction, external, internal.
For an internal heater you can pad out the volume with ceramic beads.

Peter

[gasmeter]

I should add

It also put a metal plate on top of the gastro norm (Al) with a cutout for a bora silicate glass window.
Then I bonded silicone to this so when it sat on the tank, the weight of the metal panel compresses the silicon enough to seal.

Then its easy to run thermocouples etc out of the tank via the plate .
I made a PID controller and really it worked just fine .
I monitored the temp of the heater, the temp of the Galden, the temp over the pcb and the temp 50mm or so above the pcb.



Peter

[mrpackethead]

Have you got a profile?   

[jeremy]

Hi Gastronorm's do work.

You need the 200mm deep ones and don't fit a sealed lid its not needed or it will blow off.
I simply fitted a swagelok bulkhead fitting in the lid. Then a tube up into the air to condense .
You get a lot of steam at first.

Make sure the tube has a decent bore though.

You can cool it down just with some decent power fans and if you can water cool the lid.

I have gone through several iterations from the flask (which worked amazingly well). To induction heating   huge catering  size pots (trying to work out what to do with them now ).
For home use the Gastronorm is by far the best choice in my opinion.
I had a lot of success with these.

...

I have also experimented with various types of heater , induction, external, internal.
For an internal heater you can pad out the volume with ceramic beads.

Peter

What heater do you use with the gastronorm pans? What about heating the flask?

[mrpackethead]

The IEDMS uses a bay marie ( you call them gastronoms )..  for heating its got ceramic elements under the pan. It does lead to quite uneven heating, which has over time distorted the pan.  Its just too thin for extended heat/cool cycles i think..   

[mrpackethead]

A Few more tweaks and i've now got what i think is a very satisifactory curve with the frying pan.

I reflowed a couple of pcbs today and got very good results.   I'm not loosing any noticable galden.

The next part of this, will be to make a controller board. I've decided in order to make it as flexible as useful, i'm going to make a board that can be controlled via USB.   So, your options would be to control it with a PC, or a Raspberry PI or any other number of thingss...

[gasmeter]

Hi

I put cartridge heaters into an aluminium block, then stood it off about 1mm from the base with washers.
I tried heating from below .It wasn't easy the base wasn't flat enough to get good heat transfer but it did work.

The advantage of the AL block is you can also mount thermocouples on it.

Peter

[gasmeter]

Hi

I designed a PID controller and I was able to achieve any profile I wanted.
The heater was over 2KW so no shortage of power.

When I first started testing in a flask I bought a 3l one from chine that was as big as I could get.
The advantage of the flask is that you can see the vapour forming and rising.

I simply used one of the Chinese hot plates initially, before designing my own multi sensor pid heater controller.

Peter

[mrpackethead]

I've started a new thread to document the design and build for a "practical DIY modest Cost Vapor Phase" Frying pan project.  That post will be for the specific project


https://www.eevblog.com/forum/projects/diy-vapour-phase-frying-pan-project/

[mark03]

Came here from your post in Projects.

I wonder how well this would work in 120V countries?  Generally our heating appliances don't reach 2400W power levels.

[spongle]

Yeah I tried to find a US source for that fryer, no luck.

[mrpackethead]

Came here from your post in Projects.

I wonder how well this would work in 120V countries?  Generally our heating appliances don't reach 2400W power levels.

I had a quick look on Amazon, and i see what you mean.  I suspect that 1800W or so will more than suffice.  With 2400W,  its overpowered, and my gut instinct is that an 1800W frying pan would suffice.   I've been running mine at a maxium of 70% duty cycle.   ( https://www.breville.com/us/en/products/woks-skillets-deep-fryers/bef450.html ).   THat one has a stick free surface.. I can't see why that woudl be a problem, I've just not done it, so dont' know, but it appears to be the same shape/size as the one i have.
 

[KaneTW]

Galden might be incompatible with PTFE coatings (see their FAQ), so test before use. PTFE also begins to pyrolyse at 200C, so be careful. If you can only source nonstick pans, burn it off (in a well ventilated area!) by heating it to around 500C.

[mrpackethead]

Galden might be incompatible with PTFE coatings (see their FAQ), so test before use. PTFE also begins to pyrolyse at 200C, so be careful. If you can only source nonstick pans, burn it off (in a well ventilated area!) by heating it to around 500C.

There you go,  Probably not a good idea to use a non stick pan, and try to find a stainless steel one.

[mrpackethead]

Yeah I tried to find a US source for that fryer, no luck.

take a walk to walmart and see what you can find. :-) Let us know what you find.

[Towger]

take a walk to walmart and see what you can find. :-) Let us know what you find.

Walk to Walmart!  Yanks don't walk to Walmart, they go by car. [emoji43]  If seen walking with a couple of Wallmart bags in your hands you get strange looks from drivers going by.  A regular occurrence when staying with the mother inlaw in Texas.  A big Wallmart is just 6~7 minutes walk down the road.  You actually cannot walk into it without going the final 100m on the road, as the footpath ends!!