Homebrew PCBs

Hi all,

The welding process was discussed before but i am unsure about plastic
to buy. I was to buy PVC sheets and weld, is common and suitable but
expensive. I even made myself speed welding nozzles. I always thought PE
or PP was more expensive than PVC but actually they are less than half
the price by square meter, being PE the cheaper. But i never had either
those sheets side by side to test their hardness.

PE is most suitable to chemicals, lighter and stronger than PVC it only
as a lower melting temperature but is way superior than the maximum
needed temperature. The problem is where i am to buy it, they only stock
PVC and PP weld. PE weld needs to be paid and wait for deliver which i
find silly, and the minimum order is 5 times more than i need...

I am to buy 5mm HDPE sheets they are a good deal, but PP is almost the
same price and easier to get the weld. Any advice?

BTW anyone in Europe with excess or need of PE weld?

Sim�o

--- In Homebrew_PCBs@yahoogroups.com, Simao Cardoso <simaocardoso@...> wrote:
>
> Hi all,
> 
> The welding process was discussed before but i am unsure about plastic
> to buy. I was to buy PVC sheets and weld, is common and suitable but
> expensive. I even made myself speed welding nozzles. I always thought PE
> or PP was more expensive than PVC but actually they are less than half
> the price by square meter, being PE the cheaper. But i never had either
> those sheets side by side to test their hardness.
> 
> PE is most suitable to chemicals, lighter and stronger than PVC it only
> as a lower melting temperature but is way superior than the maximum
> needed temperature. The problem is where i am to buy it, they only stock
> PVC and PP weld. PE weld needs to be paid and wait for deliver which i
> find silly, and the minimum order is 5 times more than i need...
> 
> I am to buy 5mm HDPE sheets they are a good deal, but PP is almost the
> same price and easier to get the weld. Any advice?
> 
> BTW anyone in Europe with excess or need of PE weld?
> 
> Simão
>

I used acrylic for mine, it's commonly known as Plexiglass.

If using plexiglass/acrylic, I'd think that better than welding would be 
using methylene dichloride as a solvent which disolves the acrylic, then 
evaporates, leaving one piece effectively.  It is how acrylic aquariums 
are made.

Much, much easier than heat welding, I'd think.

On 06/09/2010 12:09 AM, James wrote:
>
> --- In Homebrew_PCBs@yahoogroups.com, Simao Cardoso<simaocardoso@...>  wrote:
>    
>> Hi all,
>>
>> The welding process was discussed before but i am unsure about plastic
>> to buy. I was to buy PVC sheets and weld, is common and suitable but
>> expensive. I even made myself speed welding nozzles. I always thought PE
>> or PP was more expensive than PVC but actually they are less than half
>> the price by square meter, being PE the cheaper. But i never had either
>> those sheets side by side to test their hardness.
>>
>> PE is most suitable to chemicals, lighter and stronger than PVC it only
>> as a lower melting temperature but is way superior than the maximum
>> needed temperature. The problem is where i am to buy it, they only stock
>> PVC and PP weld. PE weld needs to be paid and wait for deliver which i
>> find silly, and the minimum order is 5 times more than i need...
>>
>> I am to buy 5mm HDPE sheets they are a good deal, but PP is almost the
>> same price and easier to get the weld. Any advice?
>>
>> BTW anyone in Europe with excess or need of PE weld?
>>
>> Simão
>>
>>      
> I used acrylic for mine, it's commonly known as Plexiglass.
>
>
>
>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>
>    


-- 
Our peculiar security is in the possession of a written Constitution.
Let us not make it a blank paper by construction."

    --Thomas Jefferson, letter to Wilson Nicholas, 1803

There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order.
  -- Ed Howdershelt (Author)

Dale J. Chatham wrote:
>   
> If using plexiglass/acrylic, I'd think that better than welding would
> be using methylene dichloride as a solvent which disolves the acrylic,
> then evaporates, leaving one piece effectively. It is how acrylic
> aquariums are made.
> 
> Much, much easier than heat welding, I'd think.


Correct, is something i have consider too. And acrylic is half price of
PVC by square meter, i don't need transparency. About the solvent, i am
already sick of the difficulty to get the required things where i live,
and invested on the plastic welder, seems fun and i want to try it, is
safer than methylene dichloride. I think will order the PE weld it's
still much cheaper than what i was to spend on PVC.

I am interested in the opinion about PVC vs PE. Are common choices in
chemistry setups.

I not want to build a single etching tank. It's 17 individual tanks for
now, for developing, striping, etching, and test my own direct plating
palladium chemistry, as well a very complicated copper plating setup
that doesn't require phosphorous copper anodes or anode bags, and
hopefully (to be tested) can work acceptable well without additives. And
a bunch test and dip tanks. Total wide 1.15m to fit the shelf. 

Simao

I've made a lot of tanks over the years for my circuit board fabrication company . The materials used were PVC, PE (polyethylene), and PP (polypropylene). The easiest tanks to fabricate were those made from PVC since it can be welded using a hot air welder. 

When welding PE and PP I always use nitrogen as the welding gas. My welder has a valve that allows it to idle on compressed air or switched to nitrogen while welding. I made a 750 gallon acid copper tank with PP using this method. That tank lasted more than twenty years with heavy use and never had a leak.

