clean up grey foam residue


Dave Brown
 

Bit the bullet today and scraped all the 'rotting' grey foam insert stuff
out of the A6303 probe box. That stuff is really horrible.
So what's the best cleaning agent to wipe out the residue? Some of what's
left are small patches where it was glued in place but overall the case and
lid need to be thoroughly cleaned inside before I make up replacement foam
inserts.
DaveB, NZ


greenboxmaven
 

Choke and carburetor cleaner from an auto supply does a good but messy job of removing the foam and it's residue. It turns it into "buggers" that can be scraped off with a plastic knife or scraper. Use a rag sprayed with the cleaner to get the final bit
remaining. Do this outdoors, the cleaner is flammable. Wear gloves and old clothing, the residue stains anything it touches.

    Bruce Gentry, KA2IVY







Bit the bullet today and scraped all the 'rotting' grey foam insert stuffout of the A6303 probe box. That stuff is really horrible.

So what's the best cleaning agent to wipe out the residue? Some of what's

left are small patches where it was glued in place but overall the case and
lid need to be thoroughly cleaned inside before I make up replacement foam
inserts.
DaveB, NZ





demianm_1
 

The foam is I believe polyurethane and I found this product https://www.sherwin-williams.com/homeowners/products/touch-n-foam-professional-polyurethane-foam-cleaner that seems to be specific to the task. There are probably others as well. There are videos of using it to clean off the gunk from guns.

Big question for me (any I'm sure others) is what to replace the foam with. The original stuff doesn't hold up real well. The "pick and pluck" stuff is really disappointing. Is there something better suited to making an insert with some life expectancy?


Roy Thistle
 

On Sun, Jun 27, 2021 at 09:29 AM, demianm_1 wrote:


The foam is I believe polyurethane
It could be.
Cleaning away this grey (or black) sticky mess, people find left inside these cases is much discussed, I think... here on TekScopes, on the HP forum, and the Web too.
Historically, polyurethane foams we much used... as polyurethane was (and is) quite versatile.
I can't find evidence that chemists knew, at the time... that given time... the polyurethane foams (particularly modified with additives to "improve" them)... that these foams would degrade in this way.
I think (but do your own research) that modern formulations of polyurethane foams... which are so much used now, as to be ubiquitous... modern polyurethane foams are much more stable. If you get polyurethane foam that isn't 30 years old... it's not going to degrade like the old foams did.
But who knows? ... 30, 50, or 100 years from now... they may turn into a stick mess too.


--
Roy Thistle


J Mcvein
 

I have been using the pink anti-static polyethylene foam to re-line the wooden
HP attenuator and cal-kit boxes. I find it as free/used semiconductor packing.
It cuts easier than PU foam with no drag and stretch. Might last another 40
years.
JimMc

-----Original Message-----
From: "demianm_1 via groups.io" <demianm_1=yahoo.com@groups.io>
Sent: Sunday, June 27, 2021 12:29pm
To: TekScopes@groups.io
Subject: Re: [TekScopes] clean up grey foam residue



The foam is I believe polyurethane and I found this product https://www.sherwin-williams.com/homeowners/products/touch-n-foam-professional-polyurethane-foam-cleaner that seems to be specific to the task. There are probably others as well. There are videos of using it to clean off the gunk from guns.

Big question for me (any I'm sure others) is what to replace the foam with. The original stuff doesn't hold up real well. The "pick and pluck" stuff is really disappointing. Is there something better suited to making an insert with some life expectancy?


stevenhorii
 

I read the product description - it says for removing uncured polyurethane.
It does not say it will remove cured polyurethane, but it may be worth a
try.

So far a replacing polyurethane foam, a very stable polymer is
polyethylene. I have had items cushioned in polyethylene foam for many
years and it has not deteriorated at all. It is not as soft as
polyurethane, but polyethylene foam does come in various grades of firmness
(though I’ve found it is not easy to figure out what the different grades
mean without squeezing them). The firmness is apparently determined by the
size of the foam cells and closed or open cells. There’s this if you are
really curious:

https://www.thefoamfactory.com/blog/index.php/the-differences-and-relationship-between-foams-density-weight-and-firmness

I still have some camera cases with fitted polyurethane foam. As a
precaution, I put the cameras and lenses in plastic bags before putting
them away in the cases.

