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Posted (edited)

I was looking for some pieces today and found this, this is the reason I will never use baking soda and superglue ever again.

This is just a warning of what could happen , I know a lot of people use this , this was built in the early 80's so it's been getting worse over the years. It's just not worth taking the chance of using it anymore for me.

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Edited by Pat Minarick
Posted

Wow, that is some great looking weathering, very realistic.  I know that is not the purpose of your post, thanks for the heads up.  I have used it on occasion and have yet to have any issues.  But, that does not mean it may not come to pass.

Posted
49 minutes ago, TarheelRick said:

Wow, that is some great looking weathering, very realistic.  I know that is not the purpose of your post, thanks for the heads up.  I have used it on occasion and have yet to have any issues.  But, that does not mean it may not come to pass.

This was built in the early 80's.

Posted
18 minutes ago, Muncie said:

Pat, is this plastic or diecast?  It looks like it might be a chemical reaction with baking soda and the base material.

It's plastic , Monogram 58 T-Bird.

Posted

Thanks for this post and the photos!  I never thought that CA/baking-soda thing was a good idea, and I always  recommend not doing it.  Especially, since the CA accelerators are readily available, and so are many different filler materials (if needed).

Posted
1 hour ago, 89AKurt said:

Oh wow, thanks for showing this.  You remember what brand glue?  I've done this a lot, so will check out old projects.

The glue is not the problem or cause of this - it is the baking soda.

I've seen examples where the CA glue did not fully get soaked into the baking soda. When moisture (if you live in a humid climate) gets to that baking soda (through some pinholes in the glue), it will be absorbed by the baking soda (because it is water-soluble), and the whole mess will start oozing out.  Bottom line is: using home-brewed solutions is not always good idea.

Posted
28 minutes ago, peteski said:

The glue is not the problem or cause of this - it is the baking soda.

I've seen examples where the CA glue did not fully get soaked into the baking soda. When moisture (if you live in a humid climate) gets to that baking soda (through some pinholes in the glue), it will be absorbed by the baking soda (because it is water-soluble), and the whole mess will start oozing out.  Bottom line is: using home-brewed solutions is not always good idea.

You are definitely correct about the moisture being the problem. St. Louis weather changes from hour to hour.

Posted

I did some baking soda in acrylic craft paints for rust and had some weird BLAH_BLAH_BLAH_BLAH grow out of it after a year or so. I use baby powder now.

Posted
14 hours ago, peteski said:

The glue is not the problem or cause of this - it is the baking soda.

I've seen examples where the CA glue did not fully get soaked into the baking soda. When moisture (if you live in a humid climate) gets to that baking soda (through some pinholes in the glue), it will be absorbed by the baking soda (because it is water-soluble), and the whole mess will start oozing out.  Bottom line is: using home-brewed solutions is not always good idea.

Exactly.

51 minutes ago, Jantrix said:

I did some baking soda in acrylic craft paints for rust and had some weird BLAH_BLAH_BLAH_BLAH grow out of it after a year or so. I use baby powder now.

Baby powder is talc (hydrated magnesium silicate) and usually, cornstarch.

Though not as hygroscopic as baking soda (which swells and turns to a solid block in the box as it absorbs moisture), and though talc is used as an industrial filler in things like tires and paper, and was the original filler added to polyester resin to make "bondo", I'd still respectfully suggest you use the real catalyzed polyester or epoxy fillers available, if you want your work to look good in 10 or 20 years.

Posted (edited)

This thread made me worry- I did a bunch of work on a 48 Ford Woody frame back in 2001 or so, filling the majority of the seams with baking soda and superglue mixture, with some of the easier access areas filled with Evercoat. This was an unfinished, stalled project that has been sitting in a drawer since the work was done. All of the sanded glue/baking soda seams were painted before being put away.

Seeing as I live in an area that gets a lot of moisture with relatively high humidity, I pulled them out just now to see the carnage that has festered in the last 18 years:

IMG-8788.jpg

IMG-8790.jpg

IMG-8789.jpg

It looks like I got lucky- no funny reactions. Maybe the fact that they were sealed up with paint shortly after finish sanding saved the parts with baking soda and superglue.

Edited by gman
Posted
3 minutes ago, gman said:

This thread made me worry- ...It looks like I got lucky- no funny reactions. Maybe the fact that they were sealed up with paint shortly after finish sanding saved the parts with baking soda and superglue.

Yup. Bondo applied to real cars will absorb moisture and allow rust to form under it on the surface of the metal that's been repaired if it's left exposed and unsealed with primer and paint.

Most likely, you got a good coat of paint that sealed the surface of your banking soda-superglue mix.

Posted
39 minutes ago, Ace-Garageguy said:

Yup. Bondo applied to real cars will absorb moisture and allow rust to form under it on the surface of the metal that's been repaired if it's left exposed and unsealed with primer and paint.

Most likely, you got a good coat of paint that sealed the surface of your banking soda-superglue mix.

...as will certain primers over bare metal. 

The reason I was worried is because I used a large amount of superglue/baking soda filler on that frame. I have been using superglue (Zap a Gap +) and baking soda as filler for small areas since the 80's without finding a science experiment forming on my model, but I usually spray primer and paint over finished areas fairly soon after finish sanding. I do the same over Evercoat 2 part filler, and used to do so over the old Squadron putties that I gave up on decades ago.

I have a '67 Impala somewhere that had some sink marks filled with baking soda and superglue mixture that remains unpainted. I'll have to find it and have a look at how it looks today, once I figure out where my "business agent" hid the box.

Posted
17 hours ago, gman said:

...as will certain primers over bare metal. 

The reason I was worried is because I used a large amount of superglue/baking soda filler on that frame....

Yup. About the only real-car primer that stops that and can be left exposed indefinitely is epoxy. Naturally, the best of the best was a Sherwin Williams concoction from the 1980s that's no longer made.

Far as the baking soda / CA goes, the deciding factor, as with the deterioration of many man-made materials like some vinyls, cellulose-based acetate promos, rubber, and lycra, will be how high the average relative humidity was and for how long.

Posted
On 2/26/2019 at 10:01 PM, peteski said:

The glue is not the problem or cause of this - it is the baking soda.

I've seen examples where the CA glue did not fully get soaked into the baking soda. When moisture (if you live in a humid climate) gets to that baking soda (through some pinholes in the glue), it will be absorbed by the baking soda (because it is water-soluble), and the whole mess will start oozing out.  Bottom line is: using home-brewed solutions is not always good idea.

I always wash everything before painting.  I found that if chunks of baking soda were exposed, they dissolved out and created tiny holes that were easy to miss before painting.  I also live in Arizona, where humidity is usually very low.  But I'm still going to check old projects when I think of it.

Posted

Yes, baking soda is a no-no.  Having a saline base, it absorbs moisture from the air.  I used baking soda for rust early on, then I noticed a damp spot on the model during the summer. Now I will use fine sand for my rust particles.  It's rock so it's inert.

Posted (edited)
2 hours ago, Tom Geiger said:

Yes, baking soda is a no-no.  Having a saline base, it absorbs moisture from the air.  I used baking soda for rust early on, then I noticed a damp spot on the model during the summer. Now I will use fine sand for my rust particles.  It's rock so it's inert.

Though baking soda is "a salt" it is not "salt" to which the word "saline" refers.

High school chemistry.

Edited by Ace-Garageguy

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