Tank stripper question for our Chemical Engineers (if we have any).

[Shadrach]

We’re getting into the left fuel tank and I plan on addressing a few seeps on the access panels as well. Polysulfide stripper is available in gallon jugs as a liquid or 5 pounds of gel. I kind of want both but don’t need that much and it’s not cheap (~$400 for both with shipping). Can any one advise as to whether the stripper can be thickened with methyl cellulose? Would like the option of buying liquid and making gel as needed to my desired consistency.

[carusoam]

To get the methyl cellulose to work… it would have to be amenable to absorbing the solvent…

The cellulose part of the chemistry is good with water… the methyl part, kind of opens things up to other organic chemistries…

Got a small amount to try mixing?

 

What you really want… is a Chemist to chime in… we have a few around here…

Best regards,

-a-

[N201MKTurbo]

You might try filling it with fumed silica. It is pretty inert.

look at the sds for the gel and see what they used.

[carusoam]

Rich,  you are brilliant!   

There is an MSDS for the gel product…

And it mentions hydroxy propyl methyl cellulose….  That might be what Ross is after…

There is enough data to find rpm technologies and their full msds….

The link below gives a hint to the msds posted at AS… but only the first page…. Both liquid and gel…

Best regards,

-a-

https://www.aircraftspruce.com/catalog/pnpages/09-03491.php?gclid=CjwKCAjwn6GGBhADEiwAruUcKqb6BVkSjOQI2ACUflbn3Nv-zsIunMl1jsxSv_1OhFzYabSqJQ-xLhoCFZEQAvD_BwE

 

[Shadrach]

8 hours ago, carusoam said:

Rich,  you are brilliant!   

There is an MSDS for the gel product…

And it mentions

8 hours ago, carusoam said:

Rich,  you are brilliant!   

There is an MSDS for the gel product…

And it mentions hydroxy propyl methyl cellulose….  That might be what Ross is after…

There is enough data to find rpm technologies and their full msds….

The link below gives a hint to the msds posted at AS… but only the first page…. Both liquid and gel…

Best regards,

-a-

https://www.aircraftspruce.com/catalog/pnpages/09-03491.php?gclid=CjwKCAjwn6GGBhADEiwAruUcKqb6BVkSjOQI2ACUflbn3Nv-zsIunMl1jsxSv_1OhFzYabSqJQ-xLhoCFZEQAvD_BwE

 

….  That might be what Ross is after…

There is enough data to find rpm technologies and their full msds….

The link below gives a hint to the msds posted at AS… but only the first page…. Both liquid and gel…

Best regards,

-a-

https://www.aircraftspruce.com/catalog/pnpages/09-03491.php?gclid=CjwKCAjwn6GGBhADEiwAruUcKqb6BVkSjOQI2ACUflbn3Nv-zsIunMl1jsxSv_1OhFzYabSqJQ-xLhoCFZEQAvD_BwE

 

Thanks Anthony, I couldn’t find the MSDS for the gel. Thank you for linking. Looks like rolling my own isn’t worth it. HPMC is pricy stuff. 

[Shadrach]

@A64PilotYour post disappeared while I was responding...weird.   The only product I have used is PolyGone. That was 10 years ago.  I believe it was 300 AG Gel.  They now have a 305 (marine) and a 310 (aviation)  formulas which are supposed to be enhanced. It's not technically a stripper but a depolymerizer ($200 word of the day).  It does not work fast but it works.   I believe that shops like "Weep no more" use the liquid form in a machine that operates a continuous bank of spray nozzles placed in the tank that filter, recycle and spray the solution. Applying with a brush is a "wholenuther" situation.   It still requires agitation.  The challenge for me in the past was evaporation.  It will break down and emulsify the the sealant but it takes 8-12hrs.  If one does not use enough PolyGone, or leaves it for too long, it dries. What you are left with is a thick, tenacious, snot like substance that smears but does not come off cleanly.  I think I would rather build a machine than hand strip a complete tank. 

Edited June 16, 2021 by Shadrach

[A64Pilot]

I deleted it as I’m not sure my experience carries over here.

‘Our wing had about a 6 foot chord was I guess maybe 10” deep and each fuel tank was 114 gl, airplane held 228 gls of fuel.

We had the spars removed, so of course the whole front of the wing was removed making access a whole lot easier. (old wings replacing spar caps)

A few times when we had to fix leaks, it was on brand new wings and of course sealer that was only maybe a couple of weeks old

Our experience was more of the tenacious snot like, gummy residue that smeared, clogged bristle brushes etc and was harder to remove than the straight B2.

‘Plus as much as possible we shot our wings together wet, and there was some concern that capillary attraction could be taking the stripper places we didn’t want it.

[steingar]

First, methyl cellulose isn't all that cheap either, I use it for craft purposes.  Second, this sounds like a perfectly awful idea.  It is just brimming with potential unintended consequences that I'd not like to use on an airplane that could easily kill me if things aren't done right.  Not a Chem E, but I minored in Chemistry in college back when the Earth was still cooling.  

[Shadrach]

Just now, steingar said:

First, methyl cellulose isn't all that cheap either, I use it for craft purposes.  Second, this sounds like a perfectly awful idea.  It is just brimming with potential unintended consequences that I'd not like to use on an airplane that could easily kill me if things aren't done right.  Not a Chem E, but I minored in Chemistry in college back when the Earth was still cooling.  

One is ~ $30 ounce (HPMC) and one is about $6 a pound.  I asked specifically because methyl cellulose is relatively inert.  I don't take Metamucil but I was not aware of any warnings on the packaging.