Steven Horii

On Sun, Jun 27, 2021 at 12:30 demianm_1 via groups.io <demianm_1=
yahoo.com@groups.io> wrote:

The foam is I believe polyurethane and I found this product
https://www.sherwin-williams.com/homeowners/products/touch-n-foam-professional-polyurethane-foam-cleaner
that seems to be specific to the task. There are probably others as well.
There are videos of using it to clean off the gunk from guns.

Big question for me (any I'm sure others) is what to replace the foam
with. The original stuff doesn't hold up real well. The "pick and pluck"
stuff is really disappointing. Is there something better suited to making
an insert with some life expectancy?






Roy Thistle
 

On Sat, Jun 26, 2021 at 10:29 PM, Dave Brown wrote:


So what's the best cleaning agent to wipe out the residue?
If you are not sure what the "residue" is... and what plastic? the case is made of... then it's hard to know what will "wipe out" the "residue" and yet not damage the plastic case.
Assuming its degraded polyurethane foam.. maybe partly dissolved in the plasticizer... maybe it's just the plasticizer.
Sometimes, using a solvent will just spread that around, and make more of a sticky mess, when the solvent evaporates... and damage the plastic too. Solvents work best when you can wash away what you are trying to dissolve, with excess solvent.
Otherwise, you want the goo to stick to what you are trying to remove it with...like a wipe... and not stick to what you are trying to remove it from... the case. The problem is the goo sticks pretty good to everything.
I have used both light and heavy mineral oils... petroleum jelly (a.k.a. vaseline) to try to get between the goo and what it is sticking too. It works... and it works by mechanical action... and it's slow, laborious, and messy too.
Sometimes the plastisizer has attacked the plastic in the case, and is dissolve into it... and so you won't get it off... because it's not on anymore... it's in the plastic of the case.
Sometimes I've put new foam into a case... and the sticky that was left... well that was good to glue the new foam into place.



--
Roy Thistle


Tom Lee
 

Thanks for the great idea, Jim. I was just looking at the cal-kits at school, and they're all in sorry shape.

-- Cheers,
Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 6/27/2021 10:53, J Mcvein wrote:
I have been using the pink anti-static polyethylene foam to re-line the wooden
HP attenuator and cal-kit boxes. I find it as free/used semiconductor packing.
It cuts easier than PU foam with no drag and stretch. Might last another 40
years.
JimMc
-----Original Message-----
From: "demianm_1 via groups.io" <demianm_1=yahoo.com@groups.io>
Sent: Sunday, June 27, 2021 12:29pm
To: TekScopes@groups.io
Subject: Re: [TekScopes] clean up grey foam residue



The foam is I believe polyurethane and I found this product https://www.sherwin-williams.com/homeowners/products/touch-n-foam-professional-polyurethane-foam-cleaner that seems to be specific to the task. There are probably others as well. There are videos of using it to clean off the gunk from guns.

Big question for me (any I'm sure others) is what to replace the foam with. The original stuff doesn't hold up real well. The "pick and pluck" stuff is really disappointing. Is there something better suited to making an insert with some life expectancy?









Richard Knoppow
 

Thanks for the info on cleaning. This foam was very popular for a couple of decades. I find it in camera cases as well as in electronics cases. Either disintegrates (if one is relatively lucky) or turns to sticky mush. Very difficult to remove. I was unaware that a special cleaner was available. Its helpful to know what the foam is.

On 6/27/2021 12:46 PM, Tom Lee wrote:
Thanks for the great idea, Jim. I was just looking at the cal-kits at school, and they're all in sorry shape.

-- Cheers,
Tom
--
Richard Knoppow
dickburk@ix.netcom.com
WB6KBL


Sergey Kubushyn
 

On Sun, 27 Jun 2021, Richard Knoppow wrote:

The problem with that "special cleaner" is that it is nothing but pure
acetone (just read their MSDS). First of all, there is no reason to buy it
in overpriced bottles. Then, it is not a very good idea to clean anything
plastic with pure acetone.

Xylene usually work miracles on that foam residue but it might destroy other
plastics. Heavy alcohols might also work but they can damage other plastics
too.

   Thanks for the info on cleaning. This foam was very popular for a couple of decades. I find it in camera cases as well as in electronics cases. Either disintegrates (if one is relatively lucky) or turns to sticky mush. Very difficult to remove. I was unaware that a special cleaner was available. Its helpful to know what the foam is.

