Homebrew PCBs

Slowly but surely I get the impression silicone is just not suitable
to make CuCl tanks with.
The current one has held some years, but finally sprung a leak as well.

I was quite pleased when, after not making a board for many months, I
held a perfect toner transfer in hand within 5 minutes.
However I was less pleased when I lifted the dust cover off my tank,
and discovered it had leaked. Luckily it is positioned in a large
plastic box which contained the etchant just fine. Must have been a
while too, since the tank holds over 2 liters and I recovered well
less than one.

I've had a number of tank leaks now, which leads me to believe that no
matter how wide the seams are the CuCl will eventually crawl out under
the silicone.


I need homemade boards so infrequently now I'm not sure if I will even
make a new tank just yet, but it would not be sealed with silicone.

Are there any alternatives to welded plastic if one wants a narrow
shape and dimensions that can't be found in any existing tank?
Anyone tried two component epoxy? On glass? Some other glue?

ST

--- On Sun, 25/4/10, Stefan Trethan <stefan_trethan@...> wrote:
> From: Stefan Trethan <stefan_trethan@...>
> Subject: [Homebrew_PCBs] CuCl Tank and silicone
> To: Homebrew_PCBs@yahoogroups.com
> Date: Sunday, 25 April, 2010, 7:46 PM

> Slowly but surely I get the
> impression silicone is just not suitable
> to make CuCl tanks with.

At last week's Dorkbot Bristol, we had a talk on making PCBs
(by UV exposure method) and the speaker mentioned this. He'd
used silicone sealer on an etching tank, and found that it had
leaked. The etchant had a warning on the label about not using
silicone sealer in contact with the liquid. But no-one knew
why this should be, chemically speaking.

-- 
John Honniball

Since it has happened several times now, and this one was glued really
well, I must assume it is incompatible.

What is interesting is that it is a very slow effect. Maybe the
british knew what they were doing when they used CuCl in timing
pencils ;-)

ST

On Sun, Apr 25, 2010 at 8:52 PM, anachrocomputer
<anachrocomputer@...> wrote:

>

>
> At last week's Dorkbot Bristol, we had a talk on making PCBs
> (by UV exposure method) and the speaker mentioned this. He'd
> used silicone sealer on an etching tank, and found that it had
> leaked. The etchant had a warning on the label about not using
> silicone sealer in contact with the liquid. But no-one knew
> why this should be, chemically speaking.
>
> --
> John Honniball
>
>

In article
<w2jafa365fa1004251146hd0fd69e6wa6fcef85db1fb5d9@...>,
   Stefan Trethan <stefan_trethan@...> wrote:
> Are there any alternatives to welded plastic if one wants a narrow
> shape and dimensions that can't be found in any existing tank?
> Anyone tried two component epoxy? On glass? Some other glue?

I've been wondering about suitable materials myself.

I have a very old tank (commercial) which is "past its use by date". A few
years ago I made the mistake of turning it on without any liquid in it and
part of it melted (It's PVC I think). This was repaired with fibreglass.

The last time I tried to use it, about a year ago, it didn't seem to be
bubbling very well and while prodding, the bubbler tube along the bottom
pretty much disintegrated.

I thought about Perspex (Acrylic) but it seemed expensive and I discovered
acids have a detrimental effect on it. I ruled out glass, which I would
have sealed with silicone sealer (!) because making holes for the heater
and bubbler tube were beyond me.

A couple of weeks ago, I was talking to an acquaintance of mine when he
mentioned that his son does things with glass-fibre for a hobby and this
seems a possibility but during my researches I also discovered this site:

http://www.plastidip.co.uk

They do a paint about which they claim:

"Plastidip resists alkalines, acids, salts, moisture, abrasion, and most
chemicals, and is an insulating dielectric coating. It will not crack,
chip or peel, and will remain flexible even under severe conditions
(-34ºc to +93ºc).

To me, this opens up the possibility of a tank made out of plywood; a
material which is easy to obtain, relatively inexpensive and which I am
very familiar with.

I also discovered:

http://www.clickonplastics.co.uk

Who sell PTFE tube at realistic prices and I consider this might be good
for a bubbler.

I don't have any connection with either of the above companies and at the
moment I don't have time to pursue this any further but I'd like to know
what others think.

-- 
Stuart
http://www.torrens.org.uk/ZFC/gallery/winsor.html

What about GOOP  It is made by Eclectic Products  Just tried going to their webpage to be sure I got the right link but can not seem to connect to the page.  They do show up in a Google Search but the links don't seem to work this evening.  It is sold at a lot of places here in the US.

