Old glue bomb kit, what went wrong?

[kymdlr]

This was a 70 superbee, initially I thought it was an AMT but due to the brown plastic I’m thinking a different manufacturer. I got it as a painted rebuilder. I’ve done plenty of glue bomb rebuilder kits before but this is a first . As usual , I soaked it between purple power and DOT3 for several days to remove the paint & glue build up. Upon removing it from the last soak in DOT3 and scrubbing the remaining paint off, the plastic basically disintegrated. I’ve done plenty of fixer uppers but this one is pretty much too far gone. Any idea what went wrong? 

[Ace-Garageguy]

Brake fluid occasionally makes old plastic brittle and crumbly.

I'd guess that's what happened here.

[Mark]

Brown plastic would make it a first issue Pro Street version from the early Nineties.

As for the brittle plastic, it may have been stripped and repainted already prior to your getting it.  I've got a couple of car bodies with damage from multiple strip/repaint/strip jobs.  One had all of the detail and crisp edges softened into mush, another is so brittle that the most gentle handling makes it crumble.

[Bainford]

Very interesting reaction. Out of curiosity, what brand and grade of brake fluid did you use?

[peteski]

DOT3 brake fluid is glycol-based.  Some hobby plastic-safe strippers are also glycol-based, but they are slightly different chemically.  I have seen many examples of DOT3 brake fluid affecting polystyrene, especially after long duration immersion.  I am not too surprised your model fell apart.

Safer plastic-safe stripping alternatives are Lye (sodium hydroxide) based  Those will not harm polystyrene, even after long exposure. Another one is 99% Isopropyl alcohol.

[StevenGuthmiller]

20 hours ago, Ace-Garageguy said:

Brake fluid occasionally makes old plastic brittle and crumbly.

I'd guess that's what happened here.

Yup.

I’ve heard this before.

That’s why I don’t use it.

 

Steve

[Dave G.]

16 hours ago, StevenGuthmiller said:

Yup.

I’ve heard this before.

That’s why I don’t use it.

 

Steve

Same here.

[Fat Brian]

On 1/6/2025 at 9:35 PM, Mark said:

Brown plastic would make it a first issue Pro Street version from the early Nineties.

As for the brittle plastic, it may have been stripped and repainted already prior to your getting it.  I've got a couple of car bodies with damage from multiple strip/repaint/strip jobs.  One had all of the detail and crisp edges softened into mush, another is so brittle that the most gentle handling makes it crumble.

I agree, I had a mud colored plastic one in around 95 or so.

[gtx6970]

You sure that's not resin kit

[LennyB]

I had an older AMT 57 T-Bird kit that was molded in black do this with dot-3. Only time I had a problem and I use brake fluid all the time. Has to do with the styrene not the brake fluid. But you don't know until you soak it. The reason why I will often just do the hood first.

[peteski]

Len, does it really matter whether the "problem" is with the plastic or the stripping fluid?  Bottom line is that the incompatibility is the real problem.  DOT3 brake fluid was never meant to be a plastic-safe paint stripper. If you use it, you run a risk of failure.  Having said that, even when using plastic-safe paint strippers (designed for that task) there is always a warning on their labels to check compatibility first.

[StevenGuthmiller]

1 hour ago, peteski said:

Len, does it really matter whether the "problem" is with the plastic or the stripping fluid?  Bottom line is that the incompatibility is the real problem.  DOT3 brake fluid was never meant to be a plastic-safe paint stripper. If you use it, you run a risk of failure.  Having said that, even when using plastic-safe paint strippers (designed for that task) there is always a warning on their labels to check compatibility first.

I agree.

I never want to put myself into a situation where I’m not certain what the outcome might be, especially if you’re dealing with a rare vintage kit.

I’m not about to have my model, or any part of it, be a guinea pig.

 

 

 

Steve

[LennyB]

 

15 hours ago, peteski said:

  to check compatibility first.