On 6/27/2021 12:46 PM, Tom Lee wrote:
Thanks for the great idea, Jim. I was just looking at the cal-kits at
school, and they're all in sorry shape.

-- Cheers,
Tom
--
Richard Knoppow
dickburk@ix.netcom.com
WB6KBL




---
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* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
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Dave Brown
 

Thanks for all the replies about the cleanup process.
I'll try a few cleaners based on the suggestions and report back in due course.
DaveB, NZ


Roy Thistle
 

On Sun, Jun 27, 2021 at 10:53 AM, J Mcvein wrote:


pink anti-static polyethylene foam
I don't think that foam is anti-static... I never use it for static sensitive items/unit... as it does hold quite a charge.

--
Roy Thistle


J Mcvein
 

Obviously Tektronix disagrees with you as it packaged their production line parts.
Since the intent here is replacing perished PU foam, the original use doesn't matter a whit.
-J-

-----Original Message-----
From: "Roy Thistle" <roy.thistle@mail.utoronto.ca>
Sent: Sunday, June 27, 2021 10:28pm
To: TekScopes@groups.io
Subject: Re: [TekScopes] clean up grey foam residue



On Sun, Jun 27, 2021 at 10:53 AM, J Mcvein wrote:


pink anti-static polyethylene foam
I don't think that foam is anti-static... I never use it for static sensitive items/unit... as it does hold quite a charge.

--
Roy Thistle


Brian Symons
 

I recently had a pile of engraved labels that the double sided tape on the back had deteriorated into a sticky mess.
I bought a few different Adhesive Remover / Goo Gone type products from the hardware store.
I was very surprised that one of the best was a citrus based product.
It works well & wasn't too hard on the hands although I do use disposable gloves normally.

I applied it quite liberally & they rubbed it around.
The goo completely softened & could be easily scraped off.
Applying it quite liberally was needed but the whole big spray bottle was only about AUS $8.

It did take some scraping to remove the goo, not hard scraping - just to remove it - but I found plastic Razor Scraper Blades on eBay.
These are the same size & shape as razor blades although a lot thicker & they are available in several different hardnesses.
They are often sold with some type of holder but most of the razor blade holders for scraping will work with them.
These aren't expensive & they really do work well.
I have seen car detailers use them & use them to remove decals from cars as well.

I was just scraping it, cleaning the blade off onto a cloth, add more cleanser if necessary, rub it around...
The whole process for all of the 20 or so engraved labels when using the citrus product took less time than doing a tiny one on its own with various other solvents.

I recently used one of the harder plastic blades to remove some hardened on material on the oven door glass.
I was afraid to use a metal blade for that job.
It took some scaping but didn't leave any marks on the glass.

Hope this helps.

Regards,
Brian.


stevenhorii
 

Probably orange oil based. If you want to see how potent a solvent orange
oil is, squirt some from an orange peel onto a Styrofoam cup.

I did this by accident some years ago. I was trying to collect some orange
oil to use in some recipe and used a styro cup that was sitting on the
counter. It dissolved the styro and left holes in it.

On Mon, Jun 28, 2021, 11:55 Brian Symons <brians@mackay.net.au> wrote:

I recently had a pile of engraved labels that the double sided tape on the
back had deteriorated into a sticky mess.
I bought a few different Adhesive Remover / Goo Gone type products from
the hardware store.
I was very surprised that one of the best was a citrus based product.
It works well & wasn't too hard on the hands although I do use disposable
gloves normally.

I applied it quite liberally & they rubbed it around.
The goo completely softened & could be easily scraped off.
Applying it quite liberally was needed but the whole big spray bottle was
only about AUS $8.

It did take some scraping to remove the goo, not hard scraping - just to
remove it - but I found plastic Razor Scraper Blades on eBay.
These are the same size & shape as razor blades although a lot thicker &
they are available in several different hardnesses.
They are often sold with some type of holder but most of the razor blade
holders for scraping will work with them.
These aren't expensive & they really do work well.
I have seen car detailers use them & use them to remove decals from cars
as well.

I was just scraping it, cleaning the blade off onto a cloth, add more
cleanser if necessary, rub it around...
The whole process for all of the 20 or so engraved labels when using the
citrus product took less time than doing a tiny one on its own with various
other solvents.

I recently used one of the harder plastic blades to remove some hardened
on material on the oven door glass.
I was afraid to use a metal blade for that job.
It took some scaping but didn't leave any marks on the glass.