I know that I used Fish Aquariums which has silcone to seal the seams.  For my first 3 tanks using Ferric Chloride and they all leaked after a few years.  Changed to using Plastic storage container.  Only had the Ferric Chloride in the Plastic storage container tanks for a year or so never had a problem and have had some Ferric Chloride stored in a 5 gal. Plastic Paint Bucket with lid for over 4 years and has not had any problem with leaks.  

Right now have CuCl in a covered Plastic Storage Container that is sitting in a larger container and so far have not had any problems with leaks.  I gave up on the Aquariums.  Myself I did my tanks so I can put 4 or so boards in at once with the Ferric Chloride so far with the CuCl I lay the board flat, normally a 8" x 10" or 8" x 12" with air bubbles.  I know that US Plastics www.usplastics.com sells some tall narrow Plastic tanks for PCB etching.

Ben

--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan <stefan_trethan@...> wrote:

>
> Slowly but surely I get the impression silicone is just not suitable
> to make CuCl tanks with.
> The current one has held some years, but finally sprung a leak as well.
> 
> I was quite pleased when, after not making a board for many months, I
> held a perfect toner transfer in hand within 5 minutes.
> However I was less pleased when I lifted the dust cover off my tank,
> and discovered it had leaked. Luckily it is positioned in a large
> plastic box which contained the etchant just fine. Must have been a
> while too, since the tank holds over 2 liters and I recovered well
> less than one.
> 
> I've had a number of tank leaks now, which leads me to believe that no
> matter how wide the seams are the CuCl will eventually crawl out under
> the silicone.
> 
> 
> I need homemade boards so infrequently now I'm not sure if I will even
> make a new tank just yet, but it would not be sealed with silicone.
> 
> Are there any alternatives to welded plastic if one wants a narrow
> shape and dimensions that can't be found in any existing tank?
> Anyone tried two component epoxy? On glass? Some other glue?
> 
> ST
>

> seems a possibility but during my researches I also discovered this site:
> 
> http://www.plastidip.co.uk
> 
> They do a paint about which they claim:
> 
> "Plastidip resists alkalines, acids, salts, moisture, abrasion, and most
> chemicals, and is an insulating dielectric coating. It will not crack,
> chip or peel, and will remain flexible even under severe conditions
> (-34ºc to +93ºc).


If this is the same stuff that I tried one time a plastic coating that sprays on like paint.  I have used it for other things as a protective coating and worked very well.  But I tried it on a Glass Aquarium sparyed the inside of the tank with I think about 4 coats to make a thick layer of the stuff.  At first it seemed to be working but after about a month or so I found that it was coming lose from the glass in places till I finnally emptied it and stopped using it.

The other thing that I have thought of using is a Plastic Ice Chest.

Ben

If I were building an etching tank I would contact Master Bond to ask
what adhesive/sealant they would recommend. I'd be surprised if they
don't have a solution.
 
Gary Webb NI9V 

--- On Sun, 4/25/10, anachrocomputer <anachrocomputer@...> wrote:

From: anachrocomputer <anachrocomputer@...>
Subject: Re: [Homebrew_PCBs] CuCl Tank and silicone
To: Homebrew_PCBs@yahoogroups.com
Date: Sunday, April 25, 2010, 1:52 PM


  




--- On Sun, 25/4/10, Stefan Trethan <stefan_trethan@ gmx.at> wrote:
> From: Stefan Trethan <stefan_trethan@ gmx.at>
> Subject: [Homebrew_PCBs] CuCl Tank and silicone
> To: Homebrew_PCBs@ yahoogroups. com
> Date: Sunday, 25 April, 2010, 7:46 PM

> Slowly but surely I get the
> impression silicone is just not suitable
> to make CuCl tanks with.

At last week's Dorkbot Bristol, we had a talk on making PCBs
(by UV exposure method) and the speaker mentioned this. He'd
used silicone sealer on an etching tank, and found that it had
leaked. The etchant had a warning on the label about not using
silicone sealer in contact with the liquid. But no-one knew
why this should be, chemically speaking.

-- 
John Honniball









      

[Non-text portions of this message have been removed]

I bought some white ABS sheet and ABS #2354 solvent from Tap Plastics and made a small ~12x10x2" tank, partly heat formed and partly
solvent glued. I use, and have stored CuCl in it for about 3 months so far, with no issues.