I not saying I use brake fluid exclusively, I usually go with the purple pond first. I'm just saying in all the decades I've used brake fluid I only had the one catastrophic failure. And by dipping the hood first is my way of checking compatibility.

[Carmak]

23 hours ago, gtx6970 said:

You sure that's not resin kit

I agree. That looks like an old resin casting. 

[StevenGuthmiller]

1 hour ago, Carmak said:

I agree. That looks like an old resin casting. 

Some of these ‘70 Dodge kits were molded in that muddy tan color, which looks a lot like old resin.

 

 

Steve

[Rodent]

41 minutes ago, StevenGuthmiller said:

Some of these ‘70 Dodge kits were molded in that muddy tan color, which looks a lot like old resin.

Look at the inside of the trunk lid. I agree with the guys that it is probably a resin repop of the 1970 annual.

[StevenGuthmiller]

3 hours ago, Rodent said:

Look at the inside of the trunk lid. I agree with the guys that it is probably a resin repop of the 1970 annual.

Well, that would be a question for the OP.

Should be extremely easy to tell the difference between plastic and resin.

If I had it in front of me, I could tell you in 2 seconds, as I’m sure most of us could.

 

 

 

Steve

[stavanzer]

I still have that kit molded in exactly that shade of Brown. I think it's plastic.

[Keef]

Freshly opened kit just for pics. I’m leaning towards it being a resin repop as well.

[Straightliner59]

On 1/8/2025 at 1:53 PM, Fat Brian said:

I agree, I had a mud colored plastic one in around 95 or so.

AMT was using some pretty funky plastic, around that time. It was almost rubbery. It was difficult to keep mods and sanded-off details from reappearing after primer. 

[Dave G.]

I use Purple Power on suspicious plastics. Otherwise I use a full submerge in 91 IPA. The 91% get's all model paint's I've ever used off very quickly. And craft paints, as well as Createx..Many just dissolve in the bath, or just light brushing with an old toothbrush. Then rinse with plain water.

But for you guys using Super Clean, I was wondering if you use it straight from the bottle, or diluted a bit ?

I'm from an era where brake fluid ate about anything plastic, so never even considered it's use for stripping plastic model cars.

[NOBLNG]

8 minutes ago, Dave G. said:

I use Purple Power on suspicious plastics. Otherwise I use a full submerge in 91 IPA. The 91% get's all model paint's I've ever used off very quickly. And craft paints, as well as Createx..Many just dissolve in the bath, or just light brushing with an old toothbrush. Then rinse with plain water.

But for you guys using Super Clean, I was wondering if you use it straight from the bottle, or diluted a bit ?

I'm from an era where brake fluid ate about anything plastic, so never even considered it's use for stripping plastic model cars.

Full strength. It won’t damage styrene or the resin that I have cast. I have used brake fluid a couple of times as a last resort on styrene and luckily had no issues.

[StevenGuthmiller]

3 hours ago, Dave G. said:

I use Purple Power on suspicious plastics. Otherwise I use a full submerge in 91 IPA. The 91% get's all model paint's I've ever used off very quickly. And craft paints, as well as Createx..Many just dissolve in the bath, or just light brushing with an old toothbrush. Then rinse with plain water.

But for you guys using Super Clean, I was wondering if you use it straight from the bottle, or diluted a bit ?

I'm from an era where brake fluid ate about anything plastic, so never even considered it's use for stripping plastic model cars.

Yup, straight out of the jug!

 

 

 

Steve

[Bills72sj]

I use SuperClean at full strength. I have had a few paint jobs that needed to go back and forth from that and brake fluid. I have not tried 91% on anything yet.

[Bucky]

I once soaked a Jo-Han '62 Dodge in brake fluid for nearly two weeks to get the half mile thick yellow paint to come off. Luckily, the styrene wasn't damaged. At the time, I didn't know about Super Clean or Purple Power, and I couldn't get Easy Off to work for me. I've also used brake fluid on AMT styrene and Tamiya styrene with no ill effects. Nowadays, I use Super Clean exclusively.