Where to buy an etching tank

[Simon]

Well i spent the grand sum of £60 on what looked like a usable etching tank with heater and all on ebay. Well it has been setup a few months now but I've not got around to using it yet. Well this morning I come into the lab and there is a pool of etching solution on the windowsill: it has leaked through the seam. I mean for "F" sake ! this was the only goddamn tank I could find without going fully professional and spending near a thousand pounds. What is it in this shit world of garbage that you can't actually find anything to do the job in hand

[/end rant!]

[RCMR]

Think yourself lucky -- I can't even get my hands on any etching solution around these parts.

It's becoming increasingly difficult to prototype your own PCBs when ferric chloride and ammonium persulfate are unavailable.

[mikeselectricstuff]

Mega Electronics do several - tanks are 1-piece mouldings so no seams to fail. They crop up on ebay occasionally.

[Simon]

Mega Electronics do several - tanks are 1-piece mouldings so no seams to fail. They crop up on ebay occasionally.

yea "only" £235, I did remember them much more expensive. Making my own is an option, but what do you use to glue the parts together ?

[mikeselectricstuff]

Considering the consequences of leaking etchant, I'd suggest looking for an existing moulded object that's about the right shape that doesn't need gluing in the critical areas.
A problem is that many of the plastics that are good for making tanks from, like polythene,  are hard to glue.

[Simon]

yea i suppose I'll end up paying the £235 as i want to start my own business soon so it is best to be properly equiped.

The crap tank actually cost £90 with shipping, a very expensive lesson, be warned all ! these tanks are on ebayat about £43 and shipping to be determined, this is the one i got, don't make my mistake !

Anyone want a 300W heater ?

[Jimmy]

Normal silocone will do the job I would just put in a drip tray just in case.

This is not me

http://youtu.be/DXjWZ9gJ4XE

I would put the air hose up the other way and run it over the top of the tank and put in a one way valve so if the power fails it dosent syphon the liquid into the pump, you could allways drop a heater in but it will work at room temp but it will just take longer.

Polly is easy to weld with the right tools it melts at about 122deg or you could vacuform it by heating it in oven and placing it over mold and use heatgun to help it form correctly. 

[Simon]

hm well if silicone is that good as an adhesive then maybe it is fairly easy to build a tank, I've always thought of it as a sealer only

[Joshua]

What about making your own? Get a rectangular vase, a cheap aquarium bubbler and heater.

Here is something that might be a suitable tank.   

http://www.amazon.com/gp/aw/d/B003JBYX5K?vid=NO

[bilko]

Will something like a HDPE container do ?
They usually hold chemicals and come in sizes from starting from 5 litres. If you cut the top off you can get a tank for next to nothing. If you need heaters and pumps these are available from aquarium suppliers.

[Zero999]

Have you tired repairing your existing tank?

Failing that, you may be able to salvage components from it to use in your own tank.

[Simon]

Have you tired repairing your existing tank?

Failing that, you may be able to salvage components from it to use in your own tank.

well best thing I can do is put silicone around it, it is a 2 piece molded tank that is glued together, nothing to recover, of course i still have the 300W heater and the air pump from it, it is still holding but it just seems to have these occasional seepage's that stop - well take that back, I put it in a bowl and there is another leak under it. another section has not been looking good for a while and showed signs of a small seepage but never actually got as far as leaking out liquid

[IanB]

I'm not sure if I fully understood they story, but you left the tank sitting for months with etching solution in it? If so, that doesn't seem like a very sensible thing to do. Etching solution is corrosive: it's main purpose in life is to eat its way through anything it can. It can eat its way through copper in minutes, so give it months and who knows what it will be able to eat through?

The correct usage of laboratory chemical equipment is to place the chemicals in proper storage bottles between uses, and to rinse and dry the equipment the chemicals are used in.

Ideally your etching lab should have a sink with running water and a work surface where you can put plastic trays for cleaning and rinsing your boards before and after etching.

[Zad]

Ferric Chloride should have no effect whatsoever on a plastic tank. How do you think FeCl is normally stored? I always used to use photographic developer trays in the past - admittedly mostly for singe sided PCBs. To heat it I sat it in a hot water bath.

Silicone is what is used to seal many tropical fishtanks now, so I guess if you get the correct version then it will be able to withstand quite a lot of stress. If it is acrylic then you may be able to use model kit glue on the seams, this melts the plastic and welds it together.

[Simon]

well it is the glue that has not withstood the chemical. I expected it to though

[Zero999]

I'm not sure if I fully understood they story, but you left the tank sitting for months with etching solution in it? If so, that doesn't seem like a very sensible thing to do. Etching solution is corrosive: it's main purpose in life is to eat its way through anything it can. It can eat its way through copper in minutes, so give it months and who knows what it will be able to eat through?

The correct usage of laboratory chemical equipment is to place the chemicals in proper storage bottles between uses, and to rinse and dry the equipment the chemicals are used in.

Ideally your etching lab should have a sink with running water and a work surface where you can put plastic trays for cleaning and rinsing your boards before and after etching.

You're right, although a properly designed etching tank should be made of inert materials which shouldn't be corroded by most common etchants, even if submersed in them for years.

[IanB]

well it is the glue that has not withstood the chemical. I expected it to though

Ferric chloride is nasty stuff. Really nasty. I mean, you might think the blood of those monsters in Aliens was nasty, but that's nothing compared to ferric chloride... (OK, you know where I'm going with this  )

But seriously, I worked with ferric chloride in an industrial etching plant once, and it really was evil stuff. All the joints and valves and pumps in the handling area were made out of solid PTFE, the floors and walls were sealed with chemically resistant cement, and anything that could corrode got corroded.

Yes, you can store it and transport it in plastic bottles or carbuoys, but whatever is holding it should not have seams or joints or anything like that.

Corrosion resistance is generally measured in time for a certain depth of damage to occur. There are many things that will withstand short term exposure, but will not necessarily withstand months of continuous contact. If there is a weak point in your system, it is going to get found given enough time.

Also, I second the above suggestion about using photographic developer trays. That's what I used in the past. Because they are flat you can watch the development of the board take place as the etching proceeds and stop at just the right time. You can stir the solution around with a plastic rod to bring fresh etchant to the board. It only takes a few minutes to complete the etching even at room temperature. When you are done you can pour the solution back into the bottle using a funnel and keep it safe and secure.

[Simon]

that looks like a plan, although 9 cm is quite deep, the dims are interesting though, the width is the length, the depth is the height and the height is the width, I must meet the guy that wrote those specs

[RCMR]

The other option is to build one using composite (fiberglass) cloth and resin.

Make up a plug for your tank from wood (just glue some MDF together), allowing a small taper so that once you've laid up the composite over the outside, you'll be able to remove this plug.

Of course you'll have to sand, fill and seal the plug so that it's nice and smooth in order that it won't catch when pulling the cured material off.

Once your plug is just the way you want the *inside* of your tank, apply several (at least 5) coats of canuba wax, buffing each one to a mirror surface.

Then lay up the tank, using some CSM (chopped stranded mat) and resin.  You can use either epoxy or polyester resin (each has it's pro's and con's).

Once the layup has cured remove the plug, trim the edges,  and you will have your very own tank that will never leak and is exactly the size/shape you need.

Total cost of materials should be under US$100.

[kaptain_zero]

HDPE sheets cut to size, weld them together with your hot air SMD rework station!

Regards

Kaptain "Always thinking inside the box" Zero