Roger

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Stefan Trethan
Sent: Sunday, April 25, 2010 11:46
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] CuCl Tank and silicone

 

  

Slowly but surely I get the impression silicone is just not suitable
to make CuCl tanks with.
The current one has held some years, but finally sprung a leak as well.

I was quite pleased when, after not making a board for many months, I
held a perfect toner transfer in hand within 5 minutes.
However I was less pleased when I lifted the dust cover off my tank,
and discovered it had leaked. Luckily it is positioned in a large
plastic box which contained the etchant just fine. Must have been a
while too, since the tank holds over 2 liters and I recovered well
less than one.

I've had a number of tank leaks now, which leads me to believe that no
matter how wide the seams are the CuCl will eventually crawl out under
the silicone.

I need homemade boards so infrequently now I'm not sure if I will even
make a new tank just yet, but it would not be sealed with silicone.

Are there any alternatives to welded plastic if one wants a narrow
shape and dimensions that can't be found in any existing tank?
Anyone tried two component epoxy? On glass? Some other glue?

ST





[Non-text portions of this message have been removed]

Heat welded HDPE or solvent welded PVC would be the best.  Years back I built a tank from plywood that I coated with a couple layers of polyester resin and fiberglass cloth.  It worked very well, materials are inexpensive and you can build it to any shape you like with normal wood working tools.  I think I will do the next tank the same way but using MDF instead of plywood.  You just need to take care to seal all the wood surfaces that may see any etchant.

Craig 

--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan <stefan_trethan@...> wrote:

>
> Slowly but surely I get the impression silicone is just not suitable
> to make CuCl tanks with.
> The current one has held some years, but finally sprung a leak as well.
> 
> I was quite pleased when, after not making a board for many months, I
> held a perfect toner transfer in hand within 5 minutes.
> However I was less pleased when I lifted the dust cover off my tank,
> and discovered it had leaked. Luckily it is positioned in a large
> plastic box which contained the etchant just fine. Must have been a
> while too, since the tank holds over 2 liters and I recovered well
> less than one.
> 
> I've had a number of tank leaks now, which leads me to believe that no
> matter how wide the seams are the CuCl will eventually crawl out under
> the silicone.
> 
> 
> I need homemade boards so infrequently now I'm not sure if I will even
> make a new tank just yet, but it would not be sealed with silicone.
> 
> Are there any alternatives to welded plastic if one wants a narrow
> shape and dimensions that can't be found in any existing tank?
> Anyone tried two component epoxy? On glass? Some other glue?
> 
> ST
>

I kind of liked the transparency of the glass. With a strong light I
could check progress without taking the board out.
I'll probably be prepared to scrap that option for a tank that holds up.

Heat welded PE or PP sounds like a good idea right now. Although HDPE
bottles do not stand up to concentrated HCl....

ST

On Mon, Apr 26, 2010 at 5:21 PM, designer_craig <cs6061@comcast.net> wrote:
> Heat welded HDPE or solvent welded PVC would be the best.  Years back I built a tank from plywood that I coated with a couple layers of polyester resin and fiberglass cloth.  It worked very well, materials are inexpensive and you can build it to any shape you like with normal wood working tools.  I think I will do the next tank the same way but using MDF instead of plywood.  You just need to take care to seal all the wood surfaces that may see any etchant.
>
> Craig
>
> --- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan <stefan_trethan@...> wrote:
>>
>> Slowly but surely I get the impression silicone is just not suitable
>> to make CuCl tanks with.
>> The current one has held some years, but finally sprung a leak as well.
>>
>> I was quite pleased when, after not making a board for many months, I
>> held a perfect toner transfer in hand within 5 minutes.
>> However I was less pleased when I lifted the dust cover off my tank,
>> and discovered it had leaked. Luckily it is positioned in a large
>> plastic box which contained the etchant just fine. Must have been a
>> while too, since the tank holds over 2 liters and I recovered well
>> less than one.
>>
>> I've had a number of tank leaks now, which leads me to believe that no
>> matter how wide the seams are the CuCl will eventually crawl out under
>> the silicone.
>>
>>
>> I need homemade boards so infrequently now I'm not sure if I will even
>> make a new tank just yet, but it would not be sealed with silicone.
>>
>> Are there any alternatives to welded plastic if one wants a narrow
>> shape and dimensions that can't be found in any existing tank?
>> Anyone tried two component epoxy? On glass? Some other glue?
>>
>> ST
>>
>
>
>
>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>
>

Regarding fiberglass, how about this crazy idea:

Find a sheet of polystyrene that has the desired inside dimensions of the tank.
Double-bag it in a polyethylene bag, one that holds water.
Fiberglass the outside of this, leaving one edge open.
Open the bag, fill in a small amount of solvent (acetone, petrol,
paint thinner) which will dissolve the styrofoam.
Pull out the inner bag with the styrofoam mess.
Pull out the outer bag away from the fiberglass.

Crazy, but might just work. I'm sure there are more practical options
like making a collapsing mold or something.

Does epoxy resin even hold up long term?

ST

In article
<g2safa365fa1004261004gddd9601ej4faaea741d3f26ac@...>,
   Stefan Trethan <stefan_trethan@...> wrote:
> Heat welded PE or PP sounds like a good idea right now. Although HDPE
> bottles do not stand up to concentrated HCl....

Polyprop is pretty safe with most chemicals and widely used for laboratory
products. It will hold up well and also has good temperature
characteristics. However, when I looked at the price of 6mm sheet (need
something rigid enough to do the job properly) I chickened out. Even 3mm
sheet is bad enough.

When I have the time to do it, I think I'm going to go with 9mm ply and
the acid resistant paint.

-- 
Stuart
http://www.torrens.org.uk/ZFC/gallery/winsor.html

In article
<s2tafa365fa1004261013q461ecd83z57e7b0de64ee4486@...>,
   Stefan Trethan <stefan_trethan@...> wrote:
> Regarding fiberglass, how about this crazy idea:

<SNIP for brevity>

> Crazy, but might just work. I'm sure there are more practical options
> like making a collapsing mold or something.

I think a well polished wooden former, posibly with some sort of mould
release agent will work just as well. Just needs a taper so it will slip
off easily.

> Does epoxy resin even hold up long term?

The repair I made to my tank has given me no problems and that was just
the ordinary stuff you buy in car accessory shops, "Davids" IIRC. Horrible
stuff to work with though, the mat just seems to want to fall apart when
you are trying to use it.

-- 
Stuart
http://www.torrens.org.uk/ZFC/gallery/winsor.html

Quite a few years ago, someone here gave a very good explanation of why silicone (the standard stuff) won't work with ferric chloride. Or any water in continuous contact with it. Essentially it works its way between the silicone and the glass or plastic.

Try aquarium sealant, it is made specifically to be in constant contact with water. Bathtub caulk is not.

Steve Greenfield

That is very well possible, but I would have to take the chance that
it will fail again in a few years.

Maybe I'll try, it would be a relatively quick fix at least (cutting
out all the old seams and replacing them with fish tank silicone).

But then, a completely new tank would allow me to fix things that
aren't perfect, and add a couple new flaws. ;-)

ST

On Tue, Apr 27, 2010 at 2:42 PM, alienrelics <alienrelics@...> wrote:
> Quite a few years ago, someone here gave a very good explanation of why silicone (the standard stuff) won't work with ferric chloride. Or any water in continuous contact with it. Essentially it works its way between the silicone and the glass or plastic.
>
> Try aquarium sealant, it is made specifically to be in constant contact with water. Bathtub caulk is not.
>
> Steve Greenfield
>
>
>

Like all those fish tanks that fall apart in a few years. :')

Steve Greenfield

--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan <stefan_trethan@...> wrote:

>
> That is very well possible, but I would have to take the chance that
> it will fail again in a few years.
> 
> Maybe I'll try, it would be a relatively quick fix at least (cutting
> out all the old seams and replacing them with fish tank silicone).
> 
> But then, a completely new tank would allow me to fix things that
> aren't perfect, and add a couple new flaws. ;-)
> 
> ST
> 
> On Tue, Apr 27, 2010 at 2:42 PM, alienrelics <alienrelics@...> wrote:
> > Quite a few years ago, someone here gave a very good explanation of why silicone (the standard stuff) won't work with ferric chloride. Or any water in continuous contact with it. Essentially it works its way between the silicone and the glass or plastic.
> >
> > Try aquarium sealant, it is made specifically to be in constant contact with water. Bathtub caulk is not.
> >
> > Steve Greenfield
> >
> >
> >
>

Well, put your fish in CuCl and see if they don't fall apart!

ST

On Tue, Apr 27, 2010 at 11:00 PM, alienrelics <alienrelics@...> wrote:
> Like all those fish tanks that fall apart in a few years. :')
>
> Steve Greenfield
>