Hope this helps.

Regards,
Brian.








Colin Herbert
 

That sounds rather like the "Label Remover" that Maplin used to sell (when they still were trading). It contains a natural chemical called limonene.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of stevenhorii
Sent: 28 June 2021 18:14
To: TekScopes@groups.io
Subject: Re: [TekScopes] clean up grey foam residue

Probably orange oil based. If you want to see how potent a solvent orange
oil is, squirt some from an orange peel onto a Styrofoam cup.

I did this by accident some years ago. I was trying to collect some orange
oil to use in some recipe and used a styro cup that was sitting on the
counter. It dissolved the styro and left holes in it.

On Mon, Jun 28, 2021, 11:55 Brian Symons <brians@mackay.net.au> wrote:

I recently had a pile of engraved labels that the double sided tape on the
back had deteriorated into a sticky mess.
I bought a few different Adhesive Remover / Goo Gone type products from
the hardware store.
I was very surprised that one of the best was a citrus based product.
It works well & wasn't too hard on the hands although I do use disposable
gloves normally.

I applied it quite liberally & they rubbed it around.
The goo completely softened & could be easily scraped off.
Applying it quite liberally was needed but the whole big spray bottle was
only about AUS $8.

It did take some scraping to remove the goo, not hard scraping - just to
remove it - but I found plastic Razor Scraper Blades on eBay.
These are the same size & shape as razor blades although a lot thicker &
they are available in several different hardnesses.
They are often sold with some type of holder but most of the razor blade
holders for scraping will work with them.
These aren't expensive & they really do work well.
I have seen car detailers use them & use them to remove decals from cars
as well.

I was just scraping it, cleaning the blade off onto a cloth, add more
cleanser if necessary, rub it around...
The whole process for all of the 20 or so engraved labels when using the
citrus product took less time than doing a tiny one on its own with various
other solvents.

I recently used one of the harder plastic blades to remove some hardened
on material on the oven door glass.
I was afraid to use a metal blade for that job.
It took some scaping but didn't leave any marks on the glass.

Hope this helps.

Regards,
Brian.








Roy Thistle
 

On Sun, Jun 27, 2021 at 07:50 PM, J Mcvein wrote:


Obviously Tektronix disagrees with you as it packaged their production line
parts.
Well then Keysight, and our anti-static/static meter disagrees with Tektronix... but I've only seen that "pink" foam used as packing material, containing anti-static protected items. It matters a lot... because someone reading the thread... they could be relining a fet-probe case, or a case for a sampling head.

--
Roy Thistle


Roy Thistle
 

On Mon, Jun 28, 2021 at 10:26 AM, Colin Herbert wrote:


chemical called limonene
d-limonene is a terpene... a copiously naturally occurring "oil" in many many plants... in this case oranges... in the orange peel... so a.k.a. "orange oil."
It's a hydrophobic molecule.
Besides being used in food, and as a cleaner, and solvent, the wacky tabacy crowd... and vapers... use it as a "flavouring."
The concentrated limonene does dissolve Styrofoam (like used in cups, and clam shell packaging)... which is a good thing... since you can recover the dissolved Styrofoam waste from the water soluble food waste.
Anyway, the concentrated stuff (100%) on a hot Texas day, in the sun, will attack/dissolve some plastics, synthetic/natural rubbers, natural gums... and others are resistant to it.
You have to know what you are trying to dissolve before using a solvent.
Limonene is also an oil... so it may work itself between what's sticking, and what that's sticking to... which may be a mechanical action or solvation.
--
Roy Thistle


Roy Thistle
 

On Sun, Jun 27, 2021 at 01:46 PM, Sergey Kubushyn wrote:


Xylene usually work miracles on that foam residue but it might destroy other
plastics.
at least pvc, polypropylene, ABS (Xylene is used in pipe cement/weld.) .... lots of sealing materials don't like it either.

--
Roy Thistle


Glenn Little
 

I use naptha aka goo-gone aka lighter fluid.
I have not damaged hard plastic, yet.

Glenn

On 6/28/2021 4:35 PM, Roy Thistle wrote:
On Sun, Jun 27, 2021 at 01:46 PM, Sergey Kubushyn wrote:


Xylene usually work miracles on that foam residue but it might destroy other
plastics.
at least pvc, polypropylene, ABS (Xylene is used in pipe cement/weld.) .... lots of sealing materials don't like it either.
--
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