Where can I get a solder paste squeegee?

[knotlogic]

I'm looking for a solder paste squeegee for small hobby-ish projects.  Where do you guys find yours?  I've done a bit of Google searching, but nearly all the results I get are for companies that manufacture stuff for, well,  manufacturing.

Any advice on where to look?  Ideally I'm looking for something on the smaller side.  The only likely items I've I've found are some "solder scrapers" on eBay which seem to be used for reballing BGAs.

[mrpackethead]

What kind of stencils are you using..  Kapton plastic?  Chemically etched Brass or Stainless.    This will determine the right type of squeegee to use.

If you are using Stainless, then i've bought some of these ( see link below ) , and they work really well.     But dont' use them on Kapton or brass, you'll destroy them.

https://www.aliexpress.com/store/product/10CM-Steel-Solder-Paste-Squeegee-scraping-knife-SMT-stencil-scraper-Tin-solder-paste-scraping-knife/1956345_32555924349.html?spm=2114.12010608.0.0.F3vOz3

Once you get the hang of it, you'll never go back to using credit cards or tools.     

[Kjelt]

Fir my stainless steel stencils I use thin stainless steel paint / wood filler blades, available in DIY stores for less than buck in different sizes. Just look around and be creative.

[knotlogic]

Thanks for the suggestions all.  I have a bank card about to expire so that should be good for a test.  Would isopropanol do the trick?

I'll also take a look around local hardware stores, but they're pretty limited in what they've got here.

I'm planning to go with kapton from OSH Stencils for a start.  It's only a few boards so stainless doesn't make sense, and since it's my first go with stencils and paste I figure they might be easier for a first timer to place an order with.

[Kjelt]

Would isopropanol do the trick?

What trick ? Cleaning the squeegee afterwards? Yes with a lot of kitchenpaper/tissues to absorb the stuff and wear disposable cheap vinyl gloves.

[mrpackethead]

Would isopropanol do the trick?

What trick ? Cleaning the squeegee afterwards? Yes with a lot of kitchenpaper/tissues to absorb the stuff and wear disposable cheap vinyl gloves.

Cheap Vinyl gloves might be ok for the clean up, but dont' wear them during pasting.. Vinyl gloves are not ESD safe,  and you cna build up a decent charge on a pcb, / stencil..

The choice of solvent to clean your gear depends on the solder paste.   I use Henkel GC10 ( its lead free ), because its by far the easiest paste to work with at low volume, ( storage is simple, its not particually sensitive to temp changes and you dont' need to mix it, and it keeps for ages.. perfect for DIY.. the only down side is that you can only buy it in minimum of 500g tubs.    ( someone should repack it into tubes ).. 
With the GC10 which has a water soluable flux,  some mild detergent and hot water is just fine.          For some leaded pastes IPA is appropriate..        The easy way is to stick your tools in an ultrasonic cleaner.  I clean my stainless stencils with Electrolub PCB Cleaner ( which you dilute ) in a ultrasonic cleaner and it works ideally.. I've not tryed cleaning kapton this way.

[jmelson]

I use a piece of .025" thick brass shim stock, but other materials will also work.  Or, you can buy a shower wall squeegee from Ikea for about $7 and cut it to the width you need.  I have one, and it works quite well, but I have not cut it down yet.  It is a bit too wide for the typical boards I do.

Jon

[Cerebus]

I've got a pastry/dough scraper with a 0.40 mm stainless steel blade and riveted wooden handle bought from the local supermarket for little enough that it wasn't worth remembering how much. Works fine and hits the right stiff/flexible compromise.

If you do pick up something impromptu like this that's metallic it's a good idea to run a de-burring tool or some 400 grit emery cloth over the edges before using. These things are often shear cut and then left essentially unfinished.

[knotlogic]

Would isopropanol do the trick?

What trick ? Cleaning the squeegee afterwards? Yes with a lot of kitchenpaper/tissues to absorb the stuff and wear disposable cheap vinyl gloves.

Yep.  Actually cleaning the bank card afterwards.  Acetone would melt the plastic used for it.  I'm less worried about a metal squegee.

With the GC10 which has a water soluable flux,  some mild detergent and hot water is just fine.          For some leaded pastes IPA is appropriate..        The easy way is to stick your tools in an ultrasonic cleaner.  I clean my stainless stencils with Electrolub PCB Cleaner ( which you dilute ) in a ultrasonic cleaner and it works ideally.. I've not tryed cleaning kapton this way.

I'm a bit wary of water soluble fluxes to be honest.  I got some leaded stuff from Zephyrtronics, and I might give Kester EP256 a try given all the good words about it.

I've found plastic razor blades available on Amazon meant for scrapers.  Looks like they come in delrin, or a harder polycarbonate.  The width sounds about right for the size of boards I'm doing, so I might give those a try.