My plastic welder is made by Seelye Electric Company and was rather expensive but the Harbor Freight welder looks like a direct knock off for a fraction of what I paid. Buy a welder, get some scrap PVC and try it out. It's not difficult to make some very nice tanks that will last for years.  Tom


--- In Homebrew_PCBs@yahoogroups.com, Simao Cardoso <simaocardoso@...> wrote:

>
> Hi all,
> 
> The welding process was discussed before but i am unsure about plastic
> to buy. I was to buy PVC sheets and weld, is common and suitable but
> expensive. I even made myself speed welding nozzles. I always thought PE
> or PP was more expensive than PVC but actually they are less than half
> the price by square meter, being PE the cheaper. But i never had either
> those sheets side by side to test their hardness.
> 
> PE is most suitable to chemicals, lighter and stronger than PVC it only
> as a lower melting temperature but is way superior than the maximum
> needed temperature. The problem is where i am to buy it, they only stock
> PVC and PP weld. PE weld needs to be paid and wait for deliver which i
> find silly, and the minimum order is 5 times more than i need...
> 
> I am to buy 5mm HDPE sheets they are a good deal, but PP is almost the
> same price and easier to get the weld. Any advice?
> 
> BTW anyone in Europe with excess or need of PE weld?
> 
> Simão
>

Have a look at http://www.usplastics.com

In particular:

http://www.usplastic.com/catalog/search.aspx?search=methylene%20dichloride&page=1 
<http://www.usplastic.com/catalog/search.aspx?search=methylene%20dichloride&page=1>

or

http://www.usplastic.com/catalog/item.aspx?itemid=28917&catid=486&clickid=searchresults 
<http://www.usplastic.com/catalog/item.aspx?itemid=28917&catid=486&clickid=searchresults>

and

http://www.usplastic.com/catalog/search.aspx?search=37524&page=1 
<http://www.usplastic.com/catalog/search.aspx?search=37524&page=1>

Also, Regal Plastics is in many major cities.  They carry the stuff as well.

I'm building a tank as well.  Am thinking of a sump under it with an 
aquarium heater.  Probably use fluorescent lighting "egg crate" to hold 
the bord with a small "V" notch on top and bottom.

BTW, U. S. Plastics also has about every container known to man.


On 06/09/2010 08:51 AM, Simao Cardoso wrote:
> Dale J. Chatham wrote:
>    
>>
>> If using plexiglass/acrylic, I'd think that better than welding would
>> be using methylene dichloride as a solvent which disolves the acrylic,
>> then evaporates, leaving one piece effectively. It is how acrylic
>> aquariums are made.
>>
>> Much, much easier than heat welding, I'd think.
>>      
>
> Correct, is something i have consider too. And acrylic is half price of
> PVC by square meter, i don't need transparency. About the solvent, i am
> already sick of the difficulty to get the required things where i live,
> and invested on the plastic welder, seems fun and i want to try it, is
> safer than methylene dichloride. I think will order the PE weld it's
> still much cheaper than what i was to spend on PVC.
>
> I am interested in the opinion about PVC vs PE. Are common choices in
> chemistry setups.
>
> I not want to build a single etching tank. It's 17 individual tanks for
> now, for developing, striping, etching, and test my own direct plating
> palladium chemistry, as well a very complicated copper plating setup
> that doesn't require phosphorous copper anodes or anode bags, and
> hopefully (to be tested) can work acceptable well without additives. And
> a bunch test and dip tanks. Total wide 1.15m to fit the shelf.
>
> Simao
>
>
>
>
>
>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>
>    


-- 
Our peculiar security is in the possession of a written Constitution.
Let us not make it a blank paper by construction."

    --Thomas Jefferson, letter to Wilson Nicholas, 1803

There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order.
  -- Ed Howdershelt (Author)

--- In Homebrew_PCBs@yahoogroups.com, "Dale J. Chatham" <dale@...> wrote:
>
> If using plexiglass/acrylic, I'd think that better than welding would be 
> using methylene dichloride as a solvent which disolves the acrylic, then 
> evaporates, leaving one piece effectively.  It is how acrylic aquariums 
> are made.
> 
> Much, much easier than heat welding, I'd think.
> 
>

Yeah, solvent welding, I thought that's what we were referring to.

twb8899 wrote:
>   
> The easiest tanks to fabricate were those made from PVC since it can
> be welded using a hot air welder. 
> When welding PE and PP I always use nitrogen as the welding gas. 

I was strongly advised towards PVC because the easier welding. I am
reconsidering PE because the price only. And since it as superior specs
for the application...

According to your description I may probably end with solder burns or
poor joint by welding PE with an hot air welder?

My little experience was a few ABS and PP repairs in vehicle plastics,
never with PVC or PE.

Thanks,
Simao

I've never tried welding PE or PP with hot air. The supplier who sold me the plastic sheets said it was best to use nitrogen on the polypropylene sheets I purchased from them. The only plastic material I've ever welded using hot air was PVC. 

When using hot air to weld PVC it's easy to scorch the plastic if you're not careful. This problem is greatly reduced or eliminated when using nitrogen since the gas displaces any oxygen in the weld zone. I only use hot air welding for minor PVC repairs otherwise I use nitrogen for all plastic welding. 

I put a micro switch on the torch holder so when the torch is laying on the holder it switches a valve that idles the torch on compressed air. When the torch is lifted from the holder the valve switches over to nitrogen. Air or gas must flow when the heating element is powered up or it will burn out. I learned that the hard (and expensive) way. Always have a spare heating element on hand!

--- In Homebrew_PCBs@yahoogroups.com, Simao Cardoso <simaocardoso@...> wrote:

>
> twb8899 wrote:
> >   
> > The easiest tanks to fabricate were those made from PVC since it can
> > be welded using a hot air welder. 
> > When welding PE and PP I always use nitrogen as the welding gas. 
> 
> I was strongly advised towards PVC because the easier welding. I am
> reconsidering PE because the price only. And since it as superior specs
> for the application...
> 
> According to your description I may probably end with solder burns or
> poor joint by welding PE with an hot air welder?
> 
> My little experience was a few ABS and PP repairs in vehicle plastics,
> never with PVC or PE.
> 
> Thanks,
> Simao
>