[steingar]

On 6/16/2021 at 3:26 PM, Shadrach said:

One is ~ $30 ounce (HPMC) and one is about $6 a pound.  I asked specifically because methyl cellulose is relatively inert.  I don't take Metamucil but I was not aware of any warnings on the packaging.

Yup, inert.  Can stay in your fuel system and clog it up, an unintended consequence that comes quickly to mind.  I can think of others.  A lot of people complain that we have to hire mechanics to work on our airplanes or go to school for the privilege of doing so. This thread reminds of why this isn't the worst idea.

Methyl cellulose is glue.  It's normally used to bind books, it has some properties that make it far superior to polyvinyl acetate for this application.  I use it to laminate papers for my Origami.  If you really want to introduce a bunch of glue to your fuel system have at it, I still think it a bad idea.  You might think about carrageenan, since at least it isn't a glue.  Or you might just pony upper the stuff to do the job. No one every said airplanes were cheap.  

Edited June 23, 2021 by steingar

[N201MKTurbo]

If there is any glue left in your tanks, you didn’t do it right. The procedure requires that the metal is extremely clean before you apply the new sealant. Where is the glue going to hide?

If you are.doing a repair, I would be more worried about the stripper depolymerizing my good sealant.

[Shadrach]

1 hour ago, steingar said:

Yup, inert.  Can stay in your fuel system and clog it up, an unintended consequence that comes quickly to mind.  I can think of others.  A lot of people complain that we have to hire mechanics to work on our airplanes or go to school for the privilege of doing so. This thread reminds of why this isn't the worst idea.

Methyl cellulose is glue.  It's normally used to bind books, it has some properties that make it far superior to polyvinyl chloride for this application.  I use it to laminate papers for my Origami.  If you really want to introduce a bunch of glue to your fuel system have at it, I still think it a bad idea.  You might think about carrageenan, since at least it isn't a glue.  Or you might just pony upper the stuff to do the job. No one every said airplanes were cheap.  

Methyl cellulose is synthetic soluble fiber as in Citrucell (OTC remedy to support regularity). It may function as a glue but it’s not a purpose designed adhesive.

 I know this because a resident MD sent a funny message to me pointing out that I had confused Citrucell (Methyl Cellulose) with Metamucil (psyllium fiber).

Any tank repair requires a thorough flushing before applying adhesive.

Edited June 17, 2021 by Shadrach

[Greg Ellis]

2 hours ago, steingar said:

Yup, inert.  Can stay in your fuel system and clog it up, an unintended consequence that comes quickly to mind.  I can think of others.  A lot of people complain that we have to hire mechanics to work on our airplanes or go to school for the privilege of doing so. This thread reminds of why this isn't the worst idea.

Methyl cellulose is glue.  It's normally used to bind books, it has some properties that make it far superior to polyvinyl chloride for this application.  I use it to laminate papers for my Origami.  If you really want to introduce a bunch of glue to your fuel system have at it, I still think it a bad idea.  You might think about carrageenan, since at least it isn't a glue.  Or you might just pony upper the stuff to do the job. No one every said airplanes were cheap.  

This is why you want a professional to do the tanks.  They are a thing of beauty when cleaned and sealed properly.   Work done by Paul Beck at Weepnomore LLC.

And just an aside, I for one, would be interested in photos of @steingar Origami.  

[carusoam]

Steingar’s origami has been on display where kids and aviation come together…

(old fuzzy memory)

 

Speaking of old and fuzzy….  Ross isn’t old enough to know his fibers as well as he does….   

Best regards,

-a-

[steingar]

4 hours ago, Greg Ellis said:

And just an aside, I for one, would be interested in photos of @steingar Origami.  

 

[Greg Ellis]

Just now, steingar said:

 

Those are pretty cool.  Thanks for sharing the photos.

[Hank]

4 hours ago, steingar said:

 

Holy crap! That's sculpture! 

[0TreeLemur]

@steingar Your work is awesome.  Thanks for sharing!  Have you ever crafted an origami Mooney Z model? 

[steingar]

Thank you so much for the compliments.  I did not mean to self aggrandize, I am in awe of the things many of you do. @0TreeLemur if you're asking about an origami model of the letter "Z", yes, I have.  Zed isn't all that difficult as far as letters go.

[67 m20F chump]

I’m currently balls deep into stripping the sealant out of my wing.  I’m swapping out my wing because of spar cap corrosion.  The wing is on a stand so it’s about as accessible as possible for stripping.  I’m honestly thinking about putting in bladders instead of the wet wing.  The money from the cost of stripper and sealant goes along way to paying for them and I will never have to do this again.

[Will.iam]

7 hours ago, 67 m20F chump said:

I’m currently balls deep into stripping the sealant out of my wing.  I’m swapping out my wing because of spar cap corrosion.  The wing is on a stand so it’s about as accessible as possible for stripping.  I’m honestly thinking about putting in bladders instead of the wet wing.  The money from the cost of stripper and sealant goes along way to paying for them and I will never have to do this again.

Sealant stripper up to my balls. Made me laugh at the visualization not sure why. Maybe because i can empathize with getting too far into a project and just wishing my CB self had just paid someone else to avoid the personal misery. 

[MinneMooney]

Long ago, I used to work with methyl cellulose at a chemical distributor. We blended methylene chloride based paint strippers. Methyl cellulose was used to thicken it, however, it had to be added in the correct sequence. Methanol was the final add to the mix and it quickly caused the entire mixture to dramatically thicken. I don’t believe that you could successfully add methyl cellulose to this stripper and have it gel. I think it would either 1. do nothing or 2. form many gelatinous clumps.

Also, methyl cellulose seems expensive (sold by the pound) however, it’s a very low density powder. A 10 pound bag was quite large.