[Kjelt]

Cheap Vinyl gloves might be ok for the clean up, but dont' wear them during pasting.. Vinyl gloves are not ESD safe,  and you cna build up a decent charge on a pcb, / stencil..

I work on an ESD bonded surface, and wear a ESD band, I place the pcb on the surface before adding the components. I don't see any problem ? Never had any problem.
Even better than working without gloves without ESD precautions I would say.

I wear vinyl gloves because they are antiallergic and keep the fingerspitzengefuhl (the fine feedback feeling of knowing what you're hands and fingers are doing) and keep the leaded garbage from my hands.
And to be honest they are dirt cheap ($0,04 a piece).
Cleaning a stencil with IPA (or other cleaner) and tissues gives a mess and it won't be the first time that my hands touch one of the already pasted pcbs during sorting.

[mikeselectricstuff]

Go to a decorating/paint supplies shop and look for stainless scrapers. I think I showed an example in my recent vid on cutting stencils on a silhouette vinyl cutter..
They typically need the edge rounding off slightly with fine abrasive paper.

[mrpackethead]

Nitrile gloves are the preferred choice for ESD 'safe' environments.  Gloves made from natural rubber latex and vinyl are inherently static insulative, holding on to a charge and releasing it in an uncontrolled manner, leading to damage.  The surface resistance of nitrile gloves, however, is normally on the border of insulative and static dissipative.
 

[mrpackethead]

I'm a bit wary of water soluble fluxes to be honest.  I got some leaded stuff from Zephyrtronics, and I might give Kester EP256 a try given all the good words about it.

I was too untill I started using GC10.  Its just so much easier.     Yes it is lead free.    I do have the advantage that i'm usign Vapour phase for reflow so that helps a lot.

Those sweggess i linked to above are only a few dollars. ( $3-$15 dpending on size. including Post. ) and they work really well.

[Kean]

What kind of stencils are you using..  Kapton plastic?  Chemically etched Brass or Stainless.    This will determine the right type of squeegee to use.

If you are using Stainless, then i've bought some of these ( see link below ) , and they work really well.     But dont' use them on Kapton or brass, you'll destroy them.

https://www.aliexpress.com/store/product/10CM-Steel-Solder-Paste-Squeegee-scraping-knife-SMT-stencil-scraper-Tin-solder-paste-scraping-knife/1956345_32555924349.html?spm=2114.12010608.0.0.F3vOz3

Once you get the hang of it, you'll never go back to using credit cards or tools.   

I just got a few of these today in the mail, and they look and feel pretty good.  I can see how they'll give much better control than a hardware store plastic or metal scraper.
They will need some emery paper to take off the edges, but otherwise they seem excellent, and at a great price.
I had been looking for some like this for a while, especially now that I have a manual stencil printer.  The only ones I found were hundreds of dollars.
Thanks mrpackethead!

[mrpackethead]

you really want a sharp edge, that is important, so i'd be not so keen to round it off...   they need to be sharp.. ( the edge of the blade ).. Over time the do degrade and become blunt as well, and youll start to notice..  ( paste starts being left on the stencil rather than being left clean.

[Yellofriend]

The Aliexpress one is no good. The blade is too short, the handle will have contact with solder paste. You will lose solder paste every time you clean up.

You do better with a stainless steel putty knife.

[Psi]

I advise against 'water soluble' paste for home/hobby use. Its hard to clean the pcb properly without proper equipment like an ultrasonic cleaner. (cheap ones may damage your ICs)
'No clean' paste on the other hand can be left or cleaned up in solvent. Its easier and doesnt matter if you miss a little flux.

[Yellofriend]

I advise against 'water soluble' paste for home/hobby use. Its hard to clean the pcb properly without proper equipment like an ultrasonic cleaner. (cheap ones may damage your ICs)

If you have a dishwasher in your kitchen you have already a perfectly suitable PCB cleaning machine. I saw dishwashers in many professional EMS companies in Europe.

Keep in mind one thing:  'water soluble' paste is more aggressive and must be cleaned!

[mrpackethead]

I' d highly recommend Locktite GC10 For Home/hobby use. And it is water soluable.     You dont' need to clean pcbs after a good reflow.    The paste is essentialy no clean.   Its an order of magniture easier to stencil, store..       Its just really the clean up for the small bits of paste that are left on your stencil/tools/spatular.

 

I advise against 'water soluble' paste for home/hobby use. Its hard to clean the pcb properly without proper equipment like an ultrasonic cleaner. (cheap ones may damage your ICs)
'No clean' paste on the other hand can be left or cleaned up in solvent. Its easier and doesnt matter if you miss a